Bioremediation and Environmental microbiology Research Papers (original) (raw)

Benzene, toluene, ethyl benzene and xylene(BTEX)are the most commonly cited monoaromatic compounds in environmental pollution in recent years due to their high solubility and toxicity in ground water and soils. This studywas conducted in order to isolate and enumerate fungi in soils heavily polluted with petroleum hydrocarbons, and to select those with BTEX degrading abilities. Screening of the fungi isolated on Mineral Salt Media (MSM) supplemented with BTEX showed Aspergillus terreus DMW-5 and Gliocladium spp. had the highest colony diameter while Penicillium spp. has the lowest colony diameter. The highest BTEX weight loss and increase in spore size was also observed with Aspergillus terreus DMW-5 and Gliocladium spp. which degraded 240mg/mL BTEXand 220mg/mL BTEX while the lowest was with Aspergillus flavus which degraded 190mg/mL BTEX. The hydrocarbon utilizing fungal (HUF) counts revealed Aspergillus terreus DMW-5 and Gliocladium spp. as having the highest number of spores (8.2 x 10 7 and6.3 x 10 7 spores/mL) and Aspergillus flavus with the lowest number of spores (1.2 x 10 7 spores/mL). Thus, Gliocladium spp.and Aspergillus terreus DMW 5 are potential candidates for the mycoremediation studies of BTEX.

- by and +1
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- Bioremediation and Environmental microbiology

Çevre, canlı ve cansız varlıkların bir arada bulundukları, birbirlerini etkiledikleri ve birbirlerinden etkilendikleri ortam olarak tanımlanmaktadır. Mikrobiyoloji, " çıplak gözle görülemeyecek kadar küçük canlı organizmaları inceleyen bir bilim disiplinidir. Mikroorganizma olarak tanımlanan bakteri, alg, mantar, virüs ve protozoa gibi mikroskobik canlılar doğada; havada, toprakta, suda, bitkiler üzerinde, insan ve hayvanların vücudunda kısacası her yerde bulunurlar. Mikrobiyoloji biliminin çalışma alanları, üzerinde çalışılan organizmalara, çalışılan süreç ve fonksiyonlara, sağlıkla ilgili alanlara ve bilginin kullanımına göre çok değişik bir yelpazede dağılım göstermektedir. Çevre mikrobiyolojisi, hayatın devamında önemli rolü olan ancak insan, hayvan ve bitkiler üzerinde hastalıklara neden olarak önemli kayıplara yol açan mikroorganizmaları inceleyen mikrobiyoloji dalıdır.

Direct Carbon Capture Machines are now being field tested in several countries. These machines promise to be part of the tool box — among many technologies — for dealing with CO2 mitigation. As machines directed to ecological goals, they arrive at a time to collaborate with organisms and programming underpinning artificial intelligence (AI) and living technology. Here, I specifically look to AI, ALife, and synthetic biology in relation to microbial and plant intelligences to ask whether next generations of direct-air capture machines might be theoretically hybridized with the intelligence of bio-performative microbes monitored by AI (on the order of Google’s DeepMind) to evolve thin, lightweight, metabolic panels for urban sculpture, buildings, and infrastructures.
I focus on theoretical systems to justify symbiotic, biochemical, and self-sustaining bacterial life (e.g. carbon eating microbes) living in association with AI hosts. If artificial intelligence connects with molecular bacterial languages (codes, pictures, symbols, logics) and, if they can be decrypted, then the realms of environmental (plant/microbe) signaling may be networked between nature, AI, buildings, and metabolic machines (e.g. CO2 capturing devices). This symbiotic speculation makes possible imaging non-neurological, living/machine performance between skyscrapers, urban infrastructures, and nature. My proposition then supports next-phase design necessitating pathways over which we may hybridize AI and biological intelligence in machines/buildings as agents in the discovery of theory and methods for metabolic architectures and cities.

- by Heather Miller
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- Environmental microbiology, Marine Ecology, Bioremediation, Oil and gas

K.G.F or Kolar gold fields is a mining town in Bangarpet taluk, in the Kolar district of Karnataka state, India. The
town was known for gold mining over a century. It was closed in 2001 because of low production of gold and being
uneconomical. Mining is one of the main sources of heavy metal pollution in the environment. It is a well-known fact that
because of mining, there will be contamination of soil thereby creating environmental hazard. Some heavy metals both in
soil as well as water have been found in the samples. Heavy metals may lead to serious health effects including reduced
growth and development, cancer, organ damage and in extreme cases can also be fatal. Hence remediation is necessary for
the removal of heavy metals from soils
This paper is about monitoring the presence of heavy metal in K.G.F soil residue for bio-remediation. The main
objective of this paper is to evaluate the quantum of heavy metals and suggest remedial measures to remove the same. There
are many methods for removal of heavy metals from contaminated soil. In this paper Bio-remediation method which is an
inexpensive, safe, environment friendly technology and harmless end products has been presented.

Gateway biofertilizers are preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants’ uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil. They are living microorganisms of bacterial, fungal and algal origin and mode of action differs and can be applied alone or in combination to reduce the use of synthetic fertilizers and pesticides. Promotes integrated nutrient management, cost effective and sustainable agriculture. Gateway broad spectrum biofertilizers contains: Bacterial biofertilizers (Rhizobium, Azospirilium, Azotobacter, Phosphobacteria); Fungal biofertilizers (Mycorhiza etcs); Algal Biofertilizers (Blue Green Algae (BGA), Azolla etcs); and Actinimycetes biofertilizer (Frankia etc).

- by Ayodele Otaiku
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- Plant Ecology, Organic agriculture, Biotechnology, Molecular Microbiology

Though several in-situ treatment methods exist to remediate polluted sites, selecting an appropriate site-specific remediation technology is challenging and is critical for successful clean up of polluted sites. Hence, a comprehensive overview of all the available remediation technologies to date is necessary to choose the right technology for an anticipated pollutant. This review has critically evaluated the (i) technological profile of existing in-situ remediation approaches for priority and emerging pollutants, (ii) recent innovative technologies for on-site pollutant remediation, and (iii) current challenges as well as future prospects for developing innovative approaches to enhance the efficacy of remediation at contaminated sites.

- by Venkateswarlu Kadiyala and +1
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- Bioremediation and Environmental microbiology

Pollution and the global health impacts from toxic environmental pollutants are presently of great concern. At present, more than 100 million people are at risk from exposure to a plethora of toxic organic and inorganic pollutants. This review is an exploration of the ex-situ technologies for cleaning-up the contaminated soil, groundwater and air emissions, highlighting their principles, advantages, deficiencies and the knowledge gaps. Challenges and strategies for removing different types of contaminants, mainly heavy metals and priority organic pollutants, are also described.

- by Saranya Kuppusamy and +2
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- Bioremediation and Environmental microbiology

Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root
surface and are directly or indirectly involved in promoting plant growth and development via production
and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally,
plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in
resource acquisition (nitrogen, phosphorus and essential minerals) or modulating plant hormone
levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth
and development in the forms of biocontrol agents. Various studies have documented the increased
health and productivity of different plant species by the application of plant growth promoting rhizobacteria
under both normal and stressed conditions. The plant-beneficial rhizobacteria may
decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems.
This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria
under the current perspectives. Further, explicit outlooks on the different mechanisms of
rhizobacteria mediated plant growth promotion have been described in detail with the recent development
and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria
in different agro-ecosystems have been presented comprehensively under both normal and stress
conditions to highlight the recent trends with the aim to develop future insights.

Heavy metal pollution of soils is of great concern.
The presence of the toxic metal species above critical
concentration not only harmfully affects human health but
also the environment. Among existing strategies to remediate
metal contaminates in soils, phytoremediation
approach using metal accumulating plants is much convincing
in terms of metal removal efficiency, but it has
many limitations because of slow plant growth and
decreased biomass owing to metal-induced stress. In
addition, constrain of metal bioavailability in soils is the
prime factor to restrict its applicability. Phytoremediation
of metals in association with phosphate-solubilizing bacteria
(PSB) considerably overcomes the practical drawbacks
imposed by metal stress on plants. This review is an
effort to describe mechanism of PSB in supporting and
intensifying phytoremediation of heavy metals in soils and
to address the developmental status of the current trend in
application of PSB in this context.

Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing.

Due to lack of vision and carelessness attitude of human beings areas of land, surface waters and ground water are affected by contamination from industrial, agricultural, household activities, which has become a serious dilemma of the hour. In these days, although various methods have putted on track to the treatment of the contaminating agents but most of these mechanisms or methods are too sophisticated and expensive to operate practically. Concerning all those things, the use of ‘Phytoremediation’ technique to the treatment of contaminants could be a masterstroke.

The bioremediation processes mainly use micro-organisms consortium (OBD-Plus®) based on the interactions of microbial cells and targeted species of contaminants of concern in order to reduce their mobility and toxicity by the production of metal chelators such as metallothioneins and biosurfactants at an optimum temperature ranging from 25-45 degree Centigrade using bioaugmentation treatment techniques. OBD-Plus® treated drill cuttings (mud in Qua Iboe , Niger Delta) at pH 9.10 control was reduced to pH 7.0 resulting to 99.83% reduction of Total Petroleum Hydrocarbon (TPH) within 21 days of treatment showing decrease in the nitrogen and phosphorous containing compound. The efficacy of the treated drill mud for re-use support Maize (Zea Mays) growth to show the enhanced nutrition capability for environmental sustainability. The OML 58 12/70 well head, Obagi, Niger Delta, Nigeria in situ surface water treatment using OBD-Plus®, Total Petroleum Hydrocarbon (TPH) was reduced to 99% under iron-reducing and sulfate-reducing coupled to the reduction of chelated Fe (III) by 96%. Dissolved organic carbon was used as organic substrate reducing the Chemical Oxygen Demand (COD) occurred in 49 days treatment. Sulphate was the principal electron acceptor for the oxidation of polycyclic aromatic hydrocarbon (PAH) at 97% and TPH (99%) reduction respectively in 42 days soil/sediment treatment as the dissolved Fe (98%) increase relative to the background , indicate Fe(III) is serving as an electron acceptor in anaerobic biodegradation. The ex situ treatment of exploration flare waste pit was under aerobic/anaerobic conditions. The effects of pH on OBD-Plus® microbes was the speciation of the treatments in both powdery treatments (1 and 5) occurred between 13-25 days and Liquid Phase treatments (2, 3 and 4) occurred between 13-25 days respectively.

Remediating crude oil polluted soil in developing countries by environment-friendly approach has attracted scientific interest. Sampled crude oil and poultry dung were obtained from oil pit and farm in Warri, Delta State. 500 g/kg of crude oil polluted soil was weighed into four different containers labeled A, B, C and D; the soil was amended with the application of sundried poultry manure at various weights of 50, 75 and 100 g/kg respectively leaving sample D without amendment as control for a period of 42 days. Isolation and identification process of bacteria strains were carried out using standard spread plate method on nutrient agar. Ten bacteria isolates were obtained from the amended and control soil in this research. Genus from pseudomonas and staphylococcus has the highest representation of three species each. The rate of degradation in the sample was determined by gravimetric analysis. The total petroleum hydrocarbon (TPH) present in sample D (control) initially was 4550.08 mg/kg. Samples A, B and C after remediation period reduced to the value of 3410.61, 2664.90 and 1598.95 mg/kg, respectively. The total hydrocarbon utilizing bacteria (HUB) increased gradually in the sample A, B, C and D to 7 × 10-4 , 7.9 10-4 , 8.0 × 10-4 and 5.0 × 10-4 respectively. The total heterotrophic bacteria count (THB) increased from 10 x 10-5 at zero week to 8.3 × 10-5 , 8.5 10-5 , 8.6 × 10-5 and 7.3 × 10-5 in the samples respectively. Physiochemical analysis of nitrogen increased from 0.04 to 0.17 mg/kg and phosphorous also increased from 1.72 to 6.73 mg/kg after the period of 42 days. This approach showed increased remediating effect of poultry dung on crude oil polluted soil.

Over the past few decades, the upcoming scientific scenario of the ever growing area of biotechnology finds a successful application of some eco-diversified microorganisms which are employed for the recovery of metals from ores and other industrial wastes. A lot of mineral oxidizers and reducers are found in natural environments which involve a different mode of action for mineral oxidation and reduction. Mineral oxidizers are found in natural leaching environments
such as acid mine drainage, dump disposal sites, tailing ponds and are mostly aerobic in nature while the reducers are found in environments under facultative anerobic or strictly anerobic conditions. Mineral Biotechnology is primarily aimed at the application of such mineral metal oxidizers and reducers for the development and advancement of a sustainable biotechnological industry in the mineral processing sector. Analyzing several aspects, the leaching microbes have a
number of features in common that make them especially suitable for their role in mineral solubilization. This particular review focuses on such mineral oxidizing and reducing microorganisms, their mode of action and area of application towards development and growth of mineral biotechnological industry.

The objective of the study was to evaluate the phytoremediation potential of three aquatic macrophytes (Commelina cyanea, Phragmites australis and Water Hyacinth (Eichhornia crassipes)) for treatment of municipal wastewater collected from Federal University of Technology, Akure (Nigeria). Laboratory scale of three constructed wetlands of dimensions 0.43 m x 0.93 m x 0.36 m in width, length and depth respectively, were developed to mimic natural conditions and was operated for a single experimental run with each macrophte at different retention time of 6, 9 and 12 days. These aquatic macrophytes were planted in separate ponds. Domestic wastewater from undergraduate students' hostel was introduced to the ponds. The raw wastewater sample and treated wastewater samples were analysed using standard laboratory methods for physical (Turbidity and Dissolved solids), chemical (pH, Nitrate, Nitrite, Phosphate, Sulphate Chemical Oxygen Demand and Biochemical Oxygen Demand) and bacteriological (Coliform bacteria) parameters. Results showed substantial diminutions in all parameters treated with the phytoremediators during the course of the study. Asides the three plants effectively removing Nitrate, Nitrite, phosphate and Sulphate pollutants, Phragmites australis gave the highest removal efciency for Phosphate (85.8%), Water hyacinth gave the highest removal efciency for pH (11.5%), Biochemical Oxygen Demand and Coliform bacteria and Commelina cyanea gave the highest removal efciency for turbidity (96.9%) and dissolved solids (82.9%) parameters of the domestic wastewater samples. The overall results of the phytoremediation studies indicate that the purication effectiveness of the three aquatic macrophytes were spontaneous, feasible and remarkable.

Se analizó la aplicabilidad del uso de Microorganismos para el tratamiento de plásticos (biodegradación). La Metodología utilizada comprendió en la planificación y organización de los procedimientos en las distintas fases (Campo, Laboratorio y Evaluación), que se establecieron para el desarrollo investigativo de los inferenciales estadísticos (toma de muestras, variables estadísticas para contraste de hipótesis).

- by Trelita de Sousa and +1
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- Environmental Science, Environmental Microbiology (Biology), Bioremediation and Environmental microbiology

Whereas microbiological quality of bottled drinking water is routinely monitored for reasons of legal compliance, microbial numbers in spring water are grossly understudied. Safety of water is a major public concern. However, the portability status of each type of water is a major concern to the public health. This study was carried out to assess of the microbiological quality of bottled and protected spring water in Ishaka-Bushenyi District. A total of 33 samples of bottled water and 8 samples of protected spring water were analysed using the Membrane Filtration Method. This method involved filtering the samples through a membrane filter (size 25um), culturing on lactose (TTC) with sodium heptadecylsulfate media and performing biochemical tests (oxidase and Indole) for confirmation of coli forms and E. coli respectively. Four (50%) of the protected springs showed growth of typical yellow colonies on lactose agar media. The presence of E. coli signified that protected springs were being contaminated with fresh faecal matter. However, no bottled water showed any signs of contamination (0%) with total coli forms or E. coli. There was a strong association (P= 0.01) between water source and water quality. Bottled water sold in Ishaka, Bushenyi District of Uganda showed high quality standards while protected spring water showed significant level of contamination with E. coli which could potentially cause disease to the consumers. Therefore all stakeholders in public health should come together to look into the matter of increasing access cheap and safe water other than the unsafe water from the so called-protected springs‖.

- by Nsiko Peter
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- Food Safety, Bioremediation and Environmental microbiology

Filamentous fungi are considered to be the most important group of microorganisms for the production
of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two
fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant
CWDE such as amylase, pectinase, xylanase and cellulases (-glucosidase, endoglucanase and
filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to
the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of
fungal strains. The titers of pectinase were significantly improved in co-culture compared to
mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture
were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed
that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26
h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and
co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded
by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential
substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be
used for improving various biotechnological and industrial processes.

- by Muhammad Sohail
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- Microbiology, Environmental microbiology, Biotechnology, Agriculture

Benzo[α]pyrene (BaP) is one of the most toxic
polycyclic aromatic hydrocarbons (PAHs) in the soilplant
system causing potential carcinogenicity and
mutagenicity for human health. The knowledge on the
behavior of BaP in soil-plant system as well as aqueous
environment is needed for minimizing the risk of human
exposure and environmental contamination. BaP, high
molecular weight PAH with five benzene rings has been
specifically classified as a primary pollutant and group
1 human carcinogen. Bioremediation is an eco-friendly
and cost-effective method for reclaiming the
environment contaminated with BaP by making use of
the microorganisms and plants to eradicate the
hazardous effects.
The present review is focused on the microbe assisted
bioremediation and phytoremediation techniques for
the removal of BaP from the soil and aqueous
environment. The information provided here will help
to plan the research in a better way to develop more
sustainable system for remediation of BaP from the
environment.

- by Sanjeeb Kumar Mandal
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- Microbiology, Phytoremediation, Bioremediation, Environmental Biotechnology

The need for high biodegradation rates requires application of microorganisms in controlled environmental and nutritional conditions. Soil slurry bioremediation is a powerful alternative to conventional methods in resolving environmental oil contamination problems. This work studied the technical viability of treating soil slurry biologically by stimulation of native microorganisms. Oil contaminated mangrove soil
from Alakiri, Nigeria was mixed with water at 1:3 ratio and treated in three different ways (A, B and C). Statistical increase in microbial population and hydrocarbon removal efficiency were observed. In terms of total petroleum hydrocarbon degradation, removal efficiency of 55.31% was achieved in Slurry B (amended and stirred slurry),
closely followed by 53.21% of Slurry A (unamended and stirred slurry) and 31.58% for slurry C (amended and unstirred slurry). The importance of mechanical mixing on the microbial population dynamics and on the biodegradation of the oil was ascertained.
This study has shown that slurry bioreactor is effective in the bioremediation of soils containing oil-contaminants.

The OML 58 12/70 well head, Obagi, Niger Delta, Nigeria in situ surface water
treatment using OBD-Plus®, Total Petroleum Hydrocarbon (TPH) was reduced
to 99% under iron-reducing and sulfate-reducing coupled to the reduction of
chelated Fe (III) by 96%. Dissolved organic carbon was used as organic
substrate reducing the Chemical Oxygen Demand (COD) occurred in 49 days
treatment. Sulphate was the principal electron acceptor for the oxidation of
polycyclic aromatic hydrocarbon (PAH) at 97% and TPH (99%) reduction
respectively in 42 days soil/sediment treatment as the dissolved Fe (98%)
increase relative to the background , indicate Fe(III) is serving as an electron
acceptor in anaerobic biodegradation. Results with OBD-Plus® bioremediation
indicated that PAH and TPH oxidation is sulphate dependent with the rate and
extent of contaminant degraded is proportional to the concentration of
bioavailable contaminant utilizing organic substrates as sources of carbon and
energy. Contaminants biodegradated to innocuous end products (CO2, cell mass,
water) is considered to be an environmentally safe and cost-effective process for
removing organic contaminants.
Post - treatment evaluation was conducted by the regulatory agency for site
closure and a conference was conducted in collaboration with National
Biotechnology Development Regulatory Agency (NABDA) Abuja, Nigeria.
Video on the conference available at YouTube:
https://www.youtube.com/watch?v=Hi_OpgVcFcg.

Conventional chemical surfactants applications usually linked with environmental unfriendliness and toxicity are associated with high production costs resulting from fluctuations in oil prices and thermal energy requirements. Sophorolipid biosurfactants can potentially be implemented with a remarkably low operating cost. Besides economic interest, sophorolipids and their derivatives have shown promise as emulsifiers, antimicrobials, surfactants and a source of specialty chemicals Original Research Article

Anionic surfactants, the earliest and the
most common surfactants in detergent and cosmetic
product formulations contribute significantly to the
pollution profile of the ecosystem. Linear alkylbenzene
sulfonates (LAS), a major chemical constituent
of detergents, forms an imperative group of anionic
surfactants. Bioremediation of LAS by conventional
processes such as activated sludge is ineffective due to
the low kinetics of degradation by unsuitable organisms
and foam production. Hence this study was focused
on isolating and characterizing indigenous LASdegrading
bacteria from soil. Twenty different LASdegrading
bacteria were isolated from detergentcontaminated
soil by enrichment culture technique
and degradation efficiency was assessed by Methylene
Blue Active Substances (MBAS) assay and by
reverse-phase high-performance liquid chromatography
(HPLC) analysis. The most efficient LASdegrading
isolates, L9 (81.33±0.7) and L12 (81.81±
0.8), were selected and identified as Pseudomonas
nitroreducens (MTCC 10463) and Pseudomonas aeruginosa
(MTCC 10462). The 16S rDNA sequences of
the isolates were deposited in NCBI GenBank under
the accession numbers HQ 271083 (L9) and HQ
271084 (L12). The isolates were capable of degrading
0.05 g/l LAS at 25 °C and pH 7.0–7.5. Presence of a
solid support caused biofilm formation which in
turn enhanced LAS degradation. The isolates tend
to display diauxic growth with alternate carbon
source such as dextrose. These isolates also have
the capability to degrade other xenobiotics like
hydrocarbons and pesticides. Since xenobiotic pollutants
in nature occur as a mixture of compounds
rather than single pollutants, the potential of these
two indigenous LAS-degrading isolates to degrade
multiple xenobiotics gains relevance.
Keywords Biodegradation . Methylene Blue Active

Microplastics (MPs) are emerging persistent contaminants in the terrestrial subsurface, and evidence has emerged for significant effects of MPs on soils’ biological and ecosystem functions. Main MPs sources include land spreading of sewage sludge and biowaste composts, plastic mulching film used in horticultural fields, wastewater irrigation, and leachate from the landfills, amongst others. This updated state-of-the-art review paper describes recent experimental and numerical research and developments in understanding the accumulation, fate and effects of MPs in soil environment (focusing on their storage, degradation, transportation, leaching to groundwater, etc.), followed by mitigation and bioremediation measures, including soil bacterial- and fungus-eating MPs, best management practices for reducing MP pollution of soil, etc. Other areas covered are the combined effects of MPs and various other environmental contaminants (heavy metals, organic pollutants and antibiotics) in soil ecosystems, and standardization of methods for detection, quantification and characterisation of MPs in soils, which is critical for MPs research. The paper concludes by identifying knowledge gaps and presents recommendations on prioritized research needs.

A chemolithotrophic bacterium was isolated from sulfur hot spring. According to phenotypic traits and 16-23S rDNA intergenic spacer region analysis, the isolate was identified and named as Acidithiobacillus sp. MR39, which was a gram-negative, rod-shape and non-motile bacterium. The strain was able to grow in a synthetic liquid medium supplemented with the mineral ore as the source of energy. The optimum conditions were found to be within initial pH range of 2.0-2.5, at 34±1˚C and with shaking at 120 rpm. The bacterium had a remarkable potential for mineralization of 88% iron, 75% copper, 59% zinc, 59% nickel and 40% cobalt upon their growth in the liquid media. After adapting the bacterial cells to copper ions in 100 mM for 5-day incubation, biorecovery of Cu increased about 10% comparing to unadapted cells that are able to dissolve approximately 15% of total cu of mineral concentrate. Considering the finding in this study, the strain MR39 offers a great prospect for in situ extraction of metals from various ores along with other indigenous bacteria that can grow under ambient conditions.

- by Abdolrazagh marzban and +1
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- Bioremediation and Environmental microbiology

As the world population continues to grow, the demand for high quality food will be on the rise. To meet the demands for safe and sustainable food, urgent agricultural practices are needed utilizing water, energy, land, and nutrient resources more efficiently. In this study, 10 different strains of microalgae from Chlorella and Scenedesmus genera were screened to test their capabilities to remove the nutrients of agricultural wastewater collected from a dairy farm. The most successful strain was cultivated in a custom designed reusable plastic photobioreactors operated in batch mode and fed with coagulated, filtered and 1/4 diluted farm wastewater. Physical and chemical parameters including total nitrogen, total phosphorus, chemical oxygen demand and total solids of photobioreactor influent and effluent were measured. Removal efficiencies of 59.4%, 64.2% and 95.7% were obtained for total phosphorus, total nitrogen, and chemical oxygen demand parameters, respectively. Biomass concentration of 1.8 g/L was achieved at reactor closure. To demonstrate a circular bioeconomy case by reusing agricultural wastewater nutrients, generated microalgal biomass was further explored as potential feed formulations for livestock and/or aqua-culturing operations by analyzing protein, carbohydrate, lipid, vitamins, aminoacids, and fatty acid profiles using visible spectrophotometry, LC-MS/MS and GC-FID. Overall, the study aimed to optimize general and specific parameters of a low-cost microalgae-based agricultural wastewater treatment application and generate value added bio-feed products for sustainable livestock production and aquaculturing operations.

This study focuses on the isolation and biodegradation of PAHs by microorganisms associated with the sediments of automobile workshops of Pondicherry. One of the bacterial isolate selectively enriched in these compounds was identified as Rhodococcus ruber based on morphology, 16S rDNA sequencing and phylogenetic characteristics. Biodegradability tests with selected PAHs supplied as sole carbon sourceshowed that Rhodococcus sp. could utilize PAH compoundsin the order of chrysene>dieseloil>benzanthracene>crudeoil>fluorene>fluorant-hene>phenanthrene>dibenzothiophene>naphthalene and anthracene. Absorbance change of mineral medium with phenanthreneat 250ppm, 500ppm and 1000ppm concentration showed a linear increase in growth of the isolate in all the concentrations of phenanthrene. At 250ppm of phenanthrene concentration a lowest average growth of 0.05±0.02 () was observed while the highest optimum growth of 1.02±0.33 () was recorded at 1000ppm concentration of phenanthrene suggesting that R.rubercan endure high concentrations of phenanthrene. Hence,R.ruberstrain has great application indegradation processes involving petrochemical products.

- by BASHEER PA and +1
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- Bioremediation and Environmental microbiology

Microbial degradation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT)-residues is one of the mechanisms for the removal of this compound from the environment. A DDT-degrading consortium was isolated by long term enrichment of soil samples collected from DDT-contaminated fields. This consortium was acclimated by repeated passages through a mineral salt medium containing increasing concentrations of DDT. This acclimated consortium could degrade 25 ppm of DDT in 144 h. The consortium consisted of four bacteria. Of these, Serratia marcescens DT-1P was used for further studies. Various factors such as inoculum size, concentration of DDT, pH, temperature, presence of co-substrates, the type of carbon source used influenced the degradation of DDT in shake flasks. Complete degradation was observed up to 15 ppm DDT, followed by inhibitory effects at higher concentrations showing a total loss of degradative ability at 50 ppm DDT. Effective degradation of DDT was obtained with the inoculum pre-exposed to DDT for 72 h. Degradation was inhibited in the presence of auxiliary carbon sources such as citrate, rice straw hydrolysate. However, the presence of yeast extract, peptone, glycerol and tryptone soya broth (TSB) showed complete disappearance of DDT. Mesophilic temperatures (26 Á/30 8C) and near neutral pH (6.0 Á/8.0) were most favourable for degradation. This microbial culture holds the potential for use in bioremediation of DDT-contaminated soils, waste deposits and water bodies.

This paper presents an example of the importance of evapotranspiration in constructed wetlands, with vertical subsurface flow, comparing different methods of treatment efficiency calculations and discussing the influence of evapotranspiration on removal rates. The application of reed, marked by high transpiration ability, is a cheap and effective method of landfill leachate disposal. A 2-year study examined the effectiveness of leachate treatment in constructed wetlands with reed. Two kinds of vertical subsurface flow systems: first with sand, and second with combined two layers of sewage sludge and sand has been tested. 1, 3, and 5 mm d−1 hydraulic loading rates of landfill leachate have been applied. Daily evapotranspiration was in the range from 0.98 to 2.99 mm d−1 in the first year of research and from 2.56 to 4.61 mm d−1 in the second year. The influence of evapotranspiration rate on chemical oxygen demand (COD) removal rate was examined. Two methods of removal efficiency calculation have been used: first based on inlet and outlet COD concentrations, second on mass balance determination. Research showed that the removal efficiency calculated as a comparison between initial and final concentration is significantly lower, than expected from mass balance, especially, when higher hydraulic loading rates were applied.

- by Andrzej Białowiec and +1
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- Environmental Engineering, Chemical Engineering, Civil Engineering, Environmental Science

This research evaluates the effect of both organic and ammonia loading rates and the presence of plants on the removal of chemical oxygen demand and ammonia nitrogen in horizontal subsurface flow constructed wetlands, 2 years after the start-up. Two sets of experiments were carried out in two mesocosms at different organic and ammonia loading rates (the loads were doubled); one without plants (control bed), the other colonized with Phragmites australis. Regardless of the organic loading rate, the organic mass removal rate was improved in the presence of plants (93.4 % higher for the lower loading rate, and 56 % higher for the higher loading rate). Similar results were observed for the ammonia mass removal rate (117 % higher for the lower loading rate, and 61.3 % higher for the higher loading rate). A significant linear relationship was observed between the organic loading rate and the respective removal rates in both beds for loads between 10 and 13 g m−2 day−1. The presence of plants markedly increase removal of organic matter and ammonia, as a result of the role of roots and rhizomes in providing oxygen for aerobic removal pathways, a higher surface area for the adhesion and development of biofilm and nitrogen uptake by roots.

- by Antonio Albuquerque and +2
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- Engineering, Environmental Engineering, Chemical Engineering, Civil Engineering
- by Maria Polizeli
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- Engineering, Microbiology, Technology, Environmental microbiology

Present study investigated the use of pulsed power technique for disinfection of water under different
operating and environmental conditions. Final concentrations of reactive oxygen species (ROS) like
hydroxyl radical, hydrogen peroxide, ozone, and superoxide radicals generated in the system were found
to be 56, 17, 1 and 18 mg/L, respectively, for an applied voltage of 23 kV, frequency of 25 Hz and a streamer
discharge time of 12 min. It was observed that disinfection efficiency was high with sequential stress
compared to continuous stress. The disinfection efficiency increased with increasing applied voltage and
frequency. Disinfection efficiency was high when pH was less than 7. Presence of alkalinity, natural
organic matter and turbidity reduced the disinfection efficiency significantly. For 7 log reduction of
Escherichia coli, the treatment time was increased from 6 to 10 min, when pH was increased from 4 to
9. Complete disinfection of E. coli was achieved in a short treatment time of 4–10 min, with an energy
consumption of 0.0056–0.014 kW h for 50 mL of contaminated water. An empirical model for optimum
disinfection efficiency was developed using Box–Behnken design (BBD). As per the model, applied voltage,
time of treatment and alkalinity were found to be the most significant factors affecting the disinfection
efficiency. Model predicted values were in good agreement with the experimental values. Rate
constant for disinfection and ROS formation was also evaluated. Rate of disinfection was between 0.59
and 1.68 log(cfu/mL)/min.

We have developed a fluorescence resonance energy transfer (FRET)-based heavy metal biosensor for the quantification of bioavailable free heavy metals in the cytoplasm of the microalga Chlamydomonas reinhardtii. The biosensor is composed of an
end-to-end fusion of cyan fluorescent protein (CFP), chicken metallothionein II (MT-II), and yellow fluorescent protein (YFP). In vitro measurements of YFP/CFP fluorescence emission ratios indicated that the addition of metals to the purified biosensor
enhanced FRET between CFP and YFP, consistent with heavy metal-induced folding of MT-II. A maximum YFP/CFP FRET ratio
of 2.8 was observed in the presence of saturating concentrations of heavy metals. The sensitivity of the biosensor was greatest for Hg2+ followed by Cd2+ Pb2+ . Zn2+ . Cu2+. The heavy metal biosensor was unresponsive to metals that do not bind to MT-II (Na+ and Mg2+). When expressed in C. reinhardtii, we observed a differential metal-dependent response to saturating external concentrations (1.6 mM) of heavy metals (Pb2+ . Cd2+) that was unlike that observed for the isolated biosensor (in vitro). Significantly, analysis of metal uptake kinetics indicated that equilibration of the cytoplasm with externally applied heavy metals occurred within seconds. Our results also indicated that algae have substantial buffering capacity for free heavy metals in their cytosol, even at high external metal concentrations.

Passive flux meters (PFMs) have become invaluable tools for site characterization and evaluation of remediation performance at groundwater contaminated sites. To date, PFMs technology has been demonstrated in the field to measure midrange hydrophobic contaminants (e.g., chlorinated ethenes, fuel hydrocarbons, perchlorate) and inorganic ions (e.g., uranium and nitrate). However, flux measurements of low partitioning contaminants (e.g., 1,4-dioxane, hexahydro-1,3,5-trinitro-s-triazine (RDX)) and reactive ions-species (e.g., sulfate (SO 4 2−), Chromium(VI) (Cr(VI)) are still challenging because of their low retardation during transport and quick transformation under highly reducing conditions, respectively. This study is the first application of PFMs for in-situ mass flux measurements of 1,4-dioxane, RDX, Cr(VI) and SO 4 2− reduction rates. Laboratory experiments were performed to model kinetic uptake rates and extraction efficiency for sorbent selections. Silver impregnated granular activated carbon (GAC) was selected for the capture of 1,4-dioxane and RDX, whereas Purolite 300A (Bala Cynwyd, PA, USA) was selected for Cr(VI) and SO 4 2−. PFM field demonstrations measured 1,4-dioxane fluxes ranging from 13.3 to 55.9 mg/m 2 /day, an RDX flux of 4.9 mg/m 2 /day, Cr(VI) fluxes ranging from 2.3 to 2.8 mg/m 2 /day and SO 4 2− consumption rates ranging from 20 to 100 mg/L/day. This data suggests other low-partitioning contaminates and reactive ion-species could be monitored using the PFM.

- by Alexander Haluska and +2
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- Bioremediation, Bioremediation and Environmental microbiology, Bioaugmentation, Reductive Dechlorination

The microbial quality of some public swimming pools in Lagos State, Nigeria was investigated to determine possible risks of infections to swimmers. Ten swimming pools (Pools A-J) were investigated for their microbial and physico-chemical qualities. The pH of the pools ranged from 5.24-8.71 and the residual chlorine ranged from 0.01-0.07. Water samples from the pools were cultured on differential and selective media. The microbial loads varied with different swimming pools. The fungal population ranged from 0-4.7×10 4 cfu ml-1 , while the bacterial population ranged from 0-1.12 x 10 5 cfu ml-1. Eight bacterial isolates were obtained and identified using Microbact 24E kit. Fungal isolates (6) were identified by microscopy, Gram's staining and chloramphenicol test. The isolates include Aeromonas hydrophila (4), Burkolderia pseudomallei (2), Serratia marcescens (1), Enterobacter agglomerans (1), Candida albicans (3), Saccharomyces spp. (2) and Aspergillus flavus (1). Antifungal sensitivity test showed 50% susceptibility to nystatin and 50% resistance to voriconazole, while the bacteria were resistant to most of the antibiotic tested. The Multiple Antibiotics Resistance (MAR) index for the isolates ranged from 0.125 to 1.000. The feedback from the questionnaires administered, showed that unhygienic practices and maintenance of pools could contribute to low levels of swimming pool water quality. The high microbial loads and the types of microorganisms isolated from the pools show that contaminated swimming pools can constitute a serious public health hazard to the users.

- by Ayodele Omotayo and +1
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- Bioremediation and Environmental microbiology

Performance of sediment microbial fuel cells (SMFCs) with aerated (A‐SMFC) and nonaerated (NA‐SMFC) cathodes was evaluated at different operating conditions in toxic metal removal and power generation. The A‐ and NA‐SMFC open‐circuit voltages were respectively about 665 and 275 mV, with quite steady performances for 120 days. The cell design points of both SMFCs were calculated by implementing polarization curves, and they were at 1 kΩ (power density 8.1 mW/m 2 and current density 0.0504 mA/m 2 with voltage 150 mV) for NA‐SMFC and 100 Ω (power density 252.81 mW/m 2 and current density 0.954 mA/m 2 with voltage of 275 mV) for A‐SMFC, respectively. Cathode potentials were at 30 kΩ 290 mV (NA‐SMFC) and 500 mV (A‐SMFC). As to the anode, at 30 KΩ, it was −180 mV (NA‐SMFC) and 190 mV (A‐SMFC). The voltammetry profiles of A‐SMFC showed maximum current (forward scan, 22.7 μA; reverse scan, −19.4 μA) followed by NA‐SMFC (forward scan, 11.3 μA; reverse scan, −9.5 μA). The cell design points of A‐SMFC and NA‐SMFC were altered after pH and temperature amendments at 200 and 700 Ω, respectively. As to metal removal rate, the maximum arsenic cadmium and lead removal was observed in A‐SMFC at pH 7.0 (77.70%, 90.86%, and 83.91%) and 45°C (66.22%, 79.03%, and 71.17%). Scanning electron microscopy confirmed, at pH 7.0 and 45°C, an optimal biofilm growth at cathode and anode graphite of both SMFCs. After 120 days of operation, genomic DNA was extracted from biofilms and analyzed for rDNA 16S sequences. Similarity search was performed by using Basic Local Alignment Search Tool algorithm against the National Center for Biotechnology Information Gen Bank showing Pseudomonas spp. dominance at both anode and cathode. The results revealed that the A‐SMFC system could be employed as an effective and long‐term tool for power generation as well as stimulated bioremedia-tion of the polluted sediments.

The increase in human population, death from starvation, civil unrest, malnutrition and related diseases in countries of the world call for serious remedy. Agriculture alone cannot meet with the high demands of protein required worldwide. Single cell protein production, therefore, can be seen as a promising technology in combating this global challenge of food protein shortage. Microorganisms like bacteria, yeast, fungi and algae have been used as sources of single cell protein. Single cell protein not only produces protein, but can also employ the technology of waste management in converting agricultural wastes to food and feed for man and animal consumption.

- by Chandrasekhar Kuppam
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- Engineering, Petroleum, Bioremediation, Phylogeny

The genus Aeromonas contains gram negative non spore forming rods that are ubiquitous to aquatic environments worldwide. They are emerging pathogens that are frequently isolated from aquatic environments, including ground water, lakes, drinking water and wastewater. A total of 274 samples from boreholes (124) and lakes (150) were collected over a one year period (January to December, 2011) in Maiduguri, at Lakes Alau and Chad; and analysed for the presence of Aeromonas species based on Aerokey II group of tests for the identification and speciation of Aeromonas. Overall, 54 (36%) Aeromonas spp were isolated with 38 (38%) and 16 (32%) from lakes Chad and Alau respectively. There was no statistically significant difference (P > 0.05) in the occurrence of the isolates among various sampling points. A. hydrophila was the most common species with an overall prevalence of 91% followed by A. sobria with 9% prevalence. Water samples from boreholes located at Gwange ward had the highest rate of isolation (87.5%) followed in descending order by Galadima shuwarin (45%), London ciki (30%), Bulabulin (25%), Custom (15.8%) and University of Maiduguri staff quarters (10%). The water samples from Mairi and Bulabulin wards did not yield any Aeromonas isolate. The findings of this study confirmed the presence of potentially pathogenic Aeromonas species in the studied lakes and water samples from boreholes in Maiduguri metropolis. These sources of water are used for fishing, drinking and household chores. As Aeromonas is considered an emerging pathogen and can cause health problems, proper surveillance of water sources is strongly recommended to protect susceptible individuals from exposure to potentially pathogenic strains of Aeromonas.

- by haruna y. ismail and +1
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- Bioremediation and Environmental microbiology

An investigation on bacteriological quality assessment of effluent discharged from NILEST tannery was carried out with view to isolate and identify the bacterial species present in the tannery effluent, and to compare the level of microbial density of treated and untreated tannery effluents. Comparison between the level of contamination of the analyzed tannery effluent and the standard given by national and international environmental regulatory bodies was carried out. A total of 40 samples were collected; 20 each from treated and untreated samples. The samples were analyzed by multiple tube fermentation technique using Most Probable Number (MPN) method. All the untreated tannery effluent samples show the presence of coliform bacteria 40 (100%), while, 6 (30%) of the treated tannery effluent samples show the presence of coliform bacteria. There is significant difference (p<0.05) between microbial load in the treated tannery effluent and untreated effluents analyzed. Most of the treated samples (70%) were able to meet up with national and international environmental regulatory bodies' standard. It was recommended that adequate treatment of effluent should be carried out to reduce its risk to the aquatic animals and society at large.

- by MUSTAPHA UMAR
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- Microbiology, Epidemiology, Aquatic Ecology, Hydrology

This study was conducted to isolate and identify bacteria associated with spent diesel oil contaminated site by collecting three replicates contaminated soil from the works department of Admiralty University of Nigeria, while the pristine soil was obtained from the biological garden. pH and temperature of all the samples were checked and the bacteria isolates were identified by morphological and biochemical techniques using the taxonomy scheme of Bergey's Manual of determinative bacteriology. The pH and temperature was highest (6.06 to 6.26) and (27 to 30 0 C) in the contaminated soil than the pristine soil (5.83) and (23 0 C). The mean microbial load count was highest (10.0x10 5 cfu/ml)in the diesel oil contaminated soils than the pristine uncontaminated soils (9.0x0x10 5 cfu/ml). However, there was no significant difference between the microbial loads in the soil samples. Eight bacteria species were obtained from the contaminated soil while six were obtained from the pristine soil. Klebsiella spp., Enterobacterae riginosa, Pseudomonas sp. and Escherichia coli showed highest growth in the contaminated soil and therefore may be considered as effective in the degradation of spent diesel oil hydrocarbons. It is likely that these bacteria when employed independently may be used to degrade hydrocarbons. Further research is necessary to assay for the degradative ability of the microorganisms.