Zerihun Tsegaye - Academia.edu (original) (raw)

Papers by Zerihun Tsegaye

Journal of Yeast and Fungal Research, Nov 30, 2016

Coffee waste represents the most abundant waste in Ethiopia, this study aims to isolate, identify... more Coffee waste represents the most abundant waste in Ethiopia, this study aims to isolate, identify and characterize yeast from coffee waste in order to utilize in the biotechnological process. 25 merged coffee waste samples were collected from Sidama and Gedio zone. Yeast strain was cultured on yeast peptone dextrose and Biolog universal yeast agar media. Pure yeast cells were suspended in sterile water at 49+ turbidity, 100 µ L and transferred into 96 wells of the biolog yeast micro Plate and incubated at 26°C for 24 to 72 h and read by the Micro Station Reader at a single wavelength of 590 nm, results were recorded and processed for identification by micro log3 software ver. 4.20.05. Biolog microstation acceptable result ≥ 75% Probability and ≥ 0.5 similarity index value identified 5 yeast species, Hanseiaspora valbyensis, (100%PROB,0.707SIM,), Hyphopichia burtonii A (98%PROB,0.060SIM), Rhodotorula hylophila (98%PROB, 0.060SIM), Rhodotrula aurantiaca A (100% PROB, 0.505SIM) and Pichia amenthionina var. menthionina, (PROB 96% SIM,0.714). There was no report on yeasts associated with coffee waste in Ethiopia for utilization in biotechnological process. Therefore characterization of yeasts is very important for industrial and environmental application.

Frontiers in Microbiology

Inoculation of plant growth-promoting rhizobacteria (PGPR) improves the growth, yield, and plant ... more Inoculation of plant growth-promoting rhizobacteria (PGPR) improves the growth, yield, and plant nutrient uptake, as well as rhizosphere fertility, without harming the environment and human health. This study aimed to examine the effect of either individual or consortium of PGP bacterial inoculation on the growth, yield, and grain nutrient uptake of teff varieties. Three potential PGPR strains (i.e., Pseudomonas fluorescens biotype G, Enterobacter cloacae ss disolvens, and Serratia marcescens ss marcescens) were used for this study. Field evaluation was carried out in RCBD with 5 treatments. Highly significant (P < 0.001) differences were observed among treatments for plant height (PH), panicle length (PL), number of the total spike (NTS), shoot dry weight (SDW), grain yield (GY), and straw yield (SY). There was also teff variety that significantly (P < 0.01) affects PL, SDW, and SY. However, the interaction effect of the two factors (treatment*variety) did not significantly i...

Research and Reviews: Journal of Microbiology and Biotechnology, 2021

Plant growth promoting rhizobacteria are the soil bacteria inhabiting around or on the root surfa... more Plant growth promoting rhizobacteria are the soil bacteria inhabiting around or on the root surface that directly involved in promoting plant growth and development through production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Properties of plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in nutrients acquisition or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of the bio-control agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria as biofertilizers under both normal and stressed conditions. PGP rhizobacteria improve seed germination, root development, increase crop yield, restore natural soil fertility, decrease pollutant toxicity, provide protection against plant pathogens and environmental ...

The use of novel PGPR as bio inoculant is an alternative sustainable agricultural practice to imp... more The use of novel PGPR as bio inoculant is an alternative sustainable agricultural practice to improve soil health, grain quality, increase crop productivity, and conserve biodiversity. The aim of this study is to isolate, and characterized PGP bacteria colonizing tef rhizosphere during the seedling stage. For this concern, 426 samples of tef rhizosphere soils and roots were collected from East Shewa zone, Oromia regional state. 200 morphologically different bacterial pure colonies were isolated and screened for their PGP traits and biocontrol properties. Among these 40.5% isolates were positive for phosphate solubilization. 36% were positive for IAA production, 4.5% were positive for ammonia production, 19% were positive for (EXPS), 15.5% were positive for protease production, 12.5% were positive for HCN productions, 9.5% were positive for cellulase production, 4 % were positive for amylase production, 3.5% were positive for chitinase production. For abiotic stress tolerance test, all of the isolates were grew well at 20 and 30oc and neutral pH, 27% isolates were grew well at 4oc, 25.5 % grew at 40oc, 25.5% were grown well on pH-9 and pH-11, 23.5 % were tolerated pH-5, 3.5% grew at 50oc and 60oc, 13.5% were grown well on 5% NaCl (w/v), 3.5% were grown well on 10 and 15% NaCl (w/v), which indicated these isolates can survive in some extreme conditions. Totally 15 bacterial species having PGP traits, biocontrol properties, and abiotic stress tolerance ability were identified using the Biolog bacterial identification system. Among these, the majority of the identified PGPR have utilized carbohydrate, carboxylic acid, and amino acid, which are the main components of plant root exudates. The above results indicated that thus PGPR can be used as biofertilizers as well as biocontrol agents to replace agrochemicals to improve crop productivity. Hence, these species can be further formulated and used for greenhouse and field applications. contained calcium, potassium and other essential minerals found in an equal amount of other grains.

Bioremediation is a biological mechanism of recycling wastes in to another form that can use and ... more Bioremediation is a biological mechanism of recycling wastes in to another form that can use and reused by other organisms. Nowadays, the world is facing the problem of different environmental pollution. Microorganisms are essential for a key alternative solution to overcome challenges. Microorganisms are survive in all place on the biospher because of their metabolic activity is astonishing; then come into existence in all over range of environmental conditions. The nutritional capacity of microorganisms is completely varied, so it is used as bioremidation of environmental pollutants. Bioremediation is highly involved in degradation, eradication, immobilization, or detoxification diverse chemical wastes and physical hazardous materials from the surrounding through the all-inclusive and action of microorganisms. The main principle is degrading and transforming pollutants such as hydrocarbons, oil, heavy metal, pesticides, dye’s and so on. That is carried out in enzymatic way through...

International Journal of Research Studies in Biosciences, 2018

Contamination is undesired introduction of impurities like chemical, microbial or physical matter... more Contamination is undesired introduction of impurities like chemical, microbial or physical matter, into or onto a starting or intermediating cell culture during sampling, holding, processing, storing, transferring, packaging and transporting. A cell culture contaminant is defined as some element in the culture system that is undesirable because of its possible adverse effects on either the system or its use. Contamination of cell cultures is easily the most common problem encountered in several microbial laboratories, sometimes with very serious consequences. In overall, the reason for contaminants are mostly happened through avoidable procedural errors and misguide techniques. Microbes are widely distributed in the environment without restriction and they are involved in different places even inside a laboratory. Microbial contamination is one of a biggest worldwide obstacle for researchers working with microbial cultures. It may lose laboratory valuable strains. False-positive cultures are reports of microbiological laboratory came from due to common and unusual laboratory contaminants. High microbial contaminate concentration is happened in a microbial lab due to lack of proper management. It is a global concern regarding health and leads to difficult for getting accurate research output. It is manually or systematically introduce in our culture and damage the quality of our work. Recently, many articles are mentioned it and previous reports act as evidence for the challenge. In the end, in order to reduce their first apply good laboratory practice next follow appropriate instructions [2, 6, 7 and 12]. Contaminates are receiving high attention, but the sources and processes of them are not well understood. The major methodological part of the study on the basis of an observational cohort study and long year visual investigation experience in the work area (laboratory). The aim of the current study was identified the critical sources of bacterial contamination inside laboratory then it forward answers for causes of cross-contamination how it happens? The purpose of this paper to describe appropriate and necessary options to prevent microbial, physical or chemical cross-contamination and to reduce false positive culture reports as well as to maximize the true result comes from the microbiological laboratory through practical techniques. 2. TYPES OF CELL-CULTURE CONTAMINATION 2.1. Physical Contaminants Physical contaminants are materials consider as natural or artificial components that act as a contaminant. It also termed as unwanted foreign bodies such as glass fragments, metal, stone, plastics,

Journal of Plant Pathology & Microbiology

Material and Methods Sample collection Eight three tef seeds accessions were collected from Ethio... more Material and Methods Sample collection Eight three tef seeds accessions were collected from Ethiopian biodiversity institute germplasm repository in 2017 G.C. Isolation of tef seed endophytic bacteria Collected seed samples were washed in sterile water and immersed in 70% ethanol for 3 min and followed by fresh sodium hypochlorite solution (2% NaClO) for 5 min; and then transferred to 70% ethanol (v/v) for 30 secs to remove the remaining NaClO. Finally, the seeds were

International Journal of Research Studies in Biosciences

Moreover, the health consciousness of the people coupled with the development of resistance to pa... more Moreover, the health consciousness of the people coupled with the development of resistance to pathogens due to continuous use of the chemicals also contributes to the restricted use of chemicals in crop protection. Under such circumstances exploitation of living organisms to reduce the disease

Open Journal of Environmental Biology

Bioremediation is a biological mechanism of recycling wastes in to another form that can used and... more Bioremediation is a biological mechanism of recycling wastes in to another form that can used and reused by other organisms. Nowadays, the world is facing the problem of different environmental pollution. Microorganisms are essential for a key alternative solution to overcome challenges. Microorganisms are survive in all place on the biosphere because of their metabolic activity is astonishing; then come into existence in all over range of environmental conditions. The nutritional capacity of microorganisms is completely varied, so it is used as bioremediation of environmental pollutants. Bioremediation is highly involved in degradation, eradication, immobilization, or detoxifi cation diverse chemical wastes and physical hazardous materials from the surrounding through the all-inclusive and action of microorganisms. The main principle is degrading and transforming pollutants such as hydrocarbons, oil, heavy metal, pesticides, dye's and so on. That is carried out in enzymatic way through metabolizing, so it have grate contribution role to solve many environmental problems There are two types of factors these are biotic and abiotic conditions are determine rate of degradation. Currently, different methods and strategies are applied in the area in different part of the world. For example, biostimulation, bioaugementation, bioventing, biopiles and bioattenuation are common one. All bioremediation techniques it has its own advantage and disadvantage because it has its own specifi c application.

Environment Pollution and Climate Change

Greenhouse gases concentration is increased through time within different human and natural facto... more Greenhouse gases concentration is increased through time within different human and natural factors. Such as the combustion of coal, oil and other fossil fuels, decay of plant matter and biomass burning. Climate change and global warming is the major problem in the world. it is damage and destroy a number of biotic componets. It have also effect in thier microbial comunity stracture and function and also their metablolic activity. In order to fight/compromize/ climate change using a number of methods are listed. For example, microorganisms and biological componets have many potential role for mitigation by contribute forward response. Microorganisms have a wide potential especialy used in greenhouse gas treatment and reduction through nutrient recycling. It act as either generators or users of these gases. It provide to reduce environment hazards which is caused by nature and antropogenic activity. Generally biogeochemical cycles and climate changes are never see separately.

Application of native PGPR as bio inoculant is an alternative sustainable agricultural practice t... more Application of native PGPR as bio inoculant is an alternative sustainable agricultural practice to enhance crop productivity, grain quality, and soil fertility. In this view, a study was to examine the effect of either individual or consortium PGPR inoculation on growth, yield, and grain nutrient uptake of two teff varieties. The pot experiment was carried out in (CRD) three replication and 10 treatments. The PGPR inoculants used in this study were Pseudomonas fluorescens biotype G, Enterobacter cloacae ss disolvens, and Serratia marcescens ss marcescen and their consortium. Dukem and Magna varieties were used in this study. The results of the analysis of variance showed significant differences (P ≤ 0.001) among the treatment and most of the agronomic traits except number of fertile tillers and also significant different (P ≤ 0.01) for grain P and N uptake. The variety was significantly affected grain Mg, Zn and Fe uptake at 5 % probability level and did not significantly influence ...

Biomedical Journal of Scientific & Technical Research

The Plant Growth-Promoting Rhizobacteria (PGPR) are the free-living plant roots colonizing bacter... more The Plant Growth-Promoting Rhizobacteria (PGPR) are the free-living plant roots colonizing bacteria that improve soil fertility, stimulating plant growth, and protecting plants from biotic and abiotic stress factors. The present study was conducted to characterize and identify native PGP bacteria colonizing tef rhizosphere during the flowering stage for a production of bio inoculant. For this concern, 426 samples of different varieties of tef roots and rhizosphere soils were collected. A total of 457 rhizobacteria were isolated and characterized for PGP traits, biocontrol properties, and abiotic stress tolerance ability. 12 rhizobacterial species were identified using the Biolog bacterial identification system. Among these, the majority of the identified bacterial species were utilized different carbon sources that similar to plant root exudates i.e. carbohydrates, carboxylic acids, amide, and amine. Seed germination and seedling growth test were conducted using four identified bacterial species having excellent plant growth-promoting, biotic and abiotic stress tolerance properties, and 100 percent tef seeds germination result occurred on 3 rd and 4 th day after inoculation. shoot and root length of inoculated seeds was measured on last day of the experiment to determine the effect of PGP bacteria on tef crops growth enhancement and increase mean shoots and root length up to 3 and 2.6 cm respectively in comparison to control. PGP bacterial species or strains can be used as bio inoculants to replacing chemical fertilizers for sustaining agricultural productivity and production without affecting soil fertility, living organisms, and their environment.