Indira sarethy - Academia.edu (original) (raw)

Papers by Indira sarethy

Study of Streptomyces diversity in arid and semi-arid soil of India

Journal of Pure and Applied Microbiology, 2010

ANTIBACTERIAL ACTIVITY OF PLANT BIOSURFACTANT EXTRACT FROM SAPINDUS MUKOROSSI AND IN SILICO EVALUATION OF ITS BIOACTIVITY Short Communication

Objective: Natural biosurfactants can replace synthetic surfactants and find applications in cosm... more Objective: Natural biosurfactants can replace synthetic surfactants and find applications in cosmetic products. Saponin extracts from Sapindus mukorossi fruits have emulsifying properties and have traditionally been used in hair care treatments. Their utility can be enhanced by studying their antimicrobial activity against common skin and other microorganisms. Methods: Aqueous biosurfactant extracts were prepared from fruits of S. mukorossi. Concentrated and diluted extracts were tested for antimicrobial activity against Micrococcus luteus, Brevibacterium linens, Bacillus subtilis, Staphylococcus epidermidis, Escherichia coli and Pseudomonas fluorescens by the well diffusion method and measuring the zone of inhibition. In silico biological activity of different saponins present in S. mukorossi was studied using the software Prediction of Activity Spectra for Substances (PASS). Results: Concentrated extracts were most active against all the target microorganisms. Gram positive organi...

Endophytes: The Unmapped Repository for Natural Products

Natural Bio-active Compounds, 2019

Endophytes are the microorganisms present within the living tissues of plants. It has been sugges... more Endophytes are the microorganisms present within the living tissues of plants. It has been suggested that every plant harbours at least one to two endophytes. However, very few plants have been characterized for their endophytic population, in comparison to their known diversity. A search in PubMed using the keyword ‘endophyte’ shows that there has been a considerable increase in the number of publications focusing on endophytes, i.e., 32 in the 2000s to ~500 in 2017 and roughly 200 in the first few months of 2018. The trend suggests increasing interest in endophytes as sources of novel metabolites. The pointers in early studies had shown the presence of novel natural compounds produced by endophytes. Indeed, the therapeutic molecules in many plants have been proposed to be produced by endophytes and not the host plants themselves. These molecules have the potential to serve as added resources in the desperate search for bio-active compounds which can combat various diseases and syn...

In the present work, a two-step sequential method employing copper sulfate (CuSO4) and Pseudomona... more In the present work, a two-step sequential method employing copper sulfate (CuSO4) and Pseudomonas putida as treatment materials was investigated to remove color and phenols from paper industry wastewater. The wastewater was first subjected to precipitation treatment using CuSO4, which removed 96% and 52% of initial color and phenols, respectively. However, this treatment induced 65 mgL of residual Cu(II) concentrations in treated water. The water treated by CuSO4 was later subjected to treatment with the bacteria, P. putida, which further reduced the color and phenols to below disposable levels. Interestingly, the latter treatment also reduced residual Cu(II) ions to below safe disposal level of 1.0 mg L. The study concludes that the proposed two-step sequential treatment involving CuSO4 and P. putida may be effectively used as an alternative tertiary treatment method for the remediation of color and toxic phenols from paper industry wastewater.

Nanotechnology in the Food Industry: Perspectives and Prospects

In the present scenario, it has been estimated that out of the 7 billion people inhabiting the Ea... more In the present scenario, it has been estimated that out of the 7 billion people inhabiting the Earth, 0.9 billion face inadequate food supply (food insecurity) and 2 billion are malnourished, out of which over 800 million suffer from severe malnutrition and 36 million more die from lack of food. The projected rise in population curves indicates that by the year 2020, the Earth will be populated by 8 billion people and by 2050, the global population is expected to hit 9.6 billion. Wastage of food in various forms (lack of efficient storage methods, delayed transportation to market, pathogen and pest attacks, natural calamities, poor bioavailability, short shelf life) leads to ineffective utilization of the produced food. While various strategies exist to counter these issues, it is postulated that nanotechnology can also play a significant role in mitigating many of the contributing factors. Food supplements can be incorporated in the form of nanoparticles to enhance nutritional valu...

Amylase produced by Bacillus sp. SI-136 isolated from sodic-alkaline soil for efficient starch desizing

Journal of Biochemical Technology, 2013

Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group ... more Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group based on 16S rDNA sequence. It produced α-amylase of 26 kDa with maximum activity at pH 10.0, stable up to pH 12.0 and 80 o C. Mn 2+ enhanced its activity as also 10% NaCl in medium. Agricultural waste substrates supported growth and enzyme activity was enhanced by 30% with sugarcane bagasse. The partially purified enzyme showed efficient desizing of cotton fabric at 50 o C (40-60 min) or 70 o C (60 min) with Tegewa rating 7-8, and at 95 o C (20 min) with Tegewa rating 9, properties

Genomics, proteomics and transcriptomics in the biological control of plant pathogens: a review

Indian Phytopathology

Plant diseases cause significant yield and quality losses and thereby need to be minimized. Sever... more Plant diseases cause significant yield and quality losses and thereby need to be minimized. Several approaches can be used to manage plant diseases. Farmers often depend more on chemical fertilizers and pesticides, in addition to good agronomic practices. Excessive use of agrochemicals has led to environmental pollution. Natural biocontrol agents have been postulated to be less harmful; however, despite successful identification of several biocontrol agents, inefficacy and inconsistency against specific plant diseases under different field and environmental conditions has been shown to be a big obstacle. This emphasizes the need for improved biocontrol agents which can withstand adverse conditions and still perform well for management of diseases caused by pathogens. Genome sequencing of biocontrol organism can provide better insights for effective management of plant diseases. Besides these, omics-technology based knowledge is increasingly contributing to better understanding of biocontrol strategies. While genetically modified microorganisms can play an important role, regulatory concerns can hamper effective commercialization. In this scenario, the omics-based technologies are expected to play a major role in future commercialization of biocontrol agents. This review provides an overview of the evolution of genomics, proteomics, and transcriptomics in the field of biocontrol agents for plant pathogens.

Designer Foods: Scope for Enrichment With Microbe-Sourced Antioxidants

Designer foods are gaining in popularity as consumers become aware of the benefits they offer in ... more Designer foods are gaining in popularity as consumers become aware of the benefits they offer in terms of disease prevention and their perceived role in enhancing immunity. While many types of designer foods cater to different market segments and address requirements, such as enhanced protein, vitamin, and micronutrient content; higher incidences of lifestyle-associated diseases have focused attention on foods tailored toward reducing or preventing conditions, such as obesity, cancer, diabetes, neurodegenerative disorders, and cardiovascular diseases. Many of these diseases also affect the growing geriatric population. Increasing healthcare costs and developing economies with disposable incomes add to the consumer interest in designer foods. Free radicals have been implicated (directly or indirectly) in many of these lifestyle-associated diseases through oxidative stress. Antioxidants are naturally generated in the body to counter the toxic free radicals; however, a better balance b...

Effect of Strychnos potatorum Linn. Seed Extracts on Water Samples from Different Sources and with Diverse Properties

In developing countries, ground water, which is contaminated with domestic and industrial waste, ... more In developing countries, ground water, which is contaminated with domestic and industrial waste, is commonly used for drinking. Colour, turbidity and microbial content affect quality of potable water. Strychnos potatorum (Linn.) seeds are known to function as coagulants and clarify water. Our study investigated the effect of the seed powder (10-40 mg L -1 ) on water samples of varying colour, turbidity and microbial content. Samples studied were of river Yamuna, industrial effluent, a recreational pond, tap water and distilled water. pH was maintained within ±5 units while alkalinity was within one unit, showing that taste parameters were not affected. There was an 82-98% decrease in absorbance, denoting the seed's clarifying effect. The reduction in heterotrophic microbial load was 99% when 10 mg L -1 of seed powder was added. Ames test demonstrated non-toxicity of the seed at the concentrations tested. This simple method can help as an effective and affordable pre-treatment me...

Essential Oils: An Update on Their Biosynthesis and Genetic Strategies to Overcome the Production Challenges

Essential oils, secreted by plants, are primarily meant for various physiological, ecological, an... more Essential oils, secreted by plants, are primarily meant for various physiological, ecological, and defense activities. These oils belong to various classes, i.e., isolates of fatty acids, isoprenoids, and phenolic complexes, and can be secreted by various organs of plants. The essential oil market globally has been predicted to grow at a compound annual growth rate (CAGR) of ~8–10%, and reach a staggering figure in excess of USD ten billion in the next 5 years or so. However, the challenge lies in commercial production, keeping pace with the demand, since their natural production in plants is in considerably low quantities, which depends on ecological conditions and growth stages of the plant. Although several investigations exist in the literature, there is a pressing need for a systematic review of the recent updates, particularly concerning the strategies that facilitate the manufacturing of such indispensable oils. The current chapter focuses on various facets of essential oil p...

Objective: Endophytes represent a niche habitat for the study of novel bio-and chemo diversity. N... more Objective: Endophytes represent a niche habitat for the study of novel bio-and chemo diversity. Nelumbo nucifera is an aquatic plant that has not been characterized for endophyte diversity. This study was undertaken with the objective of isolating endophytes from submerged and aerial part of N. nucifera , study the diversity profile of the isolated endophytes and their antimicrobial, antioxidant, and siderophore production capacity. Methods: Endophytes were isolated from aerial and submerged parts of N. nucifera on different media (Starch Casein Nitrate, Glucose Yeast Extract, Nutrient and Potato Dextrose agar). These were further characterized for morphology (colony characteristics, Gram reaction), physiological characteristics (carbon, nitrogen utilization) and activity (antimicrobial, antioxidant, siderophore production). After dereplication, twelve isolates were studied further. Results: All endophyte isolates were Gram-positive bacteria, and one was a fungus. Isolate L-300 show...

Analyzing Functional Microbial Diversity

Microbial Diversity in the Genomic Era

Abstract Ecosystem functioning is, to a large extent, dependent on the activities of microorganis... more Abstract Ecosystem functioning is, to a large extent, dependent on the activities of microorganisms. Though comprising the largest fraction of living organisms in terms of numbers and biomass, their importance in maintenance of habitats, ecological recycling of nutrients, waste and other matter, and their crucial role in interactions between biotic and abiotic components of the environment demands that their functional role in various habitats be elucidated clearly. While the output of such studies are scattered, a limitation has also been that 99% of microorganisms are believed to belong to the uncultivable fraction. This makes it imperative that this fraction should also be addressed in functional diversity studies. The interplay between taxonomic and functional diversity, where taxonomy, to a large extent, is associated with function, mandates that the chapter also emphasize on assessment of taxonomy. The current chapter focuses on the various techniques available to study cultivable and uncultivable microorganisms (with emphasis on work pertaining to bacteria), from their functional diversity point of view.

Pseudonocardiaceae sp. TD-015 from the Thar Desert, India: Antimicrobial Activity and Identification of Antimicrobial Compounds

Current Bioactive Compounds

Characterization of Streptomyces sp. UK-201 from Lachhiwala Reserve forest, a biodiversity hot spot of the Himalayas

The Natural Products Journal

Background: Multi-drug resistance among pathogens is emerging due to slow pace of development of ... more Background: Multi-drug resistance among pathogens is emerging due to slow pace of development of new antimicrobials by combinatorial chemistry. Natural products from microorganisms from under-explored habitats can be lead molecules for such discoveries. Objective: The major objectives were to characterize isolate UK-201, taxonomically identify UK-201 based on 16S rDNA sequencing and execute metabolite fingerprinting of ethyl acetate extract of UK-201 by GC-MS. Method: In search of new antimicrobial compounds, Streptomyces isolate UK-201 exhibiting broad spectrum antimicrobial and antifungal activity, obtained from under-explored Lachhiwala Reserve forest, of the Himalayas was selected in this study. Isolate UK-201 was identified by 16S rDNA sequencing. Ethyl acetate extract of this isolate exhibited antimicrobial activity against all selected panel of Gram positive, Gram negative bacteria and fungi among other organic solvent extracts. Hence, EA extract was partially purified by col...

Microbial Biodeterioration of Cultural Heritage: Events, Colonization, and Analyses

Microbial Ecology

Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eve... more Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eventually leading to formation of soil. However, when the stones and rocks are a part of historic buildings and monuments, the effects are deleterious. In addition, microorganisms also colonize these monuments over a period of time, resulting in formation of biofilms; their metabolites lead to physical weakening and discoloration of stone eventually. This process, known as biodeterioration, leads to a significant loss of cultural heritage. For formulating effective conservation strategies to prevent biodeterioration and restore monuments, it is important to know which microorganisms are colonizing the substrate and the different energy sources they consume to sustain themselves. With this view in scope, this review focuses on studies that have attempted to understand the process of biodeterioration, the mechanisms by which they colonize and affect the monuments, the techniques used for assessment of biodeterioration, and conservation strategies that aim to preserve the original integrity of the monuments. This review also includes the “omics” technologies that have started playing a large role in elucidating the nature of microorganisms, and how they can play a role in hastening the formulation of effective conservation strategies.

Antimicrobial and Antioxidant Compounds in Endophyte Isolate L-003 Obtained from the Aquatic Plant Nelumbo nucifera

The Natural Products Journal

Background: Microorganisms from understudied habitats have been shown to be an important source o... more Background: Microorganisms from understudied habitats have been shown to be an important source of novel bioactive compounds. Endophytes constitute an underexplored group of microorganisms, of which those from aquatic plants have been even less studied. Nelumbo nucifera (lotus) is an aquatic plant with medicinal properties. A screening program for endophytes from N. nucifera by our research group resulted in many microbial isolates, of which isolate L-003 was a promising candidate, exhibiting antimicrobial and antioxidant activities. Objectives: The major objectives were to characterize the endophyte L-003 for its antimicrobial and antioxidant properties, identify the constituent bioactive compounds by GC-MS and characterize their activities further using in silico software. Methods: L-003 was identified by PIBWin software. Antimicrobial activity of the aqueous and organic extracts of culture supernatant of L-003 was checked against a panel of bacteria and fungi. Since the ethyl ace...

Microbial diversity of a Himalayan forest and characterization of rare actinomycetes for antimicrobial compounds

3 Biotech

The slow pace of discovery of new effective drugs against multi-drug resistant pathogens and larg... more The slow pace of discovery of new effective drugs against multi-drug resistant pathogens and largely unsuccessful combinatorial chemistry has resulted in shifting the focus back to natural products as sources of lead molecules for antimicrobial drugs, mainly due to their structural diversity. Investigation of under-explored habitats for potentially novel microorganisms provides for wider chemodiversity. In this study, four actinomycetes, namely UK-274, UK-281, UK-282 and UK-285, which showed broad-spectrum antibacterial and antifungal activities, were isolated from Timli forest range of the biodiversity-rich Himalayan region. 16S rRNA gene sequence analysis showed that the nearest neighbours of the isolates were Actinomadura nitrigenes, Streptomyces niveiscabiei, and Kitasatospora psammotica with similarity values ranging between 97 and 98% suggesting their potential as new isolates. Further morphological and phenotypic characterization strengthened this assumption. Isolate UK-282, of the rare actinomycetes Kitasatospora group, was found to produce antimicrobial activity. Metabolite fingerprinting of ethyl acetate fraction of isolate UK-282 by GC–MS and 1H NMR analysis showed the presence of three novel compounds. The study underlines that a combination approach of bioprospecting of under-studied habitats and focus on rare actinomycetes may result in the identification of novel chemodiversity.

Saccharothrix tharensis sp. nov., an actinobacterium isolated from the Thar Desert, India

Antonie van Leeuwenhoek, Jan 26, 2018

The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was ... more The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was established using a polyphasic approach. The strain has chemotaxonomic and morphological properties consistent with its classification in the genus Saccharothrix. It forms a distinct branch in the Saccharothrix 16S rRNA gene tree, related to the type strain of Saccharothrix saharensis (96.7%) but was distinguished readily from it using a combination of phenotypic properties. The genotypic and phenotypic data show that the strain represents a novel species in the genus Saccharothrix, for which the name Saccharothrix tharensis sp. nov. is proposed with the type strain TD-093 (= KCTC 39724 = MCC 2832).

Plant Peptides: Bioactivity, Opportunities and Challenges

Protein & Peptide Letters

Process Development for Bioactive Peptide Production

Food Bioactives, 2017

Bioactive peptides (BPs) are protein hydrolysates able to induce positive physiological responses... more Bioactive peptides (BPs) are protein hydrolysates able to induce positive physiological responses when introduced into the body, making them useful ingredients in food, cosmetic and pharmaceutical products. However, the full potential of BPs has not been fully explored because research is still lacking on economical and scalable production methods. This study is therefore aimed at the development of a bioprocess for the production of novel bioactive peptides from food proteins by exploiting fermentative and the proteolytic activities of Lactobacillus delbrueckii subsp. lactis 313 (LDL 313). The optimum parameters and conditions for the production of antihypertensive peptides using LDL 313 were obtained from the literature and covered the upstream, midstream and downstream stages. The feasibility of manufacturing BPs in a large scale was also projected by conducting an economic assessment and a quantitative analysis based on the medical needs of hypertensive patients in Malaysia. Results indicated that to meet the needs of the hypertensive population, a production level of 1.267 kg milk protein/kg peptide had to be obtained at an enzyme requirement of 0.2 kg enzyme/kg milk protein. At this production level and at a peptide market value of USD 88.5/g peptide, the annual expected value of peptide will be USD 41,858,307,460. It will take about 19.5 h to produce one batch of the peptides at a total annual cost (equipment and utilities) of USD 15,081,885. An annual revenue of USD 42 billion is therefore expected from the entire bioprocess implying that the process is economically feasible.

Study of Streptomyces diversity in arid and semi-arid soil of India

Journal of Pure and Applied Microbiology, 2010

ANTIBACTERIAL ACTIVITY OF PLANT BIOSURFACTANT EXTRACT FROM SAPINDUS MUKOROSSI AND IN SILICO EVALUATION OF ITS BIOACTIVITY Short Communication

Objective: Natural biosurfactants can replace synthetic surfactants and find applications in cosm... more Objective: Natural biosurfactants can replace synthetic surfactants and find applications in cosmetic products. Saponin extracts from Sapindus mukorossi fruits have emulsifying properties and have traditionally been used in hair care treatments. Their utility can be enhanced by studying their antimicrobial activity against common skin and other microorganisms. Methods: Aqueous biosurfactant extracts were prepared from fruits of S. mukorossi. Concentrated and diluted extracts were tested for antimicrobial activity against Micrococcus luteus, Brevibacterium linens, Bacillus subtilis, Staphylococcus epidermidis, Escherichia coli and Pseudomonas fluorescens by the well diffusion method and measuring the zone of inhibition. In silico biological activity of different saponins present in S. mukorossi was studied using the software Prediction of Activity Spectra for Substances (PASS). Results: Concentrated extracts were most active against all the target microorganisms. Gram positive organi...

Endophytes: The Unmapped Repository for Natural Products

Natural Bio-active Compounds, 2019

Endophytes are the microorganisms present within the living tissues of plants. It has been sugges... more Endophytes are the microorganisms present within the living tissues of plants. It has been suggested that every plant harbours at least one to two endophytes. However, very few plants have been characterized for their endophytic population, in comparison to their known diversity. A search in PubMed using the keyword ‘endophyte’ shows that there has been a considerable increase in the number of publications focusing on endophytes, i.e., 32 in the 2000s to ~500 in 2017 and roughly 200 in the first few months of 2018. The trend suggests increasing interest in endophytes as sources of novel metabolites. The pointers in early studies had shown the presence of novel natural compounds produced by endophytes. Indeed, the therapeutic molecules in many plants have been proposed to be produced by endophytes and not the host plants themselves. These molecules have the potential to serve as added resources in the desperate search for bio-active compounds which can combat various diseases and syn...

In the present work, a two-step sequential method employing copper sulfate (CuSO4) and Pseudomona... more In the present work, a two-step sequential method employing copper sulfate (CuSO4) and Pseudomonas putida as treatment materials was investigated to remove color and phenols from paper industry wastewater. The wastewater was first subjected to precipitation treatment using CuSO4, which removed 96% and 52% of initial color and phenols, respectively. However, this treatment induced 65 mgL of residual Cu(II) concentrations in treated water. The water treated by CuSO4 was later subjected to treatment with the bacteria, P. putida, which further reduced the color and phenols to below disposable levels. Interestingly, the latter treatment also reduced residual Cu(II) ions to below safe disposal level of 1.0 mg L. The study concludes that the proposed two-step sequential treatment involving CuSO4 and P. putida may be effectively used as an alternative tertiary treatment method for the remediation of color and toxic phenols from paper industry wastewater.

Nanotechnology in the Food Industry: Perspectives and Prospects

In the present scenario, it has been estimated that out of the 7 billion people inhabiting the Ea... more In the present scenario, it has been estimated that out of the 7 billion people inhabiting the Earth, 0.9 billion face inadequate food supply (food insecurity) and 2 billion are malnourished, out of which over 800 million suffer from severe malnutrition and 36 million more die from lack of food. The projected rise in population curves indicates that by the year 2020, the Earth will be populated by 8 billion people and by 2050, the global population is expected to hit 9.6 billion. Wastage of food in various forms (lack of efficient storage methods, delayed transportation to market, pathogen and pest attacks, natural calamities, poor bioavailability, short shelf life) leads to ineffective utilization of the produced food. While various strategies exist to counter these issues, it is postulated that nanotechnology can also play a significant role in mitigating many of the contributing factors. Food supplements can be incorporated in the form of nanoparticles to enhance nutritional valu...

Amylase produced by Bacillus sp. SI-136 isolated from sodic-alkaline soil for efficient starch desizing

Journal of Biochemical Technology, 2013

Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group ... more Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group based on 16S rDNA sequence. It produced α-amylase of 26 kDa with maximum activity at pH 10.0, stable up to pH 12.0 and 80 o C. Mn 2+ enhanced its activity as also 10% NaCl in medium. Agricultural waste substrates supported growth and enzyme activity was enhanced by 30% with sugarcane bagasse. The partially purified enzyme showed efficient desizing of cotton fabric at 50 o C (40-60 min) or 70 o C (60 min) with Tegewa rating 7-8, and at 95 o C (20 min) with Tegewa rating 9, properties

Genomics, proteomics and transcriptomics in the biological control of plant pathogens: a review

Indian Phytopathology

Plant diseases cause significant yield and quality losses and thereby need to be minimized. Sever... more Plant diseases cause significant yield and quality losses and thereby need to be minimized. Several approaches can be used to manage plant diseases. Farmers often depend more on chemical fertilizers and pesticides, in addition to good agronomic practices. Excessive use of agrochemicals has led to environmental pollution. Natural biocontrol agents have been postulated to be less harmful; however, despite successful identification of several biocontrol agents, inefficacy and inconsistency against specific plant diseases under different field and environmental conditions has been shown to be a big obstacle. This emphasizes the need for improved biocontrol agents which can withstand adverse conditions and still perform well for management of diseases caused by pathogens. Genome sequencing of biocontrol organism can provide better insights for effective management of plant diseases. Besides these, omics-technology based knowledge is increasingly contributing to better understanding of biocontrol strategies. While genetically modified microorganisms can play an important role, regulatory concerns can hamper effective commercialization. In this scenario, the omics-based technologies are expected to play a major role in future commercialization of biocontrol agents. This review provides an overview of the evolution of genomics, proteomics, and transcriptomics in the field of biocontrol agents for plant pathogens.

Designer Foods: Scope for Enrichment With Microbe-Sourced Antioxidants

Designer foods are gaining in popularity as consumers become aware of the benefits they offer in ... more Designer foods are gaining in popularity as consumers become aware of the benefits they offer in terms of disease prevention and their perceived role in enhancing immunity. While many types of designer foods cater to different market segments and address requirements, such as enhanced protein, vitamin, and micronutrient content; higher incidences of lifestyle-associated diseases have focused attention on foods tailored toward reducing or preventing conditions, such as obesity, cancer, diabetes, neurodegenerative disorders, and cardiovascular diseases. Many of these diseases also affect the growing geriatric population. Increasing healthcare costs and developing economies with disposable incomes add to the consumer interest in designer foods. Free radicals have been implicated (directly or indirectly) in many of these lifestyle-associated diseases through oxidative stress. Antioxidants are naturally generated in the body to counter the toxic free radicals; however, a better balance b...

Effect of Strychnos potatorum Linn. Seed Extracts on Water Samples from Different Sources and with Diverse Properties

In developing countries, ground water, which is contaminated with domestic and industrial waste, ... more In developing countries, ground water, which is contaminated with domestic and industrial waste, is commonly used for drinking. Colour, turbidity and microbial content affect quality of potable water. Strychnos potatorum (Linn.) seeds are known to function as coagulants and clarify water. Our study investigated the effect of the seed powder (10-40 mg L -1 ) on water samples of varying colour, turbidity and microbial content. Samples studied were of river Yamuna, industrial effluent, a recreational pond, tap water and distilled water. pH was maintained within ±5 units while alkalinity was within one unit, showing that taste parameters were not affected. There was an 82-98% decrease in absorbance, denoting the seed's clarifying effect. The reduction in heterotrophic microbial load was 99% when 10 mg L -1 of seed powder was added. Ames test demonstrated non-toxicity of the seed at the concentrations tested. This simple method can help as an effective and affordable pre-treatment me...

Essential Oils: An Update on Their Biosynthesis and Genetic Strategies to Overcome the Production Challenges

Essential oils, secreted by plants, are primarily meant for various physiological, ecological, an... more Essential oils, secreted by plants, are primarily meant for various physiological, ecological, and defense activities. These oils belong to various classes, i.e., isolates of fatty acids, isoprenoids, and phenolic complexes, and can be secreted by various organs of plants. The essential oil market globally has been predicted to grow at a compound annual growth rate (CAGR) of ~8–10%, and reach a staggering figure in excess of USD ten billion in the next 5 years or so. However, the challenge lies in commercial production, keeping pace with the demand, since their natural production in plants is in considerably low quantities, which depends on ecological conditions and growth stages of the plant. Although several investigations exist in the literature, there is a pressing need for a systematic review of the recent updates, particularly concerning the strategies that facilitate the manufacturing of such indispensable oils. The current chapter focuses on various facets of essential oil p...

Objective: Endophytes represent a niche habitat for the study of novel bio-and chemo diversity. N... more Objective: Endophytes represent a niche habitat for the study of novel bio-and chemo diversity. Nelumbo nucifera is an aquatic plant that has not been characterized for endophyte diversity. This study was undertaken with the objective of isolating endophytes from submerged and aerial part of N. nucifera , study the diversity profile of the isolated endophytes and their antimicrobial, antioxidant, and siderophore production capacity. Methods: Endophytes were isolated from aerial and submerged parts of N. nucifera on different media (Starch Casein Nitrate, Glucose Yeast Extract, Nutrient and Potato Dextrose agar). These were further characterized for morphology (colony characteristics, Gram reaction), physiological characteristics (carbon, nitrogen utilization) and activity (antimicrobial, antioxidant, siderophore production). After dereplication, twelve isolates were studied further. Results: All endophyte isolates were Gram-positive bacteria, and one was a fungus. Isolate L-300 show...

Analyzing Functional Microbial Diversity

Microbial Diversity in the Genomic Era

Abstract Ecosystem functioning is, to a large extent, dependent on the activities of microorganis... more Abstract Ecosystem functioning is, to a large extent, dependent on the activities of microorganisms. Though comprising the largest fraction of living organisms in terms of numbers and biomass, their importance in maintenance of habitats, ecological recycling of nutrients, waste and other matter, and their crucial role in interactions between biotic and abiotic components of the environment demands that their functional role in various habitats be elucidated clearly. While the output of such studies are scattered, a limitation has also been that 99% of microorganisms are believed to belong to the uncultivable fraction. This makes it imperative that this fraction should also be addressed in functional diversity studies. The interplay between taxonomic and functional diversity, where taxonomy, to a large extent, is associated with function, mandates that the chapter also emphasize on assessment of taxonomy. The current chapter focuses on the various techniques available to study cultivable and uncultivable microorganisms (with emphasis on work pertaining to bacteria), from their functional diversity point of view.

Pseudonocardiaceae sp. TD-015 from the Thar Desert, India: Antimicrobial Activity and Identification of Antimicrobial Compounds

Current Bioactive Compounds

Characterization of Streptomyces sp. UK-201 from Lachhiwala Reserve forest, a biodiversity hot spot of the Himalayas

The Natural Products Journal

Background: Multi-drug resistance among pathogens is emerging due to slow pace of development of ... more Background: Multi-drug resistance among pathogens is emerging due to slow pace of development of new antimicrobials by combinatorial chemistry. Natural products from microorganisms from under-explored habitats can be lead molecules for such discoveries. Objective: The major objectives were to characterize isolate UK-201, taxonomically identify UK-201 based on 16S rDNA sequencing and execute metabolite fingerprinting of ethyl acetate extract of UK-201 by GC-MS. Method: In search of new antimicrobial compounds, Streptomyces isolate UK-201 exhibiting broad spectrum antimicrobial and antifungal activity, obtained from under-explored Lachhiwala Reserve forest, of the Himalayas was selected in this study. Isolate UK-201 was identified by 16S rDNA sequencing. Ethyl acetate extract of this isolate exhibited antimicrobial activity against all selected panel of Gram positive, Gram negative bacteria and fungi among other organic solvent extracts. Hence, EA extract was partially purified by col...

Microbial Biodeterioration of Cultural Heritage: Events, Colonization, and Analyses

Microbial Ecology

Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eve... more Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eventually leading to formation of soil. However, when the stones and rocks are a part of historic buildings and monuments, the effects are deleterious. In addition, microorganisms also colonize these monuments over a period of time, resulting in formation of biofilms; their metabolites lead to physical weakening and discoloration of stone eventually. This process, known as biodeterioration, leads to a significant loss of cultural heritage. For formulating effective conservation strategies to prevent biodeterioration and restore monuments, it is important to know which microorganisms are colonizing the substrate and the different energy sources they consume to sustain themselves. With this view in scope, this review focuses on studies that have attempted to understand the process of biodeterioration, the mechanisms by which they colonize and affect the monuments, the techniques used for assessment of biodeterioration, and conservation strategies that aim to preserve the original integrity of the monuments. This review also includes the “omics” technologies that have started playing a large role in elucidating the nature of microorganisms, and how they can play a role in hastening the formulation of effective conservation strategies.

Antimicrobial and Antioxidant Compounds in Endophyte Isolate L-003 Obtained from the Aquatic Plant Nelumbo nucifera

The Natural Products Journal

Background: Microorganisms from understudied habitats have been shown to be an important source o... more Background: Microorganisms from understudied habitats have been shown to be an important source of novel bioactive compounds. Endophytes constitute an underexplored group of microorganisms, of which those from aquatic plants have been even less studied. Nelumbo nucifera (lotus) is an aquatic plant with medicinal properties. A screening program for endophytes from N. nucifera by our research group resulted in many microbial isolates, of which isolate L-003 was a promising candidate, exhibiting antimicrobial and antioxidant activities. Objectives: The major objectives were to characterize the endophyte L-003 for its antimicrobial and antioxidant properties, identify the constituent bioactive compounds by GC-MS and characterize their activities further using in silico software. Methods: L-003 was identified by PIBWin software. Antimicrobial activity of the aqueous and organic extracts of culture supernatant of L-003 was checked against a panel of bacteria and fungi. Since the ethyl ace...

Microbial diversity of a Himalayan forest and characterization of rare actinomycetes for antimicrobial compounds

3 Biotech

The slow pace of discovery of new effective drugs against multi-drug resistant pathogens and larg... more The slow pace of discovery of new effective drugs against multi-drug resistant pathogens and largely unsuccessful combinatorial chemistry has resulted in shifting the focus back to natural products as sources of lead molecules for antimicrobial drugs, mainly due to their structural diversity. Investigation of under-explored habitats for potentially novel microorganisms provides for wider chemodiversity. In this study, four actinomycetes, namely UK-274, UK-281, UK-282 and UK-285, which showed broad-spectrum antibacterial and antifungal activities, were isolated from Timli forest range of the biodiversity-rich Himalayan region. 16S rRNA gene sequence analysis showed that the nearest neighbours of the isolates were Actinomadura nitrigenes, Streptomyces niveiscabiei, and Kitasatospora psammotica with similarity values ranging between 97 and 98% suggesting their potential as new isolates. Further morphological and phenotypic characterization strengthened this assumption. Isolate UK-282, of the rare actinomycetes Kitasatospora group, was found to produce antimicrobial activity. Metabolite fingerprinting of ethyl acetate fraction of isolate UK-282 by GC–MS and 1H NMR analysis showed the presence of three novel compounds. The study underlines that a combination approach of bioprospecting of under-studied habitats and focus on rare actinomycetes may result in the identification of novel chemodiversity.

Saccharothrix tharensis sp. nov., an actinobacterium isolated from the Thar Desert, India

Antonie van Leeuwenhoek, Jan 26, 2018

The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was ... more The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was established using a polyphasic approach. The strain has chemotaxonomic and morphological properties consistent with its classification in the genus Saccharothrix. It forms a distinct branch in the Saccharothrix 16S rRNA gene tree, related to the type strain of Saccharothrix saharensis (96.7%) but was distinguished readily from it using a combination of phenotypic properties. The genotypic and phenotypic data show that the strain represents a novel species in the genus Saccharothrix, for which the name Saccharothrix tharensis sp. nov. is proposed with the type strain TD-093 (= KCTC 39724 = MCC 2832).

Plant Peptides: Bioactivity, Opportunities and Challenges

Protein & Peptide Letters

Process Development for Bioactive Peptide Production

Food Bioactives, 2017

Bioactive peptides (BPs) are protein hydrolysates able to induce positive physiological responses... more Bioactive peptides (BPs) are protein hydrolysates able to induce positive physiological responses when introduced into the body, making them useful ingredients in food, cosmetic and pharmaceutical products. However, the full potential of BPs has not been fully explored because research is still lacking on economical and scalable production methods. This study is therefore aimed at the development of a bioprocess for the production of novel bioactive peptides from food proteins by exploiting fermentative and the proteolytic activities of Lactobacillus delbrueckii subsp. lactis 313 (LDL 313). The optimum parameters and conditions for the production of antihypertensive peptides using LDL 313 were obtained from the literature and covered the upstream, midstream and downstream stages. The feasibility of manufacturing BPs in a large scale was also projected by conducting an economic assessment and a quantitative analysis based on the medical needs of hypertensive patients in Malaysia. Results indicated that to meet the needs of the hypertensive population, a production level of 1.267 kg milk protein/kg peptide had to be obtained at an enzyme requirement of 0.2 kg enzyme/kg milk protein. At this production level and at a peptide market value of USD 88.5/g peptide, the annual expected value of peptide will be USD 41,858,307,460. It will take about 19.5 h to produce one batch of the peptides at a total annual cost (equipment and utilities) of USD 15,081,885. An annual revenue of USD 42 billion is therefore expected from the entire bioprocess implying that the process is economically feasible.