Research work focused on the study of culture-dependent and independent approaches to investigate the role of bacterial diversity in biodegradation and bio-valorization of pollutants to solve the increasing toxic waste burden at the contaminated sites.
Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its ligno... more Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its lignocellulosic substrate could be used for production of high-value green products such as biofuels, chemicals, and biomaterials. Within these frameworks, this review comprehensively explored the thermochemical and biological conversion of bamboo biomass to value-added fuels and chemicals. Additionally, this review stretches an indepth understanding of bamboo biomass lignin extraction technologies and bioengineered methodologies, as well as their biorefinery conversion strategies. Additionally, bamboo biomass often utilized in biorefineries are mostly constituted of cellulose, hemicellulose, and lignin, along with proteins, lipids, and a few micronutrients which are not utilized efficientely by current bioengineered techniques. The results indicates that the potential for producing high-value products from bamboo biomass has not been adequately explored. However, enormous potential is still available to make bamboo biorefinery technologies cost-effective, and environmentally sustainable, which are discussed in the current review comprehensively. Furthermore, processes such as pretreatment, enzymatic hydrolysis, and fermentation are essential to obtain final high-value bio-based products from bamboo biomass, therefore, this review critically designed to explore the current state of the art of these technologies. Overall, the current review establishes a zero-waste sustainable approach for the reformation of bamboo biomass into chemicals, biofuels, and value-added products.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Increasing population, industrialization, and economic growth cause several adverse impacts on th... more Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy requirements while reducing reliance on fossil fuels are the key areas, which needs significant consideration for sustainable environment. Since India has considerable biomass resources, bioenergy is a significant part of the country's energy policy. However, the selection of feedstock is a crucial step in bioenergy production that could produce raw material without compromising food reserve along with the sustainable environment. Higher growth capacity of bamboo species makes them a suitable lignocellulosic substrate for the production of high-value greener products such as fuels, chemicals, and biomaterials as well as an appropriate candidate for eco-restoration of degraded land. In that context, the current review discusses the multidimensional applications of bamboo species in India. The bioenergy potency of bamboo and probability of aligning its production, cultivation, and operation with economic and social development agendas are also addressed, making it an exceptional crop in India. Additionally, its fast growth, perennial root systems, and capability to restore degraded land make it an essential part of ecological restoration. Furthermore, this review explores additional benefits of bamboo plantation on the environment, economy, and society along with future research prospects.
Microbial Diversity in Ecosystem Sustainability and Biotechnological Applications, 2019
Globally, there are concerning trends of waste generation as we progress towards a more developed... more Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades, its metropolitanization has increased by approximately 10% and would further rise to 20% by 2026. The increasing urbanization and evolving lifestyles, food habits, and standards prompt such exponential expansion of robust waste. It is basically answerable for the introduction of a waste era posing various threats to health and causing ecological deformities. In 1996, the urban number created around 114,576 tonnes of municipal solid waste (MSW) per day, which is predicted to be 440,460 tonnes per day−1 by 2026. A large section of the waste is handled using the concept of 3Rs (reduce, reuse, and recycle), but the biological microbial potential is still underestimated. Less than 1% of the microbial community is culturable due to which the conservative ...
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the... more Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was isolated from the sediment sample collected from the Pangong lake, Jammu & Kashmir, India. In our previous study, the pyrene degradation potential of the ISTPL2 strain was studied in both mineral salt media as well as in soil artificially spiked with different concentrations of pyrene. Whole-genome sequencing of ISTPL2 strain in the current study highlighted the key genes of pyrene metabolism, including alcohol dehydrogenase and ring hydroxylating dioxygenase alpha-subunit. Pyrene cytotoxicity was evaluated on HepG2, a human hepato-carcinoma cell line. The cytotoxicity of the organic extract decreased with the increasing duration of bacterial treatment. To develop a more sustainable biodegradation approach, the potential impacts were evaluated for human health and ecosystem using life-cycle assessment (LCA) following the ReCiPe methodology for the considered PAH. The results implemented that global warming potential (GWP) had the highest impact, whereas both ecotoxicity and human toxicity had least from this study.
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7... more The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC-MS, FTIR and NMR analysis. Whole genome sequencing of strain ISTL7 unveiled an array of PHA metabolism genes which included phaA, phaB and phaC. Life cycle assessment of the protocol established that the production was most sustainable with the carbon source acetate. + Glucose as compared to acetate/glucose alone. It also concluded that solvent extraction of PHA and energy consumption during the process requires optimization to sustain the production on ecological fronts. Additionally, acetoacetyl-CoA reductase (phaB) gene was molecularly cloned, expressed and purified (27 KDa, 2.63 mg/ml). Conclusively, Cupriavidus sp. ISTL7 is a potential strain for PHA production with a scope of improvement on energy fronts which would transform the production environmentally and economically appealing.
The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production ... more The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production of EPS (Extracellular polymeric substances) using carbofuran, a toxic carbamate pesticide. Bacillus strain was isolated from landfill soil and evaluated for high growth rates and EPS production. One strain, renamed ISTL8 grew on a broad range of carbon sources, including toxic carbofuran, while producing copious EPS. Growth assays verified the strain to be thermophilic, low salt tolerant, and with a preference for neutral pH. SEM (Scanning Electron Microscopy) was used for morphological characterization of the EPS while the monomeric composition, bonding patterns and functional groups were deduced by GC-MS (Gas Chromatography-Mass Spectrometry), 1H and 13C NMR (Nuclear Magnetic Resonance) and FTIR (Fourier Transform Infrared Spectroscopy). The production of EPS using carbofuran (carbamate pesticide) as a carbon source was found to be 6.20 ± 0.29 g L-1 containing 61.17% w/w carbohydrates, 29.72% w/w proteins and 6.11% w/w lipids (of dry EPS). The potential cytotoxicity of EPS was evaluated with 3- (4,5-dimethyl thiazol-2-Yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and found non-toxic (2.25%). WGS (Whole genome sequencing) was performed for the strain Bacillus sp. ISTL8 producing EPS; an array of genes putatively involved in the EPS production were identified in several different genomic locations, guiding potential genetic manipulation studies in the future. The results highlight the potency of a bacterial isolate Bacillus sp. ISTL8 to produce non-cytotoxic EPS using carbofuran that can be further harnessed for environmental and commercial applications. Additionally, WGS revealed an array of EPS specific genes which can be effectively engineered for much enhanced production.
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristi... more A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic α-amylase enzyme. The α-amylase is a critical enzyme that catalyses the hydrolysis of α-1,4-glycosidic bonds of starch molecules and is predominately utilized in biotechnological applications. The highest enzyme activity of partially purified extracellular α-amylase was 10,064.20 U/mL after 12 h of incubation in a shake flask at pH 6.9 and 10 °C. Moreover, the maximum intracellular α-amylase enzyme activity (259.62 U/mL) was also observed at 6 h of incubation. The extracellular α-amylase was refined to the homogeneity with the specific enzyme activity of 36,690.47 U/mg protein corresponding to 6.87-fold purification. The optimized pH and temperature for the α-amylase were found to be pH 8 and 4 °C, respectively, suggesting its stability at alkaline con...
Refining Biomass Residues for Sustainable Energy and Bioproducts, 2020
Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited l... more Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited land use, industrialization, and excess waste generation, leads to a global climate shift, which is one of the leading environmental issues of the world today. The basic biomolecules for the production of biofuel include fatty acids, alcohols, and alkanes. Biodiesel is composed of monoalkyl esters of higher chain of fatty acids, produced though the transesterification reaction by alcohol in the presence of a catalyst. Hydrocarbons are the metabolic by-product of many bacterial sp. and generally produced from fatty acids and triacylglycerol (TAG). Bacterial lipids and TAG are the precursor material for improved biofuel production, because of their wide application in the production of different chain length hydrocarbons. The advance science of genetic engineering can help in modification of the conventional approaches of production in order to achieve a higher yield of such biological materials. Therefore by employing a joint strategy of natural and altered synthetic (fatty acid biosynthesis) pathways in bacteria, the production of valuable chemicals and fuels is expected to be enhanced in future.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
We report the soil microbial diversity and functional aspects related to degradation of recalcitr... more We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi, India. Metagenomic analysis revealed the presence and functional diversity of complex microbial communities responsible for waste degradation.
Pangong is a brackish water lake having environmental conditions that are hostile to supporting l... more Pangong is a brackish water lake having environmental conditions that are hostile to supporting life. This is the first report unveiling the microbial diversity of sediment from Pangong Lake, Ladakh, India, using a high-throughput metagenomic approach. Metagenomic data analysis revealed a community structure of microbes in which functional genetic diversity facilitates their survival.
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas... more An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas... more An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
Environmental Science and Pollution Research, 2019
Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern... more Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern with regard to their potential exposure and deleterious effect on human health. The current study is the first report of phenanthrene degradation by a psychrotolerant (15 °C), halophilic (5% NaCl), and alkalophilic (pH 8) bacterial strain Zhihengliuella sp. ISTPL4, isolated from the sediment sample of the Pangong Lake, Ladakh, Jammu and Kashmir, India. Degradation studies revealed that the optimum specific growth rate was observed at 250 ppm of phenanthrene with 81% and 87% removal of phenanthrene in 72 h and 168 h, respectively. During the degradation of phenanthrene; 9,10-dihydrophenanthrene; 1-phenanthrenecarboxylic acid; and phthalic acid were detected as intermediates. Whole-genome sequencing of strain ISTPL4 has predicted phenanthrene; 9,10-monooxygense; and epoxide hydrolase B that are involved in the phenanthrene metabolism. Phenanthrene cytotoxicity was evaluated with human hepatic carcinoma cell line (HepG2) and it was observed that the cytotoxicity decreased with increased duration of bacterial incubation and maximum cell viability was observed at 168 h (89.92%). Our results suggest, Zhihengliuella sp. ISTPL4 may promise a great potential for environmental remediation applications.
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes s... more Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated with LSM management and recovery of value-added products, still, technological innovation needs further upgradation in consideration with the environment, energy, and economy. This review delivered a vibrant portrait of manure management, which includes, bioenergy generation and resource recovery strategies, their current scenario, opportunities, challenges, and prospects for future researches along with global regulations and policies. Several bioenergy generation and nutrient recoveries technologies have been discussed in details, still, the major glitches allied with these technologies are its high establishment costs, operational costs, manure assortment, and digestate handling. This review also discussed the techno-economic assessment (TEA) and life cycle assessment (LCA) of LSM management operation in the context of their economical and environmental sustainability. Still, extensive researches needed to build an efficient manure management framework to advance the integrated bioenergy production, nutrients recycling, and digestate utilization with least environmental impacts and maximal economical gain, which has critically discussed in the current review.
Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its ligno... more Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its lignocellulosic substrate could be used for production of high-value green products such as biofuels, chemicals, and biomaterials. Within these frameworks, this review comprehensively explored the thermochemical and biological conversion of bamboo biomass to value-added fuels and chemicals. Additionally, this review stretches an indepth understanding of bamboo biomass lignin extraction technologies and bioengineered methodologies, as well as their biorefinery conversion strategies. Additionally, bamboo biomass often utilized in biorefineries are mostly constituted of cellulose, hemicellulose, and lignin, along with proteins, lipids, and a few micronutrients which are not utilized efficientely by current bioengineered techniques. The results indicates that the potential for producing high-value products from bamboo biomass has not been adequately explored. However, enormous potential is still available to make bamboo biorefinery technologies cost-effective, and environmentally sustainable, which are discussed in the current review comprehensively. Furthermore, processes such as pretreatment, enzymatic hydrolysis, and fermentation are essential to obtain final high-value bio-based products from bamboo biomass, therefore, this review critically designed to explore the current state of the art of these technologies. Overall, the current review establishes a zero-waste sustainable approach for the reformation of bamboo biomass into chemicals, biofuels, and value-added products.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Increasing population, industrialization, and economic growth cause several adverse impacts on th... more Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy requirements while reducing reliance on fossil fuels are the key areas, which needs significant consideration for sustainable environment. Since India has considerable biomass resources, bioenergy is a significant part of the country's energy policy. However, the selection of feedstock is a crucial step in bioenergy production that could produce raw material without compromising food reserve along with the sustainable environment. Higher growth capacity of bamboo species makes them a suitable lignocellulosic substrate for the production of high-value greener products such as fuels, chemicals, and biomaterials as well as an appropriate candidate for eco-restoration of degraded land. In that context, the current review discusses the multidimensional applications of bamboo species in India. The bioenergy potency of bamboo and probability of aligning its production, cultivation, and operation with economic and social development agendas are also addressed, making it an exceptional crop in India. Additionally, its fast growth, perennial root systems, and capability to restore degraded land make it an essential part of ecological restoration. Furthermore, this review explores additional benefits of bamboo plantation on the environment, economy, and society along with future research prospects.
Microbial Diversity in Ecosystem Sustainability and Biotechnological Applications, 2019
Globally, there are concerning trends of waste generation as we progress towards a more developed... more Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades, its metropolitanization has increased by approximately 10% and would further rise to 20% by 2026. The increasing urbanization and evolving lifestyles, food habits, and standards prompt such exponential expansion of robust waste. It is basically answerable for the introduction of a waste era posing various threats to health and causing ecological deformities. In 1996, the urban number created around 114,576 tonnes of municipal solid waste (MSW) per day, which is predicted to be 440,460 tonnes per day−1 by 2026. A large section of the waste is handled using the concept of 3Rs (reduce, reuse, and recycle), but the biological microbial potential is still underestimated. Less than 1% of the microbial community is culturable due to which the conservative ...
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the... more Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was isolated from the sediment sample collected from the Pangong lake, Jammu & Kashmir, India. In our previous study, the pyrene degradation potential of the ISTPL2 strain was studied in both mineral salt media as well as in soil artificially spiked with different concentrations of pyrene. Whole-genome sequencing of ISTPL2 strain in the current study highlighted the key genes of pyrene metabolism, including alcohol dehydrogenase and ring hydroxylating dioxygenase alpha-subunit. Pyrene cytotoxicity was evaluated on HepG2, a human hepato-carcinoma cell line. The cytotoxicity of the organic extract decreased with the increasing duration of bacterial treatment. To develop a more sustainable biodegradation approach, the potential impacts were evaluated for human health and ecosystem using life-cycle assessment (LCA) following the ReCiPe methodology for the considered PAH. The results implemented that global warming potential (GWP) had the highest impact, whereas both ecotoxicity and human toxicity had least from this study.
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7... more The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC-MS, FTIR and NMR analysis. Whole genome sequencing of strain ISTL7 unveiled an array of PHA metabolism genes which included phaA, phaB and phaC. Life cycle assessment of the protocol established that the production was most sustainable with the carbon source acetate. + Glucose as compared to acetate/glucose alone. It also concluded that solvent extraction of PHA and energy consumption during the process requires optimization to sustain the production on ecological fronts. Additionally, acetoacetyl-CoA reductase (phaB) gene was molecularly cloned, expressed and purified (27 KDa, 2.63 mg/ml). Conclusively, Cupriavidus sp. ISTL7 is a potential strain for PHA production with a scope of improvement on energy fronts which would transform the production environmentally and economically appealing.
The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production ... more The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production of EPS (Extracellular polymeric substances) using carbofuran, a toxic carbamate pesticide. Bacillus strain was isolated from landfill soil and evaluated for high growth rates and EPS production. One strain, renamed ISTL8 grew on a broad range of carbon sources, including toxic carbofuran, while producing copious EPS. Growth assays verified the strain to be thermophilic, low salt tolerant, and with a preference for neutral pH. SEM (Scanning Electron Microscopy) was used for morphological characterization of the EPS while the monomeric composition, bonding patterns and functional groups were deduced by GC-MS (Gas Chromatography-Mass Spectrometry), 1H and 13C NMR (Nuclear Magnetic Resonance) and FTIR (Fourier Transform Infrared Spectroscopy). The production of EPS using carbofuran (carbamate pesticide) as a carbon source was found to be 6.20 ± 0.29 g L-1 containing 61.17% w/w carbohydrates, 29.72% w/w proteins and 6.11% w/w lipids (of dry EPS). The potential cytotoxicity of EPS was evaluated with 3- (4,5-dimethyl thiazol-2-Yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and found non-toxic (2.25%). WGS (Whole genome sequencing) was performed for the strain Bacillus sp. ISTL8 producing EPS; an array of genes putatively involved in the EPS production were identified in several different genomic locations, guiding potential genetic manipulation studies in the future. The results highlight the potency of a bacterial isolate Bacillus sp. ISTL8 to produce non-cytotoxic EPS using carbofuran that can be further harnessed for environmental and commercial applications. Additionally, WGS revealed an array of EPS specific genes which can be effectively engineered for much enhanced production.
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristi... more A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic α-amylase enzyme. The α-amylase is a critical enzyme that catalyses the hydrolysis of α-1,4-glycosidic bonds of starch molecules and is predominately utilized in biotechnological applications. The highest enzyme activity of partially purified extracellular α-amylase was 10,064.20 U/mL after 12 h of incubation in a shake flask at pH 6.9 and 10 °C. Moreover, the maximum intracellular α-amylase enzyme activity (259.62 U/mL) was also observed at 6 h of incubation. The extracellular α-amylase was refined to the homogeneity with the specific enzyme activity of 36,690.47 U/mg protein corresponding to 6.87-fold purification. The optimized pH and temperature for the α-amylase were found to be pH 8 and 4 °C, respectively, suggesting its stability at alkaline con...
Refining Biomass Residues for Sustainable Energy and Bioproducts, 2020
Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited l... more Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited land use, industrialization, and excess waste generation, leads to a global climate shift, which is one of the leading environmental issues of the world today. The basic biomolecules for the production of biofuel include fatty acids, alcohols, and alkanes. Biodiesel is composed of monoalkyl esters of higher chain of fatty acids, produced though the transesterification reaction by alcohol in the presence of a catalyst. Hydrocarbons are the metabolic by-product of many bacterial sp. and generally produced from fatty acids and triacylglycerol (TAG). Bacterial lipids and TAG are the precursor material for improved biofuel production, because of their wide application in the production of different chain length hydrocarbons. The advance science of genetic engineering can help in modification of the conventional approaches of production in order to achieve a higher yield of such biological materials. Therefore by employing a joint strategy of natural and altered synthetic (fatty acid biosynthesis) pathways in bacteria, the production of valuable chemicals and fuels is expected to be enhanced in future.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
We report the soil microbial diversity and functional aspects related to degradation of recalcitr... more We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi, India. Metagenomic analysis revealed the presence and functional diversity of complex microbial communities responsible for waste degradation.
Pangong is a brackish water lake having environmental conditions that are hostile to supporting l... more Pangong is a brackish water lake having environmental conditions that are hostile to supporting life. This is the first report unveiling the microbial diversity of sediment from Pangong Lake, Ladakh, India, using a high-throughput metagenomic approach. Metagenomic data analysis revealed a community structure of microbes in which functional genetic diversity facilitates their survival.
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas... more An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas... more An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
Environmental Science and Pollution Research, 2019
Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern... more Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern with regard to their potential exposure and deleterious effect on human health. The current study is the first report of phenanthrene degradation by a psychrotolerant (15 °C), halophilic (5% NaCl), and alkalophilic (pH 8) bacterial strain Zhihengliuella sp. ISTPL4, isolated from the sediment sample of the Pangong Lake, Ladakh, Jammu and Kashmir, India. Degradation studies revealed that the optimum specific growth rate was observed at 250 ppm of phenanthrene with 81% and 87% removal of phenanthrene in 72 h and 168 h, respectively. During the degradation of phenanthrene; 9,10-dihydrophenanthrene; 1-phenanthrenecarboxylic acid; and phthalic acid were detected as intermediates. Whole-genome sequencing of strain ISTPL4 has predicted phenanthrene; 9,10-monooxygense; and epoxide hydrolase B that are involved in the phenanthrene metabolism. Phenanthrene cytotoxicity was evaluated with human hepatic carcinoma cell line (HepG2) and it was observed that the cytotoxicity decreased with increased duration of bacterial incubation and maximum cell viability was observed at 168 h (89.92%). Our results suggest, Zhihengliuella sp. ISTPL4 may promise a great potential for environmental remediation applications.
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes s... more Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated with LSM management and recovery of value-added products, still, technological innovation needs further upgradation in consideration with the environment, energy, and economy. This review delivered a vibrant portrait of manure management, which includes, bioenergy generation and resource recovery strategies, their current scenario, opportunities, challenges, and prospects for future researches along with global regulations and policies. Several bioenergy generation and nutrient recoveries technologies have been discussed in details, still, the major glitches allied with these technologies are its high establishment costs, operational costs, manure assortment, and digestate handling. This review also discussed the techno-economic assessment (TEA) and life cycle assessment (LCA) of LSM management operation in the context of their economical and environmental sustainability. Still, extensive researches needed to build an efficient manure management framework to advance the integrated bioenergy production, nutrients recycling, and digestate utilization with least environmental impacts and maximal economical gain, which has critically discussed in the current review.
Increasing population load and an altered lifestyle attitude are exerting extra pressure
on the p... more Increasing population load and an altered lifestyle attitude are exerting extra pressure on the production market, to satisfy the demands and desire of society. The recently developed production and consumption models largely rely on fossil-based resources, which are affecting the environment and natural resources adversely. The cost-effective production of biological materials is an emerging sector with remarkable future prospects and provides many business opportunities. With time the research endeavors are gradually shifting toward bacterial lipids-derived biofuel production, which is more suitable and compatible for an industrial application. The major challenge in the overall process of the production of lipids-derived fuels from microbes is the involved carbon source as it contributes to more than half of the production cost. Therefore the production of lipids and biodiesel from bacteria using different waste materials as carbon source involving the application of advanced biotechnological tools, and modified transesterification reactions will make the biodiesel production cost effective.
Globally, there are concerning trends of waste generation as we progress towards a more developed... more Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades, its metropolitanization has increased by approximately 10% and would further rise to 20% by 2026. The increasing urbanization and evolving lifestyles, food habits, and standards prompt such exponential expansion of robust waste.
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Papers by Rashmi Rathour
on the production market, to satisfy the demands and desire of society. The
recently developed production and consumption models largely rely on fossil-based
resources, which are affecting the environment and natural resources adversely. The
cost-effective production of biological materials is an emerging sector with remarkable
future prospects and provides many business opportunities. With time the
research endeavors are gradually shifting toward bacterial lipids-derived biofuel
production, which is more suitable and compatible for an industrial application. The
major challenge in the overall process of the production of lipids-derived fuels from
microbes is the involved carbon source as it contributes to more than half of the
production cost. Therefore the production of lipids and biodiesel from bacteria
using different waste materials as carbon source involving the application of
advanced biotechnological tools, and modified transesterification reactions will
make the biodiesel production cost effective.