Papers by Dr. Shashi K Bhatia
Journal of environmental chemical engineering, Feb 1, 2021
Biocatalysts are the backbone of bioprocessing industries that are going through a phase of trans... more Biocatalysts are the backbone of bioprocessing industries that are going through a phase of transition with reference to the requirement of extraordinary enzymes for various biochemical processes. This transition is well reported and documented by various researchers through elucidation of different features and applications of mesophilic and thermophilic enzymes. However, there is little information available about psychrophilic enzymes and their involvement in industrial processes. Therefore, understanding the features and functions of psychrophilic enzymes could suggest some of their novel applications in various industries such as food, agriculture, chemicals, pharmaceuticals, and waste management etc. Currently, different industries are looking for such novel psychrophilic enzymes to develop efficient biochemical processes that will help to reduce the reaction time, lower the energy inputs and as well as be eco-friendly. These bioprocesses will help to increase the profit margin by reducing the overall cost of the final products. This review article will provide new insights in technical and scientific analysis of psychrophilic microbes, their enzymes and low energy biochemical processes that are useful in various industries for the production of valuable products. It will also further strengthen the understanding of academia and industry about these ubiquitous biocatalysts.
Industrial Crops and Products
International Journal of Hydrogen Energy
Energies
Continuous urbanization and modernization have increased the burning of fossil fuels to meet ener... more Continuous urbanization and modernization have increased the burning of fossil fuels to meet energy needs across the globe, emanating environmental pollution and depleting fossil fuels. Therefore, a shift towards sustainable and renewable energy is necessary. Several techniques to exploit biomass to yield energy are trending, with pyrolysis one of them. Usually, a single feedstock is employed in pyrolysis for anoxygenic generation of biochar together with bio-oil at elevated temperatures (350–600 °C). Bio-oil produced through pyrolysis can be upgraded to crude oil after some modification. However, these modifications of bio-oil are one of the major drawbacks for its large-scale adoption, as upgradation increases the overall cost. Therefore, in recent years the scientific community has been researching co-pyrolysis technology that involves the pyrolysis of lignocellulosic biomass waste with non-biodegradable waste. Co-pyrolysis reduces the need for post-modification of bio-oil, unlik...
Bioresource Technology, 2022
Excessive generation of wastewater is a matter of concern around the globe. Wastewater treatment ... more Excessive generation of wastewater is a matter of concern around the globe. Wastewater treatment utilizing a microalgae-mediated process is considered an eco-friendly and sustainable method of wastewater treatment. However, low biomass productivity, costly harvesting process, and energy extensive cultivation process are the major bottleneck. The use of the microalgal-bacteria granular consortia (MBGC) process is economic and requires less energy. For efficient utilization of MBGC knowledge of its structure, composition and interaction are important. Various microscopic, molecular and metabolomics techniques play a significant role in understating consortia structure and interaction between partners. Microalgal-bacteria granular consortia structure is affected by various cultivation parameters like pH, temperature, light intensity, salinity, and the presence of other pollutants in wastewater. In this article, a critical evaluation of recent literature was carried out to develop an understanding related to interaction behavior that can help to engineer consortia having efficient nutrient removal capacity with reduced energy consumption.
Science of The Total Environment, 2022
Frontiers in Energy Research, 2021
Wastewater is not a liability, instead considered as a resource for microbial fermentation and va... more Wastewater is not a liability, instead considered as a resource for microbial fermentation and value-added products. Most of the wastewater contains various nutrients like nitrates and phosphates apart from the organic constituents that favor microbial growth. Microalgae are unicellular aquatic organisms and are widely used for wastewater treatment. Various cultivation methods such as open, closed, and integrated have been reported for microalgal cultivation to treat wastewater and resource recovery simultaneously. Microalgal growth is affected by various factors such as sunlight, temperature, pH, and nutrients that affect the growth rate of microalgae. Microalgae can consume urea, phosphates, and metals such as magnesium, zinc, lead, cadmium, arsenic, etc. for their growth and reduces the biochemical oxygen demand (BOD). The microalgal biomass produced during the wastewater treatment can be further used to produce carbon-neutral products such as biofuel, feed, bio-fertilizer, biopl...
In the current scenario of changing climatic conditions and rising global population, there is al... more In the current scenario of changing climatic conditions and rising global population, there is always a need to explore novel, efficient, and economical natural products for the benefit of human kind. Biosurfactant is one of the latest explored microbial biomolecules that have been used in numerous fields, including agriculture, pharmaceuticals, cosmetics, food processing, and environment-cleaning industries as raw material, lubrication, wetting, foaming softening, making emulsions, and stabilizing dispersions. The amphiphilic nature of biosurfactant biomolecules showed great advantage, distributing themselves into two immiscible surfaces by reducing interfacial surface tension and increasing the solubility of hydrophobic compounds. Furthermore, their eco-friendly nature, low or even no toxic nature, durability at higher temperatures, and wide range of pH fluctuations making the microbial surfactants preferable compared to their chemical counterparts. Additionally, the biosurfactant...
Biotechnological Applications of Polyhydroxyalkanoates, 2019
Bio-polymers are widely synthesized by living organisms to assist several biological functions. B... more Bio-polymers are widely synthesized by living organisms to assist several biological functions. Bacterial biopolymers are produced as a polyhydroxyalkanoates (PHA) in the form intracellular cellular storage material under the nutrient limiting or stress conditions in the excess of carbon source and recognized as a suitable alternative to petrochemical-based synthetic plastic due to their biodegradable and eco-friendly nature. Primarily, the synthesis of PHA is considered as costly process due to the high price of feed and its poor grade of thermal and mechanical properties of homopolymers such as polyhydroxybutyrate. The modification of PHA through chemical or biological synthesis and as composite materials through the incorporation of nanoparticles or other substrate and materials seems viable approaches to improve the properties of PHA for the novel application in the area of biomedical applications including anti-microbial agents. In this book chapter, we are evaluating the potential application of PHA, derivatives of PHA and modified with composite materials as anti-microbial agents.
Journal of Clinical Medicine, 2021
Coronavirus Disease 19 (COVID-19), due to severe acute respiratory syndrome coronavirus-2 (SARS-C... more Coronavirus Disease 19 (COVID-19), due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become an on-going global health emergency affecting over 94 million cases with more than 2 million deaths globally. Primarily identified as atypical pneumonia, it has developed into severe acute respiratory distress syndrome (ARDS), a multi-organ dysfunction with associated fatality. Ever since its emergence, COVID-19 with its plethora of clinical presentations has signalled its dynamic nature and versatility of the disease process. Being a disease with droplet transmission has now assumed the proportion of a suspected airborne nature which, once proved, poses a Herculean task to control. Because of the wide distribution of the human angiotensin-converting enzyme-2 (hACE2) receptors, known for its transmission, we envisage its multiorgan spread and extensive disease distribution. Thus, an extensive review of the extrapulmonary organotropism of SARS-CoV-2 with organ-specific pa...
Bioresource Technology, 2020
Metagenomics and directed evolution technology have brought a revolution in search of novel enzym... more Metagenomics and directed evolution technology have brought a revolution in search of novel enzymes from extreme environment and improvement of existing enzymes and tuning them towards certain desired properties. Using advanced tools of molecular biology i.e. next generation sequencing, site directed mutagenesis, fusion protein, surface display etc. now researchers can engineer enzymes for improved activity, stability, and substrate specificity to meet the industrial demand. Although many enzymatic processes have been developed up to industrial scale, still there is need to overcome limitations of maintaining activity during catalytic process. In this article recent developments in enzymes industrial applications and advancements in metabolic engineering approaches to improve enzymes efficacy and production are reviewed.
Science of The Total Environment, 2020
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.
Bioresource Technology, 2019
The production of bio/microbial-based polymers, polyhydroxyalkanoates (PHAs) from volatile fatty ... more The production of bio/microbial-based polymers, polyhydroxyalkanoates (PHAs) from volatile fatty acids (VFAs) of dark fermentative effluents in the bio-H 2 reactor is being paid attention, owing to their commercial demand, applications and as carbon as well as energy storage source. Since, they are the cheap precursors for such valuable renewable biopolymers which all possess the properties; those are analogous to the petro-derived plastics. Several studies were stated, related to the consumption of both individual and mixed VFAs for the potential PHAs production. Their biodegradability nature makes them extremely desirable alternative to fossil-derived synthetic polymers. In this regard, this review summarizes the use of bio-based PHAs production via both microbial and biochemical pathways using dark fermentative bio-H 2 production from waste streams as feedstock. Furthermore, this review deals the characteristics, synthesis and production of the bio-based PHAs along with their co-polymers and applications to give an outlook on future research.
Process Biochemistry, 2015
ABSTRACT The biotransformation of isonicotinamide was investigated using thermophilic intracellul... more ABSTRACT The biotransformation of isonicotinamide was investigated using thermophilic intracellular amidase produced from Geobacillus subterraneus RL-2a. Various process parameters, including amount of biocatalyst, substrate feeding rate, enzyme-to-substrate ratio and operational thermostability were systematically examined with the aim of achieving complete substrate conversion and high productivity. In 1 litre fed batch reaction containing 0.1 M isonicotinamide, in 0.2 M potassium phosphate buffer (pH 6.5, 200 rpm) and 8 U ml-1 amidase activity (12.48 mg dcw ml-1) of whole cells of Geobacillus subterraneus RL-2a (as biocatalyst) resulted in a yield of 0.1 M of isonicotinic acid after 50 min reaction time at 70 °C and a total of 61.55 g isonicotinic acid was produced at a rate of 1.18 g h-1g-1dcw respectively. The volumetric productivity was 14.8 g h-1 l-1.
3 Biotech, 2014
Xanthan gum is a biopolymer produced by Xanthomonas sp. XC6. In this study, xanthan gum is produc... more Xanthan gum is a biopolymer produced by Xanthomonas sp. XC6. In this study, xanthan gum is produced from potato starch using a stepwise bioprocess design. Potato starch is hydrolyzed using Bacillus sp. having amylase activity and 30.2 g/L reducing sugar was released, while Xanthomonas sp. XC6 can release only 14.5 g/L. Bacillus sp. hydrolyzed potato starch extract was further used as a carbon source for xanthan gum biosynthesis using Xanthomonas sp. XC6. Yeast extract acts as the best nitrogen source, and 10.0 g/L xanthan gum was recovered. Downstreaming process after stepwise bioprocess resulted in 17.4 g/L xanthan gum production, which is 2.8 times higher as compared to single step process.
Journal of Industrial Microbiology and Biotechnology, 2012
The acyl transfer activity of the amidase of Alcaligenes sp. MTCC 10674 has been applied to the c... more The acyl transfer activity of the amidase of Alcaligenes sp. MTCC 10674 has been applied to the conversion of benzamide and hydroxylamine to benzohydroxamic acid. The unique features of the acyl transfer activity of this organism include its optimal activity at 50 °C and very high substrate (100 mM benzamide) and product (90 mM benzohydroxamic acid) tolerance among the hitherto reported enzymes. The bench scale production of benzohydroxamic acid was carried out in a fed-batch reaction (final volume 1 l) by adding 50 mM benzamide and 250 mM of hydroxylamine after every 20 min for 80 min in 0.1 M potassium phosphate buffer (pH 7.0) at 50 °C, using resting cells equal to 4.0 mg dcm/ml of reaction mixture. From 1 l of reaction mixture 33 g of benzohydroxamic acid was recovered with 24.6 g l−1 h−1 productivity. The acyl transfer activity of the amidase of Alcaligenes sp. MTCC 10674 and the process developed in the present study are of industrial significance for the enzyme-mediated produ...
Bioprocess and Biosystems Engineering, 2012
Alcaligenes sp. MTCC 10674 was isolated as acetone cyanohydrin hydrolyzing bacterium from soil of... more Alcaligenes sp. MTCC 10674 was isolated as acetone cyanohydrin hydrolyzing bacterium from soil of orchid gardens of Himachal Pradesh. Acetone cyanohydrin hydrolyzing activity of this organism comprised nitrile hydratase and amidase activities. It exhibited higher substrate specificity towards aliphatic hydroxynitrile (acetone cyanohydrin) in comparison to arylaliphatic hydroxynitrile. Isobutyronitrile (40 mM) acted as a carbon source as well as inducer for growth of Alcaligenes sp. MTCC 10674 and expression of acetone cyanohydrin hydrolyzing activity. Optimization of culture condition using response surface methodology increased acetone cyanohydrin hydrolyzing activity by 1.3-fold, while inducer mediation approach increased the activity by 1.2-fold. The half life of this enzyme was 25 h at 15°C. V max and K m value for acetone cyanohydrin hydrolyzing enzyme was 0.71 lmol mg-1 min-1 and 14.3 mM, when acetone cyanohydrin was used as substrate. Acetone cyanohydrin hydrolyzing enzyme encountered product inhibition and IC50 and K i value were calculated to be 28 and 10.2 mM, respectively, when product a-hydroxyisobutyric acid was added in the reaction. Under optimized reaction conditions at 40 ml fed batch scale, 3 mg dcw ml 2 resting cells of Alcaligenes sp. MTCC 10674 fully converted 0.33 M acetone cyanohydrin into a-hydroxyisobutyric acid (1.02 g) in 6 h 40 min. The characterization of acetone cyanohydrins hydrolyzing activity revealed that it comprises bienzymatic nitrile hydrolyzing system, i.e. nitrile hydratase and amidase for the production of a-hydroxyisobutyric acid from acetone cyanohydrin and maximum 70 % yield is being reported for the first time.
Biomass Conversion and Biorefinery, 2021
Uploads
Papers by Dr. Shashi K Bhatia