Asma Ansari (KIBGE) - Academia.edu (original) (raw)
Papers by Asma Ansari (KIBGE)
International journal of biological macromolecules, Jan 22, 2018
Metallic nanoparticles have a substantial scientific interest because of their distinctive physic... more Metallic nanoparticles have a substantial scientific interest because of their distinctive physicochemical and antimicrobial properties and the emergence of multidrug resistant pathogens could unlock the potential of nanoparticles to combat infectious diseases. The aim of the current study is to enhance the antibacterial potential of purified bacteriocin by combining bacteriocin and antibacterial silver nanoparticles (AgNPs). Hence, the interaction of natural antimicrobial compounds and antibacterial nanoparticles can be used as a potential tool for combating infectious diseases. In this study, a green, simple and effective approach is used to synthesize antibacterial AgNPs using fungal exopolysaccharide as both a reducing and stabilizing agent. The AgNPs were characterized by spectroscopic analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Dynamic Light Scattering (DLS). Furthermore, the synergistic effect of bacteriocin-AgNPs was determine...
Pakistan Journal of Pharmaceutical Sciences, 2015
The bacterial strains capable of producing dextransucrase enzyme were isolated from different fru... more The bacterial strains capable of producing dextransucrase enzyme were isolated from different fruits and vegetables sources. In primary screening, five strains were selected on the basis dextransucrase production and among them L. mesenteroides KIBGE- IB26 isolated from bottle gourd (Lagenaria Vulgaris) was selected for further studies. For the enhancement of enzyme production, different physicochemical parameters were optimized. Maximum production of dextransucrase was achieved after 06 hrs using sucrose (20.0 g/l) as a substrate at 25°C. Maximum dextransucrase production was achieved when medium pH was kept 7.5 before sterilization. In addition, medium was also supplemented with CaCl2 and K2HPO4 and maximum enzyme production was achieved at 0.0025 g/dl calcium chloride and 2.0 g/dl K₂HPO₄with enzyme activity of 87 DSU/ml/hr. Production of dextransucrase in shorter period of time makes this strain an attractive candidate for commercial production of dextransucrase.
Pakistan Journal of Pharmaceutical Sciences, 2013
Utilization of highly specific enzymes for various industrial processes and applications has gain... more Utilization of highly specific enzymes for various industrial processes and applications has gained huge momentum in the field of white biotechnology. Selection of a strain by efficient plate-screening method for a specific purpose has also favored and boosted the isolation of several industrially feasible microorganisms and screening of a large number of microorganisms is an important step in selecting a potent culture for multipurpose usage. Five new bacterial isolates of Bacillus licheniformis were discovered from indigenous sources and characterized on the basis of phylogeny using 16S rDNA gene analysis. Studies on morphological and physiological characteristics showed that these isolates can easily be cultivated at different temperatures ranging from 30°C to 55°C with a wide pH values from 3.0 to 11.0 All these 05 isolates are salt tolerant and can grow even in the presences of high salt concentration ranging from 7.0 to 12.0%. All these predominant isolates of B. licheniformis...
Microbiology Monographs
The emergence of serious issues of multidrug resistance in the past few years forced the consider... more The emergence of serious issues of multidrug resistance in the past few years forced the consideration of bacteriocins for combating infections. Numerous concerns have been raised against increased bacterial resistance toward effective drugs and become a debated issue all over the world. Alongside, there is an increase in consumer demand for the antimicrobial compounds isolated or derived from natural sources. Production of antimicrobial compounds is considered as a ubiquitous anti-competitor strategy in microbial ecosystem. Research on antimicrobial compounds with a special interest on bacteriocins is opening a door of a new age. Bacteriocins play an immense role in different industries to overcome various unrestrained environmental issues. Many researchers are now focusing on the bacteriocins of lactic acid bacteria (LAB) with plenty of applications not only in food industries but also in medical and health applications. Their infrequent and targeted use leads to the reduction in the emergence of drug resistance by microbes. Currently, bacteriocins produced by LAB are extensively studied due to their generally recognized as safe (GRAS) status. Various species of LAB are reported to have therapeutic properties that confer beneficial effects on human and animal health. The public health dilemma of drug resistance can be resolved by the discovery of new antimicrobial compounds having target-specific inhibition especially against multidrug-resistant organisms. Consequently, the pool of effective drugs could be available all the time to control newly emerging drug resistance in bacteria.
Pakistan journal of pharmaceutical sciences, 2014
Increased bacterial resistance towards commonly used antibiotics has become a debated issue all o... more Increased bacterial resistance towards commonly used antibiotics has become a debated issue all over the world in a last few decades. Due to this, consumer demand towards natural anti-microbial agents is increasing day by day. Natural anti-microbial agents have gained enormous attention as an alternative therapeutic agent in pharmaceutical industry. Current study is an effort to explore and identify a bactericidal potential of various solvent extracts of Calotropis procera flower. Flowers of C. procera were extracted with hexane, butanol, ethyl acetate and aqua to evaluate the antibacterial activity by agar well diffusion method against the various human pathogens. The microorganisms used in this study includes Salmonella typhi, Escherichia coli (O157:H7), Micrococcus luteus KIBGE-IB20 (Gen Bank accession: JQ250612) and methicillin resistant Staphylococcus aureus (MRSA) KIBGE-IB23 (Gen Bank accession: KC465400). Zones of inhibition were observed against all four pathogenic strains. ...
Molecular Biology Reports
Journal of Food Processing and Preservation
Scientific Reports
Nanomaterials have significantly contributed in the field of nanomedicine as this subject matter ... more Nanomaterials have significantly contributed in the field of nanomedicine as this subject matter has combined the usefulness of natural macromolecules with organic and inorganic nanomaterials. In this respect, various types of nanocomposites are increasingly being explored in order to discover an effective approach in controlling high morbidity and mortality rate that had triggered by the evolution and emergence of multidrug resistant microorganisms. Current research is focused towards the production of biogenic silver nanoparticles for the fabrication of antimicrobial metallic-polymer-based non-cytotoxic nanocomposite system. An ecofriendly approach was adapted for the production of silver nanoparticles using fungal biomass (Aspergillus fumigatus KIBGE-IB33). The biologically synthesized nanoparticles were further layered with a biodegradable macromolecule (chitosan) to improve and augment the properties of the developed nanocomposite system. Both nanostructures were characterized ...
Journal of Basic Microbiology
The utilization of sugarcane bagasse (SB) in fermentation requires pretreatment processes to rend... more The utilization of sugarcane bagasse (SB) in fermentation requires pretreatment processes to render fermentable components available to microorganisms. Pretreatment by using ionic liquids (ILs) is considered promising but the high cost is an impediment in its adoption, therefore, a mixture of IL pretreated and untreated SB was utilized to obtain bacterial multienzyme under solid-state fermentation (SSF). Bacillus aestuarii UE25, a thermophilic strain was utilized for that purpose. Fermentation conditions were optimized by adopting a central composite design. The model showed a good correlation between the predicted and the experimental values for amylase, xylanase, endoglucanase, and β-glucosidase. Volumetric and specific productivity of xylanase (4580 IU ml-1 h-1 , 244.25 IU mg-1 substrate, and 50 IU mg-1 protein) were higher than the other enzymes. Changes in lignin content and reduced cellulose crystallinity due to IL pretreatment, followed by fermentation, were visualized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Nuclear magnetic resonance. The strategy adopted by utilizing a mixture of IL pretreated and untreated SB under SSF proved promising to obtain high titers of different enzymes simultaneously. Since the bacterial strain used is thermophilic, therefore, the multienzyme can find its application in commercial processes which are carried out at high temperatures.
Journal of Genetic Engineering and Biotechnology
Background Pakistan is one of the top five date fruit-producing countries and produced more than ... more Background Pakistan is one of the top five date fruit-producing countries and produced more than 30% wastes in picking, packing, storage, and commercialization stages. The date fruit wastes are usually considered inedible for humans and only used for livestock feed. In current research, Bacillus licheniformis KIBGE-IB3 was screened for pectinase, xylanase, cellulase, and amylase production using date fruit wastes as substrate through solid state fermentation. Results The B. licheniformis KIBGE-IB3 produced higher concentration of pectinase using date fruit wastes as substrate as compared to amylase, cellulase, and xylanase. B. licheniformis KIBGE-IB3 produced maximum pectinase using 5.0 g/dl date fruit wastes and 0.5 g/dl yeast extract. B. licheniformis KIBGE-IB3 required pH 7.0, 37 °C incubation temperature, and 72 h incubation period for maximum production of pectinase. Conclusion It has been concluded that date fruit waste is a good source of biomass and can be utilized for the c...
International Journal of Biological Macromolecules
Malathion organophosphates considered as the major constituent of herbicides, pesticides and inse... more Malathion organophosphates considered as the major constituent of herbicides, pesticides and insecticides. Extensively used in agricultural, horticultures and for numerous household applications contributes to precedence organic pollutants leading antagonistic effects on human health and environment. Therefore detoxification of malathion from contaminated site is of general interest. Simultaneously it is very emerging to isolated novel indigenous microbial strains from contaminated site with a record of pesticide application. In this study Escherichia coli IES-02 isolated from malathion contaminant effluent and the strain showed maximum efficiency in malathion degradation that utilized it as the sole source of carbon. Carboxylesterase (33.0, 30.0, 28.0 kDa) were purified (1685.71 U/mg) from Escherichia coli IES-02 showed significant results in malathion degradation approximately 81% within 20 min as compared with Escherichia coli IES-02 cells within 4 h (99.0 to 95.0%) into monocarboxylic acid and diacid derivatives. The generation time of Escherichia coli was also observed at 60 min with 0.1 ppm, 68 min with 0.5 ppm, 74.5 min with 2.0 ppm and 91.37 min with 50 ppm of malathion. The degradation rate and transformation metabolites were estimated by Gas Chromatography-Mass Spectrometry respectively. Malathion metabolites pathway proposed in this study which revealed the potential application against lethal environmental pollution.
International Journal of Peptide Research and Therapeutics
Emergence of food borne pathogens and multidrug resistant organisms has enforced the screening of... more Emergence of food borne pathogens and multidrug resistant organisms has enforced the screening of natural antimicrobial compounds. Bacteriocins are ribosomally synthesized natural antimicrobial peptides produced by numerous bacteria. These antimicrobial peptides are gaining more attention as alternative therapeutics in pharmaceutical industry as next-generation antibiotics targeting the multi-drug resistant pathogens and as a bio preservative in food industry. The current study is aimed to purify and characterize a broad spectrum bacteriocin (Bac-IB45) with the determination of its plausible mode/mechanism of action. In this research, Bac-IB45 from Lactobacillus plantarum KIBGE-IB45 was 41.71-fold purified with the molecular mass of 20.5 kDa estimated using tricine SDS-PAGE. This bacteriocin is highly thermostable and pH stable in nature. It also exhibited stability against various metal ions, surfactants and organic solvents. Purified Bac-IB45 showed broad antimicrobial potential against various multidrug resistant, food borne bacterial and fungal pathogens. However, Bac-IB45 was found to be sensitive to various proteolytic enzymes. The time-kill assay of Bac-IB45 and scanning electron microscopic analysis revealed the bactericidal mode/mechanism of action against Listeria monocytogenes ATCC 7644. This unique Bac-IB45 with broad spectrum of inhibition and bactericidal mode of action could be used as a natural food preservative and as alternative therapeutics to solve the unrestrained problems of industries.
Biocatalysis and Agricultural Biotechnology
Abstract Over the last few decades, emerging cases of chemical additives and food borne pathogens... more Abstract Over the last few decades, emerging cases of chemical additives and food borne pathogens have enforced the demand of natural antimicrobial compounds. Bacteriocins are one of the natural alternatives to the chemical food preservatives. The research on new and improved bacteriocins is in full swing due to some limitations of commercially available bacteriocins. The aim of the study is to improve the indigenously isolated strain for the enhanced production of bacteriocin like inhibitory substance (BLIS) using combinatorial approach. In the current study, the efficiency of BLIS produced by Lactobacillus plantarum KIBGE-IB45 was improved by applying a combinatorial strategies. Primarily, production of BLIS was optimized using one factor at a time approach. To further enhance the potential of L. plantarum, chemical mutagens were used followed by statistical optimization using multivariate approach. The results revealed that synergistic effect of chemical mutagen and a sequential statistical optimization have significantly enhanced the production of BLIS at 35 °C in MRS medium with an initial pH 9.0 after 16 h of incubation. Response surface methodology revealed 2.0 fold increased in the production of BLIS. The ability of BLIS to inhibit the Listeria monocytogenes ATCC 7644 has enforced its application as a natural preservative to resolve the uncontrolled issues of food industry.
Catalysis Letters
Abstract In the current research, second most abundant renewable polysaccharide chitin is utilize... more Abstract In the current research, second most abundant renewable polysaccharide chitin is utilized for meaningful purpose. Owing to auspicious features of chitin it is used as a matrix for immobilization of valuable biocatalyst dextranase. Dextranase belongs to hydrolase family and has broad commercial application in different fields. Functionality of dextranase is further improve with the help of its immobilization on chitin by different protocols. Dextranase used in this study was isolated from a thermophilic bacteria Bacillus megaterium KIBGE-IB31 explored from hydrothermal spring. Isolated dextranase was immobilized on chitin by two different methods namely; adsorption and covalent binding. A comparative study was conducted between soluble, adsorbed and covalently cross linked dextranase. It was observed that although, there was slight deviation in characteristics of dextranase after immobilization but there was marked improvement in stability of enzyme after immobilization. The comparative analysis revealed that dextranase immobilized by adsorption was less stable and fails to retained enzyme stability for increase reusability. The adsorption method was improved after treatment of chitin with acid and showed improved stability as well as reusability. However, dextranase immobilized by covalent cross linking displayed highest stability at high temperature along with increase recycling efficiency as compare to enzyme immobilized by adsorption method. Hence, it can be concluded that though chitin is cheap, easily accessible matrix for immobilization of dextranase but still among different protocols of immobilization covalent cross linking was found to be more appropriate in improving enzyme stability and its reusability at industrial scale. Graphic Abstract
International journal of biological macromolecules, Jan 22, 2018
Metallic nanoparticles have a substantial scientific interest because of their distinctive physic... more Metallic nanoparticles have a substantial scientific interest because of their distinctive physicochemical and antimicrobial properties and the emergence of multidrug resistant pathogens could unlock the potential of nanoparticles to combat infectious diseases. The aim of the current study is to enhance the antibacterial potential of purified bacteriocin by combining bacteriocin and antibacterial silver nanoparticles (AgNPs). Hence, the interaction of natural antimicrobial compounds and antibacterial nanoparticles can be used as a potential tool for combating infectious diseases. In this study, a green, simple and effective approach is used to synthesize antibacterial AgNPs using fungal exopolysaccharide as both a reducing and stabilizing agent. The AgNPs were characterized by spectroscopic analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Dynamic Light Scattering (DLS). Furthermore, the synergistic effect of bacteriocin-AgNPs was determine...
Pakistan Journal of Scientific and Industrial Research, 2009
The activity of commonly used spices and salt, sugar and pickles against Escherichia coli, Salmon... more The activity of commonly used spices and salt, sugar and pickles against Escherichia coli, Salmonella typhi, and Staphylococcus aureus was tested. The antibacterial activity was found to be in descending order like coriander > pickles > salt and sugar > clove > turmeric > black pepper > red ...
International journal of biological macromolecules, Jan 22, 2018
Metallic nanoparticles have a substantial scientific interest because of their distinctive physic... more Metallic nanoparticles have a substantial scientific interest because of their distinctive physicochemical and antimicrobial properties and the emergence of multidrug resistant pathogens could unlock the potential of nanoparticles to combat infectious diseases. The aim of the current study is to enhance the antibacterial potential of purified bacteriocin by combining bacteriocin and antibacterial silver nanoparticles (AgNPs). Hence, the interaction of natural antimicrobial compounds and antibacterial nanoparticles can be used as a potential tool for combating infectious diseases. In this study, a green, simple and effective approach is used to synthesize antibacterial AgNPs using fungal exopolysaccharide as both a reducing and stabilizing agent. The AgNPs were characterized by spectroscopic analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Dynamic Light Scattering (DLS). Furthermore, the synergistic effect of bacteriocin-AgNPs was determine...
Pakistan Journal of Pharmaceutical Sciences, 2015
The bacterial strains capable of producing dextransucrase enzyme were isolated from different fru... more The bacterial strains capable of producing dextransucrase enzyme were isolated from different fruits and vegetables sources. In primary screening, five strains were selected on the basis dextransucrase production and among them L. mesenteroides KIBGE- IB26 isolated from bottle gourd (Lagenaria Vulgaris) was selected for further studies. For the enhancement of enzyme production, different physicochemical parameters were optimized. Maximum production of dextransucrase was achieved after 06 hrs using sucrose (20.0 g/l) as a substrate at 25°C. Maximum dextransucrase production was achieved when medium pH was kept 7.5 before sterilization. In addition, medium was also supplemented with CaCl2 and K2HPO4 and maximum enzyme production was achieved at 0.0025 g/dl calcium chloride and 2.0 g/dl K₂HPO₄with enzyme activity of 87 DSU/ml/hr. Production of dextransucrase in shorter period of time makes this strain an attractive candidate for commercial production of dextransucrase.
Pakistan Journal of Pharmaceutical Sciences, 2013
Utilization of highly specific enzymes for various industrial processes and applications has gain... more Utilization of highly specific enzymes for various industrial processes and applications has gained huge momentum in the field of white biotechnology. Selection of a strain by efficient plate-screening method for a specific purpose has also favored and boosted the isolation of several industrially feasible microorganisms and screening of a large number of microorganisms is an important step in selecting a potent culture for multipurpose usage. Five new bacterial isolates of Bacillus licheniformis were discovered from indigenous sources and characterized on the basis of phylogeny using 16S rDNA gene analysis. Studies on morphological and physiological characteristics showed that these isolates can easily be cultivated at different temperatures ranging from 30°C to 55°C with a wide pH values from 3.0 to 11.0 All these 05 isolates are salt tolerant and can grow even in the presences of high salt concentration ranging from 7.0 to 12.0%. All these predominant isolates of B. licheniformis...
Microbiology Monographs
The emergence of serious issues of multidrug resistance in the past few years forced the consider... more The emergence of serious issues of multidrug resistance in the past few years forced the consideration of bacteriocins for combating infections. Numerous concerns have been raised against increased bacterial resistance toward effective drugs and become a debated issue all over the world. Alongside, there is an increase in consumer demand for the antimicrobial compounds isolated or derived from natural sources. Production of antimicrobial compounds is considered as a ubiquitous anti-competitor strategy in microbial ecosystem. Research on antimicrobial compounds with a special interest on bacteriocins is opening a door of a new age. Bacteriocins play an immense role in different industries to overcome various unrestrained environmental issues. Many researchers are now focusing on the bacteriocins of lactic acid bacteria (LAB) with plenty of applications not only in food industries but also in medical and health applications. Their infrequent and targeted use leads to the reduction in the emergence of drug resistance by microbes. Currently, bacteriocins produced by LAB are extensively studied due to their generally recognized as safe (GRAS) status. Various species of LAB are reported to have therapeutic properties that confer beneficial effects on human and animal health. The public health dilemma of drug resistance can be resolved by the discovery of new antimicrobial compounds having target-specific inhibition especially against multidrug-resistant organisms. Consequently, the pool of effective drugs could be available all the time to control newly emerging drug resistance in bacteria.
Pakistan journal of pharmaceutical sciences, 2014
Increased bacterial resistance towards commonly used antibiotics has become a debated issue all o... more Increased bacterial resistance towards commonly used antibiotics has become a debated issue all over the world in a last few decades. Due to this, consumer demand towards natural anti-microbial agents is increasing day by day. Natural anti-microbial agents have gained enormous attention as an alternative therapeutic agent in pharmaceutical industry. Current study is an effort to explore and identify a bactericidal potential of various solvent extracts of Calotropis procera flower. Flowers of C. procera were extracted with hexane, butanol, ethyl acetate and aqua to evaluate the antibacterial activity by agar well diffusion method against the various human pathogens. The microorganisms used in this study includes Salmonella typhi, Escherichia coli (O157:H7), Micrococcus luteus KIBGE-IB20 (Gen Bank accession: JQ250612) and methicillin resistant Staphylococcus aureus (MRSA) KIBGE-IB23 (Gen Bank accession: KC465400). Zones of inhibition were observed against all four pathogenic strains. ...
Molecular Biology Reports
Journal of Food Processing and Preservation
Scientific Reports
Nanomaterials have significantly contributed in the field of nanomedicine as this subject matter ... more Nanomaterials have significantly contributed in the field of nanomedicine as this subject matter has combined the usefulness of natural macromolecules with organic and inorganic nanomaterials. In this respect, various types of nanocomposites are increasingly being explored in order to discover an effective approach in controlling high morbidity and mortality rate that had triggered by the evolution and emergence of multidrug resistant microorganisms. Current research is focused towards the production of biogenic silver nanoparticles for the fabrication of antimicrobial metallic-polymer-based non-cytotoxic nanocomposite system. An ecofriendly approach was adapted for the production of silver nanoparticles using fungal biomass (Aspergillus fumigatus KIBGE-IB33). The biologically synthesized nanoparticles were further layered with a biodegradable macromolecule (chitosan) to improve and augment the properties of the developed nanocomposite system. Both nanostructures were characterized ...
Journal of Basic Microbiology
The utilization of sugarcane bagasse (SB) in fermentation requires pretreatment processes to rend... more The utilization of sugarcane bagasse (SB) in fermentation requires pretreatment processes to render fermentable components available to microorganisms. Pretreatment by using ionic liquids (ILs) is considered promising but the high cost is an impediment in its adoption, therefore, a mixture of IL pretreated and untreated SB was utilized to obtain bacterial multienzyme under solid-state fermentation (SSF). Bacillus aestuarii UE25, a thermophilic strain was utilized for that purpose. Fermentation conditions were optimized by adopting a central composite design. The model showed a good correlation between the predicted and the experimental values for amylase, xylanase, endoglucanase, and β-glucosidase. Volumetric and specific productivity of xylanase (4580 IU ml-1 h-1 , 244.25 IU mg-1 substrate, and 50 IU mg-1 protein) were higher than the other enzymes. Changes in lignin content and reduced cellulose crystallinity due to IL pretreatment, followed by fermentation, were visualized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Nuclear magnetic resonance. The strategy adopted by utilizing a mixture of IL pretreated and untreated SB under SSF proved promising to obtain high titers of different enzymes simultaneously. Since the bacterial strain used is thermophilic, therefore, the multienzyme can find its application in commercial processes which are carried out at high temperatures.
Journal of Genetic Engineering and Biotechnology
Background Pakistan is one of the top five date fruit-producing countries and produced more than ... more Background Pakistan is one of the top five date fruit-producing countries and produced more than 30% wastes in picking, packing, storage, and commercialization stages. The date fruit wastes are usually considered inedible for humans and only used for livestock feed. In current research, Bacillus licheniformis KIBGE-IB3 was screened for pectinase, xylanase, cellulase, and amylase production using date fruit wastes as substrate through solid state fermentation. Results The B. licheniformis KIBGE-IB3 produced higher concentration of pectinase using date fruit wastes as substrate as compared to amylase, cellulase, and xylanase. B. licheniformis KIBGE-IB3 produced maximum pectinase using 5.0 g/dl date fruit wastes and 0.5 g/dl yeast extract. B. licheniformis KIBGE-IB3 required pH 7.0, 37 °C incubation temperature, and 72 h incubation period for maximum production of pectinase. Conclusion It has been concluded that date fruit waste is a good source of biomass and can be utilized for the c...
International Journal of Biological Macromolecules
Malathion organophosphates considered as the major constituent of herbicides, pesticides and inse... more Malathion organophosphates considered as the major constituent of herbicides, pesticides and insecticides. Extensively used in agricultural, horticultures and for numerous household applications contributes to precedence organic pollutants leading antagonistic effects on human health and environment. Therefore detoxification of malathion from contaminated site is of general interest. Simultaneously it is very emerging to isolated novel indigenous microbial strains from contaminated site with a record of pesticide application. In this study Escherichia coli IES-02 isolated from malathion contaminant effluent and the strain showed maximum efficiency in malathion degradation that utilized it as the sole source of carbon. Carboxylesterase (33.0, 30.0, 28.0 kDa) were purified (1685.71 U/mg) from Escherichia coli IES-02 showed significant results in malathion degradation approximately 81% within 20 min as compared with Escherichia coli IES-02 cells within 4 h (99.0 to 95.0%) into monocarboxylic acid and diacid derivatives. The generation time of Escherichia coli was also observed at 60 min with 0.1 ppm, 68 min with 0.5 ppm, 74.5 min with 2.0 ppm and 91.37 min with 50 ppm of malathion. The degradation rate and transformation metabolites were estimated by Gas Chromatography-Mass Spectrometry respectively. Malathion metabolites pathway proposed in this study which revealed the potential application against lethal environmental pollution.
International Journal of Peptide Research and Therapeutics
Emergence of food borne pathogens and multidrug resistant organisms has enforced the screening of... more Emergence of food borne pathogens and multidrug resistant organisms has enforced the screening of natural antimicrobial compounds. Bacteriocins are ribosomally synthesized natural antimicrobial peptides produced by numerous bacteria. These antimicrobial peptides are gaining more attention as alternative therapeutics in pharmaceutical industry as next-generation antibiotics targeting the multi-drug resistant pathogens and as a bio preservative in food industry. The current study is aimed to purify and characterize a broad spectrum bacteriocin (Bac-IB45) with the determination of its plausible mode/mechanism of action. In this research, Bac-IB45 from Lactobacillus plantarum KIBGE-IB45 was 41.71-fold purified with the molecular mass of 20.5 kDa estimated using tricine SDS-PAGE. This bacteriocin is highly thermostable and pH stable in nature. It also exhibited stability against various metal ions, surfactants and organic solvents. Purified Bac-IB45 showed broad antimicrobial potential against various multidrug resistant, food borne bacterial and fungal pathogens. However, Bac-IB45 was found to be sensitive to various proteolytic enzymes. The time-kill assay of Bac-IB45 and scanning electron microscopic analysis revealed the bactericidal mode/mechanism of action against Listeria monocytogenes ATCC 7644. This unique Bac-IB45 with broad spectrum of inhibition and bactericidal mode of action could be used as a natural food preservative and as alternative therapeutics to solve the unrestrained problems of industries.
Biocatalysis and Agricultural Biotechnology
Abstract Over the last few decades, emerging cases of chemical additives and food borne pathogens... more Abstract Over the last few decades, emerging cases of chemical additives and food borne pathogens have enforced the demand of natural antimicrobial compounds. Bacteriocins are one of the natural alternatives to the chemical food preservatives. The research on new and improved bacteriocins is in full swing due to some limitations of commercially available bacteriocins. The aim of the study is to improve the indigenously isolated strain for the enhanced production of bacteriocin like inhibitory substance (BLIS) using combinatorial approach. In the current study, the efficiency of BLIS produced by Lactobacillus plantarum KIBGE-IB45 was improved by applying a combinatorial strategies. Primarily, production of BLIS was optimized using one factor at a time approach. To further enhance the potential of L. plantarum, chemical mutagens were used followed by statistical optimization using multivariate approach. The results revealed that synergistic effect of chemical mutagen and a sequential statistical optimization have significantly enhanced the production of BLIS at 35 °C in MRS medium with an initial pH 9.0 after 16 h of incubation. Response surface methodology revealed 2.0 fold increased in the production of BLIS. The ability of BLIS to inhibit the Listeria monocytogenes ATCC 7644 has enforced its application as a natural preservative to resolve the uncontrolled issues of food industry.
Catalysis Letters
Abstract In the current research, second most abundant renewable polysaccharide chitin is utilize... more Abstract In the current research, second most abundant renewable polysaccharide chitin is utilized for meaningful purpose. Owing to auspicious features of chitin it is used as a matrix for immobilization of valuable biocatalyst dextranase. Dextranase belongs to hydrolase family and has broad commercial application in different fields. Functionality of dextranase is further improve with the help of its immobilization on chitin by different protocols. Dextranase used in this study was isolated from a thermophilic bacteria Bacillus megaterium KIBGE-IB31 explored from hydrothermal spring. Isolated dextranase was immobilized on chitin by two different methods namely; adsorption and covalent binding. A comparative study was conducted between soluble, adsorbed and covalently cross linked dextranase. It was observed that although, there was slight deviation in characteristics of dextranase after immobilization but there was marked improvement in stability of enzyme after immobilization. The comparative analysis revealed that dextranase immobilized by adsorption was less stable and fails to retained enzyme stability for increase reusability. The adsorption method was improved after treatment of chitin with acid and showed improved stability as well as reusability. However, dextranase immobilized by covalent cross linking displayed highest stability at high temperature along with increase recycling efficiency as compare to enzyme immobilized by adsorption method. Hence, it can be concluded that though chitin is cheap, easily accessible matrix for immobilization of dextranase but still among different protocols of immobilization covalent cross linking was found to be more appropriate in improving enzyme stability and its reusability at industrial scale. Graphic Abstract
International journal of biological macromolecules, Jan 22, 2018
Metallic nanoparticles have a substantial scientific interest because of their distinctive physic... more Metallic nanoparticles have a substantial scientific interest because of their distinctive physicochemical and antimicrobial properties and the emergence of multidrug resistant pathogens could unlock the potential of nanoparticles to combat infectious diseases. The aim of the current study is to enhance the antibacterial potential of purified bacteriocin by combining bacteriocin and antibacterial silver nanoparticles (AgNPs). Hence, the interaction of natural antimicrobial compounds and antibacterial nanoparticles can be used as a potential tool for combating infectious diseases. In this study, a green, simple and effective approach is used to synthesize antibacterial AgNPs using fungal exopolysaccharide as both a reducing and stabilizing agent. The AgNPs were characterized by spectroscopic analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Dynamic Light Scattering (DLS). Furthermore, the synergistic effect of bacteriocin-AgNPs was determine...
Pakistan Journal of Scientific and Industrial Research, 2009
The activity of commonly used spices and salt, sugar and pickles against Escherichia coli, Salmon... more The activity of commonly used spices and salt, sugar and pickles against Escherichia coli, Salmonella typhi, and Staphylococcus aureus was tested. The antibacterial activity was found to be in descending order like coriander > pickles > salt and sugar > clove > turmeric > black pepper > red ...