Bhawana Bisht - Academia.edu (original) (raw)

Papers by Bhawana Bisht

An exopolysaccharide (EPS) producing strain FSW-25 was isolated from the Rasthakaadu beach Kanyak... more An exopolysaccharide (EPS) producing strain FSW-25 was isolated from the Rasthakaadu beach Kanyakumari, Tamil Nadu India. Based on polyphasic taxonomy, the strain FSW-25 was assigned to the genus Microbacterium and found to be the closest relative of the species aurantiacum. Large quantity of EPS (7.81 g/l) was secreted by the strain upon fermentation using Reasoner's 2A medium enriched with 2.5% glucose and was designated as Mi-25. FT-IR spectrum revealed presence of hydroxyl, carbonyl, carboxyl, methyl and sulfate functional groups in purified EPS. The EPS Mi-25 has a molecular weight of 7.0 × 106 Da and mainly comprises of glucuronic acid followed by glucose, mannose and fucose. Rheological study revealed that Mi-25 possesses significant viscosity with pseudoplastic nature. Interestingly, it was observed that the EPS Mi-25 has higher antioxidant activity as compared to xanthan. The characteristics of EPS Mi-25 suggested that, it can be used as a potential antioxidant with vis...

International Journal of Systematic and Evolutionary Microbiology

During a study of the bacterial diversity of mangrove habitats, a novel Gram-stain-negative, rod-... more During a study of the bacterial diversity of mangrove habitats, a novel Gram-stain-negative, rod-shaped bacterium designated as SAOS 153DT was isolated. Sequence alignment and molecular phylogenetic analyses based on 16S rRNA and core gene sequence of strain SAOS 153DT with closely related taxa revealed a sequence identity of 99.4 % and clustering with Yangia pacifica DX5-10T. The fatty acids summed feature 8 (C18:1 ω7c/C18:1 ω6c) and the lipids phosphatidylglycerol, phosphatidylethanolamine and an unknown phospholipid were the major components of the cell wall. The only ubiquinone type present was Q-10. The genomic DNA G+C content of the strain calculated from whole genome sequencing was 66.9 mol%. These chemotaxonomic and genomic characteristics supported the molecular phylogenetic analysis and placed the strain well within the radiation of the genus Yangia . The overall genome related indices using digital DNA–DNA hybridization (35.4 %) and ortho-average nucleotide identity (88.1...

Scientific Reports

The manuscript highlights the efficacy of silver ions to act as a unique probe for the detection ... more The manuscript highlights the efficacy of silver ions to act as a unique probe for the detection of bacterial contamination in water samples. The bacterial cell membrane adherence property of the silver ions was employed to develop two different bacterial detection assays employing colorimetric and electrochemical techniques. In one of the schemes, silver ion was used directly as a detector of bacteria in a colorimetric assay format, and in the other scheme surface-functionalized antibodies were used as a primary capture for specific detection of Salmonella enterica serovar Typhi. The colorimetric detection is based on silver-induced inhibition of urease activity and silver ion utilization by bacteria for the rapid screening of enteric pathogens in water. The specific detection of bacteria uses an antibody-based electrochemical method that employs silver as an electrochemical probe. The ability of silver to act as an electrochemical probe was investigated by employing Anodic Stripping Voltammetry (ASV) for targeted detection of Salmonella Typhi. for further insights into the developed assays, inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM) studies were performed. The sensitivity of the developed assay was found to be 100 cfu mL −1 for colorimetric and 10 cfu mL −1 for electrochemical assay respectively.

International Journal of Systematic and Evolutionary Microbiology, 2018

A Gram-stain-negative, non-endospore-producing, short-rod strain, KNDSS-Mac4 T , was isolated fro... more A Gram-stain-negative, non-endospore-producing, short-rod strain, KNDSS-Mac4 T , was isolated from a downstream sediment sample of the river Ganges, Kanpur, India and studied by using the polyphasic taxonomic approach. 16S rRNA gene sequence analysis uncovered that the strain had similarity to species of the genus Thauera and formed a distinct phylogenetic cluster with Thauera humireducens KACC16524 T. However, KNDSS-Mac4 T showed closest phylogenetic affiliation to Thauera aminoaromatica DSM 14742 T with 16S rRNA gene sequence similarity of 98.7 % followed by Thauera phenylacetica DSM 14743 T (98.6 %), Thauera chlorobenzoica (98.2 %), T. humireducens KACC16524 T (98.2 %), Thauera selenatis ATCC 55363 T (98.2 %) and Thauera mechernichensis DSM 12266 T (98.0 %). The digital DNA-DNA hybridization and average nucleotide identity values between strain KNDSS-Mac4 T and the two most closely related taxa, T. aminoaromatica DSM 14742 T and T. phenylacetica DSM 14743 T , were 26.0, 26.7 and 84.0, 84.3 % respectively. Major lipids present were phosphatidylglycerol, three unknown aminophospholipids, phosphatidylmethylethanolamine, two unidentified lipids and Q-8 as the only ubiquonone. The major cellular fatty acids present were C 16 : 1 !6c/C 16 : 1 !7c and C 16 : 0. The DNA G+C content of strain KNDSS-Mac4 T was 65.9 %. Based on data from phenotypic tests and the genotypic differences of strain KNDSS-Mac4 T from its closest phylogenetic relatives, it is evident that this isolate should be regarded as a new species. It is proposed that strain KNDSS-Mac4 T should be classified in the genus Thauera as a novel species, Thauera propionica sp. nov. The type strain is KNDSS-Mac4 T (=KCTC 52820 T =VTCC-B-910017 T).

International Journal of Biological Macromolecules

International journal of systematic and evolutionary microbiology, Jan 4, 2018

A Gram-stain-negative, rod-shaped, aerobic, straw yellow, motile strain, designated KNDSW-TSA6, b... more A Gram-stain-negative, rod-shaped, aerobic, straw yellow, motile strain, designated KNDSW-TSA6, belonging to the genus Acidovorax, was isolated from a water sample of the river Ganges, downstream of the city of Kanpur, Uttar Pradesh, India. Cells were aerobic, non-endospore-forming and motile with single polar flagella. It differed from its phylogenetically related strains by phenotypic characteristics such as hydrolysis of urea, gelatin, casein and DNA, and the catalase reaction. The major fatty acids were C16 : 1ω7c/C16 : 1ω6c, C16 : 0 and C18 : 1ω7c/C18 : 1ω6c. Phylogenetic analysis based on 16S rRNA and housekeeping genes (gyrb, recA and rpoB gene sequences), confirmed its placement within the genus Acidovorax as a novel species. Strain KNDSW-TSA6showed highest 16S rRNA sequence similarity to Acidovorax soli BL21(98.9 %), Acidovorax delafieldii ATCC 17505(98.8 %), Acidovorax temperans CCUG 11779(98.2 %), Acidovorax caeni R-24608(97.9 %) and Acidovorax radicis N35(97.6 %). The di...

International journal of systematic and evolutionary microbiology, Jan 29, 2017

A Gram-stain-negative, non-endospore-producing, short-rod strain, KNDSS-Mac4T, was isolated from ... more A Gram-stain-negative, non-endospore-producing, short-rod strain, KNDSS-Mac4T, was isolated from a downstream sediment sample of the river Ganges, Kanpur, India and studied by using the polyphasic taxonomic approach. 16S rRNA gene sequence analysis uncovered that the strain had similarity to species of the genus Thauera and formed a distinct phylogenetic cluster with Thauera humireducens KACC16524T. However, KNDSS-Mac4T showed closest phylogenetic affiliation to Thauera aminoaromatica DSM 14742T with 16S rRNA gene sequence similarity of 98.7 % followed by Thauera phenylacetica DSM 14743T (98.6 %), Thauera chlorobenzoica (98.2 %), T. humireducens KACC16524T (98.2 %), Thauera selenatis ATCC 55363T (98.2 %) and Thauera mechernichensis DSM 12266T (98.0 %). The digital DNA-DNA hybridization and average nucleotide identity values between strain KNDSS-Mac4T and the two most closely related taxa, T. aminoaromatica DSM 14742T and T. phenylacetica DSM 14743T, were 26.0, 26.7 and 84.0, 84.3 % ...

International journal of systematic and evolutionary microbiology, Jan 14, 2017

A bacterial strain, designated ASS-1T, was isolated and identified from a sediment sample of the ... more A bacterial strain, designated ASS-1T, was isolated and identified from a sediment sample of the river Ganges, Allahabad, India. The strain was Gram-stain-negative, formed straw-yellow pigmented colonies, was strictly aerobic, motile with a single polar flagellum, and positive for oxidase and catalase. The major fatty acids were C16 : 1ω7c/ 16 : 1 C16 : 1ω6c, C18 : 1ω7c and C16 : 0. Sequence analysis based on the 16S rRNA gene revealed that strain ASS-1T showed high similarity to Pseudomonas guguanensis CC-G9AT (98.2 %), Pseudomonas alcaligenes ATCC 14909T (98.2 %), Pseudomonas oleovorans DSM 1045T (98.1 %), Pseudomonas indolxydans IPL-1T (98.1 %) and Pseudomonas toyotomiensis HT-3T (98.0 %). Analysis of its rpoB and rpoD housekeeping genes confirmed its phylogenetic affiliation and showed identities lower than 93 % with respect to the closest relatives. Phylogenetic analysis based on the 16S rRNA, rpoB, rpoD genes and the whole genome assigned it to the genus Pseudomonas. The resul...

International journal of systematic and evolutionary microbiology, Jan 8, 2017

A Gram-stain-positive, facultatively anaerobic bacterial strain, GDSW-R2A3(T), was isolated from ... more A Gram-stain-positive, facultatively anaerobic bacterial strain, GDSW-R2A3(T), was isolated from a downstream water sample collected from the river Ganges, India. Analysis of the 16S rRNA gene sequence of strain GDSW-R2A3(T) revealed its affiliation to the family Bacillaceae. Further analysis using a polyphasic approach revealed that strain GDSW-R2A3(T) was most closely related to the genus Fictibacillus. Analysis of the almost-complete (1488 bp) 16S rRNA gene sequence of strain GDSW-R2A3(T) revealed the highest level of sequence similarity with Fictibacillus phosphorivorans CCM 8426(T) (98.3 %) and Fictibacillus nanhaiensis KCTC 13712(T) (98.3 %) followed by Fictibacillus barbaricus DSM 14730(T) (98.0 %). The digital DNA-DNA hybridization and average nucleotide identity (ANI) values between strain GDSW-R2A3(T) and the most closely related taxon, F. phosphorivorans CCM 8426(T), were 20.3 and 78.2 %, respectively. The DNA G+C content of the strain was 44.2 mol%. The cell-wall amino a...