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Papers by Bhaskar Bhadra

Archives of Microbiology, 2007

Heavy metal content analysis of River Torsa in India did not indicate any alarming level of toxic... more Heavy metal content analysis of River Torsa in India did not indicate any alarming level of toxicity for human consumption but revealed variation at the ppb level in different months. The variation in recoverable nickel and zinc resistant copiotrophic (or eutrophic) bacterial counts was explained by the variation of the zinc content (34.0–691.3 ppb) of the river water in different sampling months. Growth studies conducted with some purified nickel and/or zinc resistant strains revealed that pre-exposure of the cells to ppb levels of Zn2+, comparable to the indigenous zinc ion concentration of the river, could induce the nickel or zinc resistance. A minimum concentration of 5–10 μM Zn2+ (325–650 ppb) was found effective in inducing the Nickel resistance of the isolates. Zinc resistance of the isolates was tested by pre-exposing the cells to 4 μM Zn2+ (260 ppb). The lag phase was reduced by 6–8 h in all the cases. Biochemical characteristics and phylogenetic analysis based on 16S rDNA sequence indicated that some of the Torsa River isolates, having inducible nickel and zinc resistance, are members of the genus Pseudomonas, Acinetobacter, Bacillus, Enterobacter, Serratia and Moraxella.

World Journal of Microbiology & Biotechnology, 2006

A gram negative, motile, short rod-shaped, and nickel resistant (tolerating 6.5 mM Ni 2+ ) bacter... more A gram negative, motile, short rod-shaped, and nickel resistant (tolerating 6.5 mM Ni 2+ ) bacterium, strain BB1A, was isolated from the waters of the River Torsa in Hashimara, Jalpaiguri district, West Bengal, India. The isolate BB1A was identified as a strain of Acinetobacter junii following detailed analysis of morphological, physio-biochemical and 16S rRNA gene sequence. The expression of nickel resistance in BB1A was inducible by exposure to nickel chloride at a concentration as low as 50 lM Ni 2+ . The other metal ions, Cu 2+ , Zn 2+ , or Pb 2+ at a concentration range of 20-30 lM, also induced the nickel resistance system in this bacterium. Southern hybridizations of BB1A genomic DNA with digoxigenin-dUTP labeled DNA probes specific for well known nickel resistance determinants, cnr, ncc or nre, resulted in no detectable signal, but nir specific probe yielded weak hybridization signal with restricted genomic DNA of BB1A. The isolate BB1A, therefore, carries out a novel induction phenomenon of nickel resistance and presumably with a nickel resistance genetic system different from that previously characterized in other bacteria. 2003). The nreB of A. xylosoxidans 31A was specifically

International Journal of Systematic and Evolutionary Microbiology, 2005

A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain N... more A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain NiVa 51 T , was isolated from water of the River Torsa in Hasimara, Jalpaiguri district, West Bengal, India. On the basis of 16S rRNA gene sequence similarity, strain NiVa 51 T was shown to belong to the c-Proteobacteria and to be related to Serratia marcescens subsp. sakuensis (98?35 %) and S. marcescens subsp. marcescens (98?30 %); however, strain NiVa 51 T exhibited only 43?7 % similarity to S. marcescens by DNA-DNA hybridization. The G+C content of the genomic DNA of the isolate was 60 mol%. Both biochemical characteristics and fatty acid analysis data supported the affiliation of strain NiVa 51 T to the genus Serratia. Furthermore, strain NiVa 51 T was found to utilize urea as nitrogen source. The results of DNA-DNA hybridization as well as physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NiVa 51 T from recognized Serratia species. Strain NiVa 51 T therefore represents a novel species, for which the name Serratia ureilytica sp. nov. is proposed, with type strain NiVa 51 T (=LMG 22860 T =CCUG 50595 T ).

International Journal of Systematic and Evolutionary Microbiology, 2007

Two bacterial strains, BBH6 T and BBH9, were isolated from a deep-sea sediment sample collected f... more Two bacterial strains, BBH6 T and BBH9, were isolated from a deep-sea sediment sample collected from the Chagos Trench, Indian Ocean, at a depth of 5904 m. The two strains were closely related in their 16S rRNA gene sequences (99.7 %), belonged to one genomic species and were virtually identical at the phenotypic level. Microbacterium barkeri DSM 20145 T was the nearest phylogenetic neighbour to the new isolates, with 16S rRNA gene sequence similarity levels of 97.2-97.4 %. The new isolates exhibited levels of DNA-DNA relatedness of 32-34 % to M. barkeri and differed from it in a number of phenotypic characteristics. Therefore, it is suggested that strains BBH6 T and BBH9 represent a novel species of the genus Microbacterium, for which the name Microbacterium indicum sp. nov. is proposed. The type strain is BBH6 T (5LMG 23459 T 5IAM 15355 T ).

International Journal of Systematic and Evolutionary Microbiology, 2009

A novel aerobic, obligately mixotrophic, moderately thermophilic, thiosulfate-oxidizing bacterium... more A novel aerobic, obligately mixotrophic, moderately thermophilic, thiosulfate-oxidizing bacterium, S10 T , was isolated from hot-spring sediment samples collected from Atri, Bhubaneswar, India. The cells of this isolate stained Gram-negative and were strictly aerobic, non-sporulating, rodshaped and motile with a single polar flagellum. Strain S10 T was positive for oxidase and catalase activities. It was capable of utilizing thiosulfate under mixotrophic growth conditions. Mixotrophic growth was observed at pH 6.0-8.5 and 25-45 6C; optimum growth occurred at pH 7.5-8.0 and 30-37 6C. The major cellular fatty acids were C 12 : 0 3-OH, C 16 : 1 v7c, C 16 : 0 , C 17 : 0 cyclo, C 18 : 1 v7c and C 19 : 0 cyclo v8c. The DNA G+C content of strain S10 T was 64.8 mol%. 16S rRNA gene sequence analysis indicated that the bacterium clustered within the radiation of the genus Thiomonas and showed 98.0 % similarity with Thiomonas perometabolis ATCC 23370 T and Thiomonas intermedia ATCC 15466 T . However, DNA-DNA reassociation values of strain S10 T with Thiomonas perometabolis JCM 20426 T and Thiomonas intermedia JCM 20425 T , its nearest phylogenetic relatives, were 46 and 39 %, respectively. On the basis of phenotypic, physiological and chemotaxonomic properties, 16S rRNA gene sequence analysis and DNA-DNA reassociation studies, it is proposed that strain S10 T represents a novel species of the genus Thiomonas, Thiomonas bhubaneswarensis sp. nov.; the type strain is S10 T (5DSM 18181 T 5JCM 14806 T ).

International Journal of Systematic and Evolutionary Microbiology, 2008

A novel psychrophilic bacterium, designated strain DVS 3Y T , was isolated from a moraine sample ... more A novel psychrophilic bacterium, designated strain DVS 3Y T , was isolated from a moraine sample from the McMurdo Dry Valleys, Antarctica. Phenotypic and chemotaxonomic characteristics and data from a phylogenetic analysis based on 16S rRNA gene sequences indicated that strain DVS 3Y T was related to the genus Exiguobacterium. Strain DVS 3Y T exhibited .97 % gene sequence similarity with respect to Exiguobacterium acetylicum DSM 20416 T (97.4 %), Exiguobacterium oxidotolerans DSM 17272 T (97.4 %), Exiguobacterium indicum IAM 15368 T (97.6 %), Exiguobacterium undae DSM 14481 T (98.2 %), Exiguobacterium sibiricum DSM 17290 T (98.6 %) and Exiguobacterium antarcticum DSM 14480 T (99.6 %). However, the levels of DNA-DNA relatedness between strain DVS 3Y T and E. acetylicum DSM 20416 T , E. oxidotolerans JCM 12280 T , E. indicum IAM 15368 T , E. undae DSM 14481 T , E. sibiricum DSM 17290 T and E. antarcticum DSM 14480 T were less than 70 % (52, 25, 16, 33, 16 and 38 %, respectively). Strain DVS 3Y T also differed from these six closely related species in a number of phenotypic traits. Phenotypic, chemotaxonomic and phylogenetic data suggest that strain DVS 3Y T represents a novel species of the genus Exiguobacterium, for which the name Exiguobacterium soli sp. nov. is proposed. The type strain is DVS 3Y T (5MTCC 4816 T 5JCM 14376 T ).

International Journal of Systematic and Evolutionary Microbiology, 2008

Pichia garciniae sp. nov., isolated from a rotten mangosteen fruit (Garcinia mangostana L., Clusi... more Pichia garciniae sp. nov., isolated from a rotten mangosteen fruit (Garcinia mangostana L., Clusiaceae) Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiaceae). Based on colony morphology and RAPD analysis, the strains were grouped into four groups (G-I, G-II, G-III and G-IV). Phenotypic properties and analysis of the D1/D2 domain sequence of the 26S rRNA gene identified representative members of groups G-II, G-III and G-IV as Pichia manshurica (5Pichia galeiformis), Pichia fermentans and Pichia anomala, respectively. Representatives of group G-I, YS110 T and YS111, showed similar phenotypic traits, 99.9 % similarity in the sequence of the D1/D2 domain of the 26S rRNA gene and ITS1-5.8S rRNA gene-ITS2 sequence and 92 % DNA-DNA relatedness. Hence, YS110 T and YS111 are regarded as members of the same species. Based on D1/D2 domain and ITS region sequences, the nearest phylogenetic neighbours of YS110 T and YS111 were identified as Pichia membranifaciens and P. manshurica. However, YS110 T differs from these two nearest phylogenetic neighbours by .3 % in the D1/D2 domain sequence and by .18 % with respect to the ITS region sequence. In addition, YS110 T and YS111 differ from P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T with respect to a number of phenotypic traits. The strains show 52-57 % DNA-DNA relatedness with P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T . Strains YS110 T and YS111 are proposed as two strains of a novel species, for which the name Pichia garciniae sp. nov. is proposed. The type strain is YS110 T (5NRRL Y-48422 T 5CBS 10758 T ).

Fems Yeast Research, 2007

The ascogenous yeast YS16T was isolated from a decaying papaya fruit. Phenotypic traits such as m... more The ascogenous yeast YS16T was isolated from a decaying papaya fruit. Phenotypic traits such as multilateral budding, spheroidal or elongate shape, pseudohyphae formation, asci with one or more ascospores, ability to ferment d-glucose, inability to assimilate nitrate and the presence of Q7 ubiquinone suggest its affiliation to the genus Pichia. The nearest phylogenetic neighbor, based on D1/D2 domain sequence of the 26S rRNA gene and ITS region sequence, was identified as Issatchenkia orientalis (NRRL Y-5396T, a synonym of Pichia kudriavzevii) with similarities of 98.2% and 97% respectively. In addition to the difference in the D1/D2 and ITS region sequence, YS16T differs from I. orientalis with respect to a number of phenotypic traits. However, in the phylogenetic analysis, YS16T showed close relatedness to the P. membranifaciens clade. Thus, it is proposed to assign the status of a new species to YS16T, for which the name P. cecembensis sp. nov. is proposed. The type strain of P. cecembensis sp. nov. is YS16T (=NRRL Y-27985T=JCM 13873T=CBS 10445T).

Letters in Applied Microbiology, 2008

Aims: Isolation and identification of yeasts converting xylose to ethanol.Methods and Results: ... more Aims: Isolation and identification of yeasts converting xylose to ethanol.Methods and Results: A total of 374 yeasts were isolated from a variety of rotten fruits and barks of trees. Out of these, 27 yeast strains were able to assimilate xylose and produce 0·12–0·38 g of ethanol per gram of xylose. Based on phylogenetic analysis of D1/D2 domain sequence of LSU (Large Subunit) rRNA gene and phenotypic characteristics the ethanol-producing strains were identified as member(s) of the genera Pichia, Candida, Kluyveromyces, Issatchenkia, Zygosacchraomyces, Clavispora, Debaryomyces, Metschnikowia, Rhodotorula and Cryptococcus.Conclusion: Yeast strains producing ethanol from xylose have been isolated from a variety of rotten fruits and barks of trees and identified.Significance and Impact of the Study: Environmental isolates of yeasts which could convert xylose to ethanol could form the basis for bio-fuel production and proper utilization of xylan rich agricultural and forest wastes.

Current Microbiology, 2007

A total of 35 yeasts were isolated from the gut of beetles collected from Hyderabad city, India. ... more A total of 35 yeasts were isolated from the gut of beetles collected from Hyderabad city, India. Twenty of these yeasts utilized xylose as a sole carbon source but only 12 of these converted xylose to xylitol. The ability to convert xylose to xylitol varied among the isolates and ranged from 0.12 to 0.58 g/g xylose. Based on the phenotypic characteristics and phylogenetic analysis of the D1/D2 domain sequence of 26S rRNA gene, these isolates were identified as members of Pichia, Candida, Issatchenkia, and Clavispora. Strain YS 54 (CBS 10446), which was phylogenetically similar to Pichia caribbica and which formed hat-shaped ascospore characteristics of the genus Pichia, was the best xylitol producer (0.58 g xylitol/g xylose). YS 54 was also capable of producing xylitol from sugarcane bagasse hydrolysate and the efficiency of conversion was 0.32 g xylitol/g xylose after 20 cycles of adaptation in medium containing sugarcane bagasse hydrolysate.

Extremophiles, 2008

Twenty-five psychrophilic yeasts were isolated from the soil of Roopkund Lake, Himalayas, India. ... more Twenty-five psychrophilic yeasts were isolated from the soil of Roopkund Lake, Himalayas, India. Two colony morphotypes were identified and representatives of ‘morphotype 1’ were identified as Cryptococcus gastricus. Representatives of ‘morphotype 2’, namely 3AT, 4A, 4B and Rup4B, showed similar phenotypic properties and are identical with respect to the nucleotide sequence of the ITS1-5.8S rRNA gene-ITS2 region and D1/D2 domain of the 26S rRNA gene. The sequence of D1/D2 domain of 3AT shows 97.6–98.8% similarity with Rhodotorula psychrophila CBS10440T, Rhodotorula glacialis CBS10437T and Rhodotorula psychrophenolica CBS10438T and in the neighbour-joining phylogenetic tree strains; 3AT, 4A, 4B and Rup4B form a cluster with Rhodotorula glacialis and Rhodotorula psychrophila. Strains 3AT, 4A, 4B and Rup4B also differ from their nearest phylogenetic relatives in several biochemical characteristics such as in assimilation of d-galactose, l-sorbose, maltose, citrate, d-glucuronate and creatinine. Thus, based on the phylogenetic analysis and the phenotypic differences 3AT, 4A, 4B and Rup 4B are assigned the status of a new species of Rhodotorula for which the name Rhodotorula himalayensis sp. nov. is proposed with 3AT as the type strain (=CBS10539T =MTCC8336T).

International Journal of Systematic and Evolutionary Microbiology, 2008

Brevibacterium oceani sp. nov. from Indian Ocean Subject category New taxa -Actinobacteria GenBan... more Brevibacterium oceani sp. nov. from Indian Ocean Subject category New taxa -Actinobacteria GenBank/ EMBL accession numbers for the 16S rRNA gene sequence of Brevibacterium oceani sp. nov. BBH7 T and BBH5 are AM158906 and AM158905 respectively. Abstract Two bacterial strains BBH5 and BBH87 T were isolated from a deep-sea sediment sample collected from the Chagos Trench of the Indian Ocean (11 º 06 ' S, 72 º 31 ' E). Both the strains, based on their 16S rRNA gene sequence similarity (99.9 %), DNA-DNA relatedness (93 %) and a number of similar phenotypic characteristics are identified as strains of the same species. The phylogenetically nearest species of BBH5 and BBH7 T based on 16S rRNA gene sequence similarity (97.9 -98.4 %) were identified as Brevibacterium iodinum, Brevibacterium epidermidis, Brevibacterium linens and Brevibacterium permense. However, BBH5 and BBH7 T differ from the above four nearest phylogenetic relatives by a number of phenotypic characteristics and the DNA-DNA similarity between the two isolates and the above was 35 -42 %. Therefore, it is proposed to classify BBH5 and BBH7 T as belonging to a new species of Brevibacterium for which the name Brevibacterium oceani sp. nov. is proposed with BBH7 T

Current Microbiology, 2008

A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam ... more A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam forest areas of Andhra Pradesh, India. Based on analysis of D1/D2 domain sequence of 26S rRNA gene, 114 strains were identified as ascomycetous; 107 strains were identified as basidiomycetous yeasts; and 18 strains were identified as yeast-like fungi. Among the ascomycetous yeasts, 51% were identified as members of the genus Pichia, and the remaining 49% included species belonging to the genera Clavispora, Debaryomyces, Kluyveromyces, Hanseniaspora, Issatchenkia, Lodderomyces, Kodamaea, Metschnikowia, and Torulaspora. The predominant genera in the basidiomycetous yeasts were Cryptococcus (48.6%), Rhodotorula (29%), and Rhodosporidium (12.1%). The yeast-like fungi were represented by Aureobasidium pullulans (6.7%) and Lecythophora hoffmanii (0.8%). Of the 239 yeast strains tested for Xylanase, only five strains of Aureobasidium sp. produced xylanase on xylan-agar medium. Matrix-assisted laser desorption ionization-time of flight analysis and N-terminal amino-acid sequence of the xylanase of isolate YS67 showed high similarity with endo-1-4-β-xylanase (EC 3.2.1.8) of Aureobasidium pullulans var. melanigenum.

Fems Yeast Research, 2007

Three ascomycetous yeast strains were isolated from decaying green wine grapes, collected from Hy... more Three ascomycetous yeast strains were isolated from decaying green wine grapes, collected from Hyderabad city in India. Two strains, YS9 and YS21, were identified as Kodamaea ohmeri and Candida fermentati, respectively. The third strain, YS12 T

Fems Yeast Research, 2008

Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket sna... more Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket snake. The two isolates showed 100% sequence similarity in the D1/D2 domain of the large-subunit (LSU) rRNA gene, internal transcribed spacer (ITS) 1–5.8S rRNA gene–ITS2 region and mitochondrial small-subunit rRNA gene and the cytochrome oxidase II gene sequence and also showed similar phenotypic characteristics. The nearest phylogenetic neighbors of W113AT and W113B based on the sequence of the D1/D2 domain of the LSU rRNA gene were Blastobotrys chiropterorum NRRL Y-17017T and Blastobotrys terrestris NRRL Y-17704T with about 98% similarity. The close affiliation of W113AT and W113B with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T was also evident from the high similarity observed in the nucleotide sequences of the mitochondrial small subunit rRNA (96–97.8%) and the cytochrome oxidase II (95.5–95.6%) genes. In the neighbor-joining phylogenetic trees constructed based on the D1/D2 domain or cytochrome oxidase gene, the isolates clustered with the above-mentioned species. However, the isolates showed a number of differences in their phenotypic properties with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T and hence are regarded as representing a novel member of the genus Blastobotrys, for which the name Blastobotrys serpentis sp. nov. is proposed.

Current Microbiology, 2010

A total of 132 yeast strains were characterised from 4 sediment samples collected from small pudd... more A total of 132 yeast strains were characterised from 4 sediment samples collected from small puddles in the vicinity of Midre Lovénbreen glacier, Arctic. Based on the D1/D2 domain sequence similarity, the isolates could be categorised into 6 groups. The nearest phylogenetic neighbour of groups I to VI were identified as Cryptococcus gastricus, Cryptococcus terricolus, Rhodotorula muscorum, Mrakia psychrophila, Mrakia gelida and Rhodotorula glacialis, respectively. Strains representative of the six groups were psychrophilic and salt tolerant but varied in their ability to produce cold-active extracellular enzymes such as lipase, protease, pectinase, cellulase and amylase. C18:1 (w9C) and C18:2 (w9,12C) were the only two fatty acids common to all the yeasts and branched and (or) unsaturated fatty acids increased in yeasts growing at 8°C compared to 22°C, probably as an adaptation to low temperature. The present study establishes that psychrophilic yeasts are predominant in Arctic and could be used as work horses to produce cold-active enzymes and poly unsaturated fatty acids which have been implicated in low temperature adaptation and also for their use in biotechnology.

Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiac... more Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiaceae). Based on colony morphology and RAPD analysis, the strains were grouped into four groups (G-I, G-II, G-III and G-IV). Phenotypic properties and analysis of the D1/D2 domain sequence of the 26S rRNA gene identified representative members of groups G-II, G-III and G-IV as Pichia manshurica (5Pichia galeiformis), Pichia fermentans and Pichia anomala, respectively. Representatives of group G-I, YS110 T and YS111, showed similar phenotypic traits, 99.9 % similarity in the sequence of the D1/D2 domain of the 26S rRNA gene and ITS1-5.8S rRNA gene-ITS2 sequence and 92 % DNA-DNA relatedness. Hence, YS110 T and YS111 are regarded as members of the same species. Based on D1/D2 domain and ITS region sequences, the nearest phylogenetic neighbours of YS110 T and YS111 were identified as Pichia membranifaciens and P. manshurica. However, YS110 T differs from these two nearest phylogenetic neighbours by .3 % in the D1/D2 domain sequence and by .18 % with respect to the ITS region sequence. In addition, YS110 T and YS111 differ from P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T with respect to a number of phenotypic traits. The strains show 52-57 % DNA-DNA relatedness with P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T . Strains YS110 T and YS111 are proposed as two strains of a novel species, for which the name Pichia garciniae sp. nov. is proposed. The type strain is YS110 T (5NRRL Y-48422 T 5CBS 10758 T ).

Archives of Microbiology, 2007

Heavy metal content analysis of River Torsa in India did not indicate any alarming level of toxic... more Heavy metal content analysis of River Torsa in India did not indicate any alarming level of toxicity for human consumption but revealed variation at the ppb level in different months. The variation in recoverable nickel and zinc resistant copiotrophic (or eutrophic) bacterial counts was explained by the variation of the zinc content (34.0–691.3 ppb) of the river water in different sampling months. Growth studies conducted with some purified nickel and/or zinc resistant strains revealed that pre-exposure of the cells to ppb levels of Zn2+, comparable to the indigenous zinc ion concentration of the river, could induce the nickel or zinc resistance. A minimum concentration of 5–10 μM Zn2+ (325–650 ppb) was found effective in inducing the Nickel resistance of the isolates. Zinc resistance of the isolates was tested by pre-exposing the cells to 4 μM Zn2+ (260 ppb). The lag phase was reduced by 6–8 h in all the cases. Biochemical characteristics and phylogenetic analysis based on 16S rDNA sequence indicated that some of the Torsa River isolates, having inducible nickel and zinc resistance, are members of the genus Pseudomonas, Acinetobacter, Bacillus, Enterobacter, Serratia and Moraxella.

World Journal of Microbiology & Biotechnology, 2006

A gram negative, motile, short rod-shaped, and nickel resistant (tolerating 6.5 mM Ni 2+ ) bacter... more A gram negative, motile, short rod-shaped, and nickel resistant (tolerating 6.5 mM Ni 2+ ) bacterium, strain BB1A, was isolated from the waters of the River Torsa in Hashimara, Jalpaiguri district, West Bengal, India. The isolate BB1A was identified as a strain of Acinetobacter junii following detailed analysis of morphological, physio-biochemical and 16S rRNA gene sequence. The expression of nickel resistance in BB1A was inducible by exposure to nickel chloride at a concentration as low as 50 lM Ni 2+ . The other metal ions, Cu 2+ , Zn 2+ , or Pb 2+ at a concentration range of 20-30 lM, also induced the nickel resistance system in this bacterium. Southern hybridizations of BB1A genomic DNA with digoxigenin-dUTP labeled DNA probes specific for well known nickel resistance determinants, cnr, ncc or nre, resulted in no detectable signal, but nir specific probe yielded weak hybridization signal with restricted genomic DNA of BB1A. The isolate BB1A, therefore, carries out a novel induction phenomenon of nickel resistance and presumably with a nickel resistance genetic system different from that previously characterized in other bacteria. 2003). The nreB of A. xylosoxidans 31A was specifically

International Journal of Systematic and Evolutionary Microbiology, 2005

A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain N... more A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain NiVa 51 T , was isolated from water of the River Torsa in Hasimara, Jalpaiguri district, West Bengal, India. On the basis of 16S rRNA gene sequence similarity, strain NiVa 51 T was shown to belong to the c-Proteobacteria and to be related to Serratia marcescens subsp. sakuensis (98?35 %) and S. marcescens subsp. marcescens (98?30 %); however, strain NiVa 51 T exhibited only 43?7 % similarity to S. marcescens by DNA-DNA hybridization. The G+C content of the genomic DNA of the isolate was 60 mol%. Both biochemical characteristics and fatty acid analysis data supported the affiliation of strain NiVa 51 T to the genus Serratia. Furthermore, strain NiVa 51 T was found to utilize urea as nitrogen source. The results of DNA-DNA hybridization as well as physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NiVa 51 T from recognized Serratia species. Strain NiVa 51 T therefore represents a novel species, for which the name Serratia ureilytica sp. nov. is proposed, with type strain NiVa 51 T (=LMG 22860 T =CCUG 50595 T ).

International Journal of Systematic and Evolutionary Microbiology, 2007

Two bacterial strains, BBH6 T and BBH9, were isolated from a deep-sea sediment sample collected f... more Two bacterial strains, BBH6 T and BBH9, were isolated from a deep-sea sediment sample collected from the Chagos Trench, Indian Ocean, at a depth of 5904 m. The two strains were closely related in their 16S rRNA gene sequences (99.7 %), belonged to one genomic species and were virtually identical at the phenotypic level. Microbacterium barkeri DSM 20145 T was the nearest phylogenetic neighbour to the new isolates, with 16S rRNA gene sequence similarity levels of 97.2-97.4 %. The new isolates exhibited levels of DNA-DNA relatedness of 32-34 % to M. barkeri and differed from it in a number of phenotypic characteristics. Therefore, it is suggested that strains BBH6 T and BBH9 represent a novel species of the genus Microbacterium, for which the name Microbacterium indicum sp. nov. is proposed. The type strain is BBH6 T (5LMG 23459 T 5IAM 15355 T ).

International Journal of Systematic and Evolutionary Microbiology, 2009

A novel aerobic, obligately mixotrophic, moderately thermophilic, thiosulfate-oxidizing bacterium... more A novel aerobic, obligately mixotrophic, moderately thermophilic, thiosulfate-oxidizing bacterium, S10 T , was isolated from hot-spring sediment samples collected from Atri, Bhubaneswar, India. The cells of this isolate stained Gram-negative and were strictly aerobic, non-sporulating, rodshaped and motile with a single polar flagellum. Strain S10 T was positive for oxidase and catalase activities. It was capable of utilizing thiosulfate under mixotrophic growth conditions. Mixotrophic growth was observed at pH 6.0-8.5 and 25-45 6C; optimum growth occurred at pH 7.5-8.0 and 30-37 6C. The major cellular fatty acids were C 12 : 0 3-OH, C 16 : 1 v7c, C 16 : 0 , C 17 : 0 cyclo, C 18 : 1 v7c and C 19 : 0 cyclo v8c. The DNA G+C content of strain S10 T was 64.8 mol%. 16S rRNA gene sequence analysis indicated that the bacterium clustered within the radiation of the genus Thiomonas and showed 98.0 % similarity with Thiomonas perometabolis ATCC 23370 T and Thiomonas intermedia ATCC 15466 T . However, DNA-DNA reassociation values of strain S10 T with Thiomonas perometabolis JCM 20426 T and Thiomonas intermedia JCM 20425 T , its nearest phylogenetic relatives, were 46 and 39 %, respectively. On the basis of phenotypic, physiological and chemotaxonomic properties, 16S rRNA gene sequence analysis and DNA-DNA reassociation studies, it is proposed that strain S10 T represents a novel species of the genus Thiomonas, Thiomonas bhubaneswarensis sp. nov.; the type strain is S10 T (5DSM 18181 T 5JCM 14806 T ).

International Journal of Systematic and Evolutionary Microbiology, 2008

A novel psychrophilic bacterium, designated strain DVS 3Y T , was isolated from a moraine sample ... more A novel psychrophilic bacterium, designated strain DVS 3Y T , was isolated from a moraine sample from the McMurdo Dry Valleys, Antarctica. Phenotypic and chemotaxonomic characteristics and data from a phylogenetic analysis based on 16S rRNA gene sequences indicated that strain DVS 3Y T was related to the genus Exiguobacterium. Strain DVS 3Y T exhibited .97 % gene sequence similarity with respect to Exiguobacterium acetylicum DSM 20416 T (97.4 %), Exiguobacterium oxidotolerans DSM 17272 T (97.4 %), Exiguobacterium indicum IAM 15368 T (97.6 %), Exiguobacterium undae DSM 14481 T (98.2 %), Exiguobacterium sibiricum DSM 17290 T (98.6 %) and Exiguobacterium antarcticum DSM 14480 T (99.6 %). However, the levels of DNA-DNA relatedness between strain DVS 3Y T and E. acetylicum DSM 20416 T , E. oxidotolerans JCM 12280 T , E. indicum IAM 15368 T , E. undae DSM 14481 T , E. sibiricum DSM 17290 T and E. antarcticum DSM 14480 T were less than 70 % (52, 25, 16, 33, 16 and 38 %, respectively). Strain DVS 3Y T also differed from these six closely related species in a number of phenotypic traits. Phenotypic, chemotaxonomic and phylogenetic data suggest that strain DVS 3Y T represents a novel species of the genus Exiguobacterium, for which the name Exiguobacterium soli sp. nov. is proposed. The type strain is DVS 3Y T (5MTCC 4816 T 5JCM 14376 T ).

International Journal of Systematic and Evolutionary Microbiology, 2008

Pichia garciniae sp. nov., isolated from a rotten mangosteen fruit (Garcinia mangostana L., Clusi... more Pichia garciniae sp. nov., isolated from a rotten mangosteen fruit (Garcinia mangostana L., Clusiaceae) Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiaceae). Based on colony morphology and RAPD analysis, the strains were grouped into four groups (G-I, G-II, G-III and G-IV). Phenotypic properties and analysis of the D1/D2 domain sequence of the 26S rRNA gene identified representative members of groups G-II, G-III and G-IV as Pichia manshurica (5Pichia galeiformis), Pichia fermentans and Pichia anomala, respectively. Representatives of group G-I, YS110 T and YS111, showed similar phenotypic traits, 99.9 % similarity in the sequence of the D1/D2 domain of the 26S rRNA gene and ITS1-5.8S rRNA gene-ITS2 sequence and 92 % DNA-DNA relatedness. Hence, YS110 T and YS111 are regarded as members of the same species. Based on D1/D2 domain and ITS region sequences, the nearest phylogenetic neighbours of YS110 T and YS111 were identified as Pichia membranifaciens and P. manshurica. However, YS110 T differs from these two nearest phylogenetic neighbours by .3 % in the D1/D2 domain sequence and by .18 % with respect to the ITS region sequence. In addition, YS110 T and YS111 differ from P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T with respect to a number of phenotypic traits. The strains show 52-57 % DNA-DNA relatedness with P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T . Strains YS110 T and YS111 are proposed as two strains of a novel species, for which the name Pichia garciniae sp. nov. is proposed. The type strain is YS110 T (5NRRL Y-48422 T 5CBS 10758 T ).

Fems Yeast Research, 2007

The ascogenous yeast YS16T was isolated from a decaying papaya fruit. Phenotypic traits such as m... more The ascogenous yeast YS16T was isolated from a decaying papaya fruit. Phenotypic traits such as multilateral budding, spheroidal or elongate shape, pseudohyphae formation, asci with one or more ascospores, ability to ferment d-glucose, inability to assimilate nitrate and the presence of Q7 ubiquinone suggest its affiliation to the genus Pichia. The nearest phylogenetic neighbor, based on D1/D2 domain sequence of the 26S rRNA gene and ITS region sequence, was identified as Issatchenkia orientalis (NRRL Y-5396T, a synonym of Pichia kudriavzevii) with similarities of 98.2% and 97% respectively. In addition to the difference in the D1/D2 and ITS region sequence, YS16T differs from I. orientalis with respect to a number of phenotypic traits. However, in the phylogenetic analysis, YS16T showed close relatedness to the P. membranifaciens clade. Thus, it is proposed to assign the status of a new species to YS16T, for which the name P. cecembensis sp. nov. is proposed. The type strain of P. cecembensis sp. nov. is YS16T (=NRRL Y-27985T=JCM 13873T=CBS 10445T).

Letters in Applied Microbiology, 2008

Aims: Isolation and identification of yeasts converting xylose to ethanol.Methods and Results: ... more Aims: Isolation and identification of yeasts converting xylose to ethanol.Methods and Results: A total of 374 yeasts were isolated from a variety of rotten fruits and barks of trees. Out of these, 27 yeast strains were able to assimilate xylose and produce 0·12–0·38 g of ethanol per gram of xylose. Based on phylogenetic analysis of D1/D2 domain sequence of LSU (Large Subunit) rRNA gene and phenotypic characteristics the ethanol-producing strains were identified as member(s) of the genera Pichia, Candida, Kluyveromyces, Issatchenkia, Zygosacchraomyces, Clavispora, Debaryomyces, Metschnikowia, Rhodotorula and Cryptococcus.Conclusion: Yeast strains producing ethanol from xylose have been isolated from a variety of rotten fruits and barks of trees and identified.Significance and Impact of the Study: Environmental isolates of yeasts which could convert xylose to ethanol could form the basis for bio-fuel production and proper utilization of xylan rich agricultural and forest wastes.

Current Microbiology, 2007

A total of 35 yeasts were isolated from the gut of beetles collected from Hyderabad city, India. ... more A total of 35 yeasts were isolated from the gut of beetles collected from Hyderabad city, India. Twenty of these yeasts utilized xylose as a sole carbon source but only 12 of these converted xylose to xylitol. The ability to convert xylose to xylitol varied among the isolates and ranged from 0.12 to 0.58 g/g xylose. Based on the phenotypic characteristics and phylogenetic analysis of the D1/D2 domain sequence of 26S rRNA gene, these isolates were identified as members of Pichia, Candida, Issatchenkia, and Clavispora. Strain YS 54 (CBS 10446), which was phylogenetically similar to Pichia caribbica and which formed hat-shaped ascospore characteristics of the genus Pichia, was the best xylitol producer (0.58 g xylitol/g xylose). YS 54 was also capable of producing xylitol from sugarcane bagasse hydrolysate and the efficiency of conversion was 0.32 g xylitol/g xylose after 20 cycles of adaptation in medium containing sugarcane bagasse hydrolysate.

Extremophiles, 2008

Twenty-five psychrophilic yeasts were isolated from the soil of Roopkund Lake, Himalayas, India. ... more Twenty-five psychrophilic yeasts were isolated from the soil of Roopkund Lake, Himalayas, India. Two colony morphotypes were identified and representatives of ‘morphotype 1’ were identified as Cryptococcus gastricus. Representatives of ‘morphotype 2’, namely 3AT, 4A, 4B and Rup4B, showed similar phenotypic properties and are identical with respect to the nucleotide sequence of the ITS1-5.8S rRNA gene-ITS2 region and D1/D2 domain of the 26S rRNA gene. The sequence of D1/D2 domain of 3AT shows 97.6–98.8% similarity with Rhodotorula psychrophila CBS10440T, Rhodotorula glacialis CBS10437T and Rhodotorula psychrophenolica CBS10438T and in the neighbour-joining phylogenetic tree strains; 3AT, 4A, 4B and Rup4B form a cluster with Rhodotorula glacialis and Rhodotorula psychrophila. Strains 3AT, 4A, 4B and Rup4B also differ from their nearest phylogenetic relatives in several biochemical characteristics such as in assimilation of d-galactose, l-sorbose, maltose, citrate, d-glucuronate and creatinine. Thus, based on the phylogenetic analysis and the phenotypic differences 3AT, 4A, 4B and Rup 4B are assigned the status of a new species of Rhodotorula for which the name Rhodotorula himalayensis sp. nov. is proposed with 3AT as the type strain (=CBS10539T =MTCC8336T).

International Journal of Systematic and Evolutionary Microbiology, 2008

Brevibacterium oceani sp. nov. from Indian Ocean Subject category New taxa -Actinobacteria GenBan... more Brevibacterium oceani sp. nov. from Indian Ocean Subject category New taxa -Actinobacteria GenBank/ EMBL accession numbers for the 16S rRNA gene sequence of Brevibacterium oceani sp. nov. BBH7 T and BBH5 are AM158906 and AM158905 respectively. Abstract Two bacterial strains BBH5 and BBH87 T were isolated from a deep-sea sediment sample collected from the Chagos Trench of the Indian Ocean (11 º 06 ' S, 72 º 31 ' E). Both the strains, based on their 16S rRNA gene sequence similarity (99.9 %), DNA-DNA relatedness (93 %) and a number of similar phenotypic characteristics are identified as strains of the same species. The phylogenetically nearest species of BBH5 and BBH7 T based on 16S rRNA gene sequence similarity (97.9 -98.4 %) were identified as Brevibacterium iodinum, Brevibacterium epidermidis, Brevibacterium linens and Brevibacterium permense. However, BBH5 and BBH7 T differ from the above four nearest phylogenetic relatives by a number of phenotypic characteristics and the DNA-DNA similarity between the two isolates and the above was 35 -42 %. Therefore, it is proposed to classify BBH5 and BBH7 T as belonging to a new species of Brevibacterium for which the name Brevibacterium oceani sp. nov. is proposed with BBH7 T

Current Microbiology, 2008

A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam ... more A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam forest areas of Andhra Pradesh, India. Based on analysis of D1/D2 domain sequence of 26S rRNA gene, 114 strains were identified as ascomycetous; 107 strains were identified as basidiomycetous yeasts; and 18 strains were identified as yeast-like fungi. Among the ascomycetous yeasts, 51% were identified as members of the genus Pichia, and the remaining 49% included species belonging to the genera Clavispora, Debaryomyces, Kluyveromyces, Hanseniaspora, Issatchenkia, Lodderomyces, Kodamaea, Metschnikowia, and Torulaspora. The predominant genera in the basidiomycetous yeasts were Cryptococcus (48.6%), Rhodotorula (29%), and Rhodosporidium (12.1%). The yeast-like fungi were represented by Aureobasidium pullulans (6.7%) and Lecythophora hoffmanii (0.8%). Of the 239 yeast strains tested for Xylanase, only five strains of Aureobasidium sp. produced xylanase on xylan-agar medium. Matrix-assisted laser desorption ionization-time of flight analysis and N-terminal amino-acid sequence of the xylanase of isolate YS67 showed high similarity with endo-1-4-β-xylanase (EC 3.2.1.8) of Aureobasidium pullulans var. melanigenum.

Fems Yeast Research, 2007

Three ascomycetous yeast strains were isolated from decaying green wine grapes, collected from Hy... more Three ascomycetous yeast strains were isolated from decaying green wine grapes, collected from Hyderabad city in India. Two strains, YS9 and YS21, were identified as Kodamaea ohmeri and Candida fermentati, respectively. The third strain, YS12 T

Fems Yeast Research, 2008

Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket sna... more Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket snake. The two isolates showed 100% sequence similarity in the D1/D2 domain of the large-subunit (LSU) rRNA gene, internal transcribed spacer (ITS) 1–5.8S rRNA gene–ITS2 region and mitochondrial small-subunit rRNA gene and the cytochrome oxidase II gene sequence and also showed similar phenotypic characteristics. The nearest phylogenetic neighbors of W113AT and W113B based on the sequence of the D1/D2 domain of the LSU rRNA gene were Blastobotrys chiropterorum NRRL Y-17017T and Blastobotrys terrestris NRRL Y-17704T with about 98% similarity. The close affiliation of W113AT and W113B with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T was also evident from the high similarity observed in the nucleotide sequences of the mitochondrial small subunit rRNA (96–97.8%) and the cytochrome oxidase II (95.5–95.6%) genes. In the neighbor-joining phylogenetic trees constructed based on the D1/D2 domain or cytochrome oxidase gene, the isolates clustered with the above-mentioned species. However, the isolates showed a number of differences in their phenotypic properties with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T and hence are regarded as representing a novel member of the genus Blastobotrys, for which the name Blastobotrys serpentis sp. nov. is proposed.

Current Microbiology, 2010

A total of 132 yeast strains were characterised from 4 sediment samples collected from small pudd... more A total of 132 yeast strains were characterised from 4 sediment samples collected from small puddles in the vicinity of Midre Lovénbreen glacier, Arctic. Based on the D1/D2 domain sequence similarity, the isolates could be categorised into 6 groups. The nearest phylogenetic neighbour of groups I to VI were identified as Cryptococcus gastricus, Cryptococcus terricolus, Rhodotorula muscorum, Mrakia psychrophila, Mrakia gelida and Rhodotorula glacialis, respectively. Strains representative of the six groups were psychrophilic and salt tolerant but varied in their ability to produce cold-active extracellular enzymes such as lipase, protease, pectinase, cellulase and amylase. C18:1 (w9C) and C18:2 (w9,12C) were the only two fatty acids common to all the yeasts and branched and (or) unsaturated fatty acids increased in yeasts growing at 8°C compared to 22°C, probably as an adaptation to low temperature. The present study establishes that psychrophilic yeasts are predominant in Arctic and could be used as work horses to produce cold-active enzymes and poly unsaturated fatty acids which have been implicated in low temperature adaptation and also for their use in biotechnology.

Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiac... more Ascogenous yeasts were isolated from a decaying mangosteen fruit (Garcinia mangostana L., Clusiaceae). Based on colony morphology and RAPD analysis, the strains were grouped into four groups (G-I, G-II, G-III and G-IV). Phenotypic properties and analysis of the D1/D2 domain sequence of the 26S rRNA gene identified representative members of groups G-II, G-III and G-IV as Pichia manshurica (5Pichia galeiformis), Pichia fermentans and Pichia anomala, respectively. Representatives of group G-I, YS110 T and YS111, showed similar phenotypic traits, 99.9 % similarity in the sequence of the D1/D2 domain of the 26S rRNA gene and ITS1-5.8S rRNA gene-ITS2 sequence and 92 % DNA-DNA relatedness. Hence, YS110 T and YS111 are regarded as members of the same species. Based on D1/D2 domain and ITS region sequences, the nearest phylogenetic neighbours of YS110 T and YS111 were identified as Pichia membranifaciens and P. manshurica. However, YS110 T differs from these two nearest phylogenetic neighbours by .3 % in the D1/D2 domain sequence and by .18 % with respect to the ITS region sequence. In addition, YS110 T and YS111 differ from P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T with respect to a number of phenotypic traits. The strains show 52-57 % DNA-DNA relatedness with P. membranifaciens NRRL Y-2026 T and P. manshurica NRRL Y-27978 T . Strains YS110 T and YS111 are proposed as two strains of a novel species, for which the name Pichia garciniae sp. nov. is proposed. The type strain is YS110 T (5NRRL Y-48422 T 5CBS 10758 T ).