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Dive into the research topics where Namita Nayyar is active.

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Featured researches published by Namita Nayyar.


International Journal of Systematic and Evolutionary Microbiology | 2015

Parapedobacter indicus sp. nov., isolated from hexachlorocyclohexane-contaminated soil

Roshan Kumar; Vatsala Dwivedi; Namita Nayyar; Helianthous Verma; Amit Kumar Singh; Pooja Rani; D. L. N. Rao; Rup Lal

Strain RK1(T), a Gram-stain-negative, non-spore-forming, rod-shaped, non-motile bacterium was isolated from a hexachlorocyclohexane (HCH) dumpsite, Lucknow, India. 16S rRNA gene sequence analysis revealed that strain RK1(T) belongs to the family Sphingobacteriaceae and showed highest sequence similarity to Parapedobacter koreensis Jip14(T) (95.63%). The major cellular fatty acids of strain RK1(T) were iso-C15:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C17:0 3-OH, summed feature 9 (10-methyl C16:0 and/or iso-C17:1ω9c), iso-C15:0 3-OH and C16 : 0. The major respiratory pigment and polyamine of RK1(T) were menaquinone (MK-7) and homospermidine, respectively. The main polar lipids were phosphatidylethanolamine and sphingolipid. The G+C content of the DNA was 44.5 mol%. The results of physiological and biochemical tests and 16S rRNA sequence analysis clearly demonstrated that strain RK1(T) represents a novel species of the genus Parapedobacter, for which the name Parapedobacter indicus sp. nov. is proposed. The type strain is RK1(T) ( = DSM 28470(T) =MCC 2546(T)).


International Journal of Systematic and Evolutionary Microbiology | 2016

Pontibacter ummariensis sp. nov., isolated from a hexachlorocyclohexane contaminated soil.

Nitish Kumar Mahato; Charu Tripathi; Namita Nayyar; Amit Kumar Singh; Rup Lal

A Gram-stain-negative, pinkish-red, rod-shaped bacterium designated strain NKM1T was isolated from soil samples contaminated with hexachlorocyclohexane isomers, collected from Ummari village, Lucknow, Uttar Pradesh, India. The strain was characterized by a polyphasic taxonomic approach. 16S rRNA gene sequence analysis showed that strain NKM1T clustered exclusively with members of the genus Pontibacter of the family Cytophagaceae, phylum Bacteroidetes. The 16S rRNA gene sequence similarity to type strains of the genus Pontibacter ranged from 96.7 to 93.8 %, with the highest sequence similarity found with Pontibacter odishensis JC130T (96.7 %). Cells of strain NKM1T were aerobic, non-flagellated and non-motile. Strain NKM1T was catalase- and oxidase-positive but negative for nitrate reduction and hydrolysis of gelatin. The major fatty acids in strain NKM1T were anteiso-C15 : 0, iso-C15 : 0, C16 : 0, C18 : 1ω9c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipid profile of strain NKM1T showed the presence of phosphatidylethanolamine and unknown glycolipids as well as aminolipids. sym-Homospermidine was found to be the major polyamine and menaquinone 7 (MK-7) was the major respiratory quinone. The DNA G+C content of strain NKM1T was determined to be 58.6 mol%. Based on phenotypic, chemotaxonomic, physiological and biochemical evidence, it is proposed that isolate NKM1T represents a novel species that belongs to the genus Pontibacter, for which the name Pontibacter ummariensis sp. nov. is proposed. The type strain is NKM1T ( = DSM 100161T = KCTC 42944T = MCC 2777T).


International Journal of Systematic and Evolutionary Microbiology | 2016

Pontibacter mucosus sp. nov., isolated from hexachlorocyclohexane-contaminated pond sediment.

Namita Nayyar; Puneet Kohli; Nitish Kumar Mahato; Rup Lal

A halotolerant, Gram-stain-negative, rod-shaped and light-pink-pigmented bacterial strain, PB3T, was isolated from a pond sediment near a hexachlorocyclohexane-producing factory, located at Chinhat, Lucknow, India. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PB3T formed a distinct phyletic clade along with the members of the genus Pontibacter. The 16S rRNA gene sequence similarity with other members of the genus Pontibacter ranged from 94.5 to 98.9 %. The cells were motile, aerobic, and catalase- and oxidase-positive. The major fatty acids were iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C16:1ω5c, summed feature 3 (C16:1ω6c/C16:1ω7c) and summed feature 4 (iso-C17:1I/ anteiso-C17:1 B). The polar lipid profile of strain PB3T showed the presence of phosphatidylethanolamine, an unidentified aminophospholipid, unknown aminolipids and other unknown polar lipids. DNA-DNA hybridization based homology of strain PB3T with respect to its most closely related species, Pontibacter chinhatensis LP51T, was 44.7 %. The DNA G+C content was 53.5 mol%. On the basis of these data, it is proposed that the isolate belongs to the genus Pontibacter and represents a novel species, for which the name Pontibacter mucosus is proposed. The type strain is PB3T (=DSM 100162T=KCTC 42942T).


Genome Announcements | 2013

Genome Sequence of Novosphingobium lindaniclasticum LE124T, Isolated from a Hexachlorocyclohexane Dumpsite

Anjali Saxena; Namita Nayyar; Naseer Sangwan; Rashmi Kumari; Jitendra P. Khurana; Rup Lal

ABSTRACT Novosphingobium lindaniclasticum LE124T is a hexachlorocyclohexane (HCH)-degrading bacterium isolated from a high-dosage-point HCH dumpsite (450 mg HCH/g soil) located in Lucknow, India (27°00′N and 81°09′E). Here, we present the annotated draft genome sequence of strain LE124T, which has an estimated size of 4.86 Mb and is comprised of 4,566 coding sequences.


International Journal of Systematic and Evolutionary Microbiology | 2016

Algoriphagus roseus sp. nov., isolated from a hexachlorocyclohexane contaminated dumpsite.

Puneet Kohli; Namita Nayyar; Anukriti Sharma; Amit Kumar Singh; Rup Lal

A Gram-staining negative, reddish-pink, non-motile, rod-shaped bacterial strain designated W29T, was isolated from a hexachlorocyclohexane-contaminated dumpsite located in the northern part of India at Ummari Village, Lucknow. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain W29T formed a lineage within the genus Algoriphagusand exhibited highest sequence similarity to Algoriphagus trabzonensis MS7T (98.8 %), followed by Algoriphagusalkaliphilus AC-74T (97.1 %). The 16S rRNA gene sequence similarity between strain W29T and other species of the genus Algoriphagusranged from 93.3-98.8 %. The DNA-DNA relatedness between strain W29T and A. trabzonensisMS7T was 47 % and with other related strains was found to be less than 45 %, confirming strain W29T represents a novel species. The DNA G+C content of strain W29T was 46.2 mol%. Strain W29T was oxidase- and catalase-positive. The major fatty acids (>10 %) of strain W29T were iso-C15 : 0, summed feature 9 (comprising 10-methyl C16 : 0 and/or iso-C17 : 1ω9c) and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). The respiratory quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, two unidentified aminolipids, an unidentified aminophospholipid, an unidentified phospholipid and unidentified lipids. On the basis of the results obtained from DNA-DNA hybridization, and biochemical and physiological tests in this study, strain W29T represents a novel species of the genus Algoriphagus for which the name Algoriphagus roseus sp. nov. is proposed. The type strain is W29T (=KCTC 42940T=MCC 2876T=DSM 100160T).


Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology | 2017

Microbial taxonomy in the era of OMICS: application of DNA sequences, computational tools and techniques

Nitish Kumar Mahato; Vipin Gupta; Priya Singh; Rashmi Kumari; Helianthous Verma; Charu Tripathi; Pooja Rani; Anukriti Sharma; Nirjara Singhvi; Utkarsh Sood; Princy Hira; Puneet Kohli; Namita Nayyar; Akshita Puri; Abhay Bajaj; Roshan Kumar; Vivek Negi; Chandni Talwar; Himani Khurana; Shekhar Nagar; Monika Sharma; Harshita Mishra; Amit Kumar Singh; Gauri Dhingra; Ram Krishan Negi; Mallikarjun Shakarad; Yogendra Singh; Rup Lal

The current prokaryotic taxonomy classifies phenotypically and genotypically diverse microorganisms using a polyphasic approach. With advances in the next-generation sequencing technologies and computational tools for analysis of genomes, the traditional polyphasic method is complemented with genomic data to delineate and classify bacterial genera and species as an alternative to cumbersome and error-prone laboratory tests. This review discusses the applications of sequence-based tools and techniques for bacterial classification and provides a scheme for more robust and reproducible bacterial classification based on genomic data. The present review highlights promising tools and techniques such as ortho-Average Nucleotide Identity, Genome to Genome Distance Calculator and Multi Locus Sequence Analysis, which can be validly employed for characterizing novel microorganisms and assessing phylogenetic relationships. In addition, the review discusses the possibility of employing metagenomic data to assess the phylogenetic associations of uncultured microorganisms. Through this article, we present a review of genomic approaches that can be included in the scheme of taxonomy of bacteria and archaea based on computational and in silico advances to boost the credibility of taxonomic classification in this genomic era.


Genome Biology and Evolution | 2017

Genome Organization of Sphingobium indicum B90A: An Archetypal Hexachlorocyclohexane (HCH) Degrading Genotype

Helianthous Verma; Abhay Bajaj; Roshan Kumar; Jasvinder Kaur; Shailly Anand; Namita Nayyar; Akshita Puri; Yogendra Singh; Jitendra P. Khurana; Rup Lal

Abstract Among sphingomonads, Sphingobium indicum B90A is widely investigated for its ability to degrade a manmade pesticide, γ-hexachlorocyclohexane (γ-HCH) and its isomers (α-, β-, δ-, and ε-HCH). In this study, complete genome of strain B90A was constructed using Single Molecule Real Time Sequencing (SMRT) and Illumina platform. The complete genome revealed that strain B90A harbors four replicons: one chromosome (3,654,322 bp) and three plasmids designated as pSRL1 (139,218 bp), pSRL2 (108,430 bp) and pSRL3 (43,761 bp). The study determined the precise location of lin genes (genes associated with the degradation of HCH isomers), for example, linA2, linB, linDER, linF, linGHIJ, and linKLMN on the chromosome; linA1, linC, and linF on pSRL1 and linDEbR on pSRL3. Strain B90A contained 26 copies of IS6100 element and most of them (15 copies) was found to be associated with lin genes. Duplication of several lin genes including linA, linDER, linGHIJ, and linF along with two variants of linE, that is, linEa (hydroquinone 1,2-dioxygenase) and linEb (chlorohydroquinone/hydroquinone 1,2-dioxygenase) were identified. This suggests that strain B90A not only possess efficient machinery for upper and lower HCH degradation pathways but it can also act on both hydroquinone and chlorohydroquinone metabolites produced during γ-HCH degradation. Synteny analysis revealed the duplication and transposition of linA gene (HCH dehydrochlorinase) between the chromosome and pSRL1, possibly through homologous recombination between adjacent IS6100 elements. Further, in silico analysis and laboratory experiments revealed that incomplete tyrosine metabolism was responsible for the production of extracellular brown pigment which distinguished strain B90A from other HCH degrading sphingomonads. The precise localization of lin genes, and transposable elements (IS6100) on different replicons now opens up several experimental avenues to elucidate the functions and regulatory mechanism of lin genes acquisition and transfer that were not completely known among the bacterial population inhabiting the HCH contaminated environment.


International Journal of Systematic and Evolutionary Microbiology | 2016

Pontibacter virosus sp. nov., isolated from a hexachlorocyclohexane-contaminated dumpsite.

Puneet Kohli; Namita Nayyar; Anukriti Sharma; Amit Kumar Singh; Rup Lal

A Gram-staining-negative, red-pigmented, motile, rod-shaped bacterial strain, designated as W14T, was isolated from a hexachlorocyclohexane-contaminated dumpsite located in the northern part of India at Ummari Village, Lucknow. Phylogenetic analysis based on 16S rRNA gene sequence showed that the strain belongs to the genus Pontibacter with highest sequence similarity to Pontibacter lucknowensis DM9T (98.1 %). The 16S rRNA gene sequence similarity between strain W14T and members of other species of the genus Pontibacter ranged from 98.1 to 94.2 %. The DNA-DNA relatedness between strain W14T and P. lucknowensis DM9T was 33.7 % and with other closely related strains was found to be less than 20 %, confirming it to represent a novel species. The DNA G+C content of strain W14T was 51.3 mol%. Strain W14T was oxidase- and catalase-positive. The predominant cellular fatty acids were summed feature 4 (C17 : 1 iso I/anteiso B and C17 : 1 anteiso B/iso I), iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile of strain W14T consisted of phosphatidylethanolamine, diphosphatidylglycerol, aminolipid and glycolipid. On the basis of the results obtained from DNA-DNA hybridization, biochemical and physiological tests in this study, strain W14T represents a novel species of the genus Pontibacter, for which the name Pontibacter virosus sp. nov. is proposed. The type strain is W14T (=MCC 2932T=DSM 100231T=KCTC 42941T).


International Journal of Systematic and Evolutionary Microbiology | 2017

Pontibacter aurantiacus sp. nov. isolated from hexachlorocyclohexane (HCH) contaminated soil

Priya Singh; Rashmi Kumari; Namita Nayyar; Rup Lal

Strain NP1T, a Gram-stain-negative, orange, rod-shaped bacterium was isolated from hexacholorocyclohexane (HCH)-contaminated soil sediment samples collected from Ummari village, Lucknow, Uttar Pradesh, India. The results of 16S rRNA gene sequence analysis indicated that NP1T clustered with members of the genus Pontibacter of the order Cytophagales, family Cytophagaceae and phylum Bacteriodetes. The 16S rRNA gene sequence similarity with type strains of members of the genus Pontibacter ranged from 98.57 to 93.95 % with Pontibacter odishensis JC-130T (98.57 %), Pontibacter korlensis X14-1T (97.82 %), Pontibacter litorisediminisYKTF-7T (97.42 %) and Pontibacter virosus W-14T (97.01 %) as the closest neighbours. Cells of NP1T were aerobic, motile and oxidase- and catalase-positive. NP1T was capable of hydrolysis of gelatin, aesculin and starch and reduced nitrates to nitrogen. The major fatty acids of NP1T were summed feature 4 and iso-C15 : 0. The polar lipid profile of NP1T showed the presence of phosphatidylethanolamine (PE), unknown glycolipids and unknown aminolipids. Menaquinone-7 (MK-7) was the predominant respiratory quinone and sym-homospermidine was found to be the predominant polyamine in NP1T. The DNA G+C content of NP1T was 52.1±0.7 mol%. The levels of DNA-DNA relatedness of NP1T to P. odishensis JC-130T, P. korlensis X14-1T, P. litorisediminis YKTF-7T and P. virosus W14T were 44.9±0.6 %, 40.5±0.4 %, 34.4±0.7 % and 33.4±0.5 % respectively. Based on the phenotypic, chemotaxonomic, physiological and biochemical evidence and DNA-DNA hybridization results, it is proposed that NP1T represents a novel species of the genus Pontibacter, for which the name Pontibacter aurantiacus sp. nov. is proposed. The type strain is NP1T (KCTC 42943T=CCM 8697T=MCC 2931T).


Genome Announcements | 2014

Draft Genome Sequence of Pseudomonas sp. Strain JMM, a Sediment-Hosted Environmental Isolate

Simmi Grewal; Jyoti Vakhlu; Vipin Gupta; Naseer Sangwan; Puneet Kohli; Namita Nayyar; Pooja Rani; Shivani Singh Sance; Rup Lal

ABSTRACT Pseudomonas sp. strain JMM was isolated from the sediments of a natural water reservoir (pH, 6 to 7) located at Chambyal village in Samba district of Jammu and Kashmir, India. Here we report the annotated draft genome sequence of strain JMM having 52 contigs with 5,884 genes and an average G+C content of 66.5%.

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