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1.
Indian J Microbiol ; 62(3): 323-337, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35974919

RESUMO

A rigorous exploration of microbial diversity has revealed its presence on Earth, deep oceans, and vast space. The presence of microbial life in diverse environmental conditions, ranging from moderate to extreme temperature, pH, salinity, oxygen, radiations, and altitudes, has provided the necessary impetus to search for them by extending the limits of their habitats. Microbiology started as a distinct science in the mid-nineteenth century and has provided inputs for the betterment of mankind during the last 150 years. As beneficial microbes are assets and pathogens are detrimental, studying both have its own merits. Scientists are nowadays working on illustrating the microbial dynamics in Earth's subsurface, deep sea, and polar regions. In addition to studying the role of microbes in the environment, the microbe-host interactions in humans, animals and plants are also unearthing newer insights that can help us to improve the health of the host by modulating the microbiota. Microbes have the potential to remediate persistent organic pollutants. Antimicrobial resistance which is a serious concern can also be tackled only after monitoring the spread of resistant microbes using disciplines of genomics and metagenomics The cognizance of microbiology has reached the top of the world. Space Missions are now looking for signs of life on the planets (specifically Mars), the Moon and beyond them. Among the most potent pieces of evidence to support the existence of life is to look for microbial, plant, and animal fossils. There is also an urgent need to deliberate and communicate these findings to layman and policymakers that would help them to take an adequate decision for better health and the environment around us. Here, we present a glimpse of recent advancements by scientists from around the world, exploring and exploiting microbial diversity.

4.
Antonie Van Leeuwenhoek ; 110(10): 1357-1371, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28831610

RESUMO

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.


Assuntos
Archaea/classificação , Bactérias/classificação , Técnicas de Tipagem Bacteriana , Biologia Computacional , Genômica , Genoma Arqueal/genética , Genoma Bacteriano/genética , Metagenoma , Anotação de Sequência Molecular , Filogenia
5.
Front Microbiol ; 8: 1410, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28798737

RESUMO

Thermophilic environments represent an interesting niche. Among thermophiles, the genus Thermus is among the most studied genera. In this study, we have sequenced the genome of Thermus parvatiensis strain RL, a thermophile isolated from Himalayan hot water springs (temperature >96°C) using PacBio RSII SMRT technique. The small genome (2.01 Mbp) comprises a chromosome (1.87 Mbp) and a plasmid (143 Kbp), designated in this study as pTP143. Annotation revealed a high number of repair genes, a squeezed genome but containing highly plastic plasmid with transposases, integrases, mobile elements and hypothetical proteins (44%). We performed a comparative genomic study of the group Thermus with an aim of analysing the phylogenetic relatedness as well as niche specific attributes prevalent among the group. We compared the reference genome RL with 16 Thermus genomes to assess their phylogenetic relationships based on 16S rRNA gene sequences, average nucleotide identity (ANI), conserved marker genes (31 and 400), pan genome and tetranucleotide frequency. The core genome of the analyzed genomes contained 1,177 core genes and many singleton genes were detected in individual genomes, reflecting a conserved core but adaptive pan repertoire. We demonstrated the presence of metagenomic islands (chromosome:5, plasmid:5) by recruiting raw metagenomic data (from the same niche) against the genomic replicons of T. parvatiensis. We also dissected the CRISPR loci wide all genomes and found widespread presence of this system across Thermus genomes. Additionally, we performed a comparative analysis of competence loci wide Thermus genomes and found evidence for recent horizontal acquisition of the locus and continued dispersal among members reflecting that natural competence is a beneficial survival trait among Thermus members and its acquisition depicts unending evolution in order to accomplish optimal fitness.

6.
Stand Genomic Sci ; 11(1): 64, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27610214

RESUMO

Lampropedia cohaerens strain CT6(T), a non-motile, aerobic and coccoid strain was isolated from arsenic rich microbial mats (temperature ~45 °C) of a hot water spring located atop the Himalayan ranges at Manikaran, India. The present study reports the first genome sequence of type strain CT6(T) of genus Lampropedia cohaerens. Sequencing data was generated using the Illumina HiSeq 2000 platform and assembled with ABySS v 1.3.5. The 3,158,922 bp genome was assembled into 41 contigs with a mean GC content of 63.5 % and 2823 coding sequences. Strain CT6(T) was found to harbour genes involved in both the Entner-Duodoroff pathway and non-phosphorylated ED pathway. Strain CT6(T) also contained genes responsible for imparting resistance to arsenic, copper, cobalt, zinc, cadmium and magnesium, providing survival advantages at a thermal location. Additionally, the presence of genes associated with biofilm formation, pyrroloquinoline-quinone production, isoquinoline degradation and mineral phosphate solubilisation in the genome demonstrate the diverse genetic potential for survival at stressed niches.

7.
Indian J Microbiol ; 55(4): 357-365, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26543260

RESUMO

A Gram negative, yellow pigmented, rod shaped bacterium designated as RL(T) was isolated from a hot water spring (90-98 °C) located at Manikaran in Northern India. The isolate grows at 60-80 °C (optimum, 70 °C) and at pH 7.0-9.0 (optimum pH 7.2). Phylogenetic analysis of 16S rRNA gene sequences and levels of DNA-DNA relatedness together indicate that the new isolate represents a novel species of the genus Thermus with closest affinity to Thermus thermophilus HB8(T) (99.5 %) followed by Thermus arciformis (96.4 %). A comparative analysis of partial sequences of housekeeping genes (HKG) further revealed that strain RL(T) is a novel species belonging to the genus Thermus. The melting G+C content of strain RL(T) was calculated as 68.7 mol%. The DNA-DNA relatedness value of strain RL(T) with its nearest neighbours (>97 %) was found to be less than 70 % indicating that strain RL(T) represents a novel species of the genus Thermus. MK-8 was the predominant respiratory quinone. The presence of characteristic phospholipid and glycolipid further confirmed that strain RL(T) belongs to the genus Thermus. The predominant fatty acids of strain RL(T) were iso-C17:0 (23.67 %) and iso-C15:0 (24.50 %). The results obtained after DNA-DNA hybridization, biochemical and physiological tests clearly distinguished strain RL(T) from its closely related species. Thus, strain RL(T) represents a novel species of the genus Thermus for which the name Thermus parvatiensis is proposed (=DSM 21745(T)= MTCC 8932(T)).

8.
Genome Announc ; 2(4)2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25035332

RESUMO

Deinococcus sp. strain RL, a moderately thermophilic bacterium, was isolated from sediments of a hot water spring in Manikaran, India. Here, we report the draft genome (2.79 Mbp) of this strain, which contains 62 contigs and 2,614 coding DNA sequences, with an average G+C content of 69.4%.

9.
Genome Announc ; 1(5)2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-24051322

RESUMO

Sphingobium baderi strain LL03(T) was isolated from hexachlorocyclohexane (HCH)-contaminated soil from Spolana, Czech Republic. Strain LL03(T) is a mutant that is deficient in linB and linC (genes that encode hexachlorocyclohexane haloalkane dehalogenase and dehydrogenase, respectively). The draft genome sequence of LL03(T) (~4.85 Mb) consists of 92 contigs and 4,914 coding sequences, with a G+C content of 63.5%.

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