Lonar Soda Lake Research Articles

Spatio-temporal resolution of taxonomic and functional microbiome of Lonar soda lake of India reveals metabolic potential for bioremediation

Lonar Lake, India; a hypersaline and hyperalkaline extremophilic ecosystem having a unique microbial population has been rarely explored for bioremediation aspects. MinION-based shotgun sequencing was used to comprehensively compare the microbial diversity and functional potential of xenobiotic degradation pathways with seasonal changes. Proteobacteria and Firmicutes were prevalent bacterial phyla in the pre-monsoon and post-monsoon samples. Functional analysis from SEED-subsystem and KEGG database revealed 28 subsystems and 18 metabolic pathways for the metabolism of aromatic compounds and xenobiotic biodegradation respectively. Occurrence of N-phenyl alkanoic, benzoate, biphenyl, chloroaromatic, naphthalene, and phenol degradation genes depicted varied abundance in the pre-monsoon and post-monsoon samples. Further, KEGG analysis indicated nitrotoluene degradation pathway (ko00633) abundant in post-monsoon samples, and the benzoate degradation pathway (ko00362) predominant in 19LN4S (pre-monsoon) than 18LN7S (post-monsoon) samples. The abundant genes for benzoate degradation were pcaI: 3-oxoadipate CoA-transferase, alpha subunit, pcaH: protocatechuate 3,4-dioxygenase, beta subunit, and pcaB: 3-carboxy-cis, cis-muconate cycloisomerase, and 4-oxalocrotonate tautomerase. This metagenomic study provides a unique blueprint of hitherto unexplored xenobiotic biodegradation genes/pathways in terms of seasonal variations in the Lonar Lake, and warrants active exploitation of microbes for bioremediation purposes.

Shotgun metagenome guided exploration of anthropogenically driven resistomic hotspots within Lonar soda lake of India

Anthropogenic activities mediated antibiotic resistance genes (ARGs) in the pristine aquatic bodies (lakes) is raising concern worldwide. Long read shotgun sequencing was used to assess taxonomic diversity, distribution of ARGs and metal resistance genes (MRGs) and mobile genetic elements (MGEs) in six sites within hypersaline Lonar soda lake (India) prone to various anthropogenic activities. Proteobacteria and Euryarchaeota were dominant phyla under domain Bacteria and Archaea respectively. Higher abundance of Bacteroidetes was pragmatic at sites 18LN5 and 18LN6. Functional analysis indicated 26 broad-spectrum ARGs types, not reported earlier in this ecosystem. Abundant ARG types identified were multidrug efflux, glycopepetide, bacitracin, tetracycline and aminogylcoside resistance. Sites 18LN1 and 18LN5 depicted 167 and 160 different ARGs subtypes respectively and rpoB2, bcrA, tetA(48), mupA, ompR, patA, vanR and multidrug ABC transporter genes were present in all samples. The rpoB2 gene was dominant in 18LN1, whereas bcrA gene in 18LN2-18LN6 sites. Around 24 MRGs types were detected with higher abundance of arsenic in 18LN1 and copper in 18LN2-18LN6, signifying metal contamination linked to MRGs. The bacterial taxa Pseudomonas, Thioalkalivibrio, Burkholderia, Clostridium, Paenibacillus, Bacillus and Streptomyces were significantly associated with ARGs. This study highlights the resistomic hotspots in the lake for deploying policies for conservation efforts.

Bacillus catenulatus sp. nov., an alkalitolerant bacterium isolated from a soda lake.

Two novel (18CT and 6C) Gram-stain-positive, rod shaped, motile and endospore-forming bacterial strains were isolated from Lonar soda lake, India. Based on 16S rRNA gene sequence analysis, strains 18CT and 6C were identified as belonging to the class Firmibacteria, and were most closely related to Bacillus cohnii KCTC 3572T (99.3 and 99.9%, respectively), Bacillus zhanjiangensis KCTC 13713T (97.4 and 98.0%, respectively), Bacillus halmapalus LMG 17950T (97.0 and 97.6%, respectively) and other members in the genus Bacillus (<97.0%). However, the DNA-DNA relatedness between 18CT and 6C and B. cohnii KCTC 3572T (49.6±0.9 and 51.6±0.7, respectively), B. zhanjiangensis KCTC 13713T (42.9±0.8 and 47.1±0.3, respectively) and B. halmapalus LMG 17950T (39.9±0.8 and 40.8±0.3, respectively) indicated that the novel strains were distantly related to these strains. Further, the high 16S rRNA gene sequence similarity (100%) and DNA-DNA relatedness (90±5%) suggested that strains 18CT and 6C were members of a genomospecies. The strains grew optimally at a pH of 7.5 with 2-3% (w/v) NaCl and temperature of 37°C. Strains 18CT and 6C were catalase and oxidase negative. The cell wall of strain 18CT contained meso-diaminopimelic acid as the diagnostic diamino acid, which was in contrast with its nearest neighbour B. cohnii KCTC 3572T, which contained ornithine and aspartic acid. Polar lipids include diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), an unknown phospholipid (PL) and three unknown lipids (L1-3). The predominant isoprenoid quinone was MK-7. iso-C15:0 (32.5%) was the predominant fatty acid and significant proportions of anteiso-C15:0 (19.5%), C16:0 (11.5%), iso-C17:0 (9.5%) and anteiso-C17:0 (6.3%) were also detected. The DNA G+C content of strains 18CT and 6C were 39.3 and 39.2mol%, respectively. The results of molecular, biochemical and chemotaxonomic tests showed a clear differentiation of strains 18CT and 6C from all other members of the genus Bacillus, for which the name Bacillus catenulatus sp. nov. is proposed. The type strain is 18CT (=KCTC 33781T=CGMCC 1.15475T).

Isolation of a Cellulolytic Bacterium from the Lonar Soda Lake and Genomic Analysis of it

Isolation of a Cellulolytic Bacterium from the Lonar Soda Lake and Genomic Analysis of it

Bacillus alcaliphilum sp. nov., a bacterium isolated from a soda lake.

Two novel (14BT and 7B) Gram-stain-positive, rod-shaped, motile and endospore-forming bacterial strains were isolated from Lonar soda lake, India. Based on 16S rRNA gene sequence analysis, the strains 14BT and 7B were identified as belonging to the class Firmibacteria and were most closely related to Bacillus halodurans LMG 7121T (99.7 and 99.8%, respectively), Bacillus okuhidensis LMG 22468T (99.1 and 99.2%, respectively) and other members in the genus Bacillus (<97.0%). However, the DNA-DNA relatedness studies indicated that the strains 14BT and 7B were distantly related to B. halodurans LMG 7121T (49.1±0.6 and 45.7±0.6, respectively) and B. okuhidensis LMG 22468T (40.9±0.9 and 42.1±0.5, respectively). The high 16S rRNA gene sequence similarity (99.9%) and DNA-DNA relatedness (88±9) indicated that strains 14BT and 7B were members of a single species. The strains grew optimally at a pH of 9.0-9.5 with 2-5% (w/v) NaCl and temperature of 37°C. Strains 14BT and 7B were catalase positive and oxydase negative. The cell wall of strain 14BT contained meso-diaminopimelic acid as the diagnostic diamino acid. Polar lipids include diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), an unknown aminophospholipid (APL1) and three unknown lipids (L1-3). The predominant isoprenoid quinone is MK-7. anteiso-C15:0 (30.8%) was the predominant fatty acid, and significant proportions of iso-C15:0 (24.9%), iso-C16:0 (17.9%) and anteiso-C17:0 (12.3%) were also detected in strains 14BT and 7B. The DNA G+C content of strains 14BT and 7B was 41.6 and 41.3mol%, respectively. The results of molecular, physiological and biochemical tests allowed a clear differentiation of strains 14BT and 7B from all other members of the genus Bacillus, for which the name Bacillus alcaliphilum sp. nov. is proposed. The type strain is 14BT (=KCTC 33777T=CGMCC 1.15474T).

Nesterenkonia cremea sp. nov., a bacterium isolated from a soda lake.

A Gram-stain-positive, aerobic, non-motile, rod-shaped, non-endospore-forming bacterial strain, 10CT, was isolated from Lonar soda lake in India. Based on the 16S rRNA gene sequence analysis, this strain was identified as belonging to the genus Nesterenkonia and was most closely related to the type strains of Nesterenkonia lacusekhoensis (99.1 %, sequence similarity), Nesterenkonia aethiopica (96.9 %), Nesterenkonia flava (96.9 %) and related of the genus Nesterenkonia (<96.6 %, sequence similarity). However, the DNA-DNA relatedness of strain 10CT with N. lacusekhoensis KCTC 19283T was only 34.6±0.9. The DNA G+C content of strain 10CT was 68.6 mol%. Strain 10CT was an aerobic microbe with optimal growth at 37 °C, pH 7.5-8.0 and 5-6 % (w/v) NaCl. The cell-wall peptidoglycan of strain 10CT was of the type A4α (l-Lys-l-Glu). The major polar lipids present were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. The major isoprenoid quinones were MK-7, MK-8 and MK-9. Major fatty acids of strain 10CT were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The results of phylogenetic, chemotaxonomic and biochemical tests allowed a clear differentiation of strain 10CT, which represents a novel member of the genus Nesterenkonia for which the name Nesterenkonia cremea sp. nov. is proposed. The type strain is 10CT (=LMG 29100T=KCTC 39636T=CGMCC 1.15388T).

Saline soil microbiome: A rich source of halotolerant PGPR

Twenty halotolerant free-living, nitrogen-fixing bacterial strains were isolated from the Lonar Soda Lake and screened for growth at different NaCl concentrations. Out of 20, only Four isolates DL2, DL3, and DL6 showed optimum growth at 4% NaCl, and DL11 showed optimum growth at 6% NaCl concentration and tolerated 10% NaCl concentration. Biochemical and 16S rRNA sequencing identified DL2 as P. mendocina, DL3 as A. beijerinckii, DL6 as P. stutzeri, and DL11 as B. subtilis. Further, these four isolates were characterized for plant growth-promoting traits and all are indole acetic acid and ammonia producers and they also solubilize the phosphate under 4% NaCl concentration. The salt tolerance of these isolates was also increased from 10 to 14% by using a physical mutagen like UV and mutant strains were also screened for PGP traits. To determine the efficacy of these isolates as plant growth-promoting bacteria, Bioinoculum I (mixed culture of wild strains) and Bioinoculum II (mixed culture of mutant strains) were prepared and tested on Catharanthus roseus at 4% NaCl concentration. Plants treated with Bioinoculum II showed 12.61 and 82.35% increase in shoot and root length, respectively, and 71.42% increase in number of flowers as compared to control plants under saline conditions. These results indicate that halotolerant bacteria isolated from saline environments have the potential to enhance plant growth under saline stress through direct or indirect mechanisms and would be most appropriate as bioinoculants under such conditions.

Angiotensin I-converting enzyme inhibitory peptides in oat (Avena sativa L.) proteins-derived digests – In silico and in vitro study

Alkaline proteases are one of the industrially important enzymes and generally preferred from alkaliphilic sources. Here we have provided the data on optimized production and characterization of alkaline proteases from five newly isolated and identified alkaliphiles from Lonar soda lake, India. The data provided for optimization of physicochemical parameters for maximum alkaline proteases production is based on OVAT (one variable at a time) approach. Alkaline protease production (U/mL) recorded by using different agro industrial residues is included in the given data. Further readers can find more information in our previously published research article where we have already described about the methods used and comparative analysis of the data recorded regarding optimized production, characterization and application of alkaline proteases isolated from Lonar soda lake isolates (http://dx.doi.org/10.1016/j.bcab.2016.06.002) [1]. The data provided here by us is useful to other researchers for setting up various suitable statistical models to perform optimization studies other than OVAT approach.

Optimized production, characterization and application of alkaline proteases from taxonomically assessed microbial isolates from Lonar soda lake, India

Lonar soda lake of India was explored for isolation of the industrially important alkaline protease producers. The isolates from Lonar lake were identified based on their morphological characters, microscopic features, enzymatic profile, biochemical pattern and 16S rRNA partial gene sequences as Brachybacterium sp. LAP214, Bacillus cohnii LAP217, Bacillus pseudofirmus LAP220, Brevibacterium casei LAP223 and Halomonas venusta LAP515 and deposited in Microbial Culture Collection, NCCS, Pune (India) for public access. Production of the alkaline proteases from these isolates was optimized by adopting a one-variable-at-a-time (OVAT) approach in a submerged fermentation system in modified fermentation medium (MFM). More than 3 fold enhancement in the alkaline protease production was recorded from all these isolates after optimization of the physicochemical parameters. Molecular weights of partially purified alkaline proteases from LAP515, LAP214 and LAP223 were recorded as 20.1, 14.3 and 43 kDa respectively. Molecular weights of partially purified alkaline proteases from LAP220 and LAP217 were recorded as 29 kDa. Partially purified alkaline proteases from LAP515, LAP214, LAP220, LAP217 and LAP223 exhibited Vmax values 1000, 1290.323, 526.316, 1250 and 2000 U/mg respectively. Catalytic activities of alkaline proteases from all these isolates were partially and completely inhibited in presence of a serine protease inhibitor PMSF, at the concentrations of 1 and 10 mM respectively. The metal cations Mg2+, Ba2+, and Ca2+ enhanced the catalytic activities of these proteases. Remarkable stability of these alkaline proteases was observed in presence of selected solvents and commercial detergents. These proteases therefore can be used in various biotechnological applications.

Metagenomic data of fungal internal transcribed Spacer and 18S rRNA gene sequences from Lonar lake sediment, India.

The data in this article contains the sequences of fungal Internal Transcribed Spacer (ITS) and 18S rRNA gene from a metagenome of Lonar soda lake, India. Sequences were amplified using fungal specific primers, which amplified the amplicon lined between the 18S and 28S rRNA genes. Data were obtained using Fungal tag-encoded FLX amplicon pyrosequencing (fTEFAP) technique and used to analyze fungal profile by the culture-independent method. Primary analysis using PlutoF 454 pipeline suggests the Lonar lake mycobiome contained the 29 different fungal species. The raw sequencing data used to perform this analysis along with FASTQ file are located in the NCBI Sequence Read Archive (SRA) under accession No. SRX889598 (http://www.ncbi.nlm.nih.gov/sra/SRX889598).

Bacillus caseinilyticus sp. nov., an alkali- and thermotolerant bacterium isolated from a soda lake.

A novel Gram-stain-positive, rod-shaped, motile, endospore-forming and proteolytic bacterial strain, SPT, was isolated from Lonar soda lake, in India. On the basis of 16S rRNA gene sequence analysis it was identified as belonging to the class Firmibacteria and was most closely related to Bacillus cellulosilyticus DSM 2522T (96.7%) and other members of the genus Bacillus ( < 95.9%). Strain SPT was catalase- and oxidase-positive. The cell-wall peptidoglycan of strain SPT contained meso-diaminopimelic acid. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three phospholipids, two aminolipids and two unknown lipids. The predominant isoprenoid quinone was MK-7. Anteiso-C15 : 0 (26.8%) was the predominant fatty acid and significant proportions (>5%) of iso-C15 : 0 (20.9%), C16 : 1ω7c alcohol (6.3%), iso-C16 : 0 (6.3%) and anteiso-C17 : 0 (5.3 %) were also detected in strain SPT. The DNA G+C content of strain SPT was 38.9 mol%. The results of phylogenetic, chemotaxonomic and biochemical tests allowed a clear differentiation of strain SPT from all other members of the genus Bacillus. Strain SPT represents a novel member of the genus Bacillus, for which the name Bacilluscaseinilyticus sp. nov. is proposed. The type strain is SPT ( = MCC 2612T = JCM 30246T).

Bacterial tag encoded FLX titanium amplicon pyrosequencing (bTEFAP) based assessment of prokaryotic diversity in metagenome of Lonar soda lake, India.

Bacterial diversity and archaeal diversity in metagenome of the Lonar soda lake sediment were assessed by bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP). Metagenome comprised 5093 sequences with 2,531,282 bp and 53 ± 2% G + C content. Metagenome sequence data are available at NCBI under the Bioproject database with accession no. PRJNA218849. Metagenome sequence represented the presence of 83.1% bacterial and 10.5% archaeal origin. A total of 14 different bacteria demonstrating 57 species were recorded with dominating species like Coxiella burnetii (17%), Fibrobacter intestinalis (12%) and Candidatus Cloacamonas acidaminovorans (11%). Occurrence of two archaeal phyla representing 24 species, among them Methanosaeta harundinacea (35%), Methanoculleus chikugoensis (12%) and Methanolinea tarda (11%) were dominating species. Significant presence of 11% sequences as an unclassified indicated the possibilities for unknown novel prokaryotes from the metagenome.

Salisediminibacterium haloalkalitolerans sp. nov., isolated from Lonar soda lake, India, and a proposal for reclassification of Bacillus locisalis as Salisediminibacterium locisalis comb. nov., and the emended description of the genus Salisediminibacterium and of the species Salisediminibacterium halotolerans.

A Gram stain-positive, rod-shaped, non-motile, orange-pigmented and non-endospore-forming novel bacterial strain 10nlg(T) was isolated from Lonar soda lake in India. Based on the 16S rRNA gene sequence analysis, it was belonged to the genus Salisediminibacterium and was most closely related to Salisediminibacterium halotolerans CGMCC 1.7654(T) (99.9 %), Bacillus locisalis CGMCC 1.6286(T) (99.1 %) and other members in the Bacillaceae (<93.6 %). Further, DNA-DNA hybridization results demonstrated that strain 10nlg(T) was distantly (<70 %) related to S. halotolerans halo-2(T) (59.6 %) and B. locisalis CGMCC 1.6286(T) (53.2 %). Strain 10nlg(T) was catalase positive and oxidase negative. The cell wall of the strain 10nlg(T) contains meso-diaminopimelic acid as the diagnostic amino acid. Polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five phospholipids and two unknown lipids. The predominant isoprenoid quinone was MK-7. Anteiso-C15:0 (32.6 %) was the predominant fatty acid, and significant proportions of iso-C15:0 (9.3 %), anteiso-C17:0 (8.3 %), C16:0 (4.3 %) were also detected in the strain 10nlg(T). The DNA G+C content of the strain 10nlg(T) was 45.6 mol %. The results of phylogenetic, physiological and biochemical tests allowed a distinct differentiation of strain 10nlg(T) not only from S. halotolerans halo-2(T), the only member of the genus Salisediminibacterium, but also from the related Bacillaceae members. Strain 10nlg(T) represents a novel species of the genus Salisediminibacterium for which the name Salisediminibacterium haloalkalitolerans sp. nov. is proposed. The type strain is 10nlg(T) (=KCTC 33414(T) = CGMCC 1.12818(T)). B. locisalis CGMCC 1.6286(T) also represents a member of the genus Salisediminibacterium for which the name Salisediminibacterium locisalis CG1(T) is proposed. The type strain is CG1(T) = (CCM 7370(T) = CECT 7152(T) = CGMCC 1.6286(T) = DSM 18085(T)). In accordance with the new polar lipid data collected in this study, emended descriptions of the genus Salisediminibacterium and the species S. halotolerans halo-2(T) are also provided.

Streptomyces alkalithermotolerans sp. nov., a novel alkaliphilic and thermotolerant actinomycete isolated from a soda lake.

An alkaliphilic actinomycete, strain AC3(T), was isolated from Lonar soda lake, in India. Based on 16S rRNA gene sequence analysis it was identified that the strain belongs to the class Actinobacteria and was most closely related to Streptomyces sodiiphilus JCM 13581(T) (96.4 % sequence similarity), Streptomyces leeuwenhoekii DSM 42122(T) (96.1 %), Streptomyces albus NRRL B-2365(T) (96.1 %), Streptomyces panacagri Gsoil 519(T) (96.0 %), Streptomyces fimbriatus NBRC 15411(T) (95.9 %) and other members of the genus Streptomyces (<95.9 %).The strain formed a well separated clade in the genus Streptomyces based on the 16S rRNA gene analysis of all of the validly named Streptomyces species. Strain AC3(T) was observed to produce light-cream substrate and white aerial mycelia on most tested media. The optimum pH for growth was determined to be 9.5-10.0 with no growth at pH 7.0. The DNA G+C content of strain AC3(T) was determined to be 71.2 mol %. The results of the polyphasic analysis allowed a clear differentiation of strain AC3(T) from all other members of the genus Streptomyces. Strain AC3(T) is thus considered to represent a novel member of the genus Streptomyces, for which the name Streptomyces alkalithermotolerans sp. nov. is proposed. The type strain is AC3(T) (=KCTC 29497(T) = JCM 30167(T)).

Bacillus lonarensis sp. nov., an alkalitolerant bacterium isolated from a soda lake.

A novel Gram-stain-positive, rod-shaped, motile and endospore-forming novel bacterial strain 25nlg(T) was isolated from Lonar soda lake, in India. Based on the 16S rRNA gene sequence analysis, it was identified as a member of Firmicutes, being most closely related to Bacillus patagoniensis PAT 05(T) (96.6%) and other members in the genus Bacillus (<96.0%). Strain 25nlg(T) was catalase and oxidase-positive. The strain grows optimally at a pH of 9.5 with 4-6% (w/v) NaCl and temperature of 35-37°C. The cell wall of the strain 25nlg(T) contains meso-diaminopimelic acid as the diagnostic amino acid. Polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unknown phospholipid (PL2), an aminophospholipid (APL2) and three unknown lipids (L2-4). The predominant isoprenoid quinone was MK-7. iso-C15:0 (41.7%) was the predominant fatty acid, and significant proportions of anteiso-C15:0 (20.8%), C12:0 (5.5%), anteiso-C17:0 (4.9%), iso-C17:0 (4.5%) were also detected in the strain 25nlg(T). The DNA G+C content of the strain 25nlg(T) was 40.5mol%. The results of molecular, physiological and biochemical tests allowed a clear phenotypic differentiation of strain 25nlg(T) from all other members of the genus Bacillus. Strain 25nlg(T) represents a novel member of the genus Bacillus, for which the name Bacillus lonarensis sp. nov. is proposed. The type strain is 25nlg(T) (=KCTC 33413(T)=LMG 27974(T)=CGMCC=1.12817(T)).

Wealth from waste: Optimized alkaline protease production from agro-industrial residues by Bacillus alcalophilus LW8 and its biotechnological applications

An efficient alkaline protease producer was isolated from the water of the hyperalkaline-saline Lonar soda lake and identified as Bacillus alcalophilus LW8 by culture-dependent techniques by its morphological, microscopic, biochemical, physiological and molecular characteristics. The 16S rRNA gene sequence was submitted to the GenBank nucleotide repository under accession number KC689353. Alkaline protease production was optimized by adopting a one-variable-at-a-time approach in a submerged fermentation system in modified fermentation medium (MFM). The optimized components of MFM were (w/w) casein (1%), sugarcane molasses (1%), NaCl (1%), ammonium sulphate (0.5%), KH2PO4 (0.05%), K2HPO4 (0.05%) and Na2CO3 (1%). Optimized culture conditions were used for alkaline protease production. The final yield of partially purified alkaline protease after dialysis was 53.35%. The molecular mass of the dialysed alkaline protease was 27kDa. On a Lineweaver–Burk plot, the calculated Km and Vmax values were 24mg/mL and 1000U/mg, respectively. The enzyme was remarkably stable in the pH range 7.0–12.0, with optimum activity at pH 10.0. LW8 alkaline protease was completely inhibited by phenylmethylsulphonyl fluoride at 10mmol/L, indicating that the enzyme belongs to the serine protease class. The metal ions Ca2+, Ba2+, Mg2+, Zn2+, Fe3+, Cu2+ and Mn2+ increased the catalytic activity of partially purified alkaline protease. The protease effectively decomposed the gelatinous coating on an X-ray film, hydrolysed blood clot, a blood-stain from a piece of cotton fabric and hairs from a piece of goat skin.

Bacterial Diversity of Lonar Soda Lake of India

Total seventy four bacteria were isolated from Lonar soda lake of Maharashtra state, India. Eleven isolates were identified using morphological, biochemical and molecular analysis. The bacteria isolated belonged to phylum firmicutes and proteobacteria. Majorities (eight) were firmicutes and three were proteobacteria. For the first time we are reporting Alcanivorax spp. which is a genus well known for its oil degradation capacity, indicate the probable existence of oil reservoir in vicinity of Lonar lake. In addition all the eleven bacteria are potential producers of industrially important enzymes, pigments, antibiotics as well.

Molecular analyses of microbial diversity associated with the Lonar soda lake in India: An impact crater in a basalt area

The prokaryotic diversity associated with an Indian soda lake (Lonar Crater Lake) located in a basaltic soil area was investigated using a culture-independent approach. Community DNA was extracted directly from four sediment samples obtained by coring to depths of 10–20 cm. Small subunit rRNA genes (16S rDNA) were amplified by PCR using primers specific to the domains Bacteria and Archaea. The PCR products were cloned and sequenced. For the bacterial rDNA clone library, 500 clones were randomly selected for further analysis. After restriction fragment length polymorphism (RFLP) analysis and subsequent sequencing, a total of 44 unique phylotypes were obtained. These phylotypes spanned a wide range within the domain Bacteria, occupying eight major lineages/phyla. 34% of the clones were classified as firmicutes. The other clones were grouped into proteobacteria (29.5%), actinobacteria (6.8%), deinococcus–thermus (4.5%), cytophages–flavobacterium–bacteroidetes (13.3%), planctomycetes (6.8%), cyanobacteria (4.5%) and spirochetes (2.27%). In the case of the archaeal 16S rDNA library, analysis of 250 randomly selected clones revealed the presence of 13 distinct phylotypes; 5 phylotypes were associated with Crenarchaeota and 8 with Euryarchaeota. Most of the euryarchaeota sequences were related to methanogens. Findings from this molecular study of a site investigated for the first time have revealed the presence of a highly diverse bacterial population and a comparatively less diverse archaeal population. The majority ( ∼ 80 % ) of the cloned sequences show little affiliation with known taxa ( < 97 % sequence similarity) and may represent novel taxa/sequences and organisms specifically adapted to this basaltic soda lake environment. Diversity analyses demonstrate greater diversity and evenness of bacterial species compared to a skewed representation of species for Archaea.