Phylogenomic evaluation of Mangrovimicrobium sediminis gen. nov. sp. nov., the first nitrogen fixing member of the family Halieaceae adapted to mangrove habitat and reclassification of Halioglobus pacificus to Pseudohaliglobus pacificus comb. nov.

The taxonomic position and genomic characteristics of a nitrogen fixing and polymer degrading marine bacterium, strain SAOS 164 isolated from a mangrove sediment sample was investigated. Sequence analysis based on 16S rRNA gene identified it as a member of family Halieaceae with closest similarity to Haliea salexigens DSM 19537T (96.3 %), H. alexandrii LZ-16-2T (96.2 %) and Parahaliea maris HSLHS9T (96.0 %) but was distantly related to the genera Haliea, Parahaliea and Halioglobus in phylogenetic trees. In order to ascertain the exact taxonomic position, phylogeny based on RpoBC proteins, whole genome, core and orthologous genes, and comparative analysis of metabolic potential retrieved the strain in an independent lineage clustering along with the genera Halioglobus, Pseudohalioglobus and Seongchinamella. Further, various genome based delimitation parameters represented by mol % GC content, percentage of conserved proteins (POCP), and amino acid identity (AAI) along with chemotaxonomic markers (i.e. fatty acids and polar lipids) supported the inferences of genome based phylogeny and indicated that the strain SAOS 164 belongs to a novel genus. The genome was mapped to 4.8 Mb in size with 65.1 % DNA mol% G + C content. In-silico genomic investigation and phenotyping revealed diverse metabolite genes/pathways related to polymer hydrolysis, nitrogen fixation, light induced growth, carbohydrate, sulfur, phosphorus and amino acid metabolism, virulence factors, defense mechanism, and stress-responsive elements facilitating survival in the mangrove habitat. Based on polyphasic taxonomic approach including genome analyses, a novel genus Mangrovimicrobium sediminis gen. nov. sp. nov. (=SAOS 164T = MTCC 12907T = KCTC 52755T = JCM 32136T) is proposed. Additionally, the reclassification of Halioglobus pacificus (=DSM 27932T = KCTC 23430T = S1-72T) to Pseudhalioglobus pacificus comb. nov. is also proposed.

Analysis of Culturable Bacterial Diversity of Pangong Tso Lake via a 16S rRNA Tag Sequencing Approach.

The Pangong Tso lake is a high-altitude freshwater habitat wherein the resident microbes experience unique selective pressures, i.e., high radiation, low nutrient content, desiccation, and temperature extremes. Our study attempts to analyze the diversity of culturable bacteria by applying a high-throughput amplicon sequencing approach based on long read technology to determine the spectrum of bacterial diversity supported by axenic media. The phyla Pseudomonadota, Bacteriodetes, and Actinomycetota were retrieved as the predominant taxa in both water and sediment samples. The genera Hydrogenophaga and Rheinheimera, Pseudomonas, Loktanella, Marinomonas, and Flavobacterium were abundantly present in the sediment and water samples, respectively. Low nutrient conditions supported the growth of taxa within the phyla Bacteriodetes, Actinomycetota, and Cyanobacteria and were biased towards the selection of Pseudomonas, Hydrogenophaga, Bacillus, and Enterococcus spp. Our study recommends that media formulations can be finalized after analyzing culturable diversity through a high-throughput sequencing effort to retrieve maximum species diversity targeting novel/relevant taxa.

An experimental setup and segmentation method for CFU counting on agar plate for the assessment of drinking water.

Quantification of bacterial colonies on an agar plate is a daily routine for a microbiologist to determine the number of viable microorganisms in the sample. In general, microbiologists perform a visual assessment of bacterial colonies which is time-consuming (takes 2 min per plate), tedious, and subjective. Some automatic counting algorithms are developed that save labour and time, but their results are affected by the non-illumination on an agar plate. To improve this, the present manuscript aims to develop an inexpensive and efficient device to acquire S.aureus images via an automatic counting method using image processing techniques under real laboratory conditions. The proposed method (P_ColonyCount) includes the region of interest extraction and color space transformation followed by filtering, thresholding, morphological operation, distance transform, and watershed technique for the quantification of isolated and overlapping colonies. The present work also shows a comparative study on grayscale, K, and green channels by applying different filter and thresholding techniques on 42 images. The results of all channels were compared with the score provided by the expert (manual count). Out of all the proposed method (P_ColonyCount), the K channel gives the best outcome in comparison with the other two channels (grayscale and green) in terms of precision, recall, and F-measure which are 0.99, 0.99, and 0.99 (2 h), 0.98, 0.99, and 0.98 (4 h), and 0.98, 0.98, 0.98 (6 h) respectively. The execution time of the manual and the proposed method (P_ColonyCount) for 42 images ranges from 19 to 113 s and 15 to 31 s respectively. Apart from this, a user-friendly graphical user interface is also developed for the convenient enumeration of colonies without any expert knowledge/training. The developed imaging device will be useful for researchers and teaching lab settings.

Exploring Diversity and Polymer Degrading Potential of Epiphytic Bacteria Isolated from Marine Macroalgae.

The macroalgae surface allows specific bacterial communities to colonize, resulting in complex biological interactions. In recent years, several researchers have studied the diversity and function of the epiphytic bacteria associated with algal host, but largely these interactions remain underexplored. In the present study we analysed the cultivable diversity and polymer degradation potential of epiphytic bacteria associated with five different marine macroalgae (Sargassum, Ulva, Padina, Dictyota and Pterocladia sp.) sampled from the central west coast of India. Out of the total 360 strains isolated, purified and preserved, about 238 strains were identified through 16S rRNA gene sequence analysis and processed for polymer (cellulose, pectin, xylan and starch) degrading activities. Phylogeny placed the strains within the classes Actinobacteria, Bacilli, Alpha-proteobacteria, and Gamma-proteobacteria and clustered them into 45 genera, wherein Vibrio, Bacillus, Pseudoalteromonas, Alteromonas, Staphylococcus and Kocuria spp. were the most abundant with 20 strains identified as potentially novel taxa within the genera Bacillus, Cellulosimicrobium, Gordonia, Marinomonas, Vibrio, Luteimonas and Pseudoalteromonas. In terms of polymer hydrolysis potential, 61.3% had xylanase activity, while 59.7%, 58.8%, and 52.2% had amylase, cellulase, and pectinase activity, respectively. Overall, 75.6% of the strains degraded more than one polysaccharide, 24% degraded all polymers, while nine strains (3.8%) degraded raw sugarcane bagasse. This study showed great potential for seaweed-associated bacteria in the bio-remediation of agro-waste based raw materials, which can be employed in the form of green technology.

Geoalkalibacter halelectricus SAP-1 sp. nov. possessing extracellular electron transfer and mineral-reducing capabilities from a haloalkaline environment.

The extracellular electron transfer (EET)-capable electroactive microorganisms (EAMs) play crucial roles in mineral cycling and interspecies electron transfer in different environments and are used as biocatalysts in microbial electrochemical technologies. Studying EAMs from extreme environments is desired to advance the electromicrobiology discipline, understanding their unique metabolic traits with implications to extreme microbiology, and develop specific bioelectrochemical applications. Here, we present a novel haloalkaliphilic bacterium named Geoalkalibacter halelectricus SAP-1, isolated from a microbial electroactive biofilm enriched from the haloalkaline lake sediments. It is a rod-shaped Gram-negative heterotrophic anaerobe that uses various carbon and energy sources and respires on soluble and insoluble terminal electron acceptors. Besides 16S-rRNA and whole-genome sequence-based phylogeny, the GGDC values of 21.7%, ANI of 78.5%, and 2.77% genomic DNA GC content difference with the closest validly named species Geoalkalibacter ferrihydriticus (DSM 17813T ) confirmed its novelty. When grown with the solid-state electrode as the only electron acceptor, it produced 460 ± 23 µA/cm2 bioelectrocatalytic current, thereby confirming its electroactivity. Further electrochemical analysis revealed the presence of membrane redox components with a high formal potential, putatively involved in the direct mode of EET. These are distinct from EET components reported for any known electroactive microorganisms, including well-studied Geobacter spp., Shewanella spp., and Desulfuromonas acetexigens. The capabilities of G. halelectricus SAP-1 to respire on soluble and insoluble electron acceptors including fumarate, SO4 2- , Fe3+ , and Mn4+ suggests its role in cycling these elements in haloalkaline environments.

Exploring the Distinct Distribution of Archaeal Communities in Sites Contaminated with Explosives.

Most of the research on bioremediation and estimation of microbial diversity in waste contaminated sites is focused on the domain Bacteria, whereas details on the relevance of Archaea are still lacking. The present study examined the archaeal diversity and predicted metabolic pathways in two discrete sites (SITE1 and SITE2) contaminated with explosives (RDX and HMX) by amplicon-targeted sequencing of 16S rRNA genes. In total, 14 soil samples were processed, and 35,758 OTUs were observed, among which 981 OTUs were classified as Archaea, representing ~2.7% of the total microbial diversity in our samples. The majority of OTUs belonged to phyla Euryarchaeota (~49%), Crenarchaeota (~24%), and Thaumarchaeota (~23%), while the remaining (~4%) OTUs were affiliated to Candidatus Parvarchaeota, Candidatus Aenigmarchaeota, and Candidatus Diapherotrites. The comparative studies between explosives contaminated and agricultural soil samples (with no history of explosives contamination) displayed significant differences between the compositions of the archaeal communities. Further, the metabolic pathways pertaining to xenobiotic degradation were presumably more abundant in the contaminated sites. Our data provide a first comprehensive report of archaeal communities in explosives contaminated sites and their putative degradation role in such ecosystems which have been as yet unexplored.

Yangia mangrovi sp. nov., a novel member of the Roseobacter clade isolated from mangrove soil and emended description of Yangia pacifica Dai et al. 2006.

During a study of the bacterial diversity of mangrove habitats, a novel Gram-stain-negative, rod-shaped bacterium designated as SAOS 153DT was isolated. Sequence alignment and molecular phylogenetic analyses based on 16S rRNA and core gene sequence of strain SAOS 153DT with closely related taxa revealed a sequence identity of 99.4 % and clustering with Yangia pacifica DX5-10T. The fatty acids summed feature 8 (C18:1 ω7c/C18:1 ω6c) and the lipids phosphatidylglycerol, phosphatidylethanolamine and an unknown phospholipid were the major components of the cell wall. The only ubiquinone type present was Q-10. The genomic DNA G+C content of the strain calculated from whole genome sequencing was 66.9 mol%. These chemotaxonomic and genomic characteristics supported the molecular phylogenetic analysis and placed the strain well within the radiation of the genus Yangia. The overall genome related indices using digital DNA-DNA hybridization (35.4 %) and ortho-average nucleotide identity (88.1 %) values were much lower than the recommended thresholds for species delineation, which further consolidated the novel species status of strain SAOS 153DT within the genus Yangia as Yangia mangrovi sp. nov. The type strain is SAOS 153DT (=JCM 31345T=KCTC 52280T=MTCC 12749T).

Halomonas icarae sp. nov., a moderately halophilic bacterium isolated from beach soil in India.

A moderately halophilic, Gram-stain-negative, aerobic bacterium, strain D1-1T, belonging to the genus Halomonas, was isolated from soil sampled at Pentha beach, Odisha, India. Phylogenetic trees reconstructed based on 16S rRNA genes and multilocus sequence analysis of gyrB and rpoD genes revealed that strain D1-1T belonged to the genus Halomonas and was most closely related to Halomonas alimentaria YKJ-16T (98.1 %) followed by Halomonas ventosae Al12T (97.5 %), Halomonas sediminicola CPS11T (97.5 %), Halomonas fontilapidosi 5CRT (97.4 %) and Halomonas halodenitrificans DSM 735T (97.2 %) on the basis of 16S rRNA gene sequence similarity. Sequence identities with other species within the genus were lower than 97.0 %. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of 22.4-30 % and 79.5-85.4 % with close relatives of H. halodenitrificans DSM 735T, H. alimentaria YKJ-16T, H. ventosae Al12T and H. fontilapidosi 5CRT were lower than the threshold recommended for species delineation (70 % and 95-96 % for dDDH and ANI, respectively). Further, strain D1-1T formed yellow-coloured colonies; cells were rod-shaped, motile with optimum growth at 30 °C (range, 4-45 °C) and 2-8 % NaCl (w/v; grew up to 24 % NaCl). The major fatty acids were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c), summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C16 : 0 and the main respiratory quinone was ubiquinone Q-9 in line with description of the genus. Based on its chemotaxonomic and phylogenetic characteristics and genome uniqueness, strain D1-1T represents a novel species in the genus Halomonas, for which we propose the name Halomonas icarae sp. nov., within the family Halomonadaceae. The type strain is D1-1T (=JCM 33602T=KACC 21317T=NAIMCC-B-2254T).

Halocatena pleomorpha gen. nov. sp. nov., an extremely halophilic archaeon of family Halobacteriaceae isolated from saltpan soil.

A novel archaeal strain designated as SPP-AMP-1T was isolated from saltpan soil, using the serial dilution method on a halophilic archaeal medium supplemented with ampicillin. Cells were both rod-shaped and pleomorphic in nature, non-motile, unable to produce acid from a variety of sugars or grow anaerobically with different substrates (l-arginine) and electron acceptors (DMSO, nitrate). Optimal growth was observed at 42 °C, 3.4-4.2 M NaCl and pH 7.2. Cells did not lyse in distilled water and grew in the absence of Mg2+ ions. Phylogenetic analysis based on the sequences of 16S rRNA gene, amino acid sequence of ß'-subunit of RNA polymerase and 400 conserved proteins retrieved from the whole genome assemblies showed that strain SPP-AMP-1T was distantly related to any existing genera within the family Halobacteriaceae. MK-8 was the only quinone detected. Polar lipid analysis showed a unique combination of diethyl derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, glycosyl-mannosyl-glucosyl diether and sulphated glycosyl-mannosyl-glucosyl diether as the major lipids. The G+C content of genomic DNA is 57.7 mol%. The phenotypic, phylogenetic and genomic data supported the concept of the novel genus status of strain SPP-AMP-1T in the family Halobacteriaceae for which the name Halocatena pleomorpha gen. nov., sp. nov., is proposed; the type strain is SPP-AMP-1T (=JCM 31368T=KCTC 4276T=MTCC 12579T).

Indiicoccus explosivorum gen. nov., sp. nov., isolated from an explosives waste contaminated site.

A pink-pigmented, Gram-stain-positive, aerobic, coccoid-shaped bacterial strain, designated as S5-TSA-19T, was isolated from an explosives contaminated site in Panchkula, Haryana, India. The 16S rRNA gene sequencing blast analysis indicated that the strain is a member of the family Planococcaceae with the highest sequence similarity to Planomicrobium soli XN13T (96.1 %), followed by Planococcus maitriensis S1T (95.6 %), Planococcus plakortidis DSM 23997T (95.6 %), Planomicrobium flavidum ISL-41T (95.6 %), Planococcus rifietoensis M8T (95.5 %), Planococcus salinus LCB217T (95.5 %) and Planococcus maritimus DSM 17275T (95.5 %). Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences (based on a conserved set of 400 proteins) retrieved the strain in a distinct branch indicating a separate lineage within the family Planococcaceae. Strain S5-TSA-19T had a distinctive chemotaxonomic pattern comprising A4α type peptidoglycan based on l-Lys-d-Asp, iso-C15 : 0 as the major fatty acid, absence of phosphatidylethanolamine as a major lipid and MK-7 and MK-6 as the major menaquinones, differentiating it from the genera Planococcus and Planomicrobium, thus supporting the findings of molecular phylogeny. Further, strain S5-TSA-19T was able to biotransform hexahydro-1,3,5,-trinitro-1,2,5-triazine (RDX) into nitrite derivatives under aerobic conditions in 2-4 days, whereas the closest reference strains did not possess this property. On the basis of polyphasic taxonomic characterization and a phylogenomics approach, strain S5-TSA-19T is proposed as the type strain of a novel species in a novel genus for which the name Indiicoccus explosivorum gen. nov., sp. nov. is proposed (=JCM 31737T=KCTC 33871T=MTCC 12608T).

Taxonomic insights into the phylogeny of Bacillus badius and proposal for its reclassification to the genus Pseudobacillus as Pseudobacillus badius comb. nov. and reclassification of Bacillus wudalianchiensis Liu et al., 2017 as Pseudobacillus wudalianchiensis comb. nov.

The species Bacillus badius is one of the oldest members of the genus Bacillus isolated from faeces of children and was classified based on its ability to form endospores [8]. In 16S rRNA gene sequence and phylogenetic analysis, Bacillus badius DSM 23T shared low similarity (93.0%) and distant relationship with B. subtilis, the type species of the genus Bacillus indicating that it does not belong to this genus. Additional strains of the species, B. badius DSM 5610, DSM 30822 and B. encimensis SGD-V-25 (which has been recently reclassified as a member of this species) were included in the study to consider intraspecies diversity. Detailed molecular phylogenetic and comparative genome analysis clearly showed that the strains of B. badius were consistently retrieved outside the cluster of Bacillus sensu stricto and also distantly related to the genera Domibacillus and Quasibacillus. Further, the data from biochemical reactions (inability to ferment most carbohydrates), polar lipids profile (presence of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an aminophosphoglycolipid) and fatty acids supported the molecular analysis. Thus the four B. badius strains; DSM 23T, DSM 5610, DSM 30822 and SGD-V-25 displayed sufficient demarcating phenotypic characteristics that warrant their classification as members of a novel genus and single species, for which the name Pseudobacillus badius gen. nov. comb. nov. is proposed with Pseudobacillus badius DSM 23T (= ATCC 14574T) as the type strain. Additionally, based on our findings from phenotypic, chemotaxonomic and genotypic parameters, Bacillus wudalianchiensis DSM 100757T was reclassified as Pseudobacillus wudalianchiensis comb. nov.

Sphingomonas pokkalii sp. nov., a novel plant associated rhizobacterium isolated from a saline tolerant pokkali rice and its draft genome analysis.

Three strains L3B27T, 3CNBAF, L1A4 isolated from a brackish cultivated pokkali rice rhizosphere were characterised using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA and recA gene sequences revealed that these strains were highly similar among each other and formed a separate monophyletic cluster within the genus Sphingomonas with Sphingomonas pituitosa DSM 13101T, Sphingomonas azotifigens DSM 18530T and Sphingomonas trueperi DSM 7225T as their closest relatives sharing 97.9-98.3% 16S rRNA similarity and 91.3-94.0% recA similarity values, respectively. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridisation (dDDH) values between L3B27T (representative of the novel strains) and its phylogenetically closest Sphingomonas species were well below the established cut-off <94% (ANI/AAI) and <70% (dDDH) for species delineation. Further, the novel strains can be distinguished from its closest relatives based on several phenotypic traits. Thus, based on the polyphasic approach, we describe a novel Sphingomonas species for which the name Sphingomonas pokkalii sp. nov (type strain L3B27T=KCTC 42098T=MCC 3001T) is proposed. In addition, the novel strains were characterised for their plant associated properties and found to possess several phenotypic traits which probably explain its plant associated lifestyle. This was further confirmed by the presence of several plant associated gene features in the genome of L3B27T. Also, we could identify gene features which may likely involve in brackish water adaptation. Thus, this study provides first insights into the plant associated lifestyle, genome and taxonomy of a novel brackish adapted plant associated Sphingomonas.

Acidovorax kalamii sp. nov., isolated from a water sample of the river Ganges.

A Gram-stain-negative, rod-shaped, aerobic, straw yellow, motile strain, designated KNDSW-TSA6T, belonging to the genus Acidovorax, was isolated from a water sample of the river Ganges, downstream of the city of Kanpur, Uttar Pradesh, India. Cells were aerobic, non-endospore-forming and motile with single polar flagella. It differed from its phylogenetically related strains by phenotypic characteristics such as hydrolysis of urea, gelatin, casein and DNA, and the catalase reaction. The major fatty acids were C16 : 1ω7c/C16 : 1ω6c, C16 : 0 and C18 : 1ω7c/C18 : 1ω6c. Phylogenetic analysis based on 16S rRNA and housekeeping genes (gyrb, recA and rpoB gene sequences), confirmed its placement within the genus Acidovorax as a novel species. Strain KNDSW-TSA6T showed highest 16S rRNA sequence similarity to Acidovorax soli BL21T (98.9 %), Acidovorax delafieldii ATCC 17505T (98.8 %), Acidovorax temperans CCUG 11779T (98.2 %), Acidovorax caeni R-24608T (97.9 %) and Acidovorax radicis N35T (97.6 %). The digital DNA-DNA hybridization and average nucleotide identity values calculated from whole genome sequences between strain KNDSW-TSA6T and the two most closely related strains A. soli BL21T and A. delafieldii ATCC 17505T were below the threshold values of 70 and 95 % respectively. Thus, the data from the polyphasic taxonomic analysis clearly indicates that strain KNDSW-TSA6T represents a novel species, for which the name Acidovorax kalamii sp. nov. is proposed. The type strain is Acidovorax kalamii (=MTCC 12652T=KCTC 52819T=VTCC-B-910010T).

Pseudomonas fluvialis sp. nov., a novel member of the genus Pseudomonas isolated from the river Ganges, India.

A bacterial strain, designated ASS-1T, was isolated and identified from a sediment sample of the river Ganges, Allahabad, India. The strain was Gram-stain-negative, formed straw-yellow pigmented colonies, was strictly aerobic, motile with a single polar flagellum, and positive for oxidase and catalase. The major fatty acids were C16 : 1ω7c/ 16 : 1 C16 : 1ω6c, C18 : 1ω7c and C16 : 0. Sequence analysis based on the 16S rRNA gene revealed that strain ASS-1T showed high similarity to Pseudomonas guguanensis CC-G9AT (98.2 %), Pseudomonas alcaligenes ATCC 14909T (98.2 %), Pseudomonas oleovorans DSM 1045T (98.1 %), Pseudomonas indolxydans IPL-1T (98.1 %) and Pseudomonas toyotomiensis HT-3T (98.0 %). Analysis of its rpoB and rpoD housekeeping genes confirmed its phylogenetic affiliation and showed identities lower than 93 % with respect to the closest relatives. Phylogenetic analysis based on the 16S rRNA, rpoB, rpoD genes and the whole genome assigned it to the genus Pseudomonas. The results of digital DNA-DNA hybridization based on the genome-to-genome distance calculator and average nucleotide identity revealed low genome relatedness to its close phylogenetic neighbours (below the recommended thresholds of 70 and 95 %, respectively, for species delineation). Strain ASS-1T also differed from the related strains by some phenotypic characteristics, i.e. growth at pH 5.0 and 42 °C, starch and casein hydrolysis, and citrate utilization. Therefore, based on data obtained from phenotypic and genotypic analysis, it is evident that strain ASS-1T should be regarded as a novel species within the genus Pseudomonas, for which the name Pseudomonasfluvialis sp. nov. is proposed. The type strain is ASS-1T (=KCTC 52437T=CCM 8778T).

Fictibacillus aquaticus sp. nov., isolated from downstream river water.

A Gram-stain-positive, facultatively anaerobic bacterial strain, GDSW-R2A3T, was isolated from a downstream water sample collected from the river Ganges, India. Analysis of the 16S rRNA gene sequence of strain GDSW-R2A3T revealed its affiliation to the family Bacillaceae. Further analysis using a polyphasic approach revealed that strain GDSW-R2A3T was most closely related to the genus Fictibacillus. Analysis of the almost-complete (1488 bp) 16S rRNA gene sequence of strain GDSW-R2A3T revealed the highest level of sequence similarity with Fictibacillus phosphorivorans CCM 8426T (98.3 %) and Fictibacillus nanhaiensis KCTC 13712T (98.3 %) followed by Fictibacillus barbaricus DSM 14730T (98.0 %). The digital DNA-DNA hybridization and average nucleotide identity (ANI) values between strain GDSW-R2A3T and the most closely related taxon, F. phosphorivorans CCM 8426T, were 20.3 and 78.2 %, respectively. The DNA G+C content of the strain was 44.2 mol%. The cell-wall amino acid was meso-diaminopimelic acid. Polar lipids present were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, three aminophospholipids, two phospholipids and one unidentified lipid; the major menaquinone was MK-7; iso-C14 : 0, iso-C15 : 0 and anteiso-C15 : 0 were the major fatty acids. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, it can be concluded that strain GDSW-R2A3T represents a novel species of the genus Fictibacillus, for which the name Fictibacillus aquaticus sp. nov. is proposed. The type strain is GDSW-R2A3T (=VTCC-B-910015T=CCM 8782T).

Thauera propionica sp. nov., isolated from downstream sediment sample of the river Ganges, Kanpur, India.

A Gram-stain-negative, non-endospore-producing, short-rod strain, KNDSS-Mac4T, was isolated from a downstream sediment sample of the river Ganges, Kanpur, India and studied by using the polyphasic taxonomic approach. 16S rRNA gene sequence analysis uncovered that the strain had similarity to species of the genus Thauera and formed a distinct phylogenetic cluster with Thauera humireducens KACC16524T. However, KNDSS-Mac4T showed closest phylogenetic affiliation to Thauera aminoaromatica DSM 14742T with 16S rRNA gene sequence similarity of 98.7 % followed by Thauera phenylacetica DSM 14743T (98.6 %), Thauera chlorobenzoica (98.2 %), T. humireducens KACC16524T (98.2 %), Thauera selenatis ATCC 55363T (98.2 %) and Thauera mechernichensis DSM 12266T (98.0 %). The digital DNA-DNA hybridization and average nucleotide identity values between strain KNDSS-Mac4T and the two most closely related taxa, T. aminoaromatica DSM 14742T and T. phenylacetica DSM 14743T, were 26.0, 26.7 and 84.0, 84.3 % respectively. Major lipids present were phosphatidylglycerol, three unknown aminophospholipids, phosphatidylmethylethanolamine, two unidentified lipids and Q-8 as the only ubiquonone. The major cellular fatty acids present were C16 : 1 ω6c/C16 : 1ω7c and C16 : 0. The DNA G+C content of strain KNDSS-Mac4T was 65.9 %. Based on data from phenotypic tests and the genotypic differences of strain KNDSS-Mac4T from its closest phylogenetic relatives, it is evident that this isolate should be regarded as a new species. It is proposed that strain KNDSS-Mac4T should be classified in the genus Thauera as a novel species, Thauerapropionica sp. nov. The type strain is KNDSS-Mac4T (=KCTC 52820T=VTCC-B-910017T).

An investigation into the taxonomy of "Bacillus aminovorans" and its reclassification to the genus Domibacillus as Domibacillus aminovorans sp. nov.

The species "Bacillus aminovorans" was categorized as species Incertae Sedis meaning taxa with uncertain taxonomic position because of insufficient description of phenotypic properties and lack of understanding of its phylogenetic relationship (Claus and Berkeley [5]). In this study two strains "B. aminovorans" DSM 1314T and DSM 4337 were phenotypically and phylogenomically analyzed. The strains are Gram-staining-positive, spore forming rods and unable to utilize/ferment most of the sugars tested except glucose. The major fatty acids are anteiso-C15:0 and iso-C15:0. The major polar lipids are diphosphatidylglycerol, phosphatidylglycerol and an aminophosphoglycolipid. The cell wall peptidoglycan is of A1γ type with meso-Dpm as the diamino acid. The menaquinone type present is MK-6. The G+C content of the genomic DNA of the type strain is 40.8mol%. These characteristics were found to be in line with description of the genus Domibacillus. Moreover phylogenetic analysis based on 16S rRNA gene sequence retrieved "B. aminovorans" within the genus Domibacillus with D. antri XD 80T as the closest relative. Additionally genome sequencing of the strains and their comparison with whole genome sequences of other Domibacillus spp. confirmed their distinctiveness and separate species status within the genus based on parameters of genome to genome distance calculator (GGDC) and average nucleotide identity (ANI) values. Therefore a novel species Domibacillus aminovorans sp. nov. (DSM 1314T=LMG 16796T) is proposed.

Examination into the taxonomic position of Bacillus thermotolerans Yang et al., 2013, proposal for its reclassification into a new genus and species Quasibacillus thermotolerans gen. nov., comb. nov. and reclassification of B. encimensis Dastager et al., 2015 as a later heterotypic synonym of B. badius.

Two novel Gram-staining positive, rod-shaped, moderately halotolerant, endospore forming bacterial strains 5.5LF 38TD and 5.5LF 48TD were isolated and taxonomically characterized from a landfill in Chandigarh, India. The analysis of 16S rRNA gene sequences of the strains confirmed their closest identity to Bacillus thermotolerans SgZ-8T with 99.9% sequence similarity. A comparative phylogenetic analysis of strains 5.5LF 38TD, 5.5LF 48TD and B. thermotolerans SgZ-8T confirmed their separation into a novel genus with B. badius and genus Domibacillus as the closest phylogenetic relatives. The major fatty acids of the strains are iso-C15:0 and iso-C16:0 and MK-7 is the only quinone. The major polar lipids are diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The digital DNA-DNA hybridization (DDH) and ortho average nucleotide identity (ANI) values calculated through whole genome sequences indicated that the three strains showed low relatedness with their phylogenetic neighbours. Based on evidences from phylogenomic analyses and polyphasic taxonomic characterization we propose reclassification of the species B. thermotolerans into a novel genus named Quasibacillus thermotolerans gen. nov., comb. nov with the type strain SgZ-8T (=CCTCC AB2012108T=KACC 16706T). Further our analyses also revealed that B. encimensis SGD-V-25T is a later heterotypic synonym of Bacillus badius DSM 23T.