Aquipluma nitroreducens gen. nov. sp. nov., a novel facultatively anaerobic bacterium isolated from a freshwater lake

Baseline metagenome-assembled genome (MAG) data of Sikkim hot springs from Indian Himalayan geothermal belt (IHGB) showcasing its potential CAZymes, and sulfur-nitrogen metabolic activity

Here we present the construction and characterization of metagenome assembled genomes (MAGs) from two hot springs residing in the vicinity of Indian Himalayan Geothermal Belt (IHGB). A total of 78 and 7 taxonomic bins were obtained for Old Yume Samdong (OYS) and New Yume Samdong (NYS) hot springs respectively. After passing all the criteria only 21 and 4 MAGs were further studied based on the successful prediction of their 16 S rRNA. Various databases were used such as GTDB, Kaiju, EzTaxon, BLAST XY Plot and NCBI BLAST to get the taxonomic classification of various 16 S rRNA predicted MAGs. The bacterial genomes found were from both thermophilic and mesophilic bacteria among which Proteobacteria, Chloroflexi, Bacteroidetes and Firmicutes were the abundant phyla. However, in case of OYS, two genomes belonged to archaeal Methanobacterium and Methanocaldococcus. Functional characterization revealed the richness of CAZymes such as Glycosyl Transferase (GT) (56.7%), Glycoside Hydrolase (GH) (37.4%), Carbohydrate Esterase family (CE) (8.2%), and Polysaccharide Lyase (PL) (1.9%). There were negligible antibiotic resistance genes in the MAGs however, a significant heavy metal tolerance gene was found in the MAGs. Thus, it may be assumed that there is no coexistence of antibiotic and heavy metal resistance genes in these hot spring microbiomes. Since the selected hot springs possess good sulfur content thus, we also checked the presence of genes for sulfur and nitrogen metabolism. It was found that MAGs from both the hot springs possess significant number of genes related to sulfur and nitrogen metabolism.

Gaoshiqia sediminis gen. nov., sp. nov., isolated from coastal sediment

A Gram-stain-negative, facultative anaerobic, motile, rod-shaped and orange bacterium, designated A06^T, was obtained off the coast of Weihai, PR China. Cells were 0.4-0.5×0.6-1.0 µm in size. Strain A06^T grew at 20-40 °C (optimum, 33 °C), at pH 6.0-8.0 (optimum, pH 6.5-7.0) and in the presence of 0-8 % NaCl (w/v) (optimum, 2 %). Cells were oxidase and catalase positive. Menaquinone-7 was detected as the major respiratory quinone. The dominant cellular fatty acids were identified as C_15:0 2-OH, iso-C_15:0, anteiso-C_15:0 and iso-C_15:1  ω6c. The DNA G+C content of strain A06^T was 46.1 mol%. The polar lipids were phosphatidylethanolamine, one aminolipid, one glycolipid and three unidentified lipids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A06^T is a member of the family Prolixibacteraceae and exhibited the highest sequence similarity to Mangrovibacterium diazotrophicum DSM 27148^T (94.3 %). Based on its phylogenetic and phenotypic characteristics, strain A06^T is considered to represent a novel genus in the family Prolixibacteraceae, for which the name Gaoshiqia gen. nov. is proposed. The type species is Gaoshiqia sediminis sp. nov., with type strain A06^T (=KCTC 92029^T=MCCC 1H00491^T). The identification and acquisition of microbial species and genes in sediments will help broaden the understanding of microbial resources and lay a foundation for its application in biotechnology. Strain A06^T uses an enrichment method, so the isolation of strain A06^T is of great significance to the enrichment of marine microbial resources.

Whether interstitial space features were the main factors affecting sediment microbial community structures in Chaohu Lake

Sediments cover a majority of Earth's surface and are essential for global biogeochemical cycles. The effects of sediment physiochemical features on microbial community structures have attracted attention in recent years. However, the question of whether the interstitial space has significant effects on microbial community structures in submerged sediments remains unclear. In this study, based on identified OTUs (operational taxonomic units), correlation analysis, RDA analysis, and Permanova analysis were applied into investigating the effects of interstitial space volume, interstitial gas space, volumetric water content, sediment particle features (average size and evenness), and sediment depth on microbial community structures in different sedimentation areas of Chaohu Lake (Anhui Province, China). Our results indicated that sediment depth was the closest one to the main environmental gradient. The destruction effects of gas space on sediment structures can physically affect the similarity of the whole microbial community in all layers in river dominated sedimentation area (where methane emits actively). However, including gas space, none of the five interstitial space parameters were significant with accounting for the microbial community structures in a sediment layer. Thus, except for the happening of active physical destruction on sediment structures (for example, methane ebullition), sediment interstitial space parameters were ineffective for affecting microbial community structures in all sedimentation areas.