Insights Into the Bacterial Fraction of Sediments from the South China Sea: Physiological, Chemotaxonomic, and Genomic Characterization of 7 Novel Members of the Bacillaceae Family

Shu-Tong Ge¹Hong Cheng^1,2*Ying-Wen Zhong^1,3Jia-Ling Tang¹Xin-Yue Huang¹Bin Wei⁴Yue-Hong Wu^1,3Chun-Sheng Wang^1,2,3*

• ¹Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang Province, China
• ²Southern Ocean Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong Province, China
• ³School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
• ⁴Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China

The family Bacillaceae is phenotypically and phylogenetically heterogeneous group of bacteria, which has vast metabolic capability in carbohydrates degradation and secondary metabolite production. Deep marine sediments harbor highly diverse microorganisms, playing important roles in ecosystem. Here, we investigated the cultivable fraction of bacteria associated with the sediments of South China Sea (n=152). After performing morphological and physiological characteristics analysis, 7 novel members of the family Bacillaceae have been established: Pseudalkalibacillus nanhaiensis sp. nov. (Strain SCS-8 T ), Paraperibacillus marinus sp. nov. (Strain SCS-26 T ), Neobacillus oceani sp. nov. (Strain SCS-31 T ), Paraperibacillus esterisolvens sp. nov. (Strain SCS-37 T ), Nanhaiella sioensis gen. nov., sp. nov. (Strain SCS-151 T ), Rossellomorea sedimentorum sp. nov. (Strain SCS-153A T ) and Peribacillus sedimenti sp. nov. (Strain SCS-155 T). These strains belong to 6 different genera within the Bacillaceae family. Illumina and Nanopore sequencing, genome annotation and comparative genomic analysis revealed that these 7 novel members has specific metabolic characteristics. Based on the comparative genomic analysis, these novel species display distinctive characteristics of genome streamlining, with smaller genome sizes and more genes related to gene transfer elements.Besides, the annotation of COG homologous protein gene clusters revealed a higher specific gene abundance in these strains in the categories of carbohydrate transport and metabolism (COG-G), secondary metabolites processes (COG-Q), and the cell membrane-related functions (COG-M).These Bacillaceae species isolated from sediment have different capability to degrade carbohydrates and produce biosynthetic products compared to other reference strains, revealing that they have unique adaptation strategies to the deep marine sediments.