Evaluation of The Pathogenic Potential of Insecticidal Serratia marcescens Strains to Humans

Apirhabdus apintestini gen. nov., sp. nov., a member of a novel genus of the family Enterobacteriaceae, isolated from the gut of the western honey bee Apis mellifera

A Gram-negative, motile, rod-shaped bacterial strain, CA-0114T, was isolated from the midgut of a western honey bee, Apis mellifera. The isolate exhibited ≤96.43 % 16S rRNA gene sequence identity (1540 bp) to members of the families Enterobacteriaceae and Erwiniaceae. Phylogenetic trees based on genome blast distance phylogeny and concatenated protein sequences encoded by conserved genes atpD, fusA, gyrB, infB, leuS, pyrG and rpoB separated the isolate from other genera forming a distinct lineage in the Enterobacteriaceae. In both trees, the closest relatives were Tenebrionicola larvae YMB-R21T and Tenebrionibacter intestinalis BIT-L3T, which were isolated previously from Tenebrio molitor L., a plastic-eating mealworm. Digital DNA-DNA hybridization, orthologous average nucleotide identity and average amino acid identity values between strain CA-0114T and the closest related members within the Enterobacteriaceae were ≤23.1, 75.45 and 76.04 %, respectively. The complete genome of strain CA-0114T was 4 451669 bp with a G+C content of 52.12 mol%. Notably, the apparent inability of strain CA-0114T to ferment d-glucose, inositol and l-rhamnose in the API 20E system is unique among closely related members of the Enterobacteriaceae. Based on the results obtained through genotypic and phenotypic analysis, we propose that strain CA-0114T represents a novel species and genus within the family Enterobacteriaceae, for which we propose the name Apirhabdus apintestini gen. nov., sp. nov. (type strain CA-0114T=ATCC TSD-396T=DSM 116385T).

Bioinformatics analysis of endophytic bacteria related to berberine in the Chinese medicinal plant Coptis teeta Wall

Endophytic microorganisms absorb nutrients and prevent pathogen damage, supporting healthy plant growth. However, the relationship between endophytic bacteria and berberine synthesis in the medicinal plant Coptis teeta Wall. remains unclear. Herein, we explored the community composition of endophytic bacteria related to berberine in roots, stems, and leaves of wild-type and cultivated C. teeta. Endophytic bacterial communities were analyzed by 16S rRNA sequencing, and berberine content in roots was analyzed by high-performance liquid chromatography. Proteobacteria, Actinobacteria, and Bacteroidetes were the major phyla, and Mycobacterium, Salmonella, Nocardioides, Burkholderia-Paraburkholderia, and Rhizobium were the dominant genera in root, stem, and leaf tissues. Root berberine content was positively correlated with total N, total P, total K, and available K in rhizosphere soil. In addition, root berberine content was positively correlated with Microbacterium and norank_f_7B-8, whereas soil total K was positively correlated with Microbacterium and Burkholderia-Paraburkholderia in roots. Our results demonstrated a clear correlation between dominant endophytic bacteria and berberine synthesis in C. teeta. The findings are useful for the promotion of berberine production in C. teeta via manipulation of endophytic bacteria.