Whole-genome analysis and secondary metabolites production of a new strain Brevibacillus halotolerans 7WMA2: A potential biocontrol agent against fungal pathogens.

The extensive usage of synthetic fungicides against fungal diseases has caused adverse impacts on both human and agricultural crops. Therefore, the current study aims to establish a new bacterium 7WMA2, as a biocontrol agent to achieve better antifungal results. The strain 7WMA2 was isolated from marine sediment, displayed a broad spectrum of several fungi that includes Alternaria alternata, Cladosporium sp., Candida albicans, Fusarium oxysporum, Trichosporon pullulans, and Trichophyton rubrum. The 16S rRNA phylogeny inferred that strain 7WMA2 was a member of Brevibacillus. The phylogenetic and biochemical analyses revealed that the strain 7WMA2 belongs to the species of Brevibacillus halotolerans. The complete genome sequence of Brevibacillus halotolerans 7WMA2 consists of a circular chromosome of 5,351,077 bp length with a GC content of 41.39 mol %, including 4433 CDS, 111 tRNA genes, and 36 rRNA genes. The genomic analysis showed 23 putative biosynthetic secondary metabolite gene clusters responsible for non-ribosomal peptides, polyketides and siderophores. The antifungal compounds concentrated from cell-free fermentation broth demonstrated strong inhibition of fungi, and the compounds are considerably thermal stable and adaptable to pH range 2-12. This complete genome sequence has provided insight for further exploration of antagonistic ability and its secondary metabolite compounds indicated feasibility as biological control agents against fungal infections.

Morpho-Anatomical Study And Botanical Identification of Pogostemon auricularius (L.) Hassk. (Lamiaceae).

Pogostemon Desf. includes a wide range of taxa found in subtropical and tropical areas. Few works, however, have studied microanatomical characteristics of Pogostemon species and as yet identified features of Pogostemon auricularius (L.) Hassk. Thus, in this paper, we examined the taxonomic implications of root, stem and leaf morphology for species P. auricularius collected from Quang Tri Province. Light microscopy was mainly used in our study. Qualitative characters like stem quadrangular, hirsute; leaves opposite, ovate, margin serrulate; calyx campanulate; corolla small with separate equal lobes have been found in P. auricularius. Epidermal anatomy on the aerial parts of the species like epidermal cell shape, anticlinal walls, trichomes types, stomata types and calcium oxalate crystals types were examined as well. Quantitative characters like the length and width of leaf blade and inflorescence; the size of oil droplet, stomata and calcium oxalate crystals measured provided taxonomic significance. Based on identifying morphological characteristics of P. auricularius, we aimed to contribute to the taxonomic investigation into the genus Pogostemon and give relative morphological and microanatomical features compared with other taxa.