Optimization of culture medium for improved production of antimicrobial compounds by Amycolatopsis sp. -AS9 isolated from vermicasts

Diversity, molecular phylogenetics, and antibiotic biosynthetic potential of endophytic Actinobacteria isolated from medicinal plants in Nigeria

Actinobacteria that are found in nature have enormous promise for the growth of the pharmaceutical sector. There is a scarce report on the antimicrobial activities of endophytic Actinobacteria from Nigeria. As a result, this study evaluated the Actinobacteria isolated from Nigerian medicinal plants in terms of their biodiversity, phylogenetics, and ability to produce antimicrobial compounds. Following accepted practices, Actinobacteria were isolated from the surface-sterilized plant parts. They were identified using 16S rRNA sequencing, microscopic, and morphological methods. The cell-free broth of Actinobacteria isolates was subjected to antimicrobial assay by agar well diffusion. Molecular evolutionary and genetic analysis (MEGA) version X was used for phylogenetic analysis, and the interactive tree of life (iTOL) version 6.0 was used to view the neighbour-joining method-drawn tree. A total of 13 Actinobacteria were recovered, belonging to three genera including 10 strains of Streptomyces, 2 strains of Saccharomonospora, and only 1 strain of Saccharopolyspora. They showed inhibitory activity against several bacterial pathogens. The phylogenetic tree generated from the sequences showed that our isolates are divergent and distinct from other closely related strains on the database. Further, optimization of the antibiotic production by selected Saccharomonospora sp. PNSac2 was conducted. It showed that the optimal conditions were the ISP2 medium (1-2% w/v salt) adjusted to pH of 8 at 30-32℃ for 12-14 days. In conclusion, endophytic Actinobacteria dwelling in Nigerian soils could be a promising source of new antibiotics. Future research is warranted because more genomic analysis and characterization of their metabolites could lead to the development of new antibacterial medicines.

Earthworms and vermicompost: an eco-friendly approach for repaying nature's debt

The steady increase in the world's population has intensified the need for crop productivity, but the majority of the agricultural practices are associated with adverse effects on the environment. Such undesired environmental outcomes may be mitigated by utilizing biological agents as part of farming practice. The present review article summarizes the analyses of the current status of global agriculture and soil scenarios; a description of the role of earthworms and their products as better biofertilizer; and suggestions for the rejuvenation of such technology despite significant lapses and gaps in research and extension programs. By maintaining a close collaboration with farmers, we have recognized a shift in their attitude and renewed optimism toward nature-based green technology. Based on these relations, it is inferred that the application of earthworm-mediated vermitechnology increases sustainable development by strengthening the underlying economic, social and ecological framework.