Purification and characterization of anti-phytopathogenic fungi angucyclinone from soil-derived Streptomyces cellulosae

Discovering the secondary metabolic potential of Saccharothrix

Rare actinomycetes are highly valued as potential sources of novel bioactive secondary metabolites. Among these rare actinomycetes, the genus Saccharothrix is particularly noteworthy due to its ability to produce a diverse range of bioactive secondary metabolites. With the continuous sequencing of bacterial genomes and the rapid development of bioinformatics technologies, our knowledge of the secondary metabolic potential of Saccharothrix can become more comprehensive, but this space has not been reviewed or explored. This review presents a detailed overview of the chemical structures and bioactivities of 138 Saccharothrix-derived secondary metabolites, which are classified into five distinct groups based on their biosynthetic pathways. Furthermore, we delve into experimentally characterized biosynthetic pathways of nine bioactive metabolites. By utilizing a combination of cheminformatic and bioinformatic approaches, we attempted to establish connections between the metabolite families and the biosynthetic gene cluster families encoded by Saccharothrix strains. Our analysis provides a comprehensive perspective on the secondary metabolites that can be linked to corresponding BGCs and highlights the underexplored biosynthetic potential of Saccharothrix. This review also provides guidance for the targeted discovery and biosynthesis of novel natural products from Saccharothrix.

Mechanistic insights into the role of actinobacteria as potential biocontrol candidates against fungal phytopathogens

Worldwide mounting demand for better food production to nurture exasperating population emphasizes on reduced crop losses. The incidence of pathogens into the agricultural fields has tend to dwindle plethora of cereal, vegetable, and other fodder crops. This, in turn, has seriously impacted the economic losses on global scale. Apart from this, it is quite challenging to feed the posterity in the coming decades. To counteract this problem, various agrochemicals have been commercialized in the market that no doubt shows positive results but along with adversely affecting the ecosystem. Therefore, the excessive ill-fated use of agrochemicals to combat the plant pests and diseases highlights that alternatives to chemical pesticides are need of the hour. In recent days, management of plant diseases using plant-beneficial microbes is gaining interest as safer and potent alternatives to replace chemically based pesticides. Among these beneficial microbes, actinobacteria especially streptomycetes play considerable role in combating plant diseases along with promoting the plant growth and development along with their productivity and yield. The mechanisms exhibited by actinobacteria include antibiosis (antimicrobial compounds and hydrolytic enzymes), mycoparasitism, nutrient competition, and induction of resistance in plants. Thus, in cognizance with potential of actinobacteria as potent biocontrol agents, this review summarizes role of actinobacteria and the multifarious mechanisms exhibited by actinobacteria for commercial applications.