An Introduction to Actinobacteria

Abstract

Actinobacteria, which share the characteristics of both bacteria and fungi, are widely distributed in both terrestrial and aquatic ecosystems, mainly in soil, where they play an essential role in recycling refractory biomaterials by decomposing complex mixtures of polymers in dead plants and animals and fungal materials. They are considered as the biotechnologically valuable bacteria that are exploited for its secondary metabolite production. Approximately, 10,000 bioactive metabolites are produced by Actinobacteria, which is 45% of all bioactive microbial metabolites discovered. Especially Streptomyces species produce industrially important microorganisms as they are a rich source of several useful bioactive natural products with potential applications. Though it has various applications, some Actinobacteria have its own negative effect against plants, animals, and humans. On this context, this chapter summarizes the general characteristics of Actinobacteria, its habitat, systematic classification, various biotechnological applications, and negative impact on plants and animals.

Multi-Omics and Targeted Approaches to Determine the Role of Cellular Proteases in Streptomyces Protein Secretion

“…Microorganisms of the family Streptomycetaceae are filamentously growing key players in soil habitats all around the planet, where they vitally contribute as decomposers to recycle organic material ( Hopwood, 2007 ; Barka et al, 2016 ; Ranjani et al, 2016 ). To fulfill this duty, Streptomyces produce and secrete a large arsenal of extracellular enzymes including proteases, enabling them to exploit complex proteinogenic resources ( Chater, 2016 ).…”

Antibacterial Potential of Secondary Metabolites from Indonesian Marine Bacterial Symbionts

“…On the ISP1 medium, all of them produced white spores, but when grown on the ISP2 medium, they exhibited different colors of spores, i.e., white, pale yellow, greenish, or grey ( Figure 1 ). All spores have velvety or powdery form and pigmentation which are the main characteristics for Streptomyces [ 23 ]. Pigments produced by bacteria were grouped into two types: melanoid and other pigments [ 16 ].…”

“…Melanoid pigment production is indicated by a brown or black appearance on the reverse side of the colony. Bacteria may also produce other pigments such as red, yellow, green, blue, or violet, which are coded as distinctive (d), whereas pale yellow, olive, or yellowish brown are considered non-distinctive [ 22 , 23 ]. None of the 12 isolates produced any pigments when growth on ISP1 agar ( Table 2 ).…”

Plant-Associated Microorganisms as a Potent Bio-Factory of Active Molecules against Multiresistant Pathogens

“…Actinobacteria phyla have a high G + C DNA content and share both the characteristics of bacteria and fungi. These Gram-positive filamentous bacteria belong to one of the largest taxonomic groups recognized in the Bacteria domain, widely distributed across ecosystems [86][87][88].…”