Cultivable Actinobacteria First Found in Baikal Endemic Algae Is a New Source of Natural Products with Antibiotic Activity

Abstract

Inadequate use of antibiotics has led to spread of microorganisms resistant to effective antimicrobial compounds for humans and animals. This study was aimed to isolate cultivable strains of actinobacteria associated with Baikal endemic alga Draparnaldioides baicalensis and estimate their antibiotic properties. During this study, we isolated both widespread and dominant strains related to the genus Streptomyces and representatives of the genera Saccharopolyspora, Nonomuraea, Rhodococcus, and Micromonospora. For the first time, actinobacteria belonging to the genera Nonomuraea and Saccharopolyspora were isolated from Baikal ecosystem. Also, it was the first time when actinobacteria of the genus Nonomuraea were isolated from freshwater algae. Some rare strains demonstrated activity inhibiting growth of bacteria and yeasts. Also, it has been shown that the strains associated with Baikal alga D. baicalensis are active against both Gram-positive and Gram-negative bacteria. According to this study and previously published materials, diversity of cultivable actinobacteria and rare strains isolated from D. baicalensis is comparable to that of cultivable actinobacteria previously isolated from plant sources of Lake Baikal. Also, it exceeds the cultivable actinobacteria diversity previously described for macroinvertebrates, water, or sediments of Lake Baikal. The large number of rare and active strains associated with the endemic alga D. baicalensis could be the promising sources for biopharmaceutical and biotechnological developments and discovery of new natural compounds.

Isolation, Characterization, and Efficacy of Actinobacteria Associated with Arbuscular Mycorrhizal Spores in Promoting Plant Growth of Chili (Capsicum flutescens L.)

“…Numerous previous studies have focused on plant growth promoting actinobacteria that have been isolated from rhizosphere soils and are found inside various plants [10][11][12]. Currently, many researchers have focused on new types of habitats such as lichens [13], algae [14], mycorrhizosphere [15], and mangrove sediments [16] for the isolation of plant growth prompting actinobacteria, which can help overcome the challenges of discovering high efficacy strains. Thus, this study aimed to isolate actinobacteria associated with arbuscular mycorrhiza fungal (AMF) spores and investigate their plant growth promoting properties (production of IAA, siderophores, ammonia and cell wall degrading enzymes, and solubilization of phosphorus and potassium minerals).…”

Natural Products and Biological Activity from Actinomycetes Associated with Marine Algae

“…Then, colonies are selected, and pure cultures are obtained by repeated streaking on agar plates. Finally, actinomycetes-like strains are selected based on the colony morphology: solid density of colonies, growth inside the agar media, and steady border of the colonies [ 32 ].…”

Human impact and ecosystemic health at Lake Baikal

“…Biakal's biodiversity could serve as the foundation for future sustainable biotechnology enterprises. Among the great number and variety of highly valuable ecosystem services that Lake Baikal can provide, Baikal endemics could serve as the source of novel biomaterials and biocomposites, new biologically active substances, antibiotics, and other compounds for pharmacology, biomedicine, veterinary and aquaculture (Axenov‐Gribanov et al, 2020; Protasov et al, 2017; Protasov et al, 2020; Protasov, Axenov‐Gribanov, Shatilina, Timofeyev, & Lane, 2020; Voitsekhovskaia et al, 2020). Baikal algae could be used to enhance the cosmetics and food industries (Timofeyev, 2020).…”