Taxonomic and Metabolite Diversities of Moss-Associated Actinobacteria from Thailand

Abstract

Actinobacteria are a group of ecologically important bacteria capable of producing diverse bioactive compounds. However, much remains unknown about the taxonomic and metabolic diversities of actinobacteria from many geographic regions and ecological niches. In this study, we report the isolation of actinobacteria from moss and moss-associated rhizosphere soils in Thailand. Among the 89 isolates analyzed for their bioactivities, 86 strains produced indole-3-acetic acid (IAA, ranging from 0.04 to 59.12 mg/L); 42 strains produced hydroxamate type of siderophore; 35 strains produced catecholate type of siderophore; 21 strains solubilized tricalcium phosphate; and many strains exhibited antagonistic activities against one to several of the seven selected plant, animal, and human pathogens. Overall, actinobacteria from the rhizosphere soil of mosses showed greater abilities to produce IAA and siderophores and to solubilize tricalcium phosphate than those from mosses. Among these 89 isolates, 37 were analyzed for their 16S rRNA gene sequences, which revealed their diverse phylogenetic distributions among seven genera, Streptomyces, Micromonospora, Nocardia, Actinoplanes, Saccharothrix, Streptosporangium, and Cryptosporangium. Furthermore, gas chromatography-mass spectrometry analyses of ethyl acetate crude extracts of three selected isolates with inhibitory effects against a methicillin-resistant Staphylococcus aureus strain revealed diverse metabolites with known antimicrobial activities. Together, our results demonstrate that actinobacteria from mosses in Thailand are taxonomically diverse and capable of producing a range of metabolites with plant-growth-promoting and microbial pathogen-inhibiting potentials.

Antimicrobial Activities and Painting Application of Pigmented-Producing Actinobacteria Isolated from Rhizospheric Soils of Mosses (Taxithelium nepalense (Schwägr.) Broth. and Barbula indica (Hook.) Spreng.)

“…Streptomyces was recovered from soils in different regions and described more than 1,000 species (Law et al 2019;Rammali et al 2022). In this decade, a variety of actinobacterial taxa were isolated from soils in Thailand (Sripreechasak et al 2013;Klaysubun et al 2022;Insuk et al 2022). They were applied to biotechnological utilization included industrial, medical and others (El Othmany et al 2021;Xie and Pathom-Aree 2021).…”

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Actinobacteria were found in rhizospheric soils of mosses distributed in natural and human-made habitats, such as on the ground, tree trunks, or concrete surfaces. They are gram-positive filamentous, freeliving and saprophytic bacteria (Insuk et al 2022). The beneficial roles of these actinobacteria were assumed that they play important roles in nutrient cycling, soil temperature and moisture controls, and biodegradation and decomposition (Insuk et al 2020;Holland-Moritz et al 2021).

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Comparative analysis of salicylic acid levels and gene expression in resistant, tolerant, and susceptible cassava varieties following whitefly-mediated SLCMV infection

“…The cartridges were washed with 2 mL of 1 M formic acid and eluted with 2 mL of MeOH + 1% formic acid. The eluates were dried and derivatized as previously described 32 before GC–MS analyzes.…”

The Natural Products Discovery Center: Release of the First 8490 Sequenced Strains for Exploring Actinobacteria Biosynthetic Diversity

“…6 Actinobacteria, recently renamed as Actinomycetota, 7 are found ubiquitously, spanning environments from soil and plants (e.g., Streptomyces and Micromonospora) to humans (e.g., Corynebacterium and Mycobacterium). 8,9,10 The expansive secondary metabolomes of most non-pathogenic Actinobacteria enable them to rapidly adapt to changes in their unique ecological niches due to highly diverse scaffolds and fine-tuned regulation. 11 Consequently, Actinobacteria have emerged as the most extensively studied bacterial phylum for NP discovery, accounting for more than 60% of all characterized bacterial NPs (Fig.…”