Antivibriosis and cytotoxicity of Actinobacteria associated with red seaweed Gelidiella acerosa

Vibriosis causes a problem in aquaculture and human health. The antibiotic resistance and the limited availability of antimicrobial agents are the driving force for searching for new antivibrio compounds from natural products. Herein, we evaluated ten marine Actinobacteria isolated from red seaweed Gelidiella acerosa for antivibriosis, cytotoxicity and secondary metabolites genes in the way to find a new antivibrio agent. Five Actinobacteria isolates exhibited activity against Vibrio alginolyticus and Vibrio parahaemolyticus with MIC ranging from 0.625 to 5 µg/µl. All isolates displayed no cytotoxicity against Vero cell line except for isolate DR-2R-115–8. All isolates harbour nrps gene, which might indicate that these isolates have great potential in the production of bioactive peptides while none of the isolates showed the presence of pks I, II and hmgcr genes. Identification of ten isolates of marine Actinobacteria associated with red algae was classified into four genera of Brevibacterium, Nocardiopsis, Allokutzneria and Brachybacterium. Our study revealed that the marine Actinobacteria associated with red algae Gelidiella acerosa were promising sources for controlling vibriosis. © 2021 John Wiley & Sons Ltd