Isolation and Identification of Actinobacteria against Colletotrichum, the Causal Agent of Anthracnose Disease of Mangifera indica L.

Actinobacteria are a large group of gram-positive bacteria classified into Streptomyces and non-Streptomyces genera.Streptomyces is commonly found in nature, especially in soil samples collected in different geographic properties.It is well-known in its capability to produce bioactive compounds, including antimicrobials, immunostimulants, anticancer, and antioxidants.The aims of this study were concentrated on the isolation and screening of the antifungal-producing actinobacteria from termite mound soil and wasp soil against Colletotrichum using culture-dependent techniques with Sodium Caseinate Agar (SCA) and spread plate technique.A total of 45 actinobacterial strains were isolated and purified for testing of antifungal features.The inhibitory activities against Colletotrichum sp.PSRU-NDM65, the plant pathogen of anthracnose disease of Mangifera indica L. were tested by dual culture technique on Potato Dextrose Agar (PDA).The results indicated that two isolates, namely TM-A3 and TM-A7, had the highest percentage of inhibition against Colletotrichum sp.PSRU-NDM65 growth by 87.79% and 85.81%, respectively.Based on the morphological studies, both actinobacterial isolates produce the long chain of spore and hypha which are fitted with the typical characters of Streptomyces.Concomitantly, comparative analysis of 16S rDNA partial nucleotide sequences revealed that TM-A3 and TM-A7 belonged to the Streptomyces genus based on 99.7% similarity and 100% identity to Streptomyces misionensis and Streptomyces prasinopilosus, respectively.In the future, utilization of two Streptomyces strains will be applied on farms planted with economical Mangifera spp., and other horticulture plants.