Endophytic actinomycetes associated with <i>Cinnamomum cassia</i> Presl in Hoa Binh province, Vietnam: Distribution, antimicrobial activity and, genetic features

Abstract

Endophytic microbes associated with medicinal plants are considered to be potential producers of various bioactive secondary metabolites. The present study investigated the distribution, antimicrobial activity and genetic features of endophytic actinomycetes isolated from the medicinal plant Cinnamomum cassia Presl collected in Hoa Binh province of northern Vietnam. Based on phenotypic characteristics, 111 actinomycetes were isolated from roots, stems and leaves of the host plants by using nine selective media. The isolated actinomycetes were mainly recovered from stems (n = 67; 60.4%), followed by roots (n = 29; 26.1%) and leaves (n = 15; 13.5%). The isolates were accordingly assigned into 5 color categories of aerial mycelium, of which gray is the most dominant (n = 42; 37.8%), followed by white (n = 33; 29.7%), yellow (n = 25; 22,5%), red (n = 8; 7.2%) and green (n = 3; 2.7%). Of the total endophytic actinomycetes tested, 38 strains (occupying 34.2%) showed antimicrobial activity against at least one of nine tested microbes and, among them, 26 actinomycetes (68.4%) revealed anthracycline-like antibiotics production. Analysis of 16S rRNA gene sequences deposited on GenBank (NCBI) of the antibioticproducing actinomycetes identified 3 distinct genera, including Streptomyces, Microbacterium, and Nocardia, among which Streptomyces genus was the most dominant and represented 25 different species. Further genetic investigation of the antibioticproducing actinomycetes found that 28 (73.7%) and 11 (28.9%) strains possessed genes encoding polyketide synthase (pks) and nonribosomal peptide synthetase (nrps), respectively. The findings in the present study highlighted endophytic actinomycetes from C. cassia Presl which possessed

Antimicrobial and cytotoxic effects of endophytic Streptomyces strains isolated from Cinnamomum cassia Presl in Vietnam

“…This is the potential source for the isolation of endophytic actinomycetes producing valuable secondary metabolites. Unfortunately, so far very few studies on the distribution and biological characteristics of endophytic actinomycetes from medicinal plants in Vietnam have been published (Phan et al, 2016;Lam, 2017;Vu et al, 2019). In this context, the present study focused on the endophytic actinomycete population associated with Cinnamomum cassia Presl which is widely used in Vietnam as traditional medicine regimen for treating various infections and chronic diseases as well.…”

“…The YIM38 culture broth of actinomycete strains were centrifuged at 10.000 rpm/min for 10 min, then the supernatances were passed 0.22 µL filters. The cell-free supernatants of Streptomyces strains were used for the evaluation of antimicrobial activity against the nine microbes using the agar well diffusion method as described before (Vu et al, 2018;Vu et al, 2019). The experiments were performed in triplicates.…”

“…The cell pellets were harvested by the centrifuge at 10.000 rpm/min in 5 min. Then, total genomic DNA was extracted as previously described by (Vu et al, 2019). The amplification of 16S rRNA gene sequence of the four Streptomyces sp.…”

OPTIMAL FERMENTATION CONDITIONS FOR ANTIBIOTIC PRODUCTION BY ENDOPHYTIC Streptomyces cavourensis YBQ59 ISOLATED FROM Cinnamomum cassia Presl

“…The antimicrobial activity of S. cavourensis YBQ59 against the nine microbes (mentioned above) was performed by using the agar well diffusion method as described previously [3,7,8]. The experiments were performed in triplicates.…”

Characterization of Endophytic Streptomyces griseorubens MPT42 and Assessment of Antimicrobial Synergistic Interactions of Its Extract and Essential Oil from Host Plant Litsea cubeba

“…Furthermore, rich-EO-content medicinal plants like L. cubeba and Cinnamomum spp. could also be one of the prevalent sources for antibiotic-producing endophytic actinobacteria conveying novel features [12,13]. In fact, it has been previously demonstrated that the ecology and evolution of endophytic microorganisms might be affected by the chemical compositions of host plant EO and the participation of endophytes in the biotransformation of EO [14].…”