Characterization and evaluation of antimicrobial and cytotoxic effects of Streptomyces sp. HUST012 isolated from medicinal plant Dracaena cochinchinensis Lour.

Abstract

A highly potent secondary metabolite producing endophytic strain, Streptomyces sp. HUST012 was isolated from the stems of the medicinal plant Dracaena cochinchinensis Lour. Strain HUST012 showed antimicrobial and antitumor activities which were significantly much higher than those of dragon's blood extracted from D. cochinchinensis Lour. On further analysis, the strain was found to produce two metabolites, SPE-B11.8 (elucidated to be a novel metabolite (Z)-tridec-7-ene-1,2,13-tricarboxylic acid) and SPE-B5.4 (elucidated as Actinomycin-D). The Minimum Inhibitory Concentration values of SPE-B11.8 against a set of test bacterial organisms (Methicillin-resistant Staphylococcus epidermis ATCC 35984, Methicillin-resistant Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883) ranged between 15.63 and 62.5 μg/ml while that for SPE-B5.4 ranged between 0.04 and 2.24 μg/ml. The compound SPE-B11.8 showed cytotoxic effect at 41.63 and 29.54 μg/ml IC50-values against Hep G2 and MCF-7, respectively, while the compound SPE-B5.4 exhibited stronger activities against them at 0.23 and 0.18 μg/ml IC50-values.

Antimicrobial potential of actinobacteria isolated from the rhizosphere of the Caatinga biome plant Caesalpinia pyramidalis Tul.

“…The extract thus obtained inhibited the growth of B. subtilis (MIC = 0.25 mg/mL) and S. aureus (MIC = 0.5 to 1 mg/mL) considerably more than what was observed in this study. Khieu et al (2015) purified compounds from S. parvulus, and one of them presented an MIC of 62.5 µg/mL for MRSA, lower than the values observed in our study. These studies corroborate our findings, and also report the action of bioactive metabolites of Streptomyces against Gram-positive and multidrug-resistant bacteria.…”

Alcaligenes endophyticus sp. nov., isolated from roots of Ammodendron bifolium

“…Our standard method was followed for the surface sterilization of roots [8,9]. Following surface sterilization, the roots were ground with 9 ml sterilized water, and the homogenate (200 µl) was spread on LB agar medium and incubated for 2 weeks at 30 C. T were obtained from the German Collection of Microorganisms and Cell Cultures (DSMZ, Germany).…”

Antimicrobial Activities and Interaction Effects of Vietnamese Litsea Cubeba (Lour.) Pers Essential Oil and Its Endophytic Actinobacteria

“…For instance, dragon's blood extract has a range of MIC/IC 50 from 4.88 to 9.77 (µg ml -1 ) against same bacterial strain MRSE, MRSA, E. coli [12]. In this study, the cultured broth of MPT28 from L. cubeba also showed the antimicrobial effect against pathogenic bacteria.…”