Enhancing the activity of Amycolatopsis orientalis, a producer of antibiotic eremomycin, and study of its antibacterial action

The widespread use of antibiotics in agriculture is associated with emerging challenges, which underscores the relevance of searching for and developing effective antimicrobial agents. The aim of this work was to obtain a new highly productive strain producing the glycopeptide antibiotic eremomycin and to evaluate the antibacterial activity of a partially purified preparation isolated from the culture liquid of the obtained strain. A new strain – Amycolatopsis orientalis E 27-22 – was obtained through a combination of multistage selection and non-targeted ultraviolet mutagenesis. A simplified isolation of eremomycin was carried out by single-step sorption from the culture filtrate onto a macroporous resin. The antibacterial activity against a number of gram-positive test cultures (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis, Clostridium perfringens) was evaluated using agar diffusion and minimum inhibitory concentration determination methods, in comparison with commercial vancomycin and highly purified eremomycin. The productivity of the new strain ranged 4.51±0.23 g/L, which is 31.87% higher than that of the parent strain Amycolatopsis orientalis VKM Ac-2717D. The eremomycin content in the partially purified preparation reached 70.0 ± 2.0 wt%. Despite the simplified isolation technology, the obtained preparation was shown to retain high biological activity, being no more than twofold less active than the reference antibiotics, and comparable to vancomycin against Micrococcus luteus and Clostridium perfringens. The results obtained confirm the feasibility of further development of a simplified isolation process for potential application in agriculture.