AUTHOR=Yu Meilin , Li Yingxin , Banakar Shivakumar P. , Liu Lu , Shao Changlun , Li Zhiyong , Wang Changyun 

TITLE=New Metabolites From the Co-culture of Marine-Derived Actinomycete Streptomyces rochei MB037 and Fungus Rhinocladiella similis 35

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.00915

DOI=10.3389/fmicb.2019.00915

ISSN=1664-302X

ABSTRACT=<p>Co-culture of different microbes simulating the natural state of microbial community may produce potentially new compounds because of nutrition or space competition. To mine its metabolic potential in depth, co-culture of <italic>Streptomyces rochei</italic> MB037 with a gorgonian-derived fungus <italic>Rhinocladiella similis</italic> 35 was carried out to stimulate the production of new metabolites in this study, using pure cultivation as control. Five metabolites were isolated successfully from co-culture broth, including two new fatty acids with rare nitrile group, borrelidins J and K (<bold>1</bold> and <bold>2</bold>), one chromone derivative as a new natural product, 7-methoxy-2,3-dimethylchromone-4-one (<bold>3</bold>), together with two known 18-membered macrolides, borrelidin (<bold>4</bold>) and borrelidin F (<bold>5</bold>). The structures of <bold>1</bold>–<bold>3</bold> were elucidated by using a combination of NMR and MS spectroscopy, ester hydrolysis, and optical rotation methods. Interestingly, <bold>1</bold> and <bold>2</bold> were obtained only in co-culture. Though <bold>3</bold> was gained from either co-culture or single culture, its production was increased significantly by co-culture. Compound <bold>1</bold> exhibited significant antibacterial activity against methicillin-resistant <italic>Staphylococcus aureus</italic> with a MIC value of 0.195 μg/mL.</p>