Production of unique natural products through micro-scale co-cultivation of marine bacteria

Nature continues to supply chemically diverse and biologically active compounds, or natural products, with historically successful potential as therapeutic leads. Unfortunately, many of the biosynthetic gene clusters remain silent, or cryptic, under laboratory culture conditions. To coax the expression of cryptic biosynthetic gene clusters in marine invertebrate-associated bacteria, the bacteria were co-cultured to facilitate interspecies interactions and metabolite production. In this study, we utilize LC/MS followed by principal component analysis (PCA) for rapid and sensitive analysis, resulting in a graphical representation of metabolic differences between co-cultures and mono-culture controls. Furthermore, culture volumes were reduced to 500µL and grown in 96-well low-evaporation plates. This system allows for the simultaneous co-cultivation and chemical profiling of hundreds of strains, greatly improving throughput. Previous studies suggested natural product biosynthesis within Streptomyces sp. was induced when co-cultured them with mycolic acid-containing bacteria¹. As a preliminary study, we selected Streptomyces sp. strains with no antibiotic activity and have shown the induction of antibiotic production upon co-culturing with mycolic acid-containing bacteria.

¹Onaka, H.; Mori, Y.; Igarashi, Y.; Furumai, T. Appl. Environ. Microbiol. 2011, 77, 400–406