Utilizing the co-culture method to improve the investigation of secondary metabolites of marine bacteria

Marine bacteria, particularly those from the Actinomycetes class, such as Streptomyces spp., represent a promising source of new compounds with various bioactivities. Although the number of reported compounds is increasing, there is still massive potential for producing new compounds if cryptic gene clusters can be activated. Co-culture is one of the techniques used to activate these cryptic gene clusters. However, the results of co-culture may not only be new compounds. Therefore, we collected literature on the co-culture of marine bacteria published between 2012 and 2022 from databases such as Google Scholar, PubMed, and Scopus. The results showed that co-culturing marine bacteria may result in one of the three groups: 1) increased yield of bioactivities and/or bioactive compounds, 2) production of known compounds that were not present in single-strain cultures, and 3) production of previously undescribed compounds. The results suggest that co-culture cannot be universally applied to generate new compounds, as the outcome of the co-culture system is often specific to each study.