In cases where important compounds are isolated from marine invertebrates, bacteria associated with the invertebrates may actually be the source of the compounds of interest. If these bacteria can be isolated and cultured , the compound can be produced by bacterial fermentation rather than relying on harvesting of the invertebrate, which may deplete its natural population. The microbiology of several sponge from the Great Barrier reef is under study, with 16S ribosomal RNA sequencing being used to characterize microbes, including many unusual cyanobacteria. A major research focus is metal resistance in actinomycetes. Marine actinomycetes have been isolated that are highly resistant to toxic metals, including mercury, cadmium, cobalt and zinc.
Molecular studies are most advanced in the case of mercury resistance.
Cloning and expression of Rhodococcus genes encoding pigment production in Escherichia coli . J. Gen. Microbiol. Hill, R. T. , I. T. Knight, M. Anikis, and R. R. Colwell. Benthic distribution of sewage sludge indicated by Clostridium perfringens at a deep-ocean dumpsite. Takizawa, M., R. R. Colwell, and R. T. Hill. 1993.