Natural product discovery & development of a novel method to quantify bacteria from marine habitats in remote locations

Bacteria are an important source of natural products; however, only 1% of all bacterial species have been cultivated through the use of standard laboratory methods. To isolate new bacteria and potentially discover untapped resources of natural products, new isolation methods are required. The Kerr lab modified one such device, the isolation chip (ichip), for use in marine sponges. A representative sample of microbes isolated from marine sponges using the Kerr lab's ichip was fermented in various media to induce natural product biosynthesis. This resulted in the production of four putatively novel metabolites. One of these metabolites, referred to as metabolite 1, was confirmed to be a new amino acid, and seemed to have selective activity against Mycobacterium tuberculosis. Based on full 16S rRNA gene sequencing, it appears that the strain RKMC9, the bacterium responsible for the production of metabolite 1, is a novel species of the genus Alteromonas. Preliminary field research revealed that, to use the isolation chip efficiently, it is necessary to quantify the bacterial densities of the environmental samples. In the laboratory, this can be achieved via fluorescence microscopy; however, this technique is generally not applicable to field studies. Alternatively, adenosine triphosphate (ATP) can be used as a measure of numbers of living cells. Due to the availability of relatively low-cost portable luminometers and the commercial availability of ATP test kits, this approach is an appealing method for estimating bacterial abundance for ichip studies conducted in the field. In this project, the Hyigena EnSURE luminometers system was evaluated and preliminary data suggest that the luminometer provides linear readings for pure ATP, DAPI stained E. coli cells, as well as for viable cell counts.