Speaker
Description
Bacteria exist in nature as part of communities where they continuously interact with each other and with their own counterparts. As a result of the interaction with other microbes, microorganisms can produce numerous secondary metabolites, some of which function as signaling molecules that promote or inhibit growth. For instance, autoinducer-2(AI-2) has been shown to promote the growth of Escherichia coli and 2,4-diacetylphloroglucinol (DAPG) inhibits Pseudomonas fluorescens. Little is known about which communities display such promoting or inhibiting effects among bacteria. We isolated microbial communities from a compost heap and investigated the stimulation and inhibition of growth resulting from the microbial interaction. We utilized two gram-negative species Escherichia coli (E. coli) and Pseudomonas fluorescens (P. fluorescens) as a proxy to measure the promoting and suppressing effects of compost heap communities. Mixing bacterium with the communities or with the supernatant (juice) of communities reveals an increase in the development and proliferation of E. coli, while the growth of P. fluorescens is inhibited. Subsequent mass spectrometry analysis coupled with screening in the MELTIN database unravels the presence of antimicrobial substances and growth-promoting compounds in the supernatant of the compost-heap microbial communities. Exploring the intricacies of complex microbial interaction enhances our understanding of community dynamics and opens avenues for the discovery and development of new substances controlling bacterial growth such as fertilizer or antimicrobials.
