| Community establishment and organism interactions were assessed for a model microbial association consisting of one bacterium and one fungus. The fungal community member was Mucor bacilliformis, while Pseudomonas aeruginosa or Bacillus subtilis were used as the bacterial members. Microscopy was used to assess the physical association of the organisms, in addition to initial chemotaxic studies of bacterial response to the actively growing fungi. Fatty Acid Methyl Ester (FAME) profiles were used to monitor potential physiological changes and interactions between community members. Member species were incubated for up to 15 hours in flask cultures that contained nutrient broth. Lipid extractions and FAME transformation were conducted on each. Analysis of FAMEs with gas chromatography revealed peaks with retention times indicative of C12--22 fatty acids, based upon standard FAMEs. Principle component analysis and hierarchical cluster analysis were used to identify similarities between the FAME profiles of various culture conditions. This initial survey indicates that P. aeruginosa has the stronger ability to initiate community formation with M. bacilliformis than B. subtilis, and that community association may confer benefits to the component members. |
