THE ANALYSIS OF A MICROBIAL MAT PROFILE USING THREE COMMUNITY COMPOSITION METHODS: POLYMERASE CHAIN REACTION, COMMUNITY LEVEL SUBSTRATE UTILIZATION, AND FATTY ACID METHYL ESTER

In this study, a microbial mat from Triangle Pond, a hypersaline coastal lake in San Salvador, Bahamas was characterized during the University of Akron’s Field Research on Bahamian Lakes— Exploring Records of Anthropogenic and Climate Change Research Experience for Undergraduates (REU). The community composition was examined using three different biological characterization techniques, including polymerase chain reaction (PCR) and sequencing, community level substrate utilization (CLSU), and fatty acid methyl ester analysis (FAME). Microelectrode analysis of cores showed trends in oxygen and sulfide levels which could indicate whether aerobic or anaerobic microorganisms were present in certain layers within the collected mat. Maximum oxygen levels were found in the upper area of the mat and the gas was absent from approximately 12 mm to the bottom of the core. Sulfide levels increased with depth. To determine if these trends were due to the difference in microbial composition the mat was divided into five distinctive layers, based on the results of the microelectrode profiling and visual observations, and each layer was analyzed for community composition. Through initial CLSU analysis, it was determined that communities of aerobic and anaerobic organisms vary in the different layers of the mat. Sequencing of the 16S ribosomal RNA genes amplified through PCR indicates that that the unclassified marine metagenome AACY023318740 was present in the top cyanobacterial layer of the microbial mat. Fatty acid methyl esters were extracted and characterized using a gas chromatograph - mass spectrometer. Principle component analysis was used to statistically analyze the data, and scanning electron microscopy (SEM) was used to qualitatively analyze community and structural differences between the layers in the mat. This study shows the differences in the community fingerprints of the layers in a complicated microbial mat. Through studying the microbial ecology of these ecosystems, a greater understanding can be reached about how microorganisms interact and survive under extreme conditions.