Analyzing Microbial Metabolism of Algal Fucoidan
Board Location: #27
Discipline: Biological Sciences
Subcategory: Microbiology/Immunology/Virology
Session: 3
Donte T. Wyatt Jr. - Hampton University
Co-Author(s): Grace Busch, Hampton University, VA, Indu Sharma, Hampton University, VA
Fucoidan is an algal polysaccharide characterized by a branching structure and the presence of sulfate groups along the backbone chain. Such polysaccharides are known for their resistance to degradation by most enzymes, and thus require specific metabolic pathways in order to be catabolized. The main objectives of this work are 1) to determine whether given oceanic samples contained microorganisms capable of degrading fucoidan, 2) to classify the microorganisms, and 3) to identify and analyze the gene clusters that contribute to fucoidan breakdown.
We used 9 seawater samples from the Atlantic Ocean (three replicates from 0 m, 500 m, and 1000 m in depth) to inoculate a defined media with fucoidan as the sole source of carbon. A non-inoculated sample of media was incubated under identical conditions and showed no growth, indicating no contamination of the media. The first cultures were then used to enrich fresh fucoidan media and incubated once more. The second enrichments were serially diluted to a maximum dilution of 10-8 with buffered artificial seawater, and 10-5-10-8 were plated on seawater complete agar. The plates were incubated at 28°C, and colonies were chosen to make streak plates. There were 10 isolates from 0 m, 13 isolates from 500 m, and 10 isolates from 1000 m. The 33 isolates underwent DNA extraction and were molecular typed using 16S ribosomal RNA gene for taxonomic placement. Our findings indicate that microorganisms capable of degrading fucoidan were present in each sample at each depth. Future directions for this research include conducting a growth-rate experiment to compare the microorganisms’ metabolic efficiency in the presence of fucoidan and additional complex polysaccharides. In addition, we will perform whole genome sequencing for comparative genomics to facilitate the identification of gene clusters potentially involved in fucoidan metabolism.
References:
Ohshiro T, Ohmoto Y, Ono Y, Ohkita R, Miki Y, Kawamoto H, Izumi Y. 2010. Isolation and Characterization of a Novel Fucoidan-Degrading Microorganism. Bioscience, Biotechnology, and Biochemistry 74:1729–1732.
Funder Acknowledgement(s): This work was supported by a grant from the National Science Foundation award to I. Sharma. (Grant Number:2101073)
Faculty Advisor: Indu Sharma, indu.sharma@hamptonu.edu
Role: I conducted the majority of the work for this research, specifically the enrichment of the samples, the culturing of the isolates, and the molecular typing of the bacteria. The work was done under the direction of the two co-authors.