Students in the Biology Department at East Georgia State College (EGSC) in Swainsboro made presentations at the 2021 annual meeting of the Georgia Academy of Science held virtually Friday to Sunday, April 16-18, 2021. The presentations were the result of experiments done by students enrolled in the Environmental Toxicology and/or the Undergraduate Research classes and were classified as “works in progress.” Two oral presentations were made. The first one, entitled, “Development of a High Throughput Monitoring System for the Presence of Cyanobacteria,” was presented by Jessica L. Jones with coauthors Bret A. White, Monique N. Johnson, and Dr. Julius E. Schneider (the class instructor). The presentation focused on the fact that filters commonly used to collect algae in the monitoring of environmental water bodies differ in their binding of phycocyanin, a blue pigment in cyanobacteria. Such binding is detrimental to the monitoring procedure because it is the unbound phycocyanin extracted from the cyanobacteria (in the presence of the filter) that is used as an indicator of the amount of cyanobacteria in the water. Other data presented showed the effect of freezing on the efficiency of the extraction process, which in the case for the cyanobacterial species Limnothrix, was a minimal effect, although for other species freezing and thawing of the bacteria does increase the efficiency of extraction. This result provides evidence that cyanobacterial species differ in their cell wall and/or membrane structure.
A second presentation was made by Monique N. Johnson, with coauthors Carley K. Stapleton, Shanice McGuire, Joshua M. Horne, and Dr. Julius E. Schneider. The talk was entitled, “Protection by Fructose from Denaturation of Phycocyanin by Octanol.” Extraction and measurement of chlorophyll and phycocyanin from water samples in order to estimate the amounts of algae and cyanobacteria, respectfully, is an established environmental monitoring method. Typically, the two pigments are extracted and measured separately, as chlorophyll is hydrophobic, and phycocyanin is a hydrophilic protein. We have been exploring the simultaneous extraction and measurement of these pigments with a biphasic octanol-water system. During vigorous mixing of the cyanobacteria, both pigments are released from the cells; chlorophyll accumulates in the upper octanol phase, phycocyanin in the lower, aqueous phase. After centrifugation, the phases separate cleanly, and the two pigments are removed and measured by their color intensities. Results were presented that showed that the presence of high concentrations of fructose in the aqueous phase of the extraction process resulted in higher levels of the blue pigment phycocyanin compared to an aqueous phase of water alone. This result is attributed to the likelihood that octanol has a denaturing effect on the phycocyanin during the mixing phase, and that fructose inhibits this activity. It has been reported that fructose protects phycocyanin from heat denaturation, a finding that led to this experiment. It was also shown that, due to the higher viscosity of the 3M fructose added to the aqueous phase, a lengthier mixing step is required to release a peak amount of phycocyanin.
"We are all so proud of Jessica and Monique for representing EGSC at the GA Academy of Sciences. We are also very thankful to the USG to provide funding to support undergraduate research" said David Chevalier, Interim Dean of the School of Mathematics and Natural Sciences.
