Term of Award
Summer 2025
Degree Name
Master of Science, Civil Engineering
Document Type and Release Option
Thesis (open access)
Copyright Statement / License for Reuse
Digital Commons@Georgia Southern License
Department
Department of Civil Engineering and Construction
Committee Chair
Francisco Cubas
Committee Member 1
Stetson Rowles
Committee Member 2
Rocio Perez
Abstract
Organophosphorus such as phytic acid, a surrogate species of inositol phosphate (IP), may serve as a source for orthophosphate (OP) in freshwater. In absence of OP, competent aquatic microorganisms upregulate the production of specialized enzymes to obtain growth-sustaining OP from organic phosphorus (org-P) forms. The contribution of recalcitrant org-P to the OP pool has been overlooked due to the lack of capable tools to measure OP production from org-P accurately. The objective of this study was to quantify OP production from phytic acid (a surrogate form of recalcitrant org-P) to assess the contribution of recalcitrant org-P forms to the total OP pool. Experimental results showed that phytic acid was found in sediment samples collected from experimental sites. Fractionation of sediments revealed the presence of high levels of recalcitrant phosphorus, ranging from 13% to 19% of total phosphorus. High level of recalcitrant org-P in sediments highlighted the possibility of mineralization in freshwater. A fluorescence probe serving as a substrate analog for phytic acid was used to measure the enzymatic activity required for IP mineralization to quantify OP production from IP accurately. Results from microcosm experiments operated under different conditions (i.e., aerobic vs. anaerobic) showed that phytic acid mineralization was possible in the absence of OP. Phytic acid mineralization rates depended on different factors, including environmental conditions and previous OP concentration. Although the abundance and mineralization rate of phytic acid were relatively low, the results highlighted the importance of considering recalcitrant org-P as a viable source for soluble reactive phosphorus in freshwater.
OCLC Number
1528890043
Catalog Permalink
https://galileo-georgiasouthern.primo.exlibrisgroup.com/permalink/01GALI_GASOUTH/1r4bu70/alma9916627634502950
Recommended Citation
Tasnim, Iffat, “Quantifying Inositol Phosphate Dephosphorylation to Understand the role of Recalcitrant Organic Phosphorus forms on Harmful Algal Blooms in Freshwater Systems” (2025). Electronic Theses and Dissertations.
Research Data and Supplementary Material
No
