Bioprospecting for Phosphorus Accumulating Organisms for Water Treatment
Open Access
- Author:
- Hiestand, Gabriel
- Area of Honors:
- Environmental Systems Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Jay Regan, Thesis Supervisor
Jeremy Michael Gernand, Thesis Honors Advisor - Keywords:
- phosphorus accumulating organisms
bioprospecting
water treatment - Abstract:
- Nitrogen and phosphorus runoff into receiving waters creates a variety of harmful environmental challenges to vital aquatic ecosystems, most notably algal blooms. Phosphorus is an essential nutrient due to its role in food production, and depleted phosphorus reserves coupled with increasing global demand for food that is growing faster than phosphorus production presents a challenge that society must address. The use of phosphorus accumulating organisms (PAOs) during enhanced biological phosphorus removal (EBPR) presents an opportunity to both decrease algal blooms and recover phosphorus. In this study, bioprospecting was used to recover and identify PAOs present on rock biofilm samples taken from Spring Creek in Centre County, Pennsylvania. Cells were physically enriched using flow cytometry and DAPI staining, which imparts a yellow fluorescence emission when complexed with cells containing polyphosphate. The sorted cells enriched for PAO were cultured, and polymerase chain reaction (PCR) was used to amplify the 16S rRNA gene for sequencing. The Basic Local Alignment Search Tool (BLAST) was used to phylogenetically identify the isolated microbes based on their 16S rRNA gene sequences. Three colonies were cultured after flow cytometry, and BLAST results suggest that each of the colonies belonged to the genus Pseudomonas. Potential PAOs isolated were P. chlororaphis and P. protegens due to documented research of phosphorus metabolism and PHA catabolism, respectively. After DAPI staining of cells from the streak plates, each isolate was fluorescent using the yellow emission filter during fluorescence microscopy, suggesting that each of the isolates may have intracellular polyphosphate, even during continuously aerobic culturing conditions, and could be PAOs. Further research is required to confirm whether these microorganisms are indeed PAOs and if they are suitable for use during EBPR.