Phosphate uptake performance of bacteria isolated from a full-scale Izmir municipal wastewater treatment plant

This study investigated the phosphate uptake capacities of bacteria isolated from aerobic and anaerobic phosphate removal tanks at a municipal wastewater treatment plant in Izmir, Turkey, removing chemical oxygen demand to nitrogen (COD-N) and phosphorus (P) on a full-scale basis. Conventional plating techniques and an enrichment culture method were used to isolate the colonies, with a total of 91 monoculture isolates from the sludge samples being subjected to phosphate uptake studies. A total of 64 of these isolates had high phosphate uptake capacities ranging from 3.7 x 10-10 to 1.0 x 10-12 mg PO43- cell-1, and only 11 of the strains with high phosphate uptake were Gram-negative. The highest phosphorus uptake value was 3.7 x 10-10 mg PO4-3 cell-1, which was achieved by Gram-positive bacteria. Gram-negative strains were identified as Acinetobacter baumannii with a 99% probability and as Pseudomonas aeruginosa with a 96-98% probability (API 20 NE).