Microbial community associated with glucose-induced enhanced biological phosphorus removal

Abstract

The microbial community associated with enhanced biological phosphorus removal with glucose as the main carbon source at 11°C was investigated using microscopy and molecular fingerprinting techniques. The study lasted 77 days and comprised two stages—Stage 1 when the mixture of glucose, yeast and dried milk was the organic carbon source and Stage 2 when glucose was the single carbon source. Rhodocyclus-related polyphosphate accumulating organisms, α-Proteobacteria and Bacteroidetes constituted 42% in Stage 1 and 45% in Stage 2, 21% in Stage 1 and 16% in Stage 2, and 10% in Stage 1 and 7% in Stage 2 of the total Bacteria, respectively. The Trichococcus genus from the low GC Gram-positive bacteria was possibly responsible for lactic acid production from glucose. The microbial community was gradually changing throughout the experiment and appeared to stabilize towards the end of the experiment. Periods of suboptimal phosphorus removal could have been caused by competition among different microbial communities for carbon substrate.