the cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater

 

the cold adaptability of microorganisms with different carbon source under 5 °c was studied in activated sludge for treating synthetical wastewater. phospholipid fatty acid (plfa) analysis indicated contents of unsaturated fatty acids in cell membrane at 5 °c were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25 °c. plfa biomarkers showed more gram-negative bacteria enriched than gram-positive bacteria in low-temperature activated sludge. the shannon–wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower plfa diversity index (1.21–1.30) than that at 25 °c and sodium acetate source was reverse (1.08–0.69). the 16s rrna analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to gram-negative bacteria.