Depth distributions of alkaline phosphatase and phosphonate utilization genes in the North Pacific Subtropical Gyre

作者：Luo Haiwei^*; Zhang Hongmei; Long Richard A; Benner Ronald

来源：Aquatic Microbial Ecology, 2011, 62(1): 61-69.

DOI：10.3354/ame01458

• Phosphonate hydrolase
• C-P lyase
• Alkaline phosphatase
• Microbial phosphorus metabolism

The biochemical composition of dissolved organic phosphorus (DOP) in the ocean is dominated by phosphoesters (C-O-P and C-O-P-O-C bonds), which are hydrolyzed by a diverse group of alkaline phosphatases (PhoA, PhoD, PhoX), and by phosphonates (C-P bond), which are degraded by C-P lyases and hydrolases. We designed a bioinformatics pipeline and a statistical approach to recover and analyze the alkaline phosphatase and phosphonate utilization genes from a metagenomic database derived from water samples collected from 7 depths (between 10 and 4000 m) in the oligotrophic North Pacific Subtropical Gyre. The alkaline phosphatase genes phoD and phoX were more abundant than phoA in the euphotic zone (10-130 m) and in deep waters (500-4000 m). The C-P lyase genes were most abundant in the euphotic zone at 70 m and were rare in deep water (>= 500 m) where phosphate concentrations were relatively high. These observations indicate that phosphonates are utilized primarily as a phosphorus source by bacterial C-P lyases; this is consistent with the observation that C-P lyase genes are part of the pho regulon which is expressed upon phosphorus limitation. In contrast, C-P hydrolase and alkaline phosphatase genes were often more abundant in deep waters, indicating that DOP serves mainly as a carbon and energy source in phosphate-rich deep waters which are depleted in bioavailable dissolved organic matter (DOM). The observed differences in depth distributions and presumed functions of C-P lyase and hydrolase genes indicate variability in the chemical composition of phosphonates between the euphotic zone and deep waters.

• 出版日期2011