Abstract
The distribution of phosphatase-producing bacteria in Lake Shinseiko and their physiological properties were studied. The activities of alkaline phosphatase were 20-80 nmol⋅1-1⋅min-1 for unfiltrated lake water and 10-25 nmol⋅1-1min-1 for the filtrates. The number of phosphatase-producing bacteria was calculated to be 100-10000 cfu⋅ml-1. The bacteria were mostly found in the epilimnion during the stratification period and uniformly distributed vertically in the water column during the circulation period.
Most of the phosphatase-producing bacteria utilized glucose-6-phosphate, β-glycerophosphate and ADP as a sole P source, but scarcely utilized ATP, DNA, lecithin and phytic acid. Among these phosphatase-producing bacteria, one strain which produced extracellular alkaline phosphatase, was identified as Acinetobacter sp. and used for further growth and phosphatase experiments. The production of the enzyme increased abruptly after disappearance of phosphate in the culture medium.
