Klebsiella BOD sensor

A microorganism, Klebsiella sp., was isolated from activated sludge around a lactose rich wastewater treatment facility of an industry producing dairy products. A microbial sensor loaded with Klebsiella sp. gave BOD values of glucose, fructose and galactose well correlated with the respective BOD5 values. However, the microbial BOD sensor showed a very low sensitivity toward xylose, sucrose, maltose and soluble starch. The lower sensitivity for the higher molecular weight saccharides compared to that for glucose and fructose was not ascribed merely to the slower transport of the sterically bulkier saccharides, but also to the absence of enzymes to digest the saccharides rapidly, because the sensor sensitivity for xylose was extremely low and because the sensitivity of the sensor with the lactose-acclimated strain was higher for lactose than for any other disaccharides tested. A prolonged incubation of the sensor in a solution containing glucose reduced the sensor sensitivity for lactose, indicating that the memory of the induced β-galactosidasic activity of Klebsiella sp. faded away.