Abstract
Inhibitory effects of products formed by heating reaction (HRP) of sugar and sugar- amino acid (glycine) on the growth, nitrite production and activities of hydroxylamine oxidase (HAO) and dehydrogenases (MDH, ICDH, GDH) of ammonia-oxidizing chemoautotrophic Nitrosomonas europaea were studied. Among the HRP of each sugar alone, HRP of pentose inhibited severely the growth and nitrite prodction, but not HAO activity. Among HRP of sugar-glycine, HRP of pentoseglycine showed a more intense inhibitory action than that of sugar alone. HAO activity was inhibited by HRP of pentose and disaccharide other than sucrose. HRP of sugar-alanine showed similar inhibition. HRP of sugar and di- and tripeptide of these amino acids also exerted similar inhibitory action. GDH activity was inhibited by HRP of sugar-glycine while ICDH and MDH activitdes were not inhibited. Similar tendency of inhibition was observed with the activity of HAO produced by Pseudomonas, which is corresponding to growth inhibition. The growth of E. coli and Bacillus, heterotrophic bacteria, however, was not influenced at all.
