Enzyme and Respiration Activities on the Morphological Change of Geotrichum candidum belonging to Sludge Fungi

Abstract

Respiration and enzyme activities of Geotrichum candidum showing filamentous phase in bulking sludge was examined in comparison with yeast-like phase.
1) RQ value of endogenous respiration in F phase cells for the early period was slightly greater than that of Y-like phase cells, but considerable differences were not observed between both phases. NaN₃, CH₂ICOOH strongly inhibited the endogenous respiration of F phase cells.
2) The dissolved oxygen (DO) consumption of G. candidum on various substrates was generally greater in Y-like phase cells than in F phase cells, and there was, in particular, a remarkable difference of DO consumption when the organism was grown in the medium added with amino acid such as glycine, alanine and arginine. As³⁺ and Hg²⁺ showed almost equal inhibition on pyruvate oxidation in both phase cells, but Cu²⁺, Pb²⁺, CN^- and HCHO inhibited strongly the respiration of Y-like phase cells.
3) On enzymes of Leucine aminopeptidase, Alcohol dehydrogenase, G-6-P dehydrogenase and Glutathione reductase, except 5'-Nucleotidase, F phase cells showed high activities. Acid phosphatase (PMase) in cells of Y-like phase showed a marked lower activity than in F phase cells. However, Acid PMase in cell free extracts from Y-like phase showed opposite results.
4) Acid PMase was activated by the addition of Ca²⁺, Mg²⁺ and Ba²⁺, and it was noted that the activity was markedly accelerated by Pb²⁺ and Cu²⁺ Mo⁶⁺ and W⁶⁺ showed complete inhibition by the activity.