EFFECTS OF CARBON SOURCES ON THE VALUES OF ANTIOXIDANT INDEXES AND INTERMEDIATES METABOLITES FROM SERRATIA MARCESCES SYBC08

The effects of two different carbon sources on changes of catalase (CAT) yield, the values of antioxidant indexes and intermediate metabolites from Serratia marcescens SYBC08 were investigated at different time points (4, 8, 12, 16, 20 and 24 h). The highest CAT yield (20008 U‧mL-1) in presence of citric acid was approximately 1.46-fold higher than that in presence of glucose (13680 U‧mL-1). The maximum superoxide dismutase activity (21.53 U‧mL-1) was achieved in presence of citric acid, significantly higher than that in presence of glucose (15.20 U·mg-1protein). Intracellular alkyl hydroperoxide reductase activity in presence of citric acid or glucose was sharply increased during culture period and reached the maximum value at 24 h. Additionally, the NADH oxidase activities, total antioxidant capacities, intracellular and extracellular ascorbic acid contents, intracellular H2O2 level, malondialdehyde contents and intracellular contents of pyruvate, succinic acid and citric acid in presence of citric acid or glucose were also evaluated.