[Effects of high hydrostatic pressure on energy metabolism of Lactobacillus plantarum].
Effects of high hydrostatic pressure on energy metabolism were investigated with Lactobacillus plantarum ATCC8014 as the test microorganism in this work. An INT colorimetric method of oxidation-reduction was established to measure INT metabolic activity of deoxidization of L. plantarum ATCC8014 cells. The utilization of glucose and INT metabolic activity of deoxidization of the cells after HPP treatment were determined using colorimetric methods. The experimental results showed that survival counts of ATCC8014 cells on MRS agar medium and INT metabolic activity of deoxidization decreased significantly, and little changes of utilization of glucose took place with increasing pressure ranging from 150 to 250 MPa for 15 min. Utilization of glucose also reduced evidently at high pressure ( > 300 MPa) for 15 min. Whereas survival cell counts on MRS agar medium were below the detection limit and INT metabolic activity of deoxidization of ATCC8014 was 0% after a 15-min pressure holding time at 400MPa, utilization of glucose of the cells retained 56.1% compared with that of untreated cells. In summary, it can be concluded that enzymes absorbing and transporting glucose in cellular membrane appear to have a high resistance to pressure, enzymes and biological regulating systems involved in glycolysis are more resistant to pressure than those in TCA (tricarboxylic acid cycle) system, TCA of ATCC8014 is more sensitive to pressure than glycolysis, and the decrease of INT metabolic activity of deoxidization is highly related to cell reduction during HHP, which provide some theoretical evidences for mechanisms of HHP sterilization. Inhibition of TCA metabolism is a very important cause of ATCC8014 inactivation by HHP. High hydrostatic pressure can be used as an effective tool to explore pathways of biological metabolism.
College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210003, China. yulonggao19762001@yahoo.com.cn
Yu-long
YL
Gao
Xing-rong
XR
Ju
Han-hu
HH
Jiang
D004734:Energy Metabolism; D005947:Glucose / Q000378:metabolism; D006874:Hydrostatic Pressure; D048191:Lactiplantibacillus plantarum / Q000254:growth & development* / Q000378:metabolism*; D010084:Oxidation-Reduction; D013242:Sterilization / Q000379:methods; D013696:Temperature
D005947:Glucose