Fermentation And Extraction Of Lactate Dehydrogenase From Lactobacillus Plantarum

Lactate dehydrogenase (EC1.1.1.27; LDH) is an important glycolytic enzyme that reversibly catalyses the conversion of pyruvate to lactate. The enzymes are widely present in animals, bacteria and also in plants. Aim of exploitation and application of LDH, the research mainly focused on the culture conditions, pilot fermentation and continuous fermentation of Lactobacillus plantarum after UV mutagenesis,. It was shown that the LDH activity improved by 69.3% after UV mutagenesis. The result from 25L fermentation of LDH ushered 1.5m3 pilot fermentation, LDH activity of 1300U/g was obtained.Optimal conditions of cell disruption were also studied. High pressure homogenier, lysozyme disruption and supersonic treatment were employed to study the effects of cell disruption of the Lactobacillus plantarum in order to release the intracellular renzyme. By comparison, it was concluded that lysozyme treatment combined with high pressure homogenesis was the effective method to disrupte the cells. The activity of LDH released from the cells reached 1400U/g.Research on storage stability of LDH solution and LDH freeze-dried powder revealed that the stability of LDH solution could be improved 69% by adding cysteine, and the activity of LDH freeze-dried powder could be improved 34% by fucose...