| Ganoderma lucidum is a valuable traditional Chinese medicine with a long history, which is a medicinal and edible macrofungi. It contains a variety of biologically active ingredients, which polysaccharides represented. Polysaccharides have significant value in medical, health, industrial production. Phospholipase D is a class of phosphatidylcholine hydrolysis enzyme having hydrolytic activity and phospholipid transfer activity present in animals, plants and microorganisms. In recent years, researchers always use it to modify phospholipids and prepare rare phospholipids.Phospholipase D produced from microbial liquid fermentation has the advantages of a short growth cycle, easy extraction, and higher activity compared with the one isolated from plants and animals.The test selected Jindi Ganoderma is imported from Japan. Due to the great differences in geographical and climatic conditions between Sichuan and Japan, it’s really necessary to re-explore the culture conditions of Jindi Ganoderma.To increase polysaccharide production of Jindi Ganoderma, the effect of media and culture conditions on liquid fermentation was investigated by single factor test and response surface test using Design Expert. The test explored the relationship between polysaccharide production and time during fermentation under optimum conditions, and the relationship between the antioxidant activity of fermentation broth and time, and the relationship between the antioxidant activity of fermentation broth and polysaccharide production. The test explored the inhibitory effect of polysaccharide on Escherichia coli,Staphylococcus aureus, Salmonella, Shigella castellani, Monilia albican. The test also explored the ability of Jindi Ganoderma to produce Phospholipase D by TLC&HPLC dual detecting PS content in the product of lecithin and serine reaction catalyzed by the fermentation broth. The results for this study are as follows:1) The optimal formula of liquid fermentation medium is:3.98% cornmeal, 0.68%peptone, 0.21% Mg SO4·7H2O, 0.05% K2HPO4, 0.05% KH2PO4, 0.001% Vitamin B1.Under this condition, the production of polysaccharide comes 1.917 g/100 m L, increased by 50.8% compared with the original. The optimal culture conditions are: temperature27 ℃, p H = 6, speed 150 rpm, 10% inoculum, fermentation time 5 d. Under this condition, the production of polysaccharide comes 2.879 g/100 m L, increased by 49.5%compared with before.2) In a continuous fermentation process, the polysaccharide content reached maximum for 2.852 g / 100 m L on 5th day; the Fe3+ reducing power of fermentation broth reached the highest absorbance value of 0.520 on 7th day; the DPPH clearance of fermentation broth reached the top on 8th day of 80.7%; broth antioxidant activity and polysaccharide content was significant positive correlation.3) The polysaccharide can completely inhibit the growth of Escherichia coli,Staphylococcus aureus, Salmonella, Shigella castellani, Monilia albican. The minimal inhibitory concentrations(MIC) to Escherichia coli was 80 mg/m L, the MIC to Staphylococcus aureus was 120 mg/m L, the MIC to Salmonella was 60 mg/m L, the MIC to Shigella castellani was 100 mg/m L, the MIC to Monilia albican was 140mg/m L.4) The results showed that the reaction product contains phosphatidylserine after TLC&HPLC dual qualitative detection, which indicated that Jindi Ganoderma has the ability to produce phospholipase D.The study showed that Jindi Ganoderma has short growth cycle, and high production of polysaccharide. The products have strong antioxidant activity, good inhibitory effect. And the phospholipase D in the fermentation broth derives from fungus, which is rarely reported currently. Based on the medicinal and edible type of Ganoderma lucidum, the phospholipase D has a higher safety in the medical and health care products industry. To sum up, Jindi Ganoderma has a very high value in industrial fermentation, medical and health care products production. |
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