具有胃黏膜保护作用的羊肚菌菌株的筛选及其液体发酵

Screening and Liquid-state Fermentation of Morchellas spp.Strain Having Gastricprotective Effect

目的:筛选获得具有胃黏膜保护作用且生物量较高的羊肚菌菌株,并优化所获得菌株的发酵培养基,筛选获得对胃黏膜保护效果较好的羊肚菌发酵培养基中的碳、氮源。方法:将小鼠随机分为正常组、模型对照组和不同给药剂量组,以无水乙醇诱导胃黏膜损伤为模型,比较各组胃黏膜损伤指数,同时测定并比较不同羊肚菌菌株生物量;利用碳氮源单因素和正交试验,以胃黏膜损伤指数为主要筛选指标,同时测定并比较不同培养基发酵羊肚菌菌株生物量与胞外多糖含量。结果:羊肚菌M1液体发酵物的水提液,能显著降低小鼠急性酒精胃黏膜损伤的损伤指数(P<0.05),同时生物量达到10.28g/L;分别以可溶性淀粉与酵母膏为碳、氮源时M1液体发酵物的水提液对小鼠胃黏膜保护效果最好,抑制率分别达到80.92%、53.02%;正交试验结果表明:以质量分数2.0%可溶性淀粉和1.5%酵母膏组合时M1液体发酵物的水提液对小鼠胃黏膜保护效果较好,抑制率达到76.02%,生物量达到8.88g/L。结论:羊肚菌M1不仅对小鼠胃黏膜具有较好的保护作用,而且生物量较高,其对胃黏膜保护效果较好的发酵培养基中的最适碳、氮源为可溶性淀粉2.0%、酵母膏1.5%。

Objective：To screen a Morchellas spp.strain having gastricprotective effect and higher biomass from 9 strains,and to optimize carbon and nitrogen sources for cultivation of the screened Morchellas spp.strain.Methods：Mice were randomly divided into normal group,control group and different dose administration groups.An experimental gastric damage model was established by ethanol intragastric infusion.On the basis of selection of the optimum carbon and nitrogen sources,their optimum amounts were optimized by complete combination experiments involving three levels for achieving an optimum compromise among low lesion index and high biomass and extracellular polysaccharide production.Results：The water extract of strain M1 could significantly reduce the injury index of acute gastric mucosa lesion in ethanol-induced mice and the amount of biomass was up to 10.28 g/L.In addition,the extract exhibited the best gastricprotective effect and provided inhibition rates up to 80.92% and 53.02% against gastric mucosa damage when the carbon and nitrogen sources were soluble starch and yeast extract during liquidstate fermentation.Better gastricprotective effect and higher biomass production could simultaneously be achieved by using 2.0% soluble starch as carbon source and 1.5% yeast extract as nitrogen source.As a result,the inhibition rate against grastric mucosa lesion was 76.02% and the biomass was 8.88 g/L.Conclusion：Strain M1 has the potential to protect against gastric mucosa lesion,and higher biomass during liquid-state fermentation can be achieved by using 2.0% soluble starch as carbon source and 1.5% yeast extract as nitrogen source.