培养条件对香菇菌丝胞外多糖抵御镉毒害研究

Study on the Resistance to Cadmium Toxicity from Extracellular Polysaccharide of Lentinus edodes under Culture Conditions

摘要:

以香菇菌丝胞外多糖代谢量、胞外多糖附镉量和菌丝生物量为指标，采用培养基中碳源种类、碳源水平、氮源水平、培养时间和培养基初始镉浓度为单因素，进一步分析香菇菌丝抵抗环境重金属镉胁迫分泌胞外多糖的能力。结果表明，天然麦芽浸粉营养丰富，最适合作碳源促进胞外多糖合成，碳源浓度越高，越能够促进胞外多糖的合成抵抗镉毒害。氮源能促进糖类物质向多糖的转化，氮碳比1∶15(1.33 g)为最佳。镉环境下，香菇菌丝生长平衡期延长到15 d,15 d前胞外多糖代谢量不多，15 d后大量分泌吸附镉。低镉浓度下，胞外多糖代谢量不高，环境镉浓度增高，胞外多糖代谢附镉能力显著增加。

Abstract:

Taking the metabolic amount of Lentinus edodes mycelium exopolysaccharide, cadmium adsorption of exopolysaccharide and the mycelia biomass as indicators, the carbon source, carbon source level, nitrogen source level, culture time and initial cadmium concentration in the medium as single factors, the ability of Lentinus edodes mycelium to secrete extracellular polysaccharide against the stress of heavy metal cadmium in the environment was further analyzed. The results showed that the natural malt extract was rich in nutrition and was the most suitable carbon source to promote the synthesis of exopolysaccharide. The higher the concentration of carbon source, the more it can promote the synthesis of exopolysaccharide to resist cadmium toxicity. Nitrogen source can promote the conversion of saccharide to polysaccharide, and the nitrogen carbon ratio of 1:15(1.33 g) is the best. At low cadmium concentration, the extracellular polysaccharide metabolism was not high. The environmental cadmium concentration increased, and the extracellular polysaccharide metabolism ability increased significantly.