Effects of Different Substrates on Cellulase Activity Produced by Liquid Fermentation of Wild Lyophyllum decastes

KONG Yufei; WANG Jintao; JIA Songhan; ZHANG Qidi; YANG Ping; LIANG Yunjiang; XU Jize

doi:10.15933/j.cnki.1004-3268.2026.01.013

Abstract：To explore the optimal culture conditions for wild Lyophyllum decastes and its cellulase response characteristics to different agricultural and forestry wastes,and to provide a basis for its artificial domestication and cultivation and the resource utilization of agricultural and forestry wastes,the HMJU13047 strain collected from Changbai Mountain was identified by morphology and molecular biology.The optimal culture conditions for mycelial growth were screened using single-factor tests.Wheat bran,sawdust,corn cob,and soybean straw as substrates were used to induce fermentation,cellulase activity and physicochemical indicators of fermentation broth were determined.Principal component analysis(PCA)and Pearson correlation analysis were applied to investigate the correlation between cellulase activity and bacterial liquid indices.The results of morphological and molecular biological identification indicated that the HMJU13047 strain used in this study was Lyophyllum decastes.For the mycelial growth of strain HMJU13047,the optimal carbon source was soluble starch(growth rate 1.75 mm/d);the optimal nitrogen source was peptone(growth rate 1.49 mm/d)and the optimal inorganic salt was magnesium sulfate(growth rate 1.51 mm/d),the optimal carbon-nitrogen ratio was 15∶1(growth rate 1.37 mm/d),the optimal temperature was 25℃(growth rate 1.58 mm/d),and the optimal pH value was 6.0(growth rate 1.60 mm/d).The induction effects varied significantly among different substrates.Under wheat bran substrate induction,β-glucosidase(BG)activity was the highest(336.90 U/L),while under sawdust substrate induction,exoglucanase(CBH)activity was the highest(137.32 U/L).Corn cob and soybean straw mainly activated endoglucanase(EG).On the 21st day of induction fermentation,the wheat bran substrate-induced pellets exhibited the highest mycelial density(13.0 pieces/mL)and biomass(1.21 g),whereas the starvation-induced pellets showed the largest diameter(5.83 mm)and the highest pH value(9.3).Pearson correlation analysis revealed that the mycelial density and biomass of the pellets were positively correlated with BG and EG activities,while an increase in fermentation broth pH inhibited cellulase activity.In conclusion,this study identified the optimal culture conditions for mycelial growth of strain HMJU13047(temperature at 25℃,pH value at 6.0,carbon to nitrogen ratio at 15∶1,soluble starch as carbon source,peptone as nitrogen source,magnesium sulfate as inorganic salt).The wheat bran substrate exhibited the most optimal cellulase induction effect.