Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant path- ogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a...Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant path- ogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a lack of optimal liquid fermentation technology. In this study, we explored response surface methodologies for opti- mizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, iden- tified cornmeal, glycerol, and initial pH levels as the most significant factors （P〈0.05） for enhancing the production of chlamydospores. Subsequently, we applied the Box-Behnken design to study the interactions between, and optimal levels of, a number of factors in chlamydospore production. These statistically predicted results indicated that the highest number of chlamydospores （3.6×108 spores/ml） would be obtained under the following condition： corn flour 62.86 g/L, glycerol 7.54 ml/L, pH 4.17, and 6-d incubation in liquid fermentation. We validated these predicted values via three repeated experiments using the optimal culture and achieved maximum chlamydospores of 4.5×108 spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianurn SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31201557 and 31270155)the Natural Science Foundation of Shanghai(No.12ZR1414100)+2 种基金the Foundation of Basic Science and Technology of China(No.2014FY20900)the Ministry of Education University Doctoral Foundation(No.20120073120070)the Shanghai Jiao Tong University Medical-Engineering Cross Research Fund(No.YG2015MS37),China
文摘Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant path- ogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a lack of optimal liquid fermentation technology. In this study, we explored response surface methodologies for opti- mizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, iden- tified cornmeal, glycerol, and initial pH levels as the most significant factors （P〈0.05） for enhancing the production of chlamydospores. Subsequently, we applied the Box-Behnken design to study the interactions between, and optimal levels of, a number of factors in chlamydospore production. These statistically predicted results indicated that the highest number of chlamydospores （3.6×108 spores/ml） would be obtained under the following condition： corn flour 62.86 g/L, glycerol 7.54 ml/L, pH 4.17, and 6-d incubation in liquid fermentation. We validated these predicted values via three repeated experiments using the optimal culture and achieved maximum chlamydospores of 4.5×108 spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianurn SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents.
