title: Statistical culture-based strategies to enhance chlamydospore production by Trichoderma harzianum SH2303 in liquid fermentation.
abstract: Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant pathogens. 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 optimizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, identified 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 (3.6×10(8) 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 4.5×10(8) spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianum SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents.
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.|Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Ya-Qian
authors.initials: YQ
authors.lastname: Li
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.affiliation: Affiliated Hospital of Hebei University, Baoding 071100, China.
authors.forename: Ya-Chai
authors.initials: YC
authors.lastname: Li
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.|Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D013171:Spores, Bacterial / Q000502:physiology*; D014242:Trichoderma / Q000502:physiology*
keywords: Box-Behnken design; Chlamydospore; Fermentation optimization; Plackett-Burman screening; Trichoderma harzianum SH2303