Abstract: In the plant disease management, biological control offers distinct advantages in terms of safety and environmental friendliness. Filamentous fungi such as Trichoderma harzianum and its related strains exhibit broad-spectrum inhibitory effects against various plant pathogens. A fungal strain CBS226.95 was isolated from decayed kiwifruit and evaluated through in vitro antagonist assays. The strain identification was confirmed through morphological features and sequencing information of multiple genes, including ITS, BenA, and TEF1. Subsequently, fermentation conditions of CBS226.95 were optimized to improve chitinase production by employing a one-factor-at-a-time approach followed by a response surface methodology design. The results demonstrated that CBS226.95 significantly inhibited the growth of plant pathogens Botryosphaeria do-thidea, Diaporthe, and Botrytis cinerea, exhibiting inhibition rates of 45.35%, 44.99%, and 47.31%, respectively. Through a comprehensive integration of morphological traits and phylogenetic analyses, CBS226.95 was identified as Trichoderma harzianum. The one-factor-at-a-time and response surface experiments revealed glucose as the optimal carbon source and peptone as the preferred nitrogen source for increasing fermentation efficiency of CBS226.95-4. Additionally, the most favorable fermentation conditions were determined to be a temperature of 33.23 °C, a duration of 4.11 days, and a pH level of 6.108. The isolation, identification, and optimization of fermentation conditions of Trichoderma harzianum CBS226.95-4 provide technical support for the biocontrol application of Trichoderma and the industri- al production of chitinase.
Keywords: isolation and identification; Trichoderma harzianum; chitinase; fermentation optimization
合肥工业大学学报自科版