Combined transcriptomics and cellular analyses reveal the molecular mechanism by which Candida tropicalis ZD-3 adapts to and degrades gossypol.

Microbial degradation techniques are often considered an environmentally friendly and cost-effective strategy for reducing gossypol toxicity. However, the mechanism by which Candida tropicalis degrades gossypol remains unclear. In the current study, we aimed to establish the mechanisms of biodegradation and adaptation mechanisms by C. tropicalis ZD-3. The toxicological evaluation results revealed that ZD-3 adapts to gossypol primarily by activating the antioxidant defense system to alleviate the oxidative stress response induced by gossypol. Transcriptomic analyses further suggested that ZD-3 protects against gossypol toxicity via cell wall remodeling. The intracellular enzyme CTRG_04744 gene was significantly up-regulated under gossypol stress, and then expressed in Pichia pastoris. The purified AKR_Z1 degraded 92 % of gossypol within 48 h. In addition, the aldehyde group of gossypol was effectively eliminated to achieve the desired detoxification. Collectively, these results provide theoretical guidance for the continued development of bio-efficient strategies capable of degrading gossypol.