Process optimization of a halotolerant yeast Candida tropicalis ZQ for efficient azo dye biodegradation under high salinity
Year: 2026
Type: article
Abstract: A novel halotolerant yeast, Candida tropicalis ZQ, isolated from marine sediment, was evaluated for its potential in azo dye biodegradation under high-salt conditions. The optimization of culture parameters was performed using the single-factor experiment. The following optimal settings were established: sucrose 2.0 g/L, (NH4)2SO4 0.1 g/L, yeast extract 0.06 g/L, pH 6.0, 35 °C, ≥160 rpm. In the aforementioned conditions, the strain exhibited >96% decolorization of 1200.0 µmol/L Acid Red 3 R within 12 h. It is noteworthy that it maintained high activity (>97.0% within 32 h) even at 100.0 g/L NaCl. Intracellular enzymes, including NADH‑DCIP reductase, lignin peroxidase, manganese peroxidase and laccase, were identified as key catalysts in this process. Acute toxicity assays confirmed substantial reduction in acute toxicity of the metabolites. Integrative genomic and transcriptomic analyses suggested a proposed degradation pathway (azo bond cleavage, hydroxylation, desulfurization, ring-opening and mineralization) and multiple osmoregulatory strategies (“high-salt-in”, “compatible-solute-in”, ergosterol synthesis and casein kinase II). The combination of outstanding halotolerance, high dye-loading capacity, and efficient reduction in acute toxicity positions C. tropicalis ZQ as a promising biocatalyst for bioremediation of azo-dye-contaminated high-salinity wastewater.
Source: Bioremediation Journal
Authors: Qi Zhang, Haiyun Zhang, Bingwen Xu, Xinmei Fu, Liang Tan
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
Award: 耐盐复合菌系-SMFMBR处理印染废水及其机制研究
OpenAlex ID: W7203840148