Isolation and characterization of formaldehyde-degrading fungi and its formaldehyde metabolism

Formaldehyde is classified as a human carcinogen that may cause nasopharyngeal cancer and probably leukemia. The effects of environmental and nutritional factors on fungal growth and the biodegradation of formaldehyde were investigated. Fungal strains SGFA1 and SGFA3 isolated from untreated sewage sediment samples collected from heavily formaldehyde-contaminated areas were identified using morphological characteristics and molecular techniques and named as Aspergillus nomius SGFA1 and Penicillium chrysogenum SGFA3. Results indicate that SGFA1 and SGFA3 completely consumed 3,000 and 900 mg l−1 of formaldehyde, respectively, within 7 days under optimized conditions. Quantitative real-time PCR analyses and enzyme activity analyses demonstrated that glutathione-dependent formaldehyde dehydrogenase (GDFADH) and formate dehydrogenase (FDH) pathway may play a functional role in enhancing formaldehyde-degrading capability in SGFA1. Both fungi have potential use for remediation of formaldehyde pollution.