Formaldehyde and methanol biodegradation with the methylotrophic yeast Hansenula polymorpha. An application to real wastewater treatment

The application of methylotrophic yeast Hansenula polymorpha to the treatme nt of methanol and formaldehyde-containing wastewater was experimentally ve rified. A variety of real wastewater samples originating from chemical indu stry effluent were examined. The yeast cell culture could grow in the waste water environment, revealing low trophic requirements and a very high adapt ation potential to poor cultivation conditions. The proliferation of cells was accompanied by a concomitant xenobiotic biodegradation. Grown, preadapt ed cellular suspension at a density of about 1 x 10(7) cells/ml proved to b e able to utilize formaldehyde present in wastewater at concentrations up t o 1750 mg/l, levels toxic to most microorganisms. The biological waste trea tment method presented shows the enhanced potential by means of specific en zymatic activities of monocarbonic compound oxidations through methylotroph ic pathway reactions. The need to obtain mutants highly resistant to formal dehyde has also been rationalized.