| Summary: | 碩士 === 國立嘉義大學 === 生物科技研究所 === 91 === Phenol and formaldehyde are toxic compounds and usually found together in resin manufacturing plant wastewater. The main objective of this study is to isolate phenol degrading microorganisms which can degrading formaldehyde together with or tolerance for formaldehyde from resin manufacturing plant wastewater and to test their degrading abilities on application of treatment resin wastewater. Three (designated as P1, P2 and P3) were characterized by high effectiveness of the removal of phenol and formaldehyde which was used as sole carbon and energy source. After sequencing of 16S rDNA, it was found that strain P1 which was closely related to Acidovorax delafieldii (Davis) Willems et al. (99% similarity), strain P2 which was closely related to Bradyrhizobium japonicum (Kircher) Jordan (99% similarity) and strain P3 which was closely related to Ralstonia pickettii (Ralston et al.) Yabuuchi et al. (99% similarity). In addition, a universal primer pair pheUf and pheUr can be use to amplify the largest subunit of multicomponent phenol hydroxylases (LmPHs) gene from strains P1 and P3, but not from strain P2. Therefore, strain P2 had another phenol hydroxylases (phenol 2-monooxygenase). In this study, batch culture was constructed to determine the degradation efficiency of phenol and formaldehyde by three phenol degrading microorganisms under aerobic condition. In phenol biodegradation experiments, high efficiency of the phenol degradation was found when the initial concentration of the phenol was lower than 800 mg/L. When the phenol concentration was 400 mg/L, the strain P1 has the highest biodegrading ability for removal of phenol than strains P3 and P2. In addition, at temperature 25℃ to 35℃and pH 5 to pH 9, maximal degradation rates were observed at pH8 and 32.5℃. When the initial inoculum concentration was increased from OD600＝0.100 to OD600＝0.200 , average degradation rate increased 66.7% and 54.9% by strains P3 and P2 respectively, while strain P1 increased only 1.1%. In formaldehyde biodegradation experiment, all the three strains isolated in this study were capable of growthing on formaldehyde as the sole carbon and degrading formaldehyde completely. It indicated that the three strains had the potency to be applied for treatment of wastewater containing both phenol and formaldehyde. When three strains were applied for treatment of synthetic and real wastewater, all the three strains were observed to degrade 96﹪to 99% of phenol in 48h. In synthetic wastewater, 90% COD reduction was observed, it indicated that the three strains were grow on phenol as the only carbon and energy source. In real wastewater, COD was removed only 8.2-19.6%, therefore, suggesting the presence of non-biodegradable organic compounds in real wastewater. The addition of activated carbon in real wastewater was best chose to remove the non-biodegradable organic compounds.
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