著者

根井 仁三郎

出版者

公益社団法人日本生物工学会

雑誌

醗酵工學雑誌 (ISSN:03675963)

巻号頁・発行日

vol.49, no.10, pp.852-860, 1971-10-25

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The effects of several physiological conditions on the phenol-oxidizing activity of a strain of Rhodotorula glutinis var. glutinis were studied.1. The maximum rate of phenol oxidation was shown in cells precultured on glucose with vigorous aeration, starved and induced by phenol.2. Of the carbon sources tested in the preculture medium, glucose and xylose resulted in high yields of cells and a high rate of phenol oxidation. The strain was capable of utilizing nitrate. Among the nitrogen sources surveyed in the medium, ammonium nitrate permitted a high rate of phenol oxidation. 3. Starvation for 12 hr was required for the development of a maximal rate of phenol decomposition. The presence of organic nitrogen enhanced the potential for induction, suggesting the repression of induction of phenol oxidation by sugars.4. The optimal pH for induction and phenol oxidation of the pretreated yeast cells was 5.5 and the optimal temperature was 34℃. The development of phenol-oxidizing activity was suppressed at temperatures below 25℃ and at pH levels above 8.5. With a decrease in the concentration of phenol in the induction medium, an increase in the rate of induction of phenol oxidation was observed. The maximal rate of phenol oxidation of the cells was obtained when 500 mg/l of phenol was added to the oxidation medium. The maximum rate of initial oxidation of phenol was observed at a concentration of 200 mg/l.6. The effect of several reagents on phenol oxidation by yeast was investigated. Sodium azide, cyanide, and formaldehyde, at a concentration of 2 mM, exerted 50 % inhibition. Of the chelating agents, o-phenanthroline and 8-hydroxyquinoline, at a concentration of 10 mM, inhibited oxidation of phenol by 72% and 40%, respectively.7. Rapid oxidation of phenol by induced cells was carried out in a jar fermenter. The cells decomposed phenol at concentrations of 2,000 mg/l and 3,000 mg/l in 5.5 hr and 16 hr, respectively. These results suggest a good possibility for the application of the yeast to the treatment of phenol in industrial waste..