ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary Two alcohol dehydrogenases (ADHI and ADHII, EC 1.1.1.1) were purified to homogeneity from the cell extract of Zymomonas mobilis. The subunit molecular weights of ADHI and ADHII were 40,000 and 38,000, respectively, and both enzymes were homologous dimers. The optimal pHs of ADHI in ethanol oxidation and acetaldehyde reduction reactions were 9.5 and 4.5, and those of ADHII were 9.5 and 6.5, respectively. The optimal temperatures of ADHI and ADHII were 55° C and 45° C, respectively. ADHI was heat-inactivated at 65° C at a 10-fold higher rate than ADHII. ADHI and ADHII were inhibited by 4 μM and 1 mM p-chloromercuribenzoate, respectively, and the inhibitions were reversed by the addition of 70 mM 2-mercaptoethanol. ADHII activity was enhanced by 0.02 to 2 mM CoCl2 and inhibited by 0.4 mM o-phenanthroline; and the activity of inactivated ADHII was restored by addition of 1 mM CoCl2 or ZnCl2. ADHI was active on most primary alcohols but not secondary alcohols. ADHII was active on only ethanol, n-propanol, allylalcohol, and furfuryl alcohol. In the anaerobic culture of Z. mobilis, ADHII activity accounted for more than 80% of total alcohol dehydrogenase activity. In aerobic culture, ADHII was the main enzyme but was produced only in the early growth phase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00252025
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