ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract In a limited screening 65 microorganisms were tested with regard to their ability to reduce keto acids or esters of different chain length and position of the keto group with NADH or NADPH as coenzymes. Twenty-seven organisms exhibited reductase activity. Among these, Candida parapsilosis and Rhodococcus erythropolis have been chosen for further investigation. The keto ester reductases of both C. parapsilosis and R. erythropolis prefer NADH as coenzyme and show higher activity towards keto esters than keto acids. The keto ester reductase production of C. parapsilosis during growth passed a maximum in the late exponential phase, decreased and reaches a plateau in the stationary phase. In contrast, the specific activity of the keto ester reductase of R. erythropolis did not decrease in the stationary growth phase. The enzyme of C. parapsilosis was inducible by a keto ester when growing on glycerol as the sole carbon source. Furthermore, the enzyme of C. parapsilosis was subject to catabolite repression. When C. parapsilosis and R. erythropolis were cultivated on n-alcane the specific activity of their keto ester reductases was enhanced about seven- and eightfold, respectively, compared to growth on glucose. This leads to the assumption that, while growing on n-alcane, a degradation product is formed in both strains that induces the production of the keto ester reductase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00170082
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