Naslov
Intraparticle mass-transfer resistance and apparent time stability of immobilized yeast alcohol dehydrogenase

Autori
Vasić-Rački, Đurđa ; Gjumbir, Marijana

Izvornik
Bioprocess Engineering (0178-515X) 2 (1987); 59-63

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
enzyme immobilization; stability; diffusion

Sažetak
The stability and, consequently, the lifetime of immobilized enzymes (IME) are important factors in practical applications of IME, especially so far as design and operation of the enzyme reactors are concerned. In this paper a model is presented which describes the effect of intraparticle diffusion on time stability behaviour of IME, and which has been verified experimentally by the two-substrate enzymic reaction. As a model reaction the ethanol oxidation catalysed by immobilized yeast alcohol dehydrogenase was chosen. The reaction was performed in the batch-recycle reactor at 303 K and pH-value 8.9, under the conditions of high ethanol concentration and low coenzyme (NAD+) concentration, so that NAD+ was the limiting substrate. The values of the apparent and intrinsic deactivation constant as well as the apparent relative lifetime of the enzyme were calculated. The results show that the diffusional resistance influences the time stability of the IME catalyst and that IME appears to be more stabilized under the larger diffusion resistance.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

POVEZANOST RADA