کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
17953 | 42707 | 2008 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of furfural on nitrogen assimilating enzymes of the lactose utilizing yeasts Candida blankii 35 and Candida pseudotropicalis 11 Effect of furfural on nitrogen assimilating enzymes of the lactose utilizing yeasts Candida blankii 35 and Candida pseudotropicalis 11](/preview/png/17953.png)
The research was performed with two lactose-assimilating yeast strains—Candida blankii 35 with an oxidative metabolism and Candida pseudotropicalis 11 with a fermentative metabolism. The strains were cultivated in a chemostat under carbon limitation at dilution rates D = 0.1 and 0.25 h−1. After shock with 0.04% furfural, the changes of the following nitrogen enzyme activities were studied: NADPH-dependant glutamate dehydrogenase (NADPH-GDH), NADH-dependant glutamate dehydrogenase (NADH-GDH), glutamine synthetase (GS), glutamate synthase (GOGAT) and alanine dehydrogenase (ADH).Results show that during cultivation of C. blankii 35 at D = 0.1 h−1, furfural exhibits a clear inhibitory effect on the glutamate dehydrogenase and the alanine metabolite routes of ammonia ion assimilation. Furfural slows down the nitrogen assimilation of the strain through glutamate dehydrogenase and at D = 0.1 h−1 the GS/GOGAT system is activated.During the growth of the fermenting strain C. pseudotropicalis 11, furfural (0.04%) did not exhibit stable inhibitory effect on the enzyme activities of NADPH-GDH, NADH-GDH, GS, GOGAT and ADH. To the opposite, when reaching the steady state after furfural addition, their activities increased 6.3, 4.9, 5.6 and 4.1 times, respectively. At D = 0.25 h−1, GS activity was stronger affected by the dilution rate. Furfural did not inhibit the activity of NADPH-GDH, NADH-GDH and ADH. However, continuous inhibitory effect on GS and GOGAT activity was observed.
Journal: Enzyme and Microbial Technology - Volume 43, Issue 3, 5 September 2008, Pages 284–288