科研之友
微信
新浪微博
Facebook
分享链接
摘要
An ammonia acrylate-tolerant yeast ZZB-1, capable of nitrile- and amide-hydrolysing activity, was isolated from soil samples. Based on the morphology, 18S rRNA gene, internal-transcribed-spacer and 26S rRNA gene D1/D2 domain sequences, this strain was provisionally identified as . Strain ZZB-1 contained a two-enzyme system, i.e. nitrile-hydrolysing and amide-hydrolysing activity for the hydrolysis of nitriles/amides to corresponding acids and ammonia. The nitrile-hydrolysing activity was weakly constitutively produced by the resting cells of ZZB-1. The addition of phenylacetonitrile, acrylamide and acrylic acid significantly enhanced this hydrolysis. The cells of ZZB-1 also exhibited weakly constitutive amide-hydrolysing activity with an affinity for acrylamide (1.47 U), and this activity clearly increased to 50.29, 51.82 and 13.59 U for acrylamide, acetamide, and benzamide, respectively, in the presence of 1% acrylic acid (v/v) during cultivation. The amide-hydrolysing activity of ZZB-1 was inactivated at 40A degrees C. The cationic metals Ca2+, Zn2+, and Mn2+ had a significant positive effect on the amide-hydrolysing activity of ZZB-1, but Co2+ and Cu2+ had a significant negative effect. The resting cells of ZZB-1 achieved high amide-hydrolysing activity of 78.87 U (mu mol/min/g, dry cell weight) at under optimum conditions (35A degrees C, pH 9.5, 1 mM Zn2+).
- 出版日期2012-6
- 单位浙江工业大学
