da Silva Almeida Larissa Emanuelle, de Assis Sandra Aparecida
Enzymology and Fermentation Technology Laboratory, Health Department, State University of Feira de Santana, Transnordestina Ave., km 0, BR 116, Feira de Santana, Bahia 44036-900 Brazil.
Indian J Microbiol. 2024 Jun;64(2):650-670. doi: 10.1007/s12088-024-01223-8. Epub 2024 Mar 5.
is a methylotrophic yeast with wide geographical distribution. In the present study, the microorganism was isolated from the Bahian semiarid and the enzymatic extract containing β-glucosidase was obtained through submerged fermentation. Response surface methodology was employed to optimize of fermentation medium. The higher production of β-glucosidase was obtained after 71 h of fermentation in an optimized medium composed of 3.35% glucose, 1.78% yeast extract and 1% peptone. The optimum pH and temperature of enzymatic activity were 6.8 (citrate-phosphate buffer) and 71.7 °C, respectively. Salts tested (10 mM) CaCl, NaSO and ZnSO promotes the increase of 91%, 45% and 80% of activity, respectively. The enzyme retained 64% ± 2.3 of its initial activity after 1 h heating at 90 °C. The production of reducing sugars was 95.94% after 24 h of hydrolysis and, with the addition of metal ions, this value increased more than 2 times. Among the supports analyzed for immobilization, chitosan showed higher residual activity during reuse. The immobilized enzyme showed higher activity at 60 °C with pH 6 and preserved almost 100% of the initial activity after 30 min at 70 °C.
是一种分布广泛的甲基营养型酵母。在本研究中,该微生物从巴伊亚半干旱地区分离得到,并通过深层发酵获得了含有β-葡萄糖苷酶的酶提取物。采用响应面法对发酵培养基进行优化。在由3.35%葡萄糖、1.78%酵母提取物和1%蛋白胨组成的优化培养基中发酵71小时后,β-葡萄糖苷酶的产量更高。酶活性的最适pH和温度分别为6.8(柠檬酸-磷酸盐缓冲液)和71.7℃。所测试的盐(10 mM)CaCl、NaSO和ZnSO分别使酶活性提高了91%、45%和80%。在90℃加热1小时后,该酶保留了其初始活性的64%±2.3。水解24小时后还原糖的产量为95.94%,添加金属离子后,该值增加了2倍多。在分析的用于固定化的载体中,壳聚糖在重复使用期间显示出更高的残余活性。固定化酶在60℃、pH 6时表现出更高的活性,在70℃下30分钟后保留了几乎100%的初始活性。