do Nascimento Gustavo Carvalho, Batista Ryhára Dias, Santos Claudia Cristina Auler do Amaral, da Silva Ezequiel Marcelino, de Paula Fabrício Coutinho, Mendes Danylo Bezerra, de Oliveira Deyla Paula, de Almeida Alex Fernando
Bioprocess Engineering and Biotechnology, Federal University of Tocantins, Gurupi, Tocantins, Brazil.
Graduate Program on Food Science and Technology, Federal University of Tocantins, Palmas, Tocantins, Brazil.
ScientificWorldJournal. 2019 Jan 8;2019:6956202. doi: 10.1155/2019/6956202. eCollection 2019.
-fructofuranosidase (invertase) and -D-fructosyltransferase (FTase) are enzymes used in industrial processes to hydrolyze sucrose aiming to produce inverted sugar syrup or fructooligosaccharides. In this work, a black sp. PC-4 was selected among six filamentous fungi isolated from canned peach syrup which were initially screened for invertase production. Cultivations with pure carbon sources showed that invertase and FTase were produced from glucose and sucrose, but high levels were also obtained from raffinose and inulin. Pineapple crown was the best complex carbon source for invertase (6.71 U/mL after 3 days of cultivation) and FTase production (14.60 U/mL after 5 days of cultivation). Yeast extract and ammonium chloride nitrogen sources provided higher production of invertase (6.80 U/mL and 6.30 U/mL, respectively), whereas ammonium nitrate and soybean protein were the best nitrogen sources for FTase production (24.00 U/mL and 24.90 U/mL, respectively). Fermentation parameters for invertase using yeast extract were = 536.85 U/g and = 1.49 U/g/h. FTase production showed values of = 2,627.93 U/g and = 4.4 U/h using soybean protein. The screening for best culture conditions showed an increase of invertase production values by 5.10-fold after 96 h cultivation compared to initial experiments (fungi bioprospection), while FTase production increased by 14.60-fold (44.40 U/mL) after 168 h cultivation. PC-4 is a new promising strain for invertase and FTase production from low cost carbon sources, whose synthesized enzymes are suitable for the production of inverted sugar, fructose syrups, and fructooligosaccharides.
β-呋喃果糖苷酶（转化酶）和β-D-果糖基转移酶（FTase）是工业生产中用于水解蔗糖以生产转化糖浆或低聚果糖的酶。在这项工作中，从罐装桃糖浆中分离出的六种丝状真菌中筛选出一株黑曲霉PC-4，最初是针对其转化酶生产能力进行筛选的。以纯碳源进行培养表明，转化酶和FTase可由葡萄糖和蔗糖产生，但从棉子糖和菊粉中也能获得较高产量。菠萝冠是转化酶（培养3天后为6.71 U/mL）和FTase生产（培养5天后为14.60 U/mL）的最佳复合碳源。酵母提取物和氯化铵氮源可使转化酶产量更高（分别为6.80 U/mL和6.30 U/mL），而硝酸铵和大豆蛋白是FTase生产的最佳氮源（分别为24.00 U/mL和24.90 U/mL）。使用酵母提取物时，转化酶的发酵参数为Yp/s = 536.85 U/g和qp = 1.49 U/g/h。使用大豆蛋白时，FTase的产量为Yp/s = 2,627.93 U/g和qp = 4.4 U/h。最佳培养条件的筛选表明，与初始实验（真菌生物勘探）相比，培养96小时后转化酶产量提高了5.10倍，而培养168小时后FTase产量提高了14.60倍（44.40 U/mL）。PC-4是一种利用低成本碳源生产转化酶和FTase的新的有前景的菌株，其合成的酶适用于生产转化糖、果糖糖浆和低聚果糖。
