São Paulo State University (Unesp), Institute of Biosciences, Humanities and Exact Sciences, São José do Rio Preto, São Paulo, Brazil.
Appl Biochem Biotechnol. 2019 Aug;188(4):991-1008. doi: 10.1007/s12010-019-02973-8. Epub 2019 Feb 14.
Xylanases are enzymes that act in the depolymerization of xylan and that can be used in the food industry, the paper industry, and for bioenergy, among other uses. In this context, particular emphasis is devoted to xylooligosaccharides (XOS) that act as prebiotics, which, under the action of probiotic microorganisms, are capable of positively modifying the intestinal microbiota. In this sense, searching for microbial xylanases stands out as a sustainable strategy for the production of prebiotics. To date, there have been no reports in the literature regarding the purification of native xylanase from Myceliophthora heterothallica F.2.1.4. In this study, a xylanase from this fungus was purified and characterized. The xylanase, with 27 kDa, showed maximum activity at pH 4.5 and 65-70 °C. It maintained more than 80% of its residual activity when exposed to (i) temperatures between 30 and 60 °C for 1 h and (ii) pH 5-10 for 24 h at 4 and 25 °C. These high tolerances to different pH and different temperatures are important properties that add value to this enzyme. The hydrolysates of this enzyme on beechwood xylan, analyzed by HPAE-PAD, were mostly xylobiose (X2) and xylotriose (X3). Hydrolysates were also quantified, being retrieved from 234.2 mg xylooligosaccharides/g of hydrolyzed xylan for 12 h. According to the products obtained from the xylan hydrolysis and its tolerance properties of the enzyme, it has demonstrated potential for application production of xylooligosaccharides for use as prebiotics.
木聚糖酶是一种能够将木聚糖解聚的酶,可用于食品工业、造纸工业和生物能源等领域。在这方面,特别强调的是能够作为益生元的低聚木糖(XOS),在益生菌微生物的作用下,能够积极改变肠道微生物群。从这个意义上说,寻找微生物木聚糖酶是生产益生元的一种可持续策略。迄今为止,文献中尚无关于从异核侧耳菌 F.2.1.4 中纯化天然木聚糖酶的报道。在这项研究中,从这种真菌中纯化和表征了一种木聚糖酶。该木聚糖酶的分子量为 27 kDa,在 pH 4.5 和 65-70°C 时表现出最大活性。当暴露于(i)30-60°C 1 小时和(ii)4 和 25°C 时 pH 5-10 24 小时时,其保留了超过 80%的残余活性。这种对不同 pH 和不同温度的高耐受性是使该酶具有价值的重要特性。用 HPAE-PAD 分析该酶对山毛榉木聚糖的水解产物,主要是木二糖(X2)和木三糖(X3)。水解产物也进行了定量,12 小时可从 234.2 mg 低聚木糖/g 水解木聚糖中回收。根据木聚糖水解得到的产物及其酶的耐受性特性,该酶具有作为益生元应用生产低聚木糖的潜力。