Geetha Karuppasamy, Gunasekaran Paramasamy
Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India.
Department of Biotechnology, Center for Research, Kamaraj College of Engineering and Technology, Virudhunagar, Tamil Nadu, India.
Iran J Biotechnol. 2017 Dec 29;15(4):232-240. doi: 10.15171/ijb.1494. eCollection 2017.
The need for more cost-effective compounds is imperative because the demand for prebiotic compounds is ever on the rise. The focus of this study is the purification of the endoxylanase from B20 and its application in a cost-effective production of the prebiotic xylooligosaccharide (XOS) syrup having a high concentration of oligosaccharides. The extracellular endoxylanase was purified using ammonium sulphate fractionation, DEAE anion exchange, and Sephacryl gel filtration chromatography. The enzymatically produced XOS was used in the preparation of XOS syrup adopting the method of ultrafiltration with 10 and 3 kDa molecular weight cut-off (MWCO) membranes. Culture-dependent technique for the bacterial enumeration using selective probiotic microorganisms in an analysis was employed to confirm the prebiotic nature of XOS syrup. The molecular mass of the purified xylanase (XylB) was found to be approximately 85 kDa with the optimum pH and temperature of 6.5 and 60 °C, respectively. XylB hydrolyzed the xylan and produced short-chain xylooligosaccharides (XOS). At the end of the two-step ultrafiltration process, the hydrolysate was refi ned to form XOS syrup (44.4%) consisting of XOS with a degree of polymerization (DP) between 2 and 5, and >5. Among all the tested probiotic strains, exhibited maximum growth in the presence of 0.5% XOS syrup with a specific growth rate of 1.2 h. Through this study, we have identified a method to produce XOS syrup that can be used as an effective prebiotic supplement for the growth of several probiotic strains. Human gut probiotics was used as a model system for analysis of prebiotic oligosaccharide XOS, but for further confirmation of the prebiotic activity, feeding studies using animal models are needed to be carried out.
由于对益生元化合物的需求不断增加,因此迫切需要更具成本效益的化合物。本研究的重点是从B20中纯化内切木聚糖酶及其在高浓度低聚糖的益生元木寡糖(XOS)糖浆的经济高效生产中的应用。使用硫酸铵分级分离、DEAE阴离子交换和Sephacryl凝胶过滤色谱法纯化细胞外内切木聚糖酶。采用截留分子量为10 kDa和3 kDa的超滤方法,将酶法生产的XOS用于制备XOS糖浆。在分析中采用基于培养的技术,使用选择性益生菌微生物进行细菌计数,以确认XOS糖浆的益生元性质。发现纯化的木聚糖酶(XylB)的分子量约为85 kDa,最佳pH值和温度分别为6.5和60°C。XylB水解木聚糖并产生短链木寡糖(XOS)。在两步超滤过程结束时,将水解产物精制形成XOS糖浆(44.4%),其由聚合度(DP)在2至5之间和大于5的XOS组成。在所有测试的益生菌菌株中,在0.5% XOS糖浆存在下表现出最大生长,比生长速率为1.2 h。通过这项研究,我们确定了一种生产XOS糖浆的方法,该糖浆可作为几种益生菌菌株生长的有效益生元补充剂。人肠道益生菌被用作分析益生元低聚糖XOS的模型系统,但为了进一步确认益生元活性,需要使用动物模型进行喂养研究。