Dalli Sai Swaroop, da Silva Silvio Silverio, Uprety Bijaya K, Rakshit Sudip K
Department of Chemistry and Material Sciences, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada.
Department of Biotechnology, Engineering School of Lorena, University of Sao Paulo, Sao Paulo, 12602 810, Brazil.
Appl Biochem Biotechnol. 2017 Jul;182(3):1053-1064. doi: 10.1007/s12010-016-2381-4. Epub 2017 Jan 4.
A new strain, Candida tropicalis UFMG BX 12-a, was found to produce higher yields of xylitol on poplar wood hemicellulose hydrolysate. The hemicellulose hydrolysate liquor was detoxified using a novel method we developed, involving vacuum evaporation and solvent separation of inhibitors which made the hydrolysate free of toxins while retaining high concentrations of fermentable sugars. The effect of the detoxification method on the fermentation was also reported and compared to well-known methods reported in literature. In this study, the new strain C. tropicalis UFMG BX 12-a was used on the detoxified hydrolysate to produce xylitol. It was also compared to Candida guilliermondii FTI 20037, which has been reported to be one of the best strains for fermentative production of xylitol. To further improve the efficiency of the fermentation process, these strains were immobilized in calcium alginate beads. The yield (0.92 g g) and productivity (0.88 g L h) obtained by fermenting the wood hydrolysate detoxified by our new detoxification technique using an immobilized new Candida strain were found to be higher than the values reported in literature.
一种新菌株热带假丝酵母UFMG BX 12 - a被发现能在杨木半纤维素水解物上产生更高产量的木糖醇。半纤维素水解液采用我们开发的一种新方法进行解毒，该方法包括真空蒸发和抑制剂的溶剂分离，这使得水解物不含毒素，同时保留高浓度的可发酵糖。还报道了解毒方法对发酵的影响，并与文献中报道的知名方法进行了比较。在本研究中，新菌株热带假丝酵母UFMG BX 12 - a用于解毒后的水解物以生产木糖醇。它还与季也蒙毕赤酵母FTI 20037进行了比较，据报道该菌株是木糖醇发酵生产的最佳菌株之一。为了进一步提高发酵过程的效率，这些菌株被固定在海藻酸钙珠中。使用固定化的新假丝酵母菌株发酵经我们新解毒技术解毒的木材水解物所获得的产量（0.92 g/g）和生产率（0.88 g/L·h）高于文献报道的值。
