UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
Interfacultary Research Centre of Biomaterials (CEIB), University of Liège, B-4000 Liège, Belgium.
Carbohydr Polym. 2017 Jun 15;166:24-30. doi: 10.1016/j.carbpol.2017.02.088. Epub 2017 Feb 23.
Komagataella pastoris was cultivated in glucose/xylose mixtures for production of chitin-glucan complex (CGC), a cell-wall polysaccharide. The culture preferred glucose as substrate for growth, resulting in high biomass yields (0.46-0.54g/g). After glucose depletion, xylose was consumed but no cell growth was observed, indicating K. pastoris was unable to use it for growth. Interestingly, concomitant with xylose consumption, xylitol synthesis was noticed, reaching a maximum concentration of 7.64g/L, with a yield on xylose of 0.52g/g. Lower CGC production was reached as the xylose content was increased in the substrate mixtures, due to the lower biomass production. Moreover, cultivation in the presence of xylitol resulted in CGC enriched in chitin with higher molecular weight. These results suggest the possibility of using K. pastoris for the co-production of CGC and xylitol using glucose/xylose-rich substrates. It may also be a strategy to tailor CGC composition and average molecular weight.
毕赤酵母在葡萄糖/木糖混合物中培养生产几丁质-葡聚糖复合物（CGC），这是一种细胞壁多糖。该培养物优先利用葡萄糖作为生长基质，从而产生高生物质产量（0.46-0.54g/g）。葡萄糖耗尽后，木糖被消耗，但没有观察到细胞生长，表明毕赤酵母无法将其用于生长。有趣的是，伴随着木糖的消耗，发现了木糖醇的合成，达到了 7.64g/L 的最大浓度，木糖的得率为 0.52g/g。由于基质混合物中木糖含量的增加，导致生物量产量降低，因此达到的 CGC 产量较低。此外，在存在木糖醇的情况下进行培养会导致 CGC 富含具有更高分子量的几丁质。这些结果表明，使用富含葡萄糖/木糖的底物，毕赤酵母有可能同时生产 CGC 和木糖醇。它也可能是一种调整 CGC 组成和平均分子量的策略。
