Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.
Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy.
Microb Cell Fact. 2022 Sep 5;21(1):179. doi: 10.1186/s12934-022-01898-y.
D-Arabitol, a five-carbon sugar alcohol, represents a main target of microbial biorefineries aiming to valorize cheap substrates. The yeast Wickerhamomyces anomalus WC 1501 is known to produce arabitol in a glycerol-based nitrogen-limited medium and preliminary fed-batch processes with this yeast were reported to yield 18.0 g/L arabitol.
Fed-batch fermentations with W. anomalus WC 1501 were optimized using central composite design (CCD). Dissolved oxygen had not a significant effect, while optimum values were found for glycerol concentration (114.5 g/L), pH (5.9), and temperature (32.5 °C), yielding 29 g/L D-arabitol in 160 h, a conversion yield of 0.25 g of arabitol per g of consumed glycerol, and a volumetric productivity of 0.18 g/L/h. CCD optimal conditions were the basis for further improvement, consisting in increasing the cellular density (3✕), applying a constant feeding of glycerol, and increasing temperature during production. The best performing fed-batch fermentations achieved 265 g/L D-arabitol after 325 h, a conversion yield of 0.74 g/g, and a volumetric productivity of 0.82 g/L/h.
W. anomalus WC 1501 confirmed as an excellent producer of D-arabitol, exhibiting a remarkable capability of transforming pure glycerol. The study reports among the highest values ever reported for microbial transformation of glycerol into D-arabitol, in terms of arabitol titer, conversion yield, and productivity.
D-阿拉伯糖醇是一种五碳糖醇，是将廉价基质转化为有价值产物的微生物生物精炼的主要目标。已知异常威克汉姆酵母（Wickerhamomyces anomalus）WC 1501 在基于甘油的氮限制培养基中产生阿拉伯糖醇，并用该酵母进行初步补料分批工艺，该工艺的阿拉伯糖醇产量为 18.0 g/L。
利用中心组合设计（CCD）对异常威克汉姆酵母 WC 1501 的补料分批发酵进行了优化。溶解氧没有显著影响，而甘油浓度（114.5 g/L）、pH（5.9）和温度（32.5°C）的最佳值被发现，在 160 h 内产生 29 g/L 的 D-阿拉伯糖醇，消耗的甘油的转化率为 0.25 g 阿拉伯糖醇/g，比体积生产率为 0.18 g/L/h。CCD 优化条件是进一步提高的基础，包括增加细胞密度（3 倍）、恒速添加甘油和生产过程中提高温度。最佳补料分批发酵在 325 h 后达到 265 g/L D-阿拉伯糖醇，转化率为 0.74 g/g，比体积生产率为 0.82 g/L/h。
异常威克汉姆酵母 WC 1501 被证实是 D-阿拉伯糖醇的优秀生产者，具有将纯甘油转化为 D-阿拉伯糖醇的卓越能力。该研究报告了微生物转化甘油为 D-阿拉伯糖醇的最高值之一，在阿拉伯糖醇产量、转化率和生产率方面。
