Área Enología y Biotecnología de la Fermentación, Departamento Ciencia y Tecnología Alimentos, Facultad de Quimica, Universidad de la Republica, 11800, Montevideo, Uruguay.
J Ind Microbiol Biotechnol. 2020 Dec;47(12):1133-1140. doi: 10.1007/s10295-020-02310-7. Epub 2020 Sep 23.
Mixed strain dynamics are still not well or easily monitored although recently molecular identification methods have improved our knowledge. This study used a chromogenic differential plating medium that allows the discrimination of four of the main selected biofuel strains that are currently under development for ethanol production from cellulosic hydrolysates. Complete fermentation of hexoses and xylose was obtained with a yeast consortium composed of Spathaspora passalidarum, Scheffersomyces stipitis, Candida akabanensis and Saccharomyces cerevisiae. The results showed that C.akabanensis excessively dominated consortium balance. Reducing its inoculum from 33 to 4.8% improved population strain balance and fermentation efficiency. Comparison of the consortia with single strain fermentations showed that it optimize sugar consumption and ethanol yields. This simple and cheap method also has advantages compared with molecular methods, as the yeast strains do not need to be genetically marked and identified cell proportions are probably active in the fermentation system as compared to DNA determination methods.
尽管最近的分子鉴定方法提高了我们的认识，但混合菌株动态仍然难以或不易监测。本研究使用了一种显色差异平板培养基，可区分目前正在开发用于从纤维素水解物生产乙醇的四种主要选择的生物燃料菌株。由 Spathaspora passalidarum、Scheffersomyces stipitis、Candida akabanensis 和 Saccharomyces cerevisiae 组成的酵母混合菌可完全发酵己糖和木糖。结果表明，C.akabanensis 过度主导了混合菌的平衡。将其接种量从 33%减少到 4.8%，可改善菌群菌株的平衡和发酵效率。与单菌株发酵相比，该混合菌还可优化糖的消耗和乙醇的产量。与分子方法相比，这种简单廉价的方法也有优势，因为酵母菌株不需要遗传标记，并且与 DNA 测定方法相比，细胞比例在发酵系统中可能更活跃。
