Fiamenghi Mateus Bernabe, Bueno João Gabriel Ribeiro, Camargo Antônio Pedro, Borelli Guilherme, Carazzolle Marcelo Falsarella, Pereira Gonçalo Amarante Guimarães, Dos Santos Leandro Vieira, José Juliana
Genomics and Bioenergy Laboratory (LGE), Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, 13083-970, Brazil.
Genetics and Molecular Biology Graduate Program, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil.
Biotechnol Biofuels Bioprod. 2022 May 20;15(1):57. doi: 10.1186/s13068-022-02153-7.
The need to mitigate and substitute the use of fossil fuels as the main energy matrix has led to the study and development of biofuels as an alternative. Second-generation (2G) ethanol arises as one biofuel with great potential, due to not only maintaining food security, but also as a product from economically interesting crops such as energy-cane. One of the main challenges of 2G ethanol is the inefficient uptake of pentose sugars by industrial yeast Saccharomyces cerevisiae, the main organism used for ethanol production. Understanding the main drivers for xylose assimilation and identify novel and efficient transporters is a key step to make the 2G process economically viable.
By implementing a strategy of searching for present motifs that may be responsible for xylose transport and past adaptations of sugar transporters in xylose fermenting species, we obtained a classifying model which was successfully used to select four different candidate transporters for evaluation in the S. cerevisiae hxt-null strain, EBY.VW4000, harbouring the xylose consumption pathway. Yeast cells expressing the transporters SpX, SpH and SpG showed a superior uptake performance in xylose compared to traditional literature control Gxf1.
Modelling xylose transport with the small data available for yeast and bacteria proved a challenge that was overcome through different statistical strategies. Through this strategy, we present four novel xylose transporters which expands the repertoire of candidates targeting yeast genetic engineering for industrial fermentation. The repeated use of the model for characterizing new transporters will be useful both into finding the best candidates for industrial utilization and to increase the model's predictive capabilities.
减少和替代将化石燃料作为主要能源矩阵的需求促使人们对生物燃料作为替代能源进行研究和开发。第二代（2G）乙醇作为一种具有巨大潜力的生物燃料应运而生，这不仅是因为它能保障粮食安全，还因为它是由能源甘蔗等具有经济价值的作物生产而来。2G乙醇面临的主要挑战之一是工业酵母酿酒酵母对戊糖的吸收效率低下，而酿酒酵母是生产乙醇的主要生物。了解木糖同化的主要驱动因素并识别新型高效转运蛋白是使2G工艺在经济上可行的关键一步。
通过实施一种策略，即在木糖发酵物种中寻找可能负责木糖转运的现有基序以及糖转运蛋白过去的适应性变化，我们获得了一个分类模型，该模型成功用于选择四种不同的候选转运蛋白，以便在含有木糖消耗途径且缺失hxt基因的酿酒酵母菌株EBY.VW4000中进行评估。与传统文献对照Gxf1相比，表达转运蛋白SpX、SpH和SpG的酵母细胞对木糖的吸收性能更优。
利用酵母和细菌的少量可用数据对木糖转运进行建模是一项挑战，通过不同的统计策略得以克服。通过这一策略，我们展示了四种新型木糖转运蛋白，它们扩大了用于工业发酵的酵母基因工程候选蛋白的范围。重复使用该模型来表征新的转运蛋白，对于找到工业应用的最佳候选蛋白以及提高模型的预测能力都将是有用的。
