BACKGROUND A possible future shortage of feed protein will force mankind to explore alternative protein sources that can replace conventional soymeal or fishmeal. Several large industrial organic side-streams could potentially be upgraded to feed protein using a fermentation process to generate single cell protein. Yeast is the most widely accepted microorganism for production of single cell protein, because of its superior nutritional quality and acceptability among consumers. Here, we have assessed the growth of four different yeasts, Cyberlindnera jadinii, Wickerhamomyces anomalus, Blastobotrys adeninivorans and Thermosacc® Dry (Saccharomyces cerevisiae), on media composed of enzymatically saccharified sulfite-pulped spruce wood and hydrolysates of by-products from chicken, and we have characterized the resulting yeast biomass. RESULTS Generally, the yeast grew very well on the spruce- and chicken-based medium, with typical yields amounting to 0.4-0.5 g of cell dry weight and 0.2-0.3 g of protein per g of sugar. B. adeninivorans stood out as the most versatile yeast in terms of nutrient consumption and in this case yields were as high as 0.9 g cells and 0.5 g protein per g of sugar. The next best performing yeast in terms of yield was W. anomalus with up to 0.6 g cells and 0.3 g protein per g sugar. Comparative compositional analyses of the yeasts revealed favorable amino acid profiles that were similar to the profiles of soymeal, and even more so, fish meal, especially for essential amino acids. CONCLUSIONS The efficient conversion of industrial biomass streams to yeast biomass demonstrated in this study opens new avenues towards better valorization of these streams and development of sustainable feed ingredients. Furthermore, we conclude that production of W. anomalus or B. adeninivorans on this promising renewable medium may be potentially more efficient than production of the well-known feed ingredient C. jadinii. Further research should focus on medium optimization, development of semi-continuous and continues fermentation protocols and exploration of downstream processing methods that are beneficial for the nutritional values of the yeast for animal feed.

中文翻译：

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在由云杉衍生的糖和鸡肉副产物的蛋白水解物组成的培养基上生长的酵母的生产和表征。

背景技术未来可能饲料蛋白质的短缺将迫使人类寻找可替代常规豆粕或鱼粉的替代蛋白质来源。几种大型工业有机支流可能会通过发酵过程升级为蛋白质，以产生单细胞蛋白质。酵母是生产单细胞蛋白的最广泛接受的微生物，因为它具有优越的营养质量和在消费者中的接受度。在这里，我们评估了四种不同的酵母在由酶促糖化亚硫酸盐制的云杉木屑和鸡肉及其副产物的水解产物组成的培养基上的生长，这些酵母分别为Cyber​​berdnera jadinii，Wickerhamomyces anomalus，Blastobotrys adeninivorans和Thermosacc®Dry（酿酒酵母）。我们已经表征了所得酵母生物量。结果通常，酵母在基于云杉和鸡肉的培养基上生长良好，典型产量为每克糖0.4-0.5克细胞干重和0.2-0.3克蛋白质。就营养消耗而言，腺嘌呤芽孢杆菌是最通用的酵母，在这种情况下，每克糖的产量高达0.9克细胞和0.5克蛋白质。就产量而言，表现第二好的酵母是异常W. anomalus，每克糖含最多0.6 g细胞和0.3 g蛋白。酵母的比较组成分析显示了有利的氨基酸谱，类似于豆粕，甚至更像鱼粉，尤其是必需氨基酸。结论这项研究表明，工业生物质能有效转化为酵母生物质，为更好地评估这些生物质能和开发可持续饲料成分开辟了新途径。此外，我们得出的结论是，在这种有前途的可再生培养基上生产异常W. anomalus或B. adeninivorans可能比生产众所周知的饲料成分贾第虫（C. jadinii）更有效。进一步的研究应侧重于培养基的优化，半连续和连续发酵方案的开发以及对有利于动物饲料酵母营养价值的下游加工方法的探索。这种有希望的可再生培养基上的腺嘌呤可能比生产众所周知的饲料成分贾第虫（C. jadinii）更有效。进一步的研究应侧重于培养基的优化，半连续和连续发酵方案的开发以及对有利于动物饲料酵母营养价值的下游加工方法的探索。这种有希望的可再生培养基上的腺嘌呤可能比生产众所周知的饲料成分贾第虫（C. jadinii）更有效。进一步的研究应侧重于培养基的优化，半连续和连续发酵方案的开发以及对有利于动物饲料酵母营养价值的下游加工方法的探索。