Food Science and Technology, University of California, Davis, CA, USA.
Biological and Agricultural Engineering, University of California, Davis, CA, USA.
J Sci Food Agric. 2019 Apr;99(6):3034-3044. doi: 10.1002/jsfa.9517. Epub 2019 Jan 28.
Cassava leaves are an abundant global agricultural residue because the roots are a major source of dietary carbohydrates. Although cassava leaves are high in protein, the protein is not bioavailable. This work aimed to convert cassava leaves to a bioavailable protein-rich animal feed ingredient using high-protein yeasts.
The structural proteins (ca 200 g kg d.b.) from sundried cassava leaves were solubilized by mild alkali pretreatment, and the resulting cassava leaf hydrolysate (CLH) was used to screen for growth of 46 high-protein yeasts from 30 species. Promising candidates from the initial screen cultivated at a 10 mL scale demonstrated increases in relative abundance of essential amino acids over that of CLH. In particular, lysine, growth-limiting for some livestock, was increased up to 226% over the CLH content. One yeast, Pichia kudriavzevii UCDFST 11-602, was grown in 3 L of CLH in a bioreactor to examine the scale-up potential of the yeast protein production. While glucose was completely consumed, yeast growth exited log phase before depleting either carbon or nitrogen, suggesting other growth-limiting factors at the larger scale.
High-value animal feed with enriched essential amino acid profiles can be produced by yeasts grown on agricultural residues. Yeasts convert structural protein solubilized from cassava leaves to essential amino acid-enriched, digestible protein. The low carbohydrate content of the leaves (ca 200 g kg d.b.), however, necessitated glucose supplementation for yeast growth. © 2018 Society of Chemical Industry.
木薯叶是一种丰富的全球农业残余物，因为其根部是膳食碳水化合物的主要来源。虽然木薯叶的蛋白质含量很高，但这些蛋白质无法被生物利用。本研究旨在利用高蛋白酵母将木薯叶转化为可利用的富含蛋白质的动物饲料成分。
晒干的木薯叶中的结构蛋白（约 200 g kg d.b.）经温和碱预处理溶解，得到的木薯叶水解液（CLH）用于筛选 30 个种属中的 46 株高蛋白酵母的生长。从初步筛选中选出的有前景的候选菌株在 10 mL 规模下培养时，其必需氨基酸的相对丰度均高于 CLH。特别是赖氨酸，对一些家畜来说是生长限制因素，其含量比 CLH 增加了 226%。一株酵母，毕赤酵母 UCDFST 11-602，在生物反应器中用 3 L CLH 进行培养，以考察酵母蛋白生产的放大潜力。虽然葡萄糖被完全消耗，但酵母生长在耗尽碳源或氮源之前就退出了对数期，这表明在更大规模下存在其他生长限制因素。
可以利用农业残余物上生长的酵母生产富含必需氨基酸的高附加值动物饲料。酵母将从木薯叶中溶解的结构蛋白转化为富含必需氨基酸、易消化的蛋白质。然而，叶片的低碳水化合物含量（约 200 g kg d.b.）需要补充葡萄糖以促进酵母生长。© 2018 英国化学学会。
