Soto-Sierra Laura, Nikolov Zivko L
Molecular Templates, Inc. (MTEM), Austin, TX, United States.
Texas A&M University, College Station, TX, United States.
Front Bioeng Biotechnol. 2022 Aug 30;10:957268. doi: 10.3389/fbioe.2022.957268. eCollection 2022.
Protein hydrolysates are one of the most valuable products that can be obtained from lipid-extracted microalgae (LEA). The advantages of protein hydrolysates over other protein products encompass enhanced solubility, digestibility, and potential bioactivity. The development of an economically feasible process to produce protein hydrolysates depends on maximizing the recovery of hydrolyzed native protein from the lipid-extracted algal biomass and subsequent fractionation of hydrolyzed protein slurry. Previously, we reported a method for fractionation of enzymatically generated protein hydrolysates by acidic precipitation of algal cell debris and unhydrolyzed protein, precipitate wash, centrifugation, and depth filtration. The present study evaluates tangential flow ultrafiltration as a single-step alternative to centrifugation, precipitate wash, and depth filtration. The results demonstrate that the tangential flow ultrafiltration process has a potential that deserves further investigation. First, the membrane diafiltration process uses a single and easily scalable unit operation (tangential flow filtration) to separate and "wash out" hydrolyzed protein from the algal residue. Second, the protein recovery yield achieved with the tangential flow process was >70% compared to 64% previously achieved by centrifugation and depth filtration methods. Finally, protein hydrolysates obtained by membrane ultrafiltration exhibited slightly better heat and pH stability.
蛋白质水解产物是从脱脂微藻（LEA）中获得的最有价值的产品之一。蛋白质水解产物相对于其他蛋白质产品的优势包括更高的溶解度、消化率和潜在的生物活性。开发一种经济可行的生产蛋白质水解产物的工艺取决于从脱脂藻类生物质中最大限度地回收水解的天然蛋白质，以及随后对水解蛋白质浆液进行分级分离。此前，我们报道了一种通过酸性沉淀藻类细胞碎片和未水解蛋白质、沉淀洗涤、离心和深度过滤来分级酶促生成的蛋白质水解产物的方法。本研究评估了切向流超滤作为离心、沉淀洗涤和深度过滤的单步替代方法。结果表明，切向流超滤工艺具有值得进一步研究的潜力。首先，膜渗滤过程使用单一且易于扩大规模的单元操作（切向流过滤）从藻类残渣中分离并“洗出”水解蛋白质。其次，切向流工艺实现的蛋白质回收率超过70%，而之前通过离心和深度过滤方法实现的回收率为64%。最后，通过膜超滤获得的蛋白质水解产物表现出略好的热稳定性和pH稳定性。
