Center for Fisheries, Aquaculture, Aquatic Sciences, School of Biological Sciences, Southern Illinois University, Carbondale, IL, United States of America.
Department of Animal Science, The Ohio State University, Columbus, OH, United States of America.
PLoS One. 2021 Dec 28;16(12):e0261847. doi: 10.1371/journal.pone.0261847. eCollection 2021.
The present study utilized digestives tracts from adult largemouth bass (LMB) to hydrolyze Bighead carp muscle and obtain an optimal profile of muscle protein hydrolysates that would be easily assimilated within the primitive digestive tract of larval LMB. Specifically, muscle protein source was digested for the larva using the fully developed digestive system of the same species. The objectives of this study were: 1) to develop an optimal in vitro methodology for carp muscle hydrolysis using LMB endogenous digestive enzymes, and 2) to evaluate the effect of dietary inclusion of the carp muscle protein hydrolysate on LMB growth, survival, occurrence of skeletal deformities, and whole-body free amino acid composition. The study found that the in vitro hydrolysis method using carp intact muscle and LMB digestive tracts incubated at both acid and alkaline pH (to mimic digestive process of LMB) yielded a wide range of low molecular weight fractions (peptides), as opposed to the non-hydrolyzed muscle protein or muscle treated only with acid pH or alkaline pH without enzymes from LMB digestive tracts, which were comprised of large molecular weight fractions (polypeptides above 150 kDa). Overall, the dietary inclusion of the carp muscle hydrolysate improved growth performance of larval LMB in terms of final average weight, weight gain, DGC, SGR, and body length after 21 days of feeding compared to fish that received the diet based on non-hydrolyzed carp muscle. The study also found that hydrolysate-based feed significantly reduced skeletal deformities. The positive growth performance presented by fish in the hydrolysate-fed group possibly resulted from matching the specific requirements of the larvae with respect to their digestive organ development, levels of digestive enzymes present in the gut, and nutritional requirements.
本研究利用成体大口黑鲈的消化道来水解鳙鱼肌肉，并获得鳙鱼肌肉蛋白水解物的最佳谱，使其容易被幼鱼原始消化道吸收。具体来说，利用同一物种完全发育的消化道来消化肌肉蛋白源，以适应幼鱼的需要。本研究的目的是：1）开发一种使用大口黑鲈内源性消化酶水解鲤鱼肌肉的最佳体外方法，2）评估日粮中添加鲤鱼肌肉蛋白水解物对大口黑鲈生长、成活率、骨骼畸形发生和全身体游离氨基酸组成的影响。研究发现，使用完整的鲤鱼肌肉和在酸性和碱性 pH 下孵育的大口黑鲈消化道的体外水解方法（模拟大口黑鲈的消化过程）产生了广泛的低分子量分数（肽），而未水解的肌肉蛋白或仅用酸 pH 或碱性 pH 处理而没有来自大口黑鲈消化道的酶的肌肉蛋白则由高分子量分数（大于 150 kDa 的多肽）组成。总的来说，与基于未水解的鲤鱼肌肉的饮食相比，日粮中添加鲤鱼肌肉水解物可提高幼鱼的生长性能，表现在 21 天喂养后的最终平均体重、体重增加、特定生长率、生长率和体长。研究还发现，基于水解物的饲料显著减少了骨骼畸形。在水解物喂养组中鱼类表现出的良好生长性能可能是由于满足了幼鱼的特定需求，包括其消化器官发育、肠道中存在的消化酶水平和营养需求。
