Molinari Giovanni S, Wojno Michal, Wick Macdonald, Kwasek Karolina
Center for Fisheries, Aquaculture, and Aquatic Sciences, Southern Illinois University, Carbondale, Illinois, United States of America.
Department of Animal Science, The Ohio State University, Columbus, Ohio, United States of America.
PLoS One. 2025 Jun 24;20(6):e0326665. doi: 10.1371/journal.pone.0326665. eCollection 2025.
Protein hydrolysates have been used extensively as dietary protein for larval fish. Typically, they are expensive, difficult to produce, and show varying results when utilized for different species. This study proposed a practical hydrolysis method that utilizes endogenous enzymes within the body to "auto-hydrolyze", or digest its tissue proteins with its own endogenous enzymes, and produce a fishmeal tailored to nutritional requirements and absorptive capacity of larval fish. The objectives for this experiment were to determine the: 1) effect of the proposed hydrolysis method on tissue protein breakdown level; and 2) effect of dietary inclusion of obtained hydrolysates on larval growth performance, using Zebrafish (Danio rerio). Whole-body adult Zebrafish were utilized to produce an unhydrolyzed fishmeal, and three fishmeals hydrolyzed for 1, 2, and 3 h, respectively. Three diets were formulated, defined by their dietary protein supply. The Unhydro diet contained unhydrolyzed Zebrafish meal. The 50% Hydro diet contained 50% Zebrafish meal hydrolysates and 50% unhydrolyzed Zebrafish meal. The 100% Hydro diet contained 100% Zebrafish meal hydrolysates. Five groups were utilized in this study, with three groups receiving one of the produced Zebrafish meal-based diets. Larvae fed a commercial starter diet and Artemia, respectively, were included as reference groups. Larval fish were randomly stocked into tanks (100 fish per tank) at 3 days-post-hatch (dph), and the trial was carried out until 18 dph. Electrophoretic analysis showed that the proposed hydrolysis method was able to efficiently hydrolyze the protein within Zebrafish body. The feeding trial results found no significant differences in weight, total length, or survival between the Unhydro, 50% Hydro, and 100% Hydro groups. The proposed hydrolysis method provides a practical and potentially cost-effective approach to producing species-specific fishmeal hydrolysates. Further research is necessary to determine whether the produced hydrolysates can improve the growth of larval fish in other species.
蛋白质水解物已被广泛用作幼鱼的膳食蛋白质。通常，它们价格昂贵，生产困难，并且在用于不同物种时会显示出不同的结果。本研究提出了一种实用的水解方法，该方法利用鱼体内的内源酶进行“自水解”，即利用自身的内源酶消化其组织蛋白质，并生产出一种适合幼鱼营养需求和吸收能力的鱼粉。本实验的目的是确定：1）所提出的水解方法对组织蛋白质分解水平的影响；2）使用斑马鱼（Danio rerio），将所得水解物添加到饲料中对幼鱼生长性能的影响。使用成年斑马鱼的整体来生产未水解的鱼粉，以及分别水解1、2和3小时的三种鱼粉。配制了三种饲料，根据其膳食蛋白质供应来定义。未水解饲料（Unhydro diet）含有未水解的斑马鱼粉。50%水解饲料（50% Hydro diet）含有50%的斑马鱼粉水解物和50%未水解的斑马鱼粉。100%水解饲料（100% Hydro diet）含有100%的斑马鱼粉水解物。本研究使用了五组，其中三组分别接受一种基于斑马鱼粉生产的饲料。分别喂食商业开口饲料和卤虫的幼鱼作为参考组。孵化后3天（dph），将幼鱼随机放入水箱（每个水箱100条鱼），试验进行到18 dph。电泳分析表明，所提出的水解方法能够有效地水解斑马鱼体内的蛋白质。喂养试验结果发现，未水解组、50%水解组和100%水解组在体重、全长或存活率方面没有显著差异。所提出的水解方法为生产特定物种的鱼粉水解物提供了一种实用且可能具有成本效益的方法。有必要进行进一步的研究，以确定所生产的水解物是否能促进其他物种幼鱼的生长。
