Ceccotti Chiara, Biasato Ilaria, Gasco Laura, Caimi Christian, Bellezza Oddon Sara, Rimoldi Simona, Brambilla Fabio, Terova Genciana
Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
Department of Agricultural, Forest and Food Sciences, University of Turin, 10124 Grugliasco, Italy.
Curr Issues Mol Biol. 2022 Jul 19;44(7):3238-3252. doi: 10.3390/cimb44070223.
In aquafeeds in which plant proteins are used to replace fishmeal, exogenous methionine (Met) sources are demanded to balance the amino acid composition of diets and meet the metabolic fish requirements. Nonetheless, since different synthetic Met sources are commercially available, it is important to determine their bioavailability and efficacy. To address this issue, we conducted a two-month feeding trial with rainbow trout (), which were fed diets supplemented with five different forms of Met: Met-Met, L-Met, HMTBa, DL-Met, and Co DL-Met. No differences in growth performance were found in trout fed with different Met forms, but changes in the whole-body composition were found. In particular, Met-Met and L-Met promoted a significant body lipid reduction, whereas the protein retention was significantly increased in fish fed with HMTBa and Co DL-Met. The latter affected the hepatic Met metabolism promoting the trans-sulfuration pathway through the upregulation of gene expression. Similarly, the L-Met enhanced the remethylation pathway through an increase in gene expression to maintain the cellular demand for Met. Altogether, our findings suggest an optimal dietary intake of all tested Met sources with similar promoting effects on fish growth and hepatic Met metabolism. Nevertheless, the mechanisms underlying these effects warrant further investigation.
在使用植物蛋白替代鱼粉的水产饲料中，需要外源蛋氨酸（Met）来源来平衡日粮的氨基酸组成并满足鱼类的代谢需求。尽管如此，由于市场上有不同的合成蛋氨酸来源，确定它们的生物利用率和功效很重要。为了解决这个问题，我们对虹鳟鱼进行了为期两个月的饲养试验，给它们投喂添加了五种不同形式蛋氨酸的日粮：蛋氨酸-蛋氨酸（Met-Met）、L-蛋氨酸（L-Met）、羟基蛋氨酸钙（HMTBa）、消旋蛋氨酸（DL-Met）和蛋氨酸钴（Co DL-Met）。投喂不同形式蛋氨酸的虹鳟鱼在生长性能上没有差异，但发现鱼体组成有变化。特别是，Met-Met和L-Met显著促进鱼体脂质减少，而投喂HMTBa和Co DL-Met的鱼蛋白质保留率显著增加。后者通过上调基因表达影响肝脏蛋氨酸代谢，促进转硫途径。同样，L-Met通过增加基因表达增强再甲基化途径，以维持细胞对蛋氨酸的需求。总之，我们的研究结果表明，所有测试的蛋氨酸来源在日粮中的最佳摄入量对鱼类生长和肝脏蛋氨酸代谢具有相似的促进作用。然而，这些作用背后的机制还有待进一步研究。
