不同盐度对凡纳滨对虾血淋巴及肌肉游离氨基酸组成的影响

Effects of different salinities on free amino acid composition in muscle and hemolymph of the shrimp Litopenaeus vannamei

关键词:  凡纳滨对虾  盐度  肌肉  血淋巴  游离氨基酸组成

Key words:  Lieopenaeus.vanamei  Salinity  Muscle  Hemolymph  Free amino acid composition

摘要:

以平均体重为10.50±1.75 g的凡纳滨对虾为研究对象，分别在盐度为0、15和30的水体中用同一种饲料喂养20 d，探讨不同盐度对凡纳滨对虾肌肉及血淋巴游离氨基酸组成的影响。结果表明，盐度在0、15和30变化时，凡纳滨对虾血淋巴中总游离氨基酸总量随盐度升高而显著增加（P<0.05）；甘氨酸、谷氨酸、精氨酸和丙氨酸是凡纳滨对虾血淋巴中主要的游离氨基酸成分，其含量随盐度的增加而急剧增加。盐度为0、15和30时，凡纳滨对虾肌肉中游离氨基酸总量随着盐度的增加有增加趋势，但无显著性差异（P>0.05）。甘氨酸、亮氨酸、苯丙氨酸及精氨酸的含量随盐度由0、15、30的增加而显著增加（P<0.05)；其他氨基酸在盐度0、15和30增加时，虽无显著性增加（P>005)，但大部分氨基酸有增加趋势。当盐度在0、15和30变化时，游离甘氨酸、谷氨酸、精氨酸和丙氨酸是凡纳滨对虾体内渗透压调节的主要氨基酸。

Abstract:

The study on free amino acid variation in the muscle and hemolymph of itopenaeus vannamei in different salinities revealed that total free amino acids of the hemolymph were 87.58 mg/ml, 569.27 mg/ml, 1 038.68 mg/ml respectively and total free amino acids of the muscle were 2 250.13 mg/100 g, 2 330.42 mg/100 g and 2 548.74 mg/100 g,respectively, when salinity was 0, 15 and 30 . As salinity increased, total free amino acids of the hemolymph of L. vannamei increased significantly (P<0.05). The concentrations of free Gly, Glu, Arg, Ala in the hemolymph ofL. vanamei increased sharply, with increased salinity, in the meanwhile the concentration of free Gly, Glu, Arg, Ala in the muscle of L. vanamei correspondingly increased. However, the increase of concentrations of free Gly, Glu, Arg, Ala in the muscle of L. vanamei was less than those in the hemolymph. Free amino acids Gly, Glu, Arg, Ala played an important role in regulating osmotic pressure.