许燕茹 林岗

摘 要：以球等鞭金藻Isochrysis galbana為研究对象，分析不同浓度恩诺沙星（ENR）处理下，球等鞭金藻的生长和脂肪酸组成变化。通过细胞计数法和分光光度法测定球等鞭金藻的生长变化，采用气相色谱法测定球等鞭金藻的脂肪酸组成和含量。结果表明：恩诺沙星对球等鞭金藻的生长表现出低促高抑的作用，当恩诺沙星处理浓度≤0.625 mg·L-1  时表现出促进作用，恩诺沙星处理浓度≥5 mg·L-1  时表现出抑制作用，但未体现浓度-效应关系。在恩诺沙星的胁迫下，球等鞭金藻脂肪酸组成和含量均发生变化;随着培养时间的增加，球等鞭金藻脂肪酸总含量呈降低趋势，当培养时间为24、96 h时，各浓度组不饱和脂肪酸含量均低于对照组（ENR浓度为0 mg·L-1  ），DHA含量与对照组差异不显著;当恩诺沙星处理浓度≥5 mg·L-1  ，培养时间为240 h时，球等鞭金藻不饱和脂肪酸含量极显著高于对照组，DHA含量显著高于对照组。因此，在恩诺沙星胁迫下，球等鞭金藻中的不饱和脂肪酸占比得以提高。

关键词：球等鞭金藻;恩诺沙星;脂肪酸;胁迫

中图分类号：S 917.3 文献标志码：A 文章编号：0253-2301（2021）09-0008-07

DOI： 10.13651/j.cnki.fjnykj.2021.09.002

Effects of Enrofloxacin on the Growth and Fatty Acids of Isochrysis Galbana

XU Yan ru 1， LIN Gang

（1. College of Life Sciences， Fujian Normal University， Fuzhou， Fujian 350117， China; 2. Fujian Key Laboratory

of Sustainable Utilization of Featured Marine Biological Resources， Fuzhou， Fujian 350117， China）

Abstract： In this study， by taking Isochrysis galbana as the research object， the growth and the changes of fatty acid composition of Isochrysis galbana were analyzed under the treatments of different concentrations of enrofloxacin. The growth changes of Isochrysis galbana were measured by using the cell counting method and spectrophotometric method， and the composition and content of fatty acid in Isochrysis galbana were measured by using the gas chromatographic method. The results showed that enrofloxacin exhibited a low promoting and high inhibiting effect on the growth of Isochrysis galbana， namely， showing a promoting effect when the concentration of enrofloxacin was ≤0.625  mg·L-1  ， and showing an inhibiting effect when the concentration of enrofloxacin was ≥5 mg·L-1  ， but there was no concentration effect relationship. Under the stress of enrofloxacin， the composition and content of fatty acid in Isochrysis galbana changed. With the increase of incubation time， the total content of fatty acid in Isochrysis galbana decreased， and when the incubation time was 24 h and 96 h， the content of unsaturated fatty acid in each concentration group was lower than that in the control group （the concentration of enrofloxacin was 0

mg·L-1  ）， and the content of DHA was not significantly different from that in the control group. When the concentration of enrofloxacin was ≥5 mg·L-1 and the incubation time was 240 h， the contents of unsaturated fatty acid and DHA in Isochrysis galbana were significantly higher than those in the control group. Therefore， the proportion of unsaturated fatty acids in Isochrysis galbana was increased under the stress of enrofloxacin.

Key words： Isochrysis galbana; Enrofloxacin; Fatty acids; Stress

金藻门的球等鞭金藻Isochrysis galbana是单细胞微藻，无细胞壁，有两条等长的鞭毛，富含色素、蛋白质、脂肪酸等营养物质，具有个体大小适中，易被贝类幼虫捕捉、吞噬、消化吸收，代谢产物对贝类幼虫无毒等饵料藻类所需条件，可作为水产养殖的活体饵料[1] 。球等鞭金藻富含不饱和脂肪酸，能提高水生生物幼体时期的孵化率、存活率和生长率[2] ，是广泛使用的海产养殖动物幼体的理想基础饵料。……