海洋微藻的无菌化处理及对其生长特性和生化组成的影响

Axenation of marine microalgae and effects of axenic cultivation on growth characteristics and biochemical compositions of marine microalgae

利用常用抗生素(氨苄青霉素、链霉素、氯霉素和卡那霉素)对4株海洋微藻(1株金藻和3株小球藻)进行了无菌化处理,并对这4株微藻在带菌和无菌培养时的生长特征和生化组成进行了比较。结果表明:中高浓度(≥100mg/dm3)的单种抗生素或抗生素组合可抑制微藻的生长,个别低浓度(50mg/dm3)的抗生素或抗生素组合可促进微藻的生长;氨苄青霉素、链霉素和卡那霉素各200mg/dm3联合使用处理球等鞭金藻,氯霉素100,50,50mg/dm3单独使用分别处理小球藻C95,CV和C146,可获得这4株微藻的无菌藻系;无菌培养的4株海洋微藻的稳定期持续时间由除菌前的4～5d延长到15～20d,藻液悬浮性增强,藻细胞不易老化;除菌后微藻的主要生化成分发生明显变化,球等鞭金藻的叶绿素A、叶黄素和总脂含量显著增加,小球藻C95和CV的总蛋白含量显著增加,3株小球藻的脂肪酸组成如EPA,PUFA等的含量发生显著变化。

Axenation of four strains of marine microalgae（Isochrysis galbana, Chlorella sp. CV, Chlorella sp. C95 and Chlorella sp. C146） was carried out by using several common antibiotics（including ampicillin, streptomycin, chloramphenicol and kanamycin）. The growth characteristics and biochemical compositions of four strains between axenic and nonaxenic cultures were investigated. The results showed, the growth of microalgae would be inhibited if the concentrations of single antibiotic or combined antibiotics were equal or higher than 100 mg/L, while the growth would be stimulated if the concentrations of some single or combined antibiotics were at 50mg/L;the axenic culture of I. galbana was obtained by combinedly using 200 mg/L of ampicillin, streptomycin and kanamycin, and the axenic cultures of C. CV, C. 95 and C. C146 were obtained by singly using 100, 50 and 50 mg/L of chloramphenicol respectively; the duration of stationary phase of the four axenic cultures prolonged for about 15 days, and the axenic algae could main- tain a good suspension property rather than began aging prematurely; the con＇tents of chlorophyll A, lutein and total lipids in axenic I. galbana and total protein in axenic C. CV and C. 95 increased significantly, and the composition of fatty acids such as EPA and PUFA in axenic Chlorella species changed markedly.