解淀粉芽孢杆菌化感作用对球等鞭金藻生长抑制效果

Allelopathic effect of Bacillus amyloliquefaciens on the growth of Isochrysis galbana

为探明解淀粉芽孢杆菌及其代谢物对海水养殖环境中微藻的化感作用,本文以实验生态学方法研究了解淀粉芽孢杆菌对球等鞭金藻生长的生态作用。实验设计了不同剂量(100mL、500mL、1000mL)的解淀粉芽孢杆菌纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液三种组合研究其对球等鞭金藻的培养影响。结果显示,添加纯菌液组金藻在第1~2 d增长缓慢,藻细胞数无显著差异,但均低于对照组,其中第3~4 d显著低于对照组(P<0.05);添加菌代谢产物组第1 d金藻细胞数与对照组相比无显著差异,2~4 d显著低于对照组(P<0.05);添加菌液及代谢产物混合液组中100mL组金藻生长较缓慢,500μL和1000μL组藻细胞数呈下降趋势,藻细胞数显著低于对照组(P<0.05),1000μL组金藻第2 d已全部死亡。各剂量组藻细胞数均呈现解淀粉芽孢杆纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液依次下降,另外,除菌代谢物1000μL剂量组藻细胞数大于500μL剂量组外,其余各组添加量越大藻细胞数越少,呈现剂量效应关系。解淀粉芽孢杆纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液抑制率最高分别为35.84%、69.75%、100%,表明解淀粉芽孢杆菌对球等鞭金藻的作用为化感抑制,且抑制效果具有剂量效应。本研究为解淀粉芽孢杆菌在水产养殖中应用效果评价提供了科学依据,同时为赤潮藻类治理提供新思路。

To investigate the allelopathic effects of Bacillus amyloliquefaciens and its metabolites on microalgae in the marine aquaculture environment,we studied the ecological functions of B.amyloliquefaciens on the growth of Isochrysis galbana by using experimental ecological methods.We used three combinations of B.amyloliquefaciens,B.amyloliquefaciens metabolites,and a mixture of B.amyloliquefaciens and its metabolites at different doses(100μL,500μL,and 1000μL)to study their effects on the cultivation of I.galbana.The results showed that in the group with B.amyloliquefaciens,the algae cell number of I.galbana grew slowly in the first two days with no significant difference,but was lower than that in the control group(P>0.05).In 3~4 days,the algal cell number of three groups with different doses was significantly lower than that of the control group(P<0.05).In the group with metabolites of B.amyloliquefaciens,the algal cell number of three groups with different doses had no significant difference with the control group,but it was significantly lower than that of the control group in 2~4 days(P<0.05).In the group with the mixture of B.amyloliquefaciens and its metabolites,the growth of 100μL group was slower than that of the other groups.The algae cell number of the 500μL group and 1000μL group showed a downward trend,and was significantly lower than that of the control group(P<0.05).In the 1000μL group,the mortality of 100%was achieved on the second day after treatment.In general,studies have shown that the algae cell number in each dose group showed a sequential decrease in B.amyloliquefaciens,B.amyloliquefaciens metabolites,and the mixture of B.amyloliquefaciens and its metabolites.Moreover,the algae cell number of 1000μL group of B.amyloliquefaciens metabolites was larger than that in the 500μL group.The larger dose would indicate a fewer number of algae cells,thus showing a dose effect.The inhibition rates of B.amyloliquefaciens,B.amyloliquefaciens metabolites,and the mixture of B.amyloliquefaciens and its metabolites were 35.84%,69.75%,and 100%,respectively.The study showed that the allelopathy of B.amylolyticus on I.galbana showed an inhibition effect,which further showed a dose effect.This study provided a scientific basis for the evaluation of the effect of B.amylolyticus in aquaculture.It also provided a new idea for the management of algae in the red tide.