一株藻际芽孢杆菌对条斑紫菜生长及生理的影响

Effects of a strain of Bacillus spp.on the growth and physiology of Pyropia yezoensis

为阐释藻际芽孢杆菌对条斑紫菜生长生理的影响,以条斑紫菜(Pyropia yezoensis)叶状体及其一种附生菌——芽孢杆菌(Bacillus sp.LPyS1)为材料,研究不同时间点(0、6、12、24、48、72 h)藻-菌共培养后芽孢杆菌对条斑紫菜叶状体相对生长率(RGR)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、光和色素(Chla)、藻胆蛋白(RPE、RPC、APC)、总蛋白(TP)、丙二醛(MDA)和游离脯氨酸(Pro)含量的影响。结果表明:与对照组相比,短期内芽孢杆菌可显著促进条斑紫菜RGR上升(P<0.05),但对条斑紫菜叶状体SOD、POD的活性和丙二醛(MDA)含量无显著性影响(P>0.05);培养24 h后,共培养组与对照组条斑紫菜均产生过量渗透调节物质,其中总蛋白、光合色素、藻胆蛋白共培养组在48 h均显著高于对照组(P<0.05),而Pro含量在48 h极显著低于对照组(P<0.01)。研究表明,芽孢杆菌(Bacillus sp.LPyS1)有利于促进条斑紫菜生长,推测该藻际附生菌可能为藻际环境中的条斑紫菜提供营养物质,从而影响条斑紫菜的生长与生理状态。

To explain the effect of Bacillus spp.on the growth and physiology of Pyropia yezoensis,Pyropia yezoensis fronds and one of its epiphytic bacteria-Bacillus sp.LPyS1 were used as materials.Effects of the different time points(0,6,12,24,48,72 h),the relative growth rate(RGR),the activity of superoxide dismutase(SOD),peroxidase(POD),phycobiliprotein(Chla),photosynthetic pigments(RPE,RPC and APC),total protein(TP),malondialdehyde(MDA)and free proline(Pro)content were studied.The results showed that,compared with the control group,Bacillus could significantly increase the RGR of Pyropia yezoensis in a short period of time(P<0.05),Bacillus had no significant effect on the activity of SOD,POD and the content of malondialdehyde(MDA)in Pyropia yezoensis fronds(P>0.05).After 24 h of culture,the co-culture group and control group Pyropia yezoensis produced excessive osmotic adjustment substances.The total protein,photosynthetic pigment and phycobiliprotein of co-culture group were significantly higher than that of the control group at 48 h(P<0.05),but the content of Pro in the co-culture group was significantly lower than that in the control group at 48 h(P<0.01).This experimental study showed Bacillus sp.LPyS1 was beneficial to promote the growth of Pyropia yezoensis.Therefore,it is speculated that this algal epiphytic bacteria might provide nutrients for Pyropia yezoensis in the algal environment,thereby affecting the growth and physiological state of Pyropia yezoensis.