【摘要】 将300 mL紫菜振荡液涂布于Zobell 2216E海水培培养基中接种0.2 g无菌处理过的条斑紫菜(Pyropia yezoensis叶状体与约3×10~6 cells/mLBacillus sp.LPyS1,在22℃、盐度30、光强3 500 lx,光周期12L:12D,充气条件下培养0 h、6 h、12 h、24 h、48 h和72 h取样,测定其相对生长率(RGR)、可溶性蛋白、藻胆蛋白、游离脯氨酸(Pro)和丙二醛(MDA)含量,以及超氧化物岐化酶(SOD)和过氧化物酶(POD)活性。以仅接种条斑紫菜叶状体、相同培养作为对照,探究高温胁迫下藻际附生菌对条斑紫菜叶状体生长和成活的影响。结果发现,与对照组相比,24h时藻菌共培养组条斑紫菜的RGR、MDA和藻胆蛋白水平及SOD、POD活性均显著增加(P<0.05),但渗透调节物质Pro与可溶性蛋白含量均显著低于对照组(P<0.05);而72 h共培养组的RGR无显著变化(P>0.05),POD、MDA、藻胆蛋白和Pro均显著高于对照组(P<0.05);连续培养4 d后两组条斑紫菜均出现腐烂现象,对照组藻体腐烂更为严重。研究表明:高温条件下短期内藻际芽孢杆菌可以增强条斑紫菜的抗逆性和生长,而后培养时间的延长会加剧渗透压和活性氧胁迫,芽孢杆菌对条斑紫菜的促生长作用随其抗逆能力的减弱而缓慢下降,说明该菌株的生态功能因环境变化而发生了改变。更多还原

【Abstract】 Relative growth rate(RGR),soluble protein,contents of phycobiliprotein,free proline(Pro),malondialdehyde(MDA),activities of superoxide dismutase(SOD) and peroxidase(POD) were determined in laver Pyropia yezoensis fronds cultured in Zobell2216 E seawater culture medium and inoculated 0.2 g of sterile laver and about 3 × 10~6 cells/mL Bacillus sp.LPySl at 22℃,salinity of30,light intensity of 3,500 lx,photoperiod of 12 L : 12 D,under aerated conditions for 0 h,6 h,12 h,24 h,48 h,and 72 h,with only inoculation of laver fronds as a control,to evaluate the effect of epiphytic bacteria on algae under high temperature stress.The results showed that there were significantly higher RGR,contents of MDA,phycobiliprotein,Pro,activities of SOD and POD in the 24 h treat group than those in the control group(P <0.05),without significant difference between the 72 h treat group and the control group(P> 0.05).Four days culture later,the laver was rotted in the two groups,more severely in the control group,indicating that Bacillus sp.LPyS1 enhanced the stress resistance and promoted the growth of laver in a short period of time at high temperature.Then the elapse of the culture time intensified the osmotic pressure and reactive oxygen stress,and the growth-promoting effect of Bacillus on laver was slowly decreased as its resistance to stress weakens.The finding shows that the ecological function of the laver has changed with environmental changes.更多还原