低氧化还原电位对铜绿微囊藻(Microcystis aeruginosa)生长的抑制及恢复的影响

在实验室光照黑暗交替培养下,用半胱氨酸下调黑暗起始时的氧化还原电位(ORP),研究低电位对铜绿微囊藻(Microcystis aeruginosa FACHB 469)生长的影响,并探索低电位胁迫消除后铜绿微囊藻生长的恢复潜力.结果表明,在-50～-100 mV范围内水体ORP越低,其对铜绿微囊藻生长的抑制作用越强.低ORP可抑制铜绿微囊藻对磷的吸收,且这种抑制程度与电位变化无关.-50～-75 mV的电位对铜绿微囊藻SOD酶活性有促进作用,而-90～-100 mV电位明显抑制SOD酶活.当低ORP胁迫消除后,铜绿微囊藻能够恢复至最初的生长状态,同时伴随含磷量的提高和SOD酶活的恢复,-50～-75 mV电位胁迫对藻消除胁迫后的生长更有促进作用.因此,低ORP对铜绿微囊藻的生长会产生不利影响,但是该影响是可逆的.

Growth inhibition and recovery from low oxidation reduction potential to Microcystis aeruginosa

In this experiment,cysteine was used as an Oxidation Reduction Potential(ORP) adjustment to explore the responses of Microcystis aeruginosa(FACHB 469) under different ORPs’ stimulation.A recovery experiment was also designed with M.aeruginosa separated from the former experiment and cultured in fresh medium.Results showed a negative effect of low ORP stimulation on the growth of M.aeruginosa.Within the range of-50 to-100 mV,inhibition effect was intensified with the ORP’s decline.The uptake rate of phosphorus decreased under low ORP’s stress but had no relationship with stress strength.A proper low ORP’s stimulation(e.g.-50 and-75 mV) could intensify the SOD enzyme activity of M.aeruginosa,while over low(e.g.-90 and-100 mV) had negative effects.M.aeruginosa could recover its growing ability after removing the lower ORP’s stimulation.The uptake rate of phosphorus and the SOD enzyme activity returned to normal as well.Moreover,the enhancement of growth ability was observed by a low ORP’s stimulation(e.g.-50 and-75 mV).Thus,the low ORP’s stimulation had negative effect on the growth of M.aeruginosa,however the process can be reversible.