枯草芽孢杆菌发酵液对拟柱孢藻的抑制效果及作用方式  

INHIBITORY EFFECT AND MECHANISM OF BACILLUS SUBTILIS FERMENTATION BROTH ON CYLINDROSPERMOPSIS RACIBORSKII

作　　者：刘湘 徐蕾 王纯波[1,3] 肖邦定 LIU Xiang;XU Lei;WANG Chun-Bo;XIAO Bang-Ding(Key Laboratory of Algal Biology of Chinese Academy of Sciences,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China;Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province,Kunming 650228,China)

机构地区：[1]中国科学院水生生物研究所中国科学院藻类生物学重点实验室,武汉430072 [2]中国科学院大学,北京100049 [3]滇池湖泊生态系统云南省野外科学观测研究站,昆明650228

出　　处：《水生生物学报》2023年第12期1889-1898,共10页Acta Hydrobiologica Sinica

基　　金：国家重点研发计划(2022YFC3203601);湖北省重点研发计划(2022BCA068)资助。

摘　　要：全球气候变暖和水体富营养化导致拟柱孢藻(Cylindrospermopsis raciborskii)逐渐扩散并在大量湖泊和水库形成水华,其产生的毒素对水生态系统和人类健康构成威胁,实验系统研究了枯草芽孢杆菌发酵液在不同条件下对拟柱孢藻的剂量效应关系、抑藻机制及持续时间,并分析了处理过程中胞内有机物释放的风险。结果表明,10μL/L的枯草芽孢杆菌发酵液处理初始密度为2.26×10^(9)cells/L拟柱孢藻4d后抑制率达到90.48%,并在第5天接近100%。抑制效果受处理水体的pH和水温影响较小。低剂量的枯草芽孢杆菌发酵液(5μL/L)处理1d后拟柱孢藻的光合系统受到抑制,并使超氧化物歧化酶(SOD)活性显著增加。但2d后拟柱孢藻又能恢复生长。高浓度发酵液(10μL/L)导致拟柱孢藻在1d内光合系统的完全失活,并且裂解释放了大量有机物,这些大量释放的胞内有机物在5d内能降低至6.27 mg/L。扫描电镜(SEM)显示处理组拟柱孢藻藻丝横隔收缢收缩加剧,细胞表面出现明显褶皱和萎缩,并有大量细胞裂解残体。总体而言,采用枯草芽孢杆菌控制湖泊和水库的拟柱孢水华是一种可行的方法。Global warming and water eutrophication have led to the increased prevalence and extent of harmful algal blooms (cyanoHABs),including the potentially toxic cyanobacterial species Cylindrospermopsis raciborskii.Bacillus subtilis,one of the most commonly reported microorganisms that could inhibit the growth of cyanobacteria among microbial agents,provides an efficient,safe,and sustainable solution for controlling blooms.Most research has found that the primary or significant mechanism by which Bacillus subtilis inhibits the growth of cyanobacteria is through the release of biologically active substances with algicidal properties.In this study,the dose-effect relationship,inhibition mechanism and lasting time of Bacillus subtilis fermentation broth were systematically studied under different conditions.We also analyzed the concentrations of dissolved organic carbon,protein,and polysaccharides after treatment to assess the risk of intracellular organic matter release.In addition,we analyzed the mechanism by which microbial agents inhibit C.raciborskii by assessing its photosynthetic activity and superoxide dismutase activity (SOD) during treatment,as well as through scanning electron microscopy.The results showed that the inhibition rate reached 90.48% with 10μL/L Bacillus subtilis fermentation broth at the 4th day when the initial concentration is 2.26×10^(9) cells/L,and it grows closely to 100% at the following day.The pH and water temperature had the minimal effects on the inhibition effect.Under the treatment of 10—50μL/L Bacillus subtilis fermentation broth,the maximum photochemical quantum yield (Fv/Fm) of C.raciborskii decreased to 0 after the first day,indicating that almost all the C.raciborskii cells lost their activity within one day.Low-dose treatment (5μL/L) inhibited the photosynthetic system of C.raciborskii and caused a sharp increase in SOD activity.but C.raciborskii was able to resume growth after 2d.The high concentration of fermentation liquid resulted in the lysis of C.raciborskii and the r

关 键 词：枯草芽孢杆菌发酵液 溶藻特性 生理响应 细胞形态 拟柱孢藻 

分 类 号：X172[环境科学与工程—环境科学]