CAJ | 학술논문

以铜绿微囊藻（Microcystis aeruginosa）为溶解对象，利用液体感染分离技术从浙江大学华家池校区湖水样品中分离到1株溶藻菌 N10，对其生长及溶藻相关特性进行了研究.结果表明：经过16S rDNA 核苷酸序列分析，该菌株属于柠檬酸杆菌属（Citrobacter sp.）；当 N10无细胞培养物（cell-free culture filtrate，CCF）与铜绿微囊藻液按照体积比为1∶5混合后，在24 h 内 N10 CCF 对铜绿微囊藻的溶藻率可达到86.55%，并且溶藻率随着溶藻时间的延长而增强，在72 h 内溶藻率可达到97.08%；对 N10生长量影响最大的是 pH 值，其次是 NaCl 质量分数，最后是温度，但 N10菌株对铜绿微囊藻的溶藻率受培养温度和培养基中 NaCl 质量分数的影响很小；N10菌株通过分泌一种对高温（115℃）敏感但却能抗蛋白酶 K 的物质来溶解铜绿微囊藻；透射电子显微镜观察表明，经过 N10 CCF 处理后的藻细胞出现了细胞膜、细胞壁破裂，伪空胞结构、细胞质中磷酸颗粒以及蓝色体等颗粒性物质消失，细胞中的光合片层排列趋于松散且混乱的现象.
이동록미낭조（Microcystis aeruginosa）위용해대상，이용액체감염분리기술종절강대학화가지교구호수양품중분리도1주용조균 N10，대기생장급용조상관특성진행료연구.결과표명：경과16S rDNA 핵감산서렬분석，해균주속우저몽산간균속（Citrobacter sp.）；당 N10무세포배양물（cell-free culture filtrate，CCF）여동록미낭조액안조체적비위1∶5혼합후，재24 h 내 N10 CCF 대동록미낭조적용조솔가체도86.55%，병차용조솔수착용조시간적연장이증강，재72 h 내용조솔가체도97.08%；대 N10생장량영향최대적시 pH 치，기차시 NaCl 질량분수，최후시온도，단 N10균주대동록미낭조적용조솔수배양온도화배양기중 NaCl 질량분수적영향흔소；N10균주통과분비일충대고온（115℃）민감단각능항단백매 K 적물질래용해동록미낭조；투사전자현미경관찰표명，경과 N10 CCF 처리후적조세포출현료세포막、세포벽파렬，위공포결구、세포질중린산과립이급람색체등과립성물질소실，세포중적광합편층배렬추우송산차혼란적현상.
Summary In recent decades,harmful algal blooms(HABs),which are natural phenomena that occur across all the world, have posed threats to decrease dissolved oxygen and have had a negative effect on fisheries, aquaculture,drinking water,tourism and human health.It is increasingly urgent to develop useful strategies for predicting and reducing the negative impacts of HABs.Actually,many methods have been devoted to controlling HABs,including copper sulfate,hydrogen peroxide,ozonization,ultrasonication,collection of algae from water surface using nets,iron powder and magnets,centrifugal separation,or ultraviolet radiation.As an effective and environment friendly strategy to control harmful algal bloom outbreaks,biologic control methods such as using algicidal bacteria against M.aeruginosa have been more and more attractive.It has been demonstrated that algicidal bacteria could serve as potential ways in reducing the impacts of HABs. <br> In this study,a Citrobacter sp.N10 with algicidal activity against the toxic algae M.aeruginosa was isolated and identified from a lake of Zhejiang University using liquid infection technology and 1 6S rDNA sequence analysis.The growth and algicidal characters of Citrobacter sp.N10 were then studied in order to offer some useful information for HABs controlling. <br> The results showed that the bacterium was gram-negative and its colonies were smooth, convex, low moisture,translucent or opaque and gray,and its colony surfaces were glossy.Sequence analysis of 1 6S rDNA demonstrated that strain N10 belonged to Citrobacter sp.When inoculation time was 2 to 12 h,N10 grew in logarithmic-growth period,and when inoculation time was beyond 12 h,N10 was in stationary phase.Strain N10 showed a high lysis of M.aeruginosa with an algicidal rate of 86.55% within 24 h.The algicidal rate of N10 increased with increasing incubation time and reached 97.08% within 72 h.pH value had the most significant effect on the growth of strain N10,followed by NaCl concentration and culture temperature,while these three conditions had different effects on algicidal activities of strain N10 against M.aeruginosa .A kind of substance against M.aeruginosa was secreted by strain N10,and the substance was sensitive to high temperature(121 ℃) but resistant to protease K.Relatively speaking,the thalli of strain N10 had hardly algicidal effect against M. aeruginosa .Transmission electron microscope was subsequently used to investigate algal cells??structures after 3 d with treatment of strain N10 cell-free culture filtrate(CCF).The results indicated that the cell membranes and cell walls of M.aeruginosa were broken,while the gas vesicles and some particulate matters such as the cytoplasm phosphate particles and blue bodies disappeared.In addition,the cellular ultrastructure of the photosynthetic lamellae was also found to be disordered and disappeared. <br> In conclusion,the research on the characteristics of N10 against M.aeruginosa can provide a tool in controlling the bloom of M.aeruginosa .The findings are of theoretical significance and potential in reducing the impacts of HABs.