作　　者： (聂利华）; (杨东娟）; (韩博平）; ; (查广才）;

机构地区： 揭阳职业技术学院

出　　处： 《微生物学报》 2019年第7期1307-1317,共11页

摘　　要： 【目的】探讨凡纳滨对虾养殖水体中入侵蓝藻拟柱孢藻的生长生理特性。【方法】从汕头澄海人工对虾养殖池分离纯化藻株,通过形态及其16SrRNA基因鉴定,之后在CT与BG11两种蓝藻通用培养基的基础上优化最佳培养条件,最后分析了不同浓度的3种重金属离子即Cu2+(0–0.8 mg/L)、Cd2+(0–4 mg/L)和Pb2+(0–80 mg/L)对藻株生长的影响。【结果】澄海虾池来源的分离纯化藻株形态呈卷曲螺旋型,16S rRNA基因序列与多株其他来源的拟柱孢藻相似度均达98%以上。实验室培养,藻株最佳生长状态的培养条件是在BG11培养基的基础上调整氮浓度及氮磷比分别为N 62 mg/L,N︰P=9︰1,在此条件下,藻丝生物量可达(0.632±0.170)×10^7/L,藻丝比平均生长速率最高为(0.063±0.001)/d。本分离藻株活体对重金属Cu2+、Cd2+和Pb2+具有一定的耐受性,其耐受浓度范围分别为0–0.2、0–0.5和1–40 mg/L,其中,Cu2+和Cd2+对藻的生长具有抑制作用,而且此抑制作用随着金属离子剂量的增加及作用时间的延长更加显著,Cu2+和Cd2+对藻体的半数抑制浓度(96 h EC50)分别为0.125和0.551 mg/L;而浓度范围为0–80 mg/L的Pb2+对藻体的生长则表现为低剂量(≤40 mg/L)呈促进,高剂量(≥80 mg/L)则抑制。【结论】从凡纳滨对虾养殖池中分离鉴定出一株形态呈螺旋型的拟柱孢藻,命名为螺旋拟柱孢藻(Cylindrospermopsis raciborskii helix),本藻株活体能够在一定浓度的Cu2+、Cd2+和Pb2+中生长,为螺旋拟柱孢藻活藻生物吸附重金属离子而改善虾池水体环境提供了可能性。 [Objective] We examined the physiological characteristics of invasive cyanobacterium Cylindrospermopsis raciborskii helix isolated from Litopenaeus vannamei culture ponds. [Methods] The algal strain was isolated and purified from shrimp ponds in Chenghai, Shantou, and identified by morphology and 16 S rRNA sequence analysis. Then, with the general culture media of CT and BG11, we optimized the culture conditions. Finally, we analyzed the effect of heavy metals Cu2+(0–0.8 mg/L), Cd2+(0–4 mg/L) and Pb2+(0–80 mg/L)on the growth of the isolated strain. [Results] The identity of 16 S rRNA sequence of the isolated strain was higher than 98% with that of typical strains of Cylindrospermopsis raciborskii from GenBank. Under laboratory culture conditions, the optimal culture medium for the growth of the isolated strain was the modified BG11(N 62 mg/L,N:P=9:1), the exponential biomass and growth rate were up to(0.632±0.170)×10^7/L,(0.063±0.001)/d, respectively.The isolated strain tolerated heavy metals Cu2+, Cd2+ and Pb2+, and the tolerance concentrations was Pb2+1–40 mg/L, Cd2+ 0–0.5 mg/L, Cu2+ 0–0.2 mg/L. Furthermore, Cu2+ and Cd2+ inhibited the growth of the isolated strain, and the inhibition increased with enhancing of heavy metal concentration and contact time, the 96 h EC50 of Cu2+ and Cd2+ were 0.125 and 0.551 mg/L for the strain, respectively, but Pb2+(0–80 mg/L) had a dual effect on its growth, which promoted growth at low concentration(≤40 mg/L) and inhibited growth at high concentration(≥80 mg/L). [Conclusion] A strain of Cylindrospermopsis raciborskii isolated from L. vannamei culture ponds has the potential of adsorbing heavy metal ions in shrimp ponds.

关 键 词： 螺旋拟柱孢藻 鉴定 重金属 耐受性

领　　域： [环境科学与工程—环境工程] [生物学—植物学]