岩扇贝原种和繁育后代肠道和内脏团细菌多样性分析

为研究岩扇贝Crassadoma gigantean的生物学特性和消化代谢机能,采用传统培养方法分离培养加拿大原种岩扇贝内脏团(JN)和肠道(JC)及中国育种得到的子一代岩扇贝内脏团(YN)和肠道(YC)4种样品中的细菌,测定分离到的可培养细菌的16S rRNA基因并确定其分类地位;提取上述样品中的总DNA,运用Ion S5^(TM)XL高通量测序平台,对样品中细菌群落多样性进行分析。结果表明:用传统方法获得可培养菌株83株,选取代表菌31株测序并比对,其分别属于嗜冷杆菌属Psychrobacter、动性球菌属Planococcus、弧菌属Vibrio、假单胞菌属Pseudomonas、假交替单胞菌属Pseudoalteromonas、芽孢杆菌属Bacillus、库克菌属Kocuria和副球菌属Paracoccus;高通量测序结果显示,4种样品中有效序列群落结构可分为9个门,分别为变形菌门Proteobacteria、异常球菌-栖热菌门Deinococcus-Thermus、拟杆菌门Bacteroidetes、厚壁菌门Firmicutes、蓝细菌门Cyanobacteria、软壁菌门Tenericutes、放线菌门Actinobacteria、浮霉菌门Planctomycetes和疣微菌门Verrucomicrobia;加拿大原种岩扇贝肠道样品中的优势菌门为变形菌门(占80%),次优势菌门为拟杆菌门(占15%),内脏团样品中的优势菌门为变形菌门(占52%),次优势门为拟杆菌门(占18%);中国育种得到的子一代岩扇贝肠道样品中的优势菌门为变形菌门(占61%),次优势菌门为拟杆菌门(占26%),内脏团样品中的优势菌门为变形菌门(占73%),次优势菌门为拟杆菌门(占17%)。研究表明,岩扇贝的肠道和内脏团微生物具有丰富的多样性,加拿大原种岩扇贝和国内子一代岩扇贝的肠道和内脏团细菌群落结构存在一定差异。

Effects of temperature on keeping-alive without water and antioxidant enzyme of the rock scallop Crassadoma gigantea

Temperature was one of the key factors for the living environment of aquatic organisms, especially for shellfish. The effects of temperature was studied on the survival rate and the median lethal time （LT50） of the rock scallop Crassadoma gigantea, and the effects of temperature stress on the antioxidant enzymes of rock scallop Crassadoma gigantea were studied in order to explore the effects of temperature on keeping-alive without water and antioxidant system of the rock scallop Crassadoma gigantea. The rock scallop Crassadoma gigantea （shell length （39.7± 5） mm） at different temperatures （5℃ and 15℃）, humidity （moisture treatment, not moisturizing treatment） and oxygen （aerobic treatment, not aerobic treatment） in laboratory was studied by the survival analysis and the analysis of factors affecting the effects of the median lethal time （LTso） in order to investigate the effects of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea. Results showed that low temperature, moisture and aerobic treatment can significantly improve the survival rate and the median lethal time of the rock scallop Crassadoma gigantea （P〈0.05）. The effect of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea was most significant, followed by the effect of oxygen, and that of humidity was the most weakest. Interaction between temperature and humidity, temperature and oxygen significant interaction（P〉0.05）, and interaction between humidity and oxygen interaction was not significant （P〈0.05） in the interaction of three factors. It provided an important basis for the determination of the rock scallop Crassadoma gigantea in the seedling transportation time. In the article, the rock scallop Crassadoma gigantea larvae antioxidant enzymes activity was detected, including SOD activity,CAT activity ,T-A℃ activity （superoxide dismutase activity, catalase activity, total antioxidant capacity） changes through raising the temperature from the low temperature （5℃, 10℃, 15℃, 20℃, 25℃）, to explore the change of the antioxidant enzymes activity under the influence of temperature on the rock scallop Crassadoma gigantea larvae. The SODactivity was significantly lower than that of the other groups （P〈0.05） at 5℃, and the CAT activity had no significant difference between groups （p=0.05）, and the T - AOC level was the lowest significantly below 15℃, 25℃ （P〈0.05）.The SOD and CAT activity had no significant difference in the same experimental time （P〉0.05）, and the T - AOC activity temperature was significantly higher than the rest of the group （P=〈0.05） when temperature at 10℃ and 20℃. The SOD activity had no significant difference （P〉0.05）between groups at 25℃, and the CAT activity was significantly higher than 5℃ 10℃, 15℃ group （P〈0.05）. The T-AOC activity was only lower than 15℃ group （P〉0.05）. It indicated that the high temperature had a clear inducing effect on the CAT activity in the rock scallop Crassadoma gigantea larvae, and had a significant inhibitory effect on the T-AOC activity. The low temperature had a significant inhibitory effect on the activity of T-AOC in the tissue fluid of the scallop. The above results showed that the high and low temperature had a significant effect on the antioxidant enzymes activity of the rock scallop Crassadoma gigantea larvae.

Effect of temperature on the growth of juvenile rock scallop (Crassadoma gigantea)

In order to study the effect of temperature on the growth of juvenile rock scallop(Crassadoma gigantea),learn more about its growth with temperature changes under the conditions of indoor circulating water temperature-controlled culture.Four temperature gradients of10℃,12.5℃,15℃and17.5℃were set,observed the growth of juvenile rock scallop at different test temperatures during two month.The results show:With the increase of test temperature,the growth rate first increased and then decreased.One-way analysis of variance showed that temperature had a significant effect on the growth rate(P<0.05),the optimum temperature was15℃,under this condition,the shell height average daily growth was significantly higher than the other three groups,the average daily growth of shell length and wet weight had no significant difference with17.5℃experimental group but significantly higher than the previous two groups.Within the experimental range,the change of temperature had no significant effect on the survival rate of juvenile rock scallop(P>0.05).