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为研究中国明对虾(Fenneropenaeus chinensis)血蓝蛋白C末端(FcHC-C)的抗菌功能,将血蓝蛋白基因FcHC的2个C末端基因片段连接到毕赤酵母表达载体pPIC9K中,构建酵母表达载体pPIC9K/FcHC-C。该载体经SalI酶切后,采用PEG法转化毕赤酵母(Pichia pastoris GS115)。转化子经过PCR鉴定后,阳性克隆通过含有G418的YPD平板筛选,获得高拷贝重组子。重组毕赤酵母利用甲醇诱导表达目的基因。经Tricine-SDS-PAGE和Western blot分析结果表明,利用酵母工程菌成功表达了血蓝蛋白C末端片段(rFcHC-C1和rFcHC-C2)。抑菌活性鉴定实验结果显示,重组蛋白rFcHC-C1和rFcHC-C2作为阴离子抗菌肽具有抗真菌和抗细菌的活性。 相似文献
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奥利亚罗非鱼饥饿后补偿生长对血液理化指标的影响 总被引：2，自引：0，他引：2
设计了3种不同的奥利亚罗非鱼摄食类型:A组(鲜活饵料组)、B组(饥饿3周后饱食投喂组)和C组(人工饲料组),研究了奥利亚罗非鱼在不同的摄食类型下血液生理生化指标变化的情况,并试图解释补偿生长时快速生长的机理。实验结果表明,B组补偿生长期间(后2周)的增重率和特定生长率显著高于C组的(P<0.05),高于A组的;B组第4周时血清总蛋白、碱性磷酸酶、钙离子、胆固醇、甘油三脂、血红细胞、血红蛋白与第3周的相比显著上升(P<0.05),且上述指标除碱性磷酸酶外,均高于同时期A组和C组的,因此认为,上述指标的升高促进了细胞的合成代谢,从而实现了补偿生长时的快速生长。 相似文献
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以初始体质量为(2.74±0.17)g 的刺参(Apostichopus japonicus)为研究对象, 在室内养殖池进行60 d饲喂实验, 研究饲料中添加乳酸菌制剂和乳酸菌代谢产物对刺参肠道菌群、部分免疫指标及生长的影响。在基础饲料中分别添加乳酸菌制剂和乳酸菌代谢产物各2 mL/m3(按饲养水体折算), 配制2 种实验饲料。实验结果显示: 与对照组比, 饲料中添加乳酸菌与乳酸菌代谢产物均显著降低了刺参肠道弧菌数及大肠杆菌数(P＜0.05); 饲料中添加乳酸菌及其代谢产物能使刺参肠道酸性磷酸酶和碱性磷酸酶活力显著升高, 溶菌酶活性有所提升, 其中乳酸菌制剂实验组与代谢产物实验组免疫酶活力差异不显著;两实验组刺参的特定生长率显著高于对照组(P＜0.05)。上述结果表明, 乳酸菌制剂与乳酸菌代谢产物对刺参的肠道菌群平衡、免疫力及生长均具有良好的促进作用, 且两者之间差异不显著。 相似文献
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Different amounts of vitamin C were added to diets fed to juveniles(2.5 ± 0.15 g) of sea cucumber Apostichopus japonic u s(Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels(0.5, 1.0, and 1.5 mg/L) of nitrite stress for 4, 8, and 12 h at four time intervals(0, 15, 30, and 45 d). Growth of the animals was recorded during the experiment. Reactive oxygen species(ROS)(i.e. hydroxyl free radical(-OH), malondialdehyde(MDA) and total antioxidant capacity(T-AOC)) and antioxidant enzyme activities(i.e., superoxide dismutase(SOD) and catalase(CAT)) were measured. Response surface methodology(RSM) was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain(WG) and special growth rate(SGR) of vitamin C supplementation groups were significantly higher than those of control group( P 0.05). The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400–2 000 mg/kg diet for 29–35 days could reduce effectively the effects of nitrite exposure. 相似文献
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