【目的】底泥中的微生物群落对维持池塘生态系统平衡具有重要意义。探讨罗非鱼高密度养殖池塘底泥微生物的碳氮代谢特征与季节变化规律。【方法】在养殖季采集罗非鱼养殖池塘底泥样品,检测底泥中的硝酸盐氮、亚硝酸盐氮、氨氮和总氮含量...【目的】底泥中的微生物群落对维持池塘生态系统平衡具有重要意义。探讨罗非鱼高密度养殖池塘底泥微生物的碳氮代谢特征与季节变化规律。【方法】在养殖季采集罗非鱼养殖池塘底泥样品,检测底泥中的硝酸盐氮、亚硝酸盐氮、氨氮和总氮含量,并通过Biolog-ECO平板技术分析底泥微生物对含氮碳源、含磷碳源和只含碳的碳源代谢的平均颜色变化率(Average Well Colour Development,AWCD)。【结果】养殖中期和末期底泥中的总氮和氨氮含量显著高于养殖初期;底泥中的微生物能较好地利用β-甲基-D-葡萄糖苷、丙酮酸甲酯、D-半乳糖醛酸、吐温80、D-甘露醇、肝糖、D-纤维二糖等只含碳的碳源和L-天门冬酰胺、N-乙酰-D-葡萄糖胺(AWCD>0.5)等含氮碳源,也可以利用D,L-α-磷酸甘油、葡萄糖-1-磷酸(AWCD<0.5)等含磷碳源,不能利用2-羟基苯甲酸、衣康酸和α-丁酮酸。养殖初期罗非鱼养殖池塘底泥微生物对只含碳的碳源和含氮碳源的利用率高于养殖中期和末期。底泥微生物对含氮碳源和只含碳的碳源的利用率与底泥中的硝酸盐含量呈正相关。【结论】可以尝试利用Biolog-ECO平板技术分析底泥微生物的氮利用指数,评估底泥菌群对氮的利用能力。展开更多
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rare...Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.展开更多
文摘【目的】底泥中的微生物群落对维持池塘生态系统平衡具有重要意义。探讨罗非鱼高密度养殖池塘底泥微生物的碳氮代谢特征与季节变化规律。【方法】在养殖季采集罗非鱼养殖池塘底泥样品,检测底泥中的硝酸盐氮、亚硝酸盐氮、氨氮和总氮含量,并通过Biolog-ECO平板技术分析底泥微生物对含氮碳源、含磷碳源和只含碳的碳源代谢的平均颜色变化率(Average Well Colour Development,AWCD)。【结果】养殖中期和末期底泥中的总氮和氨氮含量显著高于养殖初期;底泥中的微生物能较好地利用β-甲基-D-葡萄糖苷、丙酮酸甲酯、D-半乳糖醛酸、吐温80、D-甘露醇、肝糖、D-纤维二糖等只含碳的碳源和L-天门冬酰胺、N-乙酰-D-葡萄糖胺(AWCD>0.5)等含氮碳源,也可以利用D,L-α-磷酸甘油、葡萄糖-1-磷酸(AWCD<0.5)等含磷碳源,不能利用2-羟基苯甲酸、衣康酸和α-丁酮酸。养殖初期罗非鱼养殖池塘底泥微生物对只含碳的碳源和含氮碳源的利用率高于养殖中期和末期。底泥微生物对含氮碳源和只含碳的碳源的利用率与底泥中的硝酸盐含量呈正相关。【结论】可以尝试利用Biolog-ECO平板技术分析底泥微生物的氮利用指数,评估底泥菌群对氮的利用能力。
基金Supported by the Qingdao Postdoctoral Application Research Project(No.Y6KY01110N)the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)+2 种基金the Qingdao Innovation Talents Program(No.13-CX-16)the National Key Technologies R&D Program of China(No.2014BAD08B09)the Earmarked Fund for Modem AgroIndustry Technology Research System(No.CARS-48)
文摘Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.
