【目的】采用荧光染色标记细菌(fluorescence labeled bacteria,FLB)技术,研究山羊瘤胃中原虫对细菌的吞噬速率。【方法】利用4只装有永久性瘤胃瘘管的徐淮山羊,采集瘤胃液以获取瘤胃原虫和细菌。试验设置清洗原虫祛除瘤胃自由细菌的荧光全标组(WFLB)及未清洗原虫保留瘤胃自由细菌荧光标记组(FLB)。【结果】WFLB组和FLB组的吞噬速率分别为398.4cells/(cell·h)和230.4cells/(cell·h),换算为细菌N为:2.15pgN/(cell·h)/和1.24pgN/(cell·h)。【结论】每天每头羊由原虫在瘤胃内循环中带出的细菌N损失在WFLB组和FLB组分别估计为103.2mgN/(d·头)、59.5mgN/(d·头),或者细菌蛋白损失为0.645g/(d·头)和0.372g/(d·头)。结果同时表明,荧光染色标记技术可以应用于瘤胃原虫对细菌吞噬速率的研究。
[ Objective ] Studies on the bacterial predation rate by rumen protozoa were carried out under laboratory conditions using a technique of fluorescence-labeled bacteria. [Method] Four Xuhuai goats were used in this experiment to obtain rumen protozoa and bacteria. Two groups were designed as follows: one group contained the whole bacteria which were labeled using fluorescence through removing free bacteria from rumen fluid (WFLB); the other group contained bacteria which were labeled using fluorescence without removing free bacteria from rumen fluid (FLB). [Result] The result showed that, the bacterial predation rates of rumen protozoa was 398.4 cells/(cell· h) for the group WFLB, 230.4 cells/(cell· h) for the group FLB; When the corresponding values expressed as bacteria-N were: 2.15 pg N/(cell· h) for the group WFLB and 1.24 pg N/(cell· h) for the group FLB, respectively. [Conclusion] Extrapolating the assimilation quantity of nitrogen by ciliates on bacteria of Xuhuai goat, there were 103.2 mg N/(d·capita) for the group WFLB, 59.5 nag N/(d·capita) for the group FLB, respectively. It was estimated that protein losses due to microbial recycling were 0.645 g protein/(d·capita) for the group WFLB and 0.372 g protein/(d·capita)for the group FLB, respectively. In addition, the fluorescence-labeled technique would be a potential assay for determination of bacterial predation rate by rumen protozoa.