用荧光染色法研究山羊瘤胃原虫对细菌吞噬速率的初报

A Preliminary Report on Determination of Bacterial Predation Rate by Rumen Protozoa Based on a Fluorescence-Labeled Technique

【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.