Edwards Joan E, Kingston-Smith Alison H, Jimenez Hugo R, Huws Sharon A, Skøt Kirsten P, Griffith Gareth W, McEwan Neil R, Theodorou Michael K
Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Wales, UK.
FEMS Microbiol Ecol. 2008 Dec;66(3):537-45. doi: 10.1111/j.1574-6941.2008.00563.x. Epub 2008 Jul 30.
Anaerobic fungi (Neocallimastigales) are active degraders of fibrous plant material in the rumen. However, only limited information is available relating to how quickly they colonize ingested feed particles. The aim of this study was to determine the dynamics of initial colonization of forage by anaerobic fungi in the rumen and the impact of different postsampling wash procedures used to remove loosely associated microorganisms. Neocallimastigales-specific molecular techniques were optimized to ensure maximal coverage before application to assess the population size (quantitative PCR) and composition (automated ribosomal intergenic spacer analysis) of the colonizing anaerobic fungi. Colonization of perennial ryegrass (PRG) was evident within 5 min, with no consistent effect of time or wash procedure on fungal population composition. Wash procedure had no effect on population size unlike time, which had a significant effect. Colonizing fungal population size continued to increase over the incubation period after an initial lag of c. 4 min. This dynamic differs from that reported previously for rumen bacteria, where substantial colonization of PRG occurred within 5 min. The observed delay in colonization of plant material by anaerobic fungi is suggested to be primarily mediated by the time taken for fungal zoospores to locate, attach and encyst on plant material.
厌氧真菌（新美鞭菌目）是瘤胃中纤维状植物材料的活跃降解者。然而，关于它们在摄入的饲料颗粒上定殖的速度，目前仅有有限的信息。本研究的目的是确定瘤胃中厌氧真菌对草料初始定殖的动态过程，以及不同的采样后冲洗程序对去除松散附着微生物的影响。在应用新美鞭菌目特异性分子技术评估定殖的厌氧真菌的种群大小（定量PCR）和组成（自动核糖体基因间隔区分析）之前，对其进行了优化以确保最大覆盖范围。多年生黑麦草（PRG）在5分钟内就出现了明显的定殖，时间或冲洗程序对真菌种群组成没有一致的影响。与时间不同，冲洗程序对种群大小没有影响，而时间有显著影响。在最初约4分钟的滞后期后，定殖真菌种群大小在孵育期内持续增加。这种动态过程与之前报道的瘤胃细菌不同，瘤胃细菌在5分钟内就对PRG进行了大量定殖。厌氧真菌对植物材料定殖的延迟被认为主要是由真菌游动孢子在植物材料上定位、附着和形成包囊所需的时间介导的。
