不同精粗比底物下瘤胃真菌和纤维降解细菌共培养发酵特性及菌群变化  

The dynamics of microorganism populations and fermentation characters of co-cultures of rumen fungi and cellulolytic bacteria on different substrates

作　　者：孙云章[1] 毛胜勇[1] 姚文[1] 朱伟云[1] 

机构地区：[1]南京农业大学消化道微生物研究室,南京210095

出　　处：《微生物学报》2006年第3期422-426,共5页Acta Microbiologica Sinica

基　　金：教育部科学技术研究重点项目(02119);国家自然科学基金(30371041)~~

摘　　要：采用体外厌氧共培养技术，研究了瘤胃真菌和纤维降解细菌在不同精粗比（A组为全粗料，B组3：7，C组5：5，D组7：3，E组为全精料）底物下菌群变化及其共培养发酵特性。结果表明：与Oh相比，发酵至24h时B组和C组的厌氧真菌数量有较大幅度的上升，A组和D组则有所下降，E组未检测到真菌生长；纤维降解细菌随精粗比的增加呈上升趋势。发酵至48h时，各组均未检测到真菌生长；从A组到C组细菌数量呈上升趋势，此后急剧下降。DGGE结果表明，A、B和C组（精粗比低于5：5）的DGGE图谱相似，有11条共有条带，但是当精粗比上升到7：3时，条带数目显著下降。随精料比例的增加，整个发酵期共培养系统中pH值显著下降（P〈0．05）。整个发酵期问，共培养系统发酵产生的VFA主要为乙酸，丙酸和丁酸的量较少，乙酸与丙酸比值从A组到C组呈下降趋势，此后呈上升趋势。随精料比例的上升，发酵48h时总挥发性脂肪酸浓度从A组到C组呈上升趋势，此后呈下降趋势。发酵48h的羧甲基纤维素酶活和术聚糖酶活均以A组最高，而α-淀粉酶活从A组到D组逐渐增大，而E组最低，仅为B、C、D组的1／4～1／3。In vitro co-culture technique and DGGE were used to investigate the dynamics of microorganism populations and fermentation characters of co-cultures of rumen fungi and cellulolytic bacteria at different substrates （concentrate to crude ratio in treatment A to E was all rice straw, 3：7, 5：5, 7：3 and all corn, respectively）. The results showed that, compared with Oh, fungal population density at 24h increased in treatment B and C, but decreased in treatment A and D, and no fungi was detected in treatment E; but cellulolytic bacteria population at 24h increased with the increasing of concentrate to crude ratio. At the end of 48h fermentation, no fungi were detected in all treatments; cellulolytic bacteria population increased from treatment A to treatment C, but decreased from treatment D. DGGE results showed that samples collected in treatment A, B and C had similar DGGE patterns with about 11 dominant bands, but dominant bands in treatment D and E decreased markedly compared to treatments A, B and C. Withthe increasing of concentrate to crude ratio, pH value of the co-culture decreased dramatically （P 〈 0.05）. During the fermentation periods, acetate was the maior VFA in co-culture, the acetate to propionate ratio decreased from treatment A to treatment C, but increased from treatment D. With the increasing of concentrate to crude ratio, the total VFA at 48h increased from treatment A to treatment C, and then decreased. At the end of 48h fermentation, CMCase activity and xylanase activity were highest in treatment A.α-Amylase activity increased from treatment A to treatment D, but treatment E was the lowest in all treatments.

关 键 词：瘤胃真菌 纤维降解细菌 共培养 精粗比 发酵 微生物菌群 

分 类 号：S852.6[农业科学—基础兽医学]