大豆低聚糖及其功能组分对体外条件下肉仔鸡盲肠内容物粪臭素产量及菌群组成的影响

摘要

本试验旨在研究大豆低聚糖(SBO)及其功能组分对体外条件下肉仔鸡盲肠内容物粪臭素产量及菌群组成的影响.试验采用单因素完全随机设计,以42日龄肉仔鸡盲肠内容物为菌源,将厌氧培养液分装于无菌培养瓶中,分成5个组,每组3个重复.对照组添加250μmol/L的L-色氨酸,蔗糖(SUC)、水苏糖(STA)、棉籽糖(RAF)和SBO组分别在对照组的基础上添加1%的SUC、STA、RAF和SBO.另外,每组均设1个不加L-色氨酸但其他成分都相同的空白对照.利用ANKOM RFS体外产气系统,39℃厌氧培养24 h.采用PCR-变性梯度胶凝电泳(DGGE)技术研究了发酵液菌群组成的差异.结果表明:1)SUC、STA、SBO组24 h发酵液累积产气量极显著高于对照组和RAF组(P<0.01);SBO、SUC和STA组吲哚浓度分别比对照组降低了98.15%、97.72%和94.17%(P<0.01),粪臭素浓度分别比对照组降低了79.04%、71.88%和70.28%(P<0.05);SUC组乳酸浓度极显著高于其他各组(P<0.01);对照组pH极显著高于除RAF组之外的其他各组(P<0.01).2)SBO组菌群均匀度显著低于对照组(P<0.05);SUC、STA、RAF、SBO组菌群丰富度显著高于对照组(P<0.05);SBO、STA、RAF组菌群相似性高于对照组;试验组有3条特异性条带,相似菌分别为延长布劳特氏菌(Blautia producta)、迪氏副拟杆菌(Parabacteroides distasonis)、路氏乳杆菌(Lactobacillus reuteri).综上,在本试验条件下,添加1%的SUC、STA和SBO显著降低了肉仔鸡体外盲肠内容物培养液中L-色氨酸代谢生成吲哚和粪臭素的浓度,提高了菌群丰富度,并促进了特异性菌的增殖.降低粪臭素效果优劣依次为SBO、SUC、STA.%The aim of this study was to investigate the effects of soybean oligosaccharide ( SBO) and its func-tional components on skatole production and microbiota composition of broilers cecal contents in vitro. This ex-periment used a single-factor completely randomized design, the 42 days of age broiler cecal contents was used as bacterial source, and the anaerobic culture medium was divided into sterile culture bottles, and divided into 5 groups with 3 replicates per group. The control group was added 250 μmol/L L-tryptophan, sucrose ( SUC) , stachyose ( STA) , raffinose ( RAF) and SBO groups were supplemented with 1% SUC, STA group RAF and SBO on the basis of control group, respectively. In addition, each group also had a blank control which L-tryptophan was absent and the other components were the same. Microbial suspensions were anaerobi-cally incubated at 39 ℃ for 24 h using ANKOM RFS gas production system in vitro. The microbiota composi-tion in fermentation broth were analyzed by PCR-denatured gradient gel electrophoresis ( DGGE) . The results showed as follows:1) the 24 h cumulative gas production in fermentation broth in SUC, STA and SBO groups was significantly higher than that in control and RAF groups ( P<0.01) . Compared with the control group, the indole concentration in fermentation broth in SBO, SUC, and STA groups was significantly reduced by 98.15%, 97.72% and 94.17%, respectively (P<0.01), and the skatole concentration was significantly re-duced by 79.04%, 71.88% and 70.28%, respectively (P<0.05). The lactate concentration in fermentation broth in SUC group was significantly higher than that in the other groups (P<0.01), and pH in the control group was significantly higher than that in the other groups except for the RAF group ( P<0.01) . 2) The mi-crobiota evenness in fermentation broth in SBO group was significantly lower than that in the control group ( P<0.05) , and the microbiota richness in SUC, STA, RAF and SBO groups was significantly higher than that in control group ( P<0.05) . The microbiota similarity in fermentation broth in SBO, STA and RAF groups was higher than that in control group. Three specific bands were present only in experimental groups, the similar strain were Blautia producta, Parabacteroides distasonis, and Lactobacillus reuteri, respectively. In conclu-sion, under the present experimental condition, addition 1% SUC, STA, and SBO in broiler cecal contents culture medium significantly decreases the concentrations of indole and skatole by metabolism of L-tryptophan, improves the microbiota richness, and promotes the proliferation of specific bacteria. The effect of skatole re-duction is as follow: SBO>SUC>STA.