Adjiri D, Bouillier-Oudot M, Lebas F, Candau M
Ecole nationale supérieure agronomique de Toulouse, laboratoire de zootechnie et de productions animales, France.
Reprod Nutr Dev. 1992;32(4):351-60.
A Rusitec semi-continuous flow fermentor was used to study the influence of enzyme pretreatment of food substrates on the fermentation profile over a 2-week period following inoculation with rabbit caecal contents. Three types of substrate were examined: 1) homogenized commercial rabbit feed; 2) the solid remains of this feed after digestion with alpha-amylase for 24 h; and 3) substrate 2 digested for 4 h with pepsin (double enzyme treatment). One of a pair of nylon pouches containing 15 g substrate was replaced each day, thus producing a uniform 48-h fermentation. Fermentation of the untreated feed (1) for 5-6 days produced a fermentation profile quite different from that obtained in vivo in the rabbit caecum: propionic acid accounted for over 35% of total volatile fatty acid (VFA), and butyric acid for about 15%. Amylase digestion (2) gave a stable ferment profile closer to the in vivo profile, except that propionic and butyric acids were similar at 15% of total VFA. Digestion with both amylase and pepsin (3) produced a stable fermentation profile very close to the in vivo profile: C2 > 60%, C3 < 11% and 17% < C4 < 21%. The rate at which membrane constituents (acid detergent fibre, ADF) were lost in 48 h was similar to the digestibility coefficient measured in vivo by others for the same basic feed. Lastly, there was a high percentage (about 5%) of volatile C5 fatty acids; this could be due to the discontinuous fermentor input of one pouch per 24 h. Thus, feed pretreated with both amylase and pepsin simulates, in vitro, rabbit caecal fermentation in a semi-continuous Rusitec type fermentor.
使用Rusitec半连续流动发酵罐研究食物底物的酶预处理对接种兔盲肠内容物后两周内发酵情况的影响。研究了三种类型的底物：1）均质化的商业兔饲料；2）用α-淀粉酶消化24小时后的该饲料固体残余物；3）用胃蛋白酶消化4小时的底物2（双重酶处理）。每天更换一对装有15克底物的尼龙袋中的一个，从而产生均匀的48小时发酵。未处理饲料（1）发酵5 - 6天产生的发酵情况与兔盲肠体内发酵情况有很大不同：丙酸占总挥发性脂肪酸（VFA）的35%以上，丁酸约占15%。淀粉酶消化（2）产生的稳定发酵情况更接近体内情况，只是丙酸和丁酸在总VFA中占比相似，均为15%。用淀粉酶和胃蛋白酶同时消化（3）产生的稳定发酵情况非常接近体内情况：乙酸>60%，丙酸<11%，丁酸在17% - 21%之间。膜成分（酸性洗涤纤维，ADF）在48小时内损失的速率与其他人对相同基础饲料在体内测得的消化系数相似。最后，挥发性C5脂肪酸的比例很高（约5%）；这可能是由于每24小时向发酵罐中不连续输入一个袋子的底物所致。因此，用淀粉酶和胃蛋白酶预处理的饲料在体外半连续Rusitec型发酵罐中模拟了兔盲肠发酵。
