Dietary fibres are main substances in the pig’s feed. Because of the recalcitrance, they could enter swine wastewater and become a serious obstruction factor for the anaerobic digestion process. In this work, three dietary fibres abundant in pig feedstocks: Wheat Bran Fibre (WBF), Alfalfa Fibre (AF) and Rice Chaff Fibre (RCF) were chosen and their anaerobic degradability was determined. The results showed that the biochemical methane potential in 10 days (BMP₁₀) of WBF, AF and RCF was 258, 176 and 86 mL/g-VS, respectively. The size, purity, crystallinity, and lignin coating in particular, were found having influences on the anaerobic biodegradability of dietary fibres. To surprise, a negative rather than positive effect was observed for the direct addition of extraneous cellulase into the anaerobic digestion systems, leading to a longer lag time and a smaller BMP₁₀. The enhancement was achieved for the addition of extraneous bacteria in the form of anaerobic granular sludge (AnGS), shortening the lag time of WBF and AF by 36% and 13%, respectively. By high-throughput sequencing analysis, abundant protein and amino acids degraders found in anaerobic activated sludge (AnAS) could degrade the exogenous enzymes. Abundant members affiliated to the family Anaerolineaceae, and Syntrophobacteraceae in AnGS, related to the cellulolytic and syntrophic activity respectively, probably contribute to the acceleration effect of AnGS.

中文翻译：

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猪废水厌氧消化中的一个挑战：食物纤维的顽强分解和降解。

膳食纤维是猪饲料中的主要物质。由于它们的顽固性，它们可能进入猪废水，并成为厌氧消化过程中的严重阻碍因素。在这项工作中，选择了猪饲料中富含的三种膳食纤维：小麦麸皮纤维（WBF），苜蓿纤维（AF）和稻米糠纤维（RCF），并确定了它们的厌氧降解性。结果显示10天后的生化甲烷潜力（BMP ₁₀WBF，AF和RCF分别为258、176和86 mL / g-VS。发现尺寸，纯度，结晶度和木质素涂层尤其对膳食纤维的厌氧生物降解性有影响。出乎意料的是，在厌氧消化系统中直接添加外来纤维素酶会产生负面影响而不是正面影响，从而导致更长的滞后时间和更小的BMP ₁₀。通过添加厌氧颗粒污泥（AnGS）形式的外来细菌实现了增强，将WBF和AF的滞后时间分别缩短了36％和13％。通过高通量测序分析，厌氧活性污泥（AnAS）中发现的大量蛋白质和氨基酸降解物可以降解外源酶。家庭成员众多Anaerolineaceae，并Syntrophobacteraceae在AnGS，涉及到分别的纤维素和互养活动，可能有助于AnGS的加速效果。