Animal and Poultry Nutrition Department, Desert Research Center, Cairo, Egypt.
Renewable Energy Department, Desert Research Center, Cairo, Egypt.
PLoS One. 2022 Jan 7;17(1):e0262304. doi: 10.1371/journal.pone.0262304. eCollection 2022.
Lignocellulosic biomass such as barley straw is a renewable and sustainable alternative to traditional feeds and could be used as bioenergy sources; however, low hydrolysis rate reduces the fermentation efficiency. Understanding the degradation and colonization of barley straw by rumen bacteria is the key step to improve the utilization of barley straw in animal feeding or biofuel production. This study evaluated the hydrolysis of barley straw as a result of the inoculation by rumen fluid of camel and sheep. Ground barley straw was incubated anaerobically with rumen inocula from three fistulated camels (FC) and three fistulated sheep (FR) for a period of 72 h. The source of rumen inoculum did not affect the disappearance of dry matter (DMD), neutral detergent fiber (NDFD). Group FR showed higher production of glucose, xylose, and gas; while higher ethanol production was associated with cellulosic hydrolysates obtained from FC group. The diversity and structure of bacterial communities attached to barley straw was investigated by Illumina Mi-Seq sequencing of V4-V5 region of 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes and Bacteroidetes. The dominant genera were RC9_gut_group, Ruminococcus, Saccharofermentans, Butyrivibrio, Succiniclasticum, Selenomonas, and Streptococcus, indicating the important role of these genera in lignocellulose fermentation in the rumen. Group FR showed higher RC9_gut_group and group FC revealed higher Ruminococcus, Saccharofermentans, and Butyrivibrio. Higher enzymes activities (cellulase and xylanase) were associated with group FC. Thus, bacterial communities in camel and sheep have a great potential to improve the utilization lignocellulosic material in animal feeding and the production of biofuel and enzymes.
以大麦秸秆为代表的木质纤维素生物质是传统饲料的可再生和可持续替代品，可用作生物能源；然而，其水解率低，降低了发酵效率。了解瘤胃液细菌对大麦秸秆的降解和定殖是提高大麦秸秆在动物饲养或生物燃料生产中利用率的关键步骤。本研究评估了接种骆驼和绵羊瘤胃液对大麦秸秆水解的影响。将粉碎的大麦秸秆在厌氧条件下与来自 3 只瘘管化骆驼（FC）和 3 只瘘管化绵羊（FR）的瘤胃液接种物共培养 72 h。瘤胃液接种物的来源并不影响干物质（DMD）、中性洗涤纤维（NDFD）的消失。FR 组产生更多的葡萄糖、木糖和气体；而与 FC 组获得的纤维素水解物相关的是更高的乙醇产量。通过对 V4-V5 区 16S rRNA 基因进行 Illumina Mi-Seq 测序，研究了附着在大麦秸秆上的细菌群落的多样性和结构。细菌群落主要由厚壁菌门和拟杆菌门组成。优势属为 RC9_gut_group、瘤胃球菌属、糖蜜发酵单胞菌属、丁酸弧菌属、琥珀酸拟杆菌属、唾液链球菌属和链球菌属，表明这些属在瘤胃中木质纤维素发酵中发挥着重要作用。FR 组 RC9_gut_group 较高，FC 组 Ruminococcus、Saccharofermentans 和 Butyrivibrio 较高。较高的酶活性（纤维素酶和木聚糖酶）与 FC 组相关。因此，骆驼和绵羊中的细菌群落具有很大的潜力，可以提高木质纤维素材料在动物饲养中的利用率，以及生物燃料和酶的生产。
