Recovery of the fibrolytic microorganisms from rumen fluid by flocculation for simultaneous treatment of lignocellulosic biomass and volatile fatty acid production
Recovery of the fibrolytic microorganisms from rumen fluid by flocculation for simultaneous treatment of lignocellulosic biomass and volatile fatty acid production
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DOI：
10.1016/j.jclepro.2020.120626
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发表时间：
2020-06-01
影响因子：
11.1
通讯作者：
Nakai, Yutaka
中科院分区：
文献类型：
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作者：
Takizawa, Shuhei;Abe, Kenichi;Nakai, Yutaka
屠宰场不断排出大量瘤胃液，这些液通常被运输至木质纤维素生物质处理设施。从瘤胃液中回收纤维分解微生物能够减轻废水处理和瘤胃液运输的负荷。然而，没有用于回收瘤胃微生物的标准化方法。在这里，我们建立了一种基于絮凝的方法，具有回收具有纤维溶解活性的瘤胃微生物所需的优化絮凝剂浓度。瘤胃液用0.4％、0.7％、1.0％、2.0％的聚合硫酸铁和13.0％的无机中性絮凝剂进行絮凝。 0.4%、0.7%和1.0%的聚合硫酸铁可有效恢复瘤胃微生物，使瘤胃液体积分别减少85.6%、77.3%和75.6%。这些回收的微生物保留了大小为 52 kDa 和 53 kDa 的内切葡聚糖酶活性。此外，瘤胃微生物的回收使得絮凝后滤液的固体和有机化合物浓度大幅降低。作为该方法的实际演示，用絮凝的瘤胃液在 37°C 处理番茄叶 48 小时。使用用 0.7% 聚合硫酸铁絮凝的瘤胃液水解番茄叶表明，在处理过程中，内切葡聚糖酶活性升高，大小分别为 37 kDa、46 kDa、57 kDa、61 kDa 和 66 kDa。因此，0.7%聚合硫酸铁是回收瘤胃微生物同时保持其纤维分解活性的最佳浓度。这是第一项研究，提出了一种从大量瘤胃液中有效回收瘤胃微生物的新方法，为减少屠宰场废水处理和瘤胃液运输的负荷提供了实用且可持续的解决方案。 (C) 2020 年由爱思唯尔有限公司出版。
Large volumes of rumen fluid are continuously discharged from slaughterhouses, which are typically transported to facilities for treatments of lignocellulosic biomass. Recovery of fibrolytic microorganisms from the rumen fluid enables to reduce the load for wastewater treatment and transportation of rumen fluid. However, there is no standardized method for recovering ruminal microorganisms. Here, we established a flocculation-based method with an optimized flocculant concentration required to recover ruminal microorganisms with fibrolytic activity. Rumen fluid was flocculated with poly-ferric sulfate at 0.4%, 0.7%, 1.0%, and 2.0% and with an inorganic neutral flocculant at 13.0%. Poly-ferric sulfate at 0.4%, 0.7%, and 1.0% effectively recovered ruminal microorganisms, which resulted in an 85.6%, 77.3%, and 75.6% reduction in rumen fluid volume, respectively. These recovered microorganisms retained the endoglucanase activity at 52 kDa and 53 kDa in size. In addition, recovery of ruminal microorganisms allowed for substantial reductions in the solids and organic compound concentrations of the filtrates after the flocculation. As a practical demonstration of this method, tomato leaves were treated with the flocculated rumen fluid at 37 degrees C for 48 h. Hydrolysis of the tomato leaves using the rumen fluid flocculated with 0.7% poly-ferric sulfate demonstrated elevated endoglucanase activity at 37 kDa, 46 kDa, 57 kDa, 61 kDa, and 66 kDa in size during treatment. Therefore, 0.7% poly-ferric sulfate is the optimal concentration for recovering ruminal microorganisms while maintaining their fibrolytic activity. This is the first study which suggest a novel method to efficiently recover ruminal microorganisms from huge amounts of rumen fluid offers a practical and sustainable solution to reduce the load for wastewater treatment at slaughterhouses and in the transportation of rumen fluid. (C) 2020 Published by Elsevier Ltd.