Humic acids (HA) have been used in biorefinery process due to its surfactant properties as an aid to the pretreatment of lignocellulose, with results indicating a positive effect on delignification. However, the HA remaining on the surface of the pretreated lignocellulose has also been shown to provide a negative effect on ensuing enzymatic digestibility. Hence, a strategy of complexing metallic cations with HA prior to enzymatic hydrolysis was proposed and demonstrated in this work in an effort to provide a means of HA mitigation that does not involve significant water consumption via extensive washing. Results showed that the enzymatic hydrolysis efficiency of waste wheat straw decreased from 81.9% to 66.1% when it was pretreated by 10 g/L HA, attributed to the inhibition ability of the residual HA on enzyme activity of cellulase with a debasement of 36.3%. Interestingly, enzymatic hydrolysis efficiency could be increased from 66.1% to 77.3% when 10 mM Fe3+ was introduced to the system and allowed to associate with HA during saccharification. The addition of high-priced metallic cations (Fe3+) has successfully alleviated the effect of HA on cellulase activity. It is our hope in demonstrating the complexation affinity between metallic cations and HA, future researchers and biorefinery developers will evaluate this strategy as a unit operation that could allow economic biorefining of WWS to produce valuable biochemicals, biofuels, and biomaterials.

中文翻译：

---

全面了解金属阳离子对腐殖酸预处理的废麦草秸秆酶解的影响

腐殖酸（HA）由于其表面活性剂特性可用于生物纤维素的预处理，因此已被用于生物精炼工艺，结果表明其对去木质素有积极作用。然而，还显示出残留在预处理的木质纤维素表面上的HA对随后的酶消化率具有负面影响。因此，提出并提出了在酶促水解之前将金属阳离子与HA络合的策略，并在这项工作中得到了证明，旨在提供一种减少HA的方法，该方法不涉及通过大量洗涤而大量消耗的水。结果表明，用10 g / L HA预处理后，废麦草的酶解效率从81.9％降低到66.1％，这归因于残余HA对纤维素酶的酶活性的抑制能力，降低了36.3％。有趣的是，当将10 mM Fe3 +引入系统并在糖化过程中与HA结合时，酶促水解效率可以从66.1％提高到77.3％。高价金属阳离子（Fe3 +）的添加已成功减轻了HA对纤维素酶活性的影响。我们希望能证明金属阳离子与HA之间的络合亲和力，未来的研究人员和生物炼制开发商将对该策略作为一个单元操作进行评估，该单元操作可使WWS进行经济的生物精制，从而生产出有价值的生物化学物质，生物燃料和生物材料。当将10 mM Fe3 +引入系统并在糖化过程中与HA缔合时为3％。高价金属阳离子（Fe3 +）的添加已成功减轻了HA对纤维素酶活性的影响。我们希望能证明金属阳离子与HA之间的络合亲和力，未来的研究人员和生物炼制开发商将对该策略作为一个单元操作进行评估，该单元操作可使WWS进行经济的生物精制，从而生产出有价值的生物化学物质，生物燃料和生物材料。当将10 mM Fe3 +引入系统并在糖化过程中与HA缔合时为3％。高价金属阳离子（Fe3 +）的添加已成功减轻了HA对纤维素酶活性的影响。我们希望能证明金属阳离子与HA之间的络合亲和力，未来的研究人员和生物炼制开发商将对该策略作为一个单元操作进行评估，该单元操作可使WWS进行经济的生物精制，从而生产出有价值的生物化学物质，生物燃料和生物材料。