ITANOA-CONICET, EEAOC, Av. William Cross 3150 (T4101XAC), Las Talitas, Tucumán, Argentina.
PROIMI-CONICET, Av. Belgrano y Caseros (T4000INI), SM de Tucumán, Tucumán, Argentina.
Biodegradation. 2022 Aug;33(4):333-348. doi: 10.1007/s10532-022-09985-y. Epub 2022 May 7.
Vinasse is a high pollutant liquid residue from bioethanol production. Due to its toxicity, most vinasse is used not disposed of in water bodies but employed for the fertigation of sugarcane crops, potentially leading to soil salinization or heavy metal deposition. The anaerobic digestion of vinasse for energy production is the main alternative to fertigation, but the process cannot eliminate colored compounds such as melanoidins, caramels, or phenolic compounds. The treatment of raw vinasse with white-rot fungi could remove colored and persistent toxic compounds, but is generally considered cost-ineffective. We report the treatment of vinasse by an autochthonous Trametes sp. strain immobilized in polyurethane foam and the concomitant production of high titers of laccase, a high value-added product that could improve the viability of the process. The reuse of the immobilized biomass and the discoloration of raw vinasse, the concentration of phenolic compounds, BOD and COD, and the phytotoxicity of the treated vinasse were measured to assess the viability of the process and the potential use of treated vinasse in fertigation or as a complementary treatment to anaerobic digestion. Under optimal conditions (vinasse 0.25X, 30 °C, 21 days incubation, 2% glucose added in the implantation stage), immobilized Trametes sp. causes a decrease of 75% in vinasse color and total phenolic compounds, reaching 1082 U L of laccase. The fungi could be used to treat 0.50X vinasse (BOD 44,400 mg O L), causing a 26% decolorization and a 30% removal of phenolic compounds after 21 days of treatment with maximum laccase titers of 112 U L, while reducing COD and BOD from 103,290 to 42,500 mg O L (59%) and from 44,440 to 21,230 mg O L (52%), respectively. The re-utilization of immobilized biomass to treat 0.50X vinasse proved to be successful, leading to the production of 361 U L of laccase with 77% decolorization, 61% degradation of phenolic compounds, and the reduction of COD and BOD by 75% and 80%, respectively. Trametes sp. also reduced vinasse phytotoxicity to Lactuca sativa seedlings. The obtained results show that the aerobic treatment of vinasse by immobilized Trametes sp. is an interesting technology that could be employed as a sole treatment for the bioremediation of vinasse, with the concomitant the production of laccase. Alternatively, the methodology could be used in combination with anaerobic digestion to achieve greater decolorization and reduction of phenolic compounds, melanoidins, and organic load.
酒糟是生物乙醇生产过程中产生的高污染液体废渣。由于其毒性，大多数酒糟未被处理而是用于甘蔗作物的施肥，这可能导致土壤盐化或重金属沉积。将酒糟进行厌氧消化以产生能源是施肥的主要替代方法，但该过程无法消除类黑素、焦糖或酚类化合物等有色化合物。用白腐真菌处理原始酒糟可以去除有色和持久性有毒化合物，但通常被认为成本效益不高。我们报告了一种本土 Trametes sp.菌株固定在聚氨酯泡沫中的酒糟处理方法，同时产生了高浓度的漆酶，这是一种高附加值的产品，可以提高该过程的可行性。我们测量了固定化生物质的再利用、原始酒糟的脱色、酚类化合物、BOD 和 COD 的浓度以及处理后的酒糟的植物毒性，以评估该过程的可行性以及处理后的酒糟在施肥或作为厌氧消化的补充处理中的潜在用途。在最佳条件下（酒糟 0.25X、30°C、21 天孵育、在植入阶段添加 2%葡萄糖），固定化 Trametes sp. 导致酒糟颜色和总酚类化合物下降 75%，达到 1082 U L 的漆酶。真菌可用于处理 0.50X 酒糟（BOD 44400 mg O L），在 21 天的处理后，漆酶的最大浓度为 112 U L，可使酒糟脱色 26%，酚类化合物去除率为 30%，同时将 COD 和 BOD 从 103290 降低到 42500 mg O L（59%）和从 44440 降低到 21230 mg O L（52%）。固定化生物质的再利用来处理 0.50X 酒糟被证明是成功的，导致产生 361 U L 的漆酶，脱色率为 77%，酚类化合物降解率为 61%，COD 和 BOD 的去除率分别为 75%和 80%。Trametes sp. 还降低了酒糟对莴苣幼苗的植物毒性。所得结果表明，用固定化 Trametes sp.进行酒糟的需氧处理是一种很有前途的技术，可单独用于酒糟的生物修复，同时生产漆酶。或者，该方法可以与厌氧消化结合使用，以实现更高的脱色率和减少酚类化合物、类黑素和有机负荷。
