Cranfield University, Bedfordshire, UK.
University of Oviedo, Oviedo, ES.
Water Res. 2014 Nov 15;65:350-61. doi: 10.1016/j.watres.2014.07.040. Epub 2014 Aug 6.
Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This work investigated the effect of four pre-treatments on three microalgae species, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. The analysis of the composition of the soluble COD released and of the TEM images of the cells showed two main degradation actions associated with the processes: (1) cell wall damage with the release of intracellular AOM (thermal, thermal hydrolysis and ultrasound) and (2) degradation of the cell wall constituents with the release of intracellular AOM and the solubilisation of the cell wall biopolymers (enzymatic hydrolysis). As a result of this, enzymatic hydrolysis showed the greatest biogas yield increments (>270%) followed by thermal hydrolysis (60-100%) and ultrasounds (30-60%).
微藻的厌氧消化（AD）主要受到其细胞壁化学成分的抑制，这些细胞壁含有能够抵抗细菌降解的生物聚合物。采用热预处理、热水解、超声和酶解等预处理方法，有可能去除这些抑制性化合物，并通过降解细胞壁和释放细胞内藻类有机物质（AOM）来提高沼气产量。本研究考察了四种预处理方法对三种微藻的影响及其对培养基中释放的可溶性生物质数量的影响，从而影响消化过程的产率。对释放的可溶性 COD 的组成分析和细胞的 TEM 图像表明，与这些过程相关的有两种主要的降解作用：（1）细胞壁损伤，伴随着细胞内 AOM 的释放（热、热水解和超声）；（2）细胞壁成分的降解，伴随着细胞内 AOM 的释放和细胞壁生物聚合物的溶解（酶解）。因此，酶解表现出最大的沼气产量增量（>270%），其次是热水解（60-100%）和超声（30-60%）。
