Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
Department of Biology, University of Padua, Via U. Bassi 58/b, 35131 Padova, Italy.
Bioresour Technol. 2014 Sep;167:24-32. doi: 10.1016/j.biortech.2014.05.080. Epub 2014 May 28.
Foam formation can lead to total failure of digestion process in biogas plants. In the present study, possible correlation between foaming and the presence of specific microorganisms in biogas reactors was elucidated. The microbial ecology of continuous fed digesters overloaded with proteins, lipids and carbohydrates before and after foaming incidents was characterized using 16S rRNA gene sequencing. Moreover, the microbial diversity between the liquid and foaming layer was assessed. A number of genera that are known to produce biosurfactants, contain mycolic acid in their cell wall, or decrease the surface tension of the media, increased their relative abundance after foam formation. Finally, a microorganism similar to widely known foaming bacteria (Nocardia and Desulfotomaculum) was found to increase its relative abundance in all reactors once foam was observed, regardless of the used substrate. These findings suggest that foaming and specific microorganisms might have direct association which requires to be further investigated.
泡沫的形成可能导致沼气厂消化过程的完全失效。在本研究中，阐明了泡沫的形成与沼气反应器中特定微生物存在之间的可能相关性。使用 16S rRNA 基因测序，对在发生泡沫之前和之后用蛋白质、脂肪和碳水化合物过载的连续进料消化器的微生物生态学进行了描述。此外，还评估了液体层和泡沫层之间的微生物多样性。在泡沫形成后，一些已知能够产生生物表面活性剂、细胞壁中含有类脂酸或降低介质表面张力的属的相对丰度增加。最后，发现一种类似于广泛存在的泡沫细菌（诺卡氏菌和脱硫梭菌）的微生物，无论使用何种底物，一旦观察到泡沫，其相对丰度都会在所有反应器中增加。这些发现表明，泡沫和特定微生物之间可能存在直接关联，这需要进一步研究。
