Novozymes Biologicals, Inc., 5400 Corporate Circle, Salem, VA 24153, USA.
Marquette University, Department of Biological Sciences, P.O. Box 1881, Milwaukee, WI 53201-1881, USA.
Water Res. 2015 Mar 1;70:138-47. doi: 10.1016/j.watres.2014.11.037. Epub 2014 Dec 3.
Adding beneficial microorganisms to anaerobic digesters for improved performance (i.e. bioaugmentation) has been shown to decrease recovery time after organic overload or toxicity upset. Compared to strictly anaerobic cultures, adding aerotolerant methanogenic cultures may be more practical since they exhibit higher methanogenic activity and can be easily dried and stored in ambient air for future shipping and use. In this study, anaerobic digesters were bioaugmented with both anaerobic and aerated, methanogenic propionate enrichment cultures after a transient organic overload. Digesters bioaugmented with anaerobic and moderately aerated cultures recovered 25 and 100 days before non-bioaugmented digesters, respectively. Increased methane production due to bioaugmentation continued a long time, with 50-120% increases 6 to 12 SRTs (60-120 days) after overload. In contrast to the anaerobic enrichment, the aerated enrichments were more effective as bioaugmentation cultures, resulting in faster recovery of upset digester methane and COD removal rates. Sixty days after overload, the bioaugmented digester archaeal community was not shifted, but was restored to one similar to the pre-overload community. In contrast, non-bioaugmented digester archaeal communities before and after overload were significantly different. Organisms most similar to Methanospirillum hungatei had higher relative abundance in well-operating, undisturbed and bioaugmented digesters, whereas organisms similar to Methanolinea tarda were more abundant in upset, non-bioaugmented digesters. Bioaugmentation is a beneficial approach to increase digester recovery rate after transient organic overload events. Moderately aerated, methanogenic propionate enrichment cultures were more beneficial augments than a strictly anaerobic enrichment.
向厌氧消化器中添加有益微生物以提高性能（即生物增强）已被证明可以缩短有机负荷或毒性冲击后的恢复时间。与严格的厌氧培养物相比，添加兼性产甲烷培养物可能更实际，因为它们表现出更高的产甲烷活性，并且可以在环境空气中轻松干燥和储存，以备将来运输和使用。在这项研究中，在短暂的有机过载后，向厌氧消化器中添加了厌氧和充气的产甲烷丙酸盐富集培养物。用厌氧和适度充气培养物生物增强的消化器分别在非生物增强的消化器之前恢复了 25 和 100 天。由于生物增强，甲烷产量增加持续时间长，在过载后 6 到 12 个 SRT（60-120 天）时，增加了 50-120%。与厌氧富集物相比，充气富集物作为生物增强培养物更有效，导致受冲击的消化器甲烷和 COD 去除率更快恢复。过载 60 天后，生物增强消化器的古菌群落没有发生变化，但恢复到类似于过载前的群落。相比之下，过载前后非生物增强消化器的古菌群落差异显著。在运行良好、未受干扰和生物增强的消化器中，与 Methanospirillum hungatei 最相似的生物具有更高的相对丰度，而在受冲击、非生物增强的消化器中，与 Methanolinea tarda 相似的生物丰度更高。生物增强是增加消化器在短暂有机过载事件后恢复速度的有益方法。与严格的厌氧富集物相比，中度充气的产甲烷丙酸盐富集培养物是更有益的增强物。
