Abstract

Monitoring of methanogenic communities in anaerobic digesters using molecular-based methods is very attractive but can be cost-intensive. A new and fast quantification method by microscopic image analysis was developed to accompany molecular-based methods. This digitalized method, called quantitative microscopic fingerprinting (QMF), enables quantification of active methanogenic cells (NmL(-1)) by their characteristic auto-fluorescence based on coenzyme F-420. QMF was applied to analyze the methanogenic communities in three biogas plant samples, and the results were compared with the relative proportion of gene copy numbers obtained with the quantitative PCR (qPCR). Analysis of QMF demonstrated dominance of Methanomicrobiales and Methanobacteriales in relation to the total methanogenic community in digesters operating at high ammonia concentrations, which corresponded to the results established by qPCR. Absolute microbial counts by QMF and the numbers obtained by qPCR were not always comparable. On the other hand, the restricted morphological analysis by QMF was enhanced by the capability of qPCR to identify microbes. Consequently, dual investigations of both methods are proposed to improve monitoring of anaerobic digesters. For a rough estimation of the methanogenic composition in anaerobic digesters, the QMF method seems to be a promising approach for the rapid detection of microbial changes.

Keywords

bacteria; image analysis; methanogens; quantitative microscopic fingerprinting; qPCR

Published in

FEMS Microbiology Letters
2014, Volume: 360, number: 1, pages: 76-84
Publisher: WILEY-BLACKWELL

SLU Authors

• Westerholm, Maria

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Bioenergy
Microbiology


Publication identifier

DOI: https://doi.org/10.1111/1574-6968.12592

Permanent link to this page (URI)

https://res.slu.se/id/publ/65633