Open AccessPhenotypic Properties and Microbial Diversity of Methanogenic Granules from a Full-Scale Upflow Anaerobic Sludge Bed Reactor Treating Brewery Wastewater
Author(s) -
Emiliano Díaz,
A.J.M. Stams,
Ricardo Amils,
J. L. Sanz
Publication year - 2006
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02985-05
Subject(s) - firmicutes , methanosaeta , granule (geology) , archaea , methanosarcina , biology , nitrospira , microbiology and biotechnology , bacteria , food science , methanogenesis , bioreactor , chemistry , microbial population biology , 16s ribosomal rna , botany , paleontology , genetics
Methanogenic granules from an anaerobic bioreactor that treated wastewater of a beer brewery consisted of different morphological types of granules. In this study, the microbial compositions of the different granules were analyzed by molecular microbiological techniques: cloning, denaturing gradient gel electrophoresis and fluorescent in situ hybridization (FISH), and scanning and transmission electron microscopy. We propose here that the different types of granules reflect the different stages in the life cycle of granules. Young granules were small, black, and compact and harbored active cells. Gray granules were the most abundant granules. These granules have a multilayer structure with channels and void areas. The core was composed of dead or starving cells with low activity. The brown granules, which were the largest granules, showed a loose and amorphous structure with big channels that resulted in fractured zones and corresponded to the older granules.Firmicutes (as determined by FISH) andNitrospira andDeferribacteres (as determined by cloning and sequencing) were the predominantBacteria . Remarkably,Firmicutes could not be detected in the brown granules. The methanogenicArchaea identified wereMethanosaeta concilii (70 to 90% by FISH and cloning),Methanosarcina mazei , andMethanospirillum spp. The phenotypic appearance of the granules reflected the physiological condition of the granules. This may be valuable to easily select appropriate seed sludges to start up other reactors.