Microwave radiation and reactor design influence microbial communities during methane fermentation

• Published in: Journal of industrial microbiology & biotechnology Vol. 39; no. 9; pp. 1397 - 1405
• Main Authors: Cydzik-Kwiatkowska, Agnieszka, Zieliński, Marcin, Jaranowska, Paulina
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-09-2012; Springer; Oxford University Press
• Subjects: Archaea; Bacteria - genetics; Bacteria - isolation & purification; Bacteria - metabolism; Bacteria - radiation effects; bacterial communities; Biochemistry; Biofilms; Biogas; Bioinformatics; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Bioreactors - microbiology; Biotechnology; Chemical reactors; Denaturing Gradient Gel Electrophoresis; Energy consumption; Environmental science; Experiments; Fermentation; Fermentation - radiation effects; Fisheries; Fundamental and applied biological sciences. Psychology; Genetic Engineering; Genetics and Molecular Biology of Industrial Organisms; Heat; heat treatment; Heating; Inorganic Chemistry; Life Sciences; Methane; Methane - metabolism; Methanosarcina; Methanosarcina - genetics; Methanosarcina - isolation & purification; Methanosarcina - metabolism; Methanosarcina - radiation effects; Methods. Procedures. Technologies; Microbial activity; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Microorganisms; Microwave heating; Microwave radiation; Microwaves; Polymerase Chain Reaction; quantitative polymerase chain reaction; Radiation; Reactors; Real-Time Polymerase Chain Reaction; Retention; Sludge; Species composition; species diversity; Studies; diversity; Microwave radiation; sp; Methanogenic; Methane; Archaeobacteria; Methanosarcina sp; Diversity; Radiation; Microwave; Methanosarcinaceae; Fermentation; Methanogenic Archaea diversity; Methanomicrobiales; Design; Methanosarcina; Methanogenesis; Bacteria; Reactor; Microbial community
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-012-1141-x

The effect of reactor design and method of heating on the efficiency of methane fermentation and composition of microbial communities, especially methanogenic Archaea, were determined. The research was carried out using submerge- and trickling-bed reactors fed with wastewater and the heat supply into the reactors included a convection heating method and microwave radiation. The polymerase chain reaction-denaturing gradient gel electrophoresis and relative real-time PCR were used in order to assess the biofilm communities. The best fermentation results and the highest abundance of methanogenic Archaea in biomass were observed in microwave heated trickling-bed reactors. The research proved that in reactors of identical design, the application of microwaves enabled a higher fermentation efficiency to be obtained and simultaneously increased the diversity of methanogenic Archaea communities that favors process stability. All the identified sequences of Archaea belonged to Methanosarcina sp., suggesting that species from this genera are susceptible to non-thermal effects of microwaves. There were no effects from microwaves on the bacterial communities in both types of reactors, however, the bacterial species composition varied in the reactors of different design.