Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (AOM-SR) is a biological process mediated by anaerobic methanotrophs (ANME) and sulfate reducing bacteria. It has scientifi c and societal relevance in regulating the global carbon cycle and biotechnological application for treating sulfate-rich wastewater. This research aimed to enhance the recent knowledge on ANME distribution and its enrichment in different bioreactor confi gurations, i.e. membrane bioreactor (MBR), biotrickling fi lter (BTF) and high pressure bioreactor (HPB). Marine sediment from Ginsburg mud volcano, Gulf of Cadiz was used as inoculum in the BTF and MBR. The BTF operation showed the enrichment of ANME in the biofi lm, especially ANME-1 (40%) and ANME-2 (10%). Whereas, the dominancy of ANME-2 and Desulfosarcina aggregates was observed in the MBR. Moreover, HPB study was performed by using highly enriched ANME-2 community from Captain Arutyunov mud volcano. During the study of HPB at different temperature and pressure conditions, the incubation at 10 MPa pressure and 15˚C was observed to be the most suitable condition for the studied AOM-SR community. Furthermore, AOM-SR activity in the coastal sediments from marine Lake Grevelingen (the Netherlands) was explored and the microbial community was characterised which was dominated by ANME-3 among known ANME types.
Table of Contents
1. General introduction and outline
2. Physiology and distribution of anaerobic oxidation of methane by archaeal methanotrophs
3. Microbial sulfate reducing activities in anoxic sediment from Marine Lake Grevelingen
4. Anaerobic methane oxidizing microbial community in a coastal marine sediment: anaerobic methanotrophy dominated by ANME-3
5. Enrichment of anaerobic methane oxidizing ANME-1 from Ginsburg Mud Volcano (Gulf of Cadiz) sediment in a biotrickling filter
6. Enrichment of ANME-2 dominated anaerobic oxidation of methane coupled to sulfate reduction consortia from cold seep sediment (Ginsburg Mud Volcano, Gulf of Cadiz) in a membrane bioreactor
7. Response of highly enriched ANME-2a community to different pressure and temperature conditions.
8. General discussion
Dr. Susma Bhattarai Gautam is from Nepal. She obtained her bachelor (BSc) and MSc in Environmental Science with the specialization in water resource management from Tribuvan University, Nepal. She obtained her masters (MSc) in Environmental Science from UNESCO-IHE, Institute of Water Education, Delft, the Netherlands, during which she worked on a research project from EAWAG, Switzerland which characterized the microbial community of Lake Kivu sediment, East Africa. Susma did her PhD in Environmental Science and Technology in Erasmus Mundus Joint Doctorate Programme Environmental Technologies for Contaminated Solids, Soils and Sediments (ETeCoS3). Her research was mainly focused on the study of anaerobic oxidation of methane, enrichment of anaerobic methanotrophic communities which perform anaerobic oxidation of methane in bioreactors and understand their ecophysiology.
Susma's main research interest are environmental biotechnology, anaerobic processes and molecular biology.