The potential of microbial enrichment for enhancing methanogenesis in brown coal was investigated by using microbial communities from coal formation water and a mangrove swamp as treatments. After 30 days of incubation with a 'mixed' culture, both the rates and yields of methane generation were enhanced compared to microbial enrichment cultures having just a single origin. The microbial community derived from a mangrove swamp alone, appeared to lack the ability to degrade coal. The pH of the mixed origin treatment was favourable for growth of the mangrove derived microbial community possibly explaining the higher gas yield observed with this culture. (C) 2015 Elsevier B.V. All rights reserved.