Abstract: Shale gas, due to its large reserves worldwide and green nature, has drawn extreme attention in recent years in energyrelated research. Microorganisms play important roles in the formation and exploration of shale gas. Studies of the molecular microbial ecology associated with shale gas can help to better understand the mechanism of shale gas formation and management of gas production and wastewater treatment. The current paper is a review on research progresses in the stated areas, including shale gas genesis, pathways of methane formation, effects of environmental factors on methane formation, impacts of drilling mud and hydraulic fracturing liquids on microorganisms, and the existence of microbial communities on production facilities. A better understanding of microbial ecology in the production facilities of deep shale gas wells and how commercial exploration affects the subsurface microorganisms would help extract the valuable shale gas resources.

Key words: Minjiang River Estuary, nitrification, salinity, Cyperus tegetiformis.