In general, the gasification of biomass is often followed by a gas clean-up and conditioning. The gas mixture is passed through a series of cyclones and filters to remove most of the unde­sirable pollutants (e. g., tar, particulate matter, and char). Datar et al. (2004) employed a con­densation tower followed by acetone scrubbers to remove tar and moisture from the producer gas. A series of 0.025-gm filters were successfully used to clean producer gas mixture to pre­vent cell dormancy and product redistribution (Ahmed et al., 2006). Further, trace amounts of NO can be removed by using chemicals such as sodium hypochlorite, potassium permanga­nate, or sodium hydroxide. Syngas fermentation shows a high tolerance toward sulfur gases such as hydrogen sulfide (H2S), and COS. Vega et al. (1990) found that CO-utilizing methanogenic microbes can grow in the presence of H2S up to 2%.