Versatile Medium for the Isolation of Sulfur-Reducing Bacteria from Natural Ecotypes
Nyamath Syed
Department of Agricultural Microbiology, Directorate of Natural Resource Management, Agricultural College and Research Institute, Coimbatore-641003, India.
Karthikeyan Subburamu *
Department of Agricultural Microbiology, Directorate of Natural Resource Management, Agricultural College and Research Institute, Coimbatore-641003, India and Centre for Post-Harvest Technology, Agricultural Engineering College and Research Institute, Coimbatore-641003, India.
Balachandar Dananjeyan
Department of Agricultural Microbiology, Directorate of Natural Resource Management, Agricultural College and Research Institute, Coimbatore-641003, India.
Meena Suresh
Department of Soil Science and Agricultural Chemistry, Agricultural College and Research Institute, Trichy-620009, India.
Sara Parwin Banu Kamaludeen
Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore-641003, India.
*Author to whom correspondence should be addressed.
Abstract
Sulfate-reducing bacteria (SRB) are a diverse group of microorganisms that are commonly isolated from anoxygenic environments (lake depths, soil, or swamps) and are also found in the intestines of humans and animals. They are well known for outcompeting methanogens for common substrates thereby helping in the decrease of methane emissions and also playing a major role in sulfur cycling. Therefore, determining the cultivable methods for their isolation is important. Various media has been used for the cultivation and purification of SRB from natural wetlands. The luxuriant growth of SRB was observed in all the media tested, out of which the best suitable media to recover a maximum of colonies from the natural soil/sediment samples was discovered as a modified postage medium. The enumeration of the isolated SRB was done by the most probable number (MPN) technique. A total of twenty pure isolates of SRB were isolated from different ecotypes.
Keywords: Sulfate-reducing bacteria (SRB), anoxic environment, MPN technique, natural wetlands