Structural and Geomicrobiological Characteristics of a Microbial Community from a Cold Sulfide Spring
2Department of Microbiology, Key Words: sulfur spring, green sulfur bacteria, purple sulfur bacteria, qanobacteria 'To whom correspondence should be addressed. Email: Susanne.Dougla@jpl.nasa.gov Phone: (8 18)3546322; Fax: (8 18)393"445 ABSTRACT The Ancaster sulhr spring is a cold (9°C) sulfbr spring located near Ancaster, Ontario, Canada which hosts an abundant and diverse micobial mat community.We have conducted an extensive microscopical study of this spring using a number of techniques:
... of techniques: phase light, confocal scanning laser microscopy, conventional scanning electron microscopy using both chemical/criticai point drying and cryofixation preparative tFhniques, environmental scanning electron microscopy, and transmission electron microscopy. With the latter two techniques we also used energy dispersive nay spectroscopy for elemental analysis to complement wet geochemical data collected on bulk spring water and mat pore water. This approach allowed us to gain an appreciation of the characteristics of this microbial community on a variety of length scales and allowed us to develop a good understanding of the types of microorganisms present in this community, inferring some of the relationships among its members. In the spring, different mat types existed, based on differing colours and textures, due to the predominance of specific microbial groups. Segregation of these types and examination by microscopy showed that all the major groups of sulfide-oxidising bacteria, purple bacteria, green bacteria, cyanobacteria, and colourless s u h oxidising bacteria were represented. In some cases there seemed to be types present that have not previously been described in the literature; we hope to learn more about these as we pursue phylogenetic analysis of the Ancaster sulhr spring community. In the present study, we describe the members of these groups, in terms of their structural characteristics, and how their activity may relate to some of the minerals found in association with them. In addition, we wish to convey the utility of a thorough microscopical approach in microbial ecological studies.