Prokaryotes are key players in the global sulfur cycle, which is one of the major element cycles on earth (the carbon, nitrogen, and iron cycles being the others). This project involves obtaining the genome sequence of the sulfide oxidizing gamma-proteobacterium Beggiatoa alba B18LD (type strain). The ecologically successful genus Beggiatoa is worldwide in its distribution. Macroscopically visible assemblages dominated by members of this genus can be observed in a diverse set of environments, all of which are characterized by the presence of a detectable level of hydrogen sulfide (H2S). When growing at oxic/anoxic (oxygen/no oxygen) interfaces, Beggiatoa serves the extremely important function of preventing the aerobic phase of an ecosystem from becoming poisoned by sulfide. Beggiatoa species are also distinguished by their strong behavioral response, involving gliding motility to gradients of sulfide and oxygen. Gliding motility is still a poorly understood process, even though the ability to move on solid surfaces and within biofilms is of tremendous environmental, industrial, and medical importance.
Knowledge of the genome sequence of B. alba B18LD would help to advance research on fundamental aspects of environmental microbiology. With the genome sequence, we will be able to obtain a better understanding of the role of this microbe and related strains in the cycling of sulfur, as well as carbon and nitrogen, in sulfide-rich habitats such as wetlands, rice paddy fields, methane seeps, and wastewater treatment plants. We will also gain insights into the molecular components of behavioral responses to sulfide and oxygen and of gliding motility. The research will allow us to interrogate patterns of global gene expression analysis using in-situ synthesized oligonucleotide microarrays. In combination with bioinformatic approaches, microarrays will be used to help in identifying regulatory networks such as those involved in sulfide oxidation and carbon metabolism, which will greatly enhance our understanding of the metabolic performance of this ubiquitous microbe under various environmental conditions.
Principal Investigators: Jochen A Mueller and Kenneth P Samuel (Morgan State Univ.) and Andreas P Teske (Univ. of North Carolina)