Project description:Sulfurospirillum multivorans is one of the few bacteria, which can anaerobically respire organohalides such as tetrachloroethene. The regulation of this organohalide respiration is in most parts unknown. Sulfurospirillum multivorans was shown to downregulate the expression of organohalide respiration-specific genes slowly when no substrate is present, over the time of approximately 100 generations. To unravel the molecular details of this peculiar regulation and the involved factors, we sequenced the primary transcriptome of the organism.
Project description:The experiments were done to investigate fermentation and hydrogen production by the Epsilonproteobacterium Sulfurospirillum multivorans and Sulfurospirillum cavolei. they were grown on pyurvate with or without the electron acceptor fumarate. S. multivorans was cultivated additionally with lactate and fumarate to gather information on lactate oxidation.
Project description:Organohalide respiration is an environmentally important but poorly characterized type of anaerobic respiration. We compared the global proteome of the versatile organohalide-respiring Epsilonproteobacterium Sulfurospirillum multivorans grown with different electron acceptors (fumarate, nitrate, or tetrachloroethene [PCE]).The most significant differences in protein abundance were found for gene products of the organohalide respiration region. This genomic region encodes the corrinoid and FeS cluster containing PCE reductive dehalogenase PceA and other proteins putatively involved in PCE metabolism such as those involved in corrinoid biosynthesis. The latter gene products as well as PceA and a putative quinol dehydrogenase were almost exclusively detected in cells grown with PCE. This finding suggests an electron flow from the electron donor such as formate or pyruvate via the quinone pool and a quinol dehydrogenase to PceA and the terminal electron acceptor PCE. Two putative accessory proteins, an IscU-like protein and a peroxidase-like protein, were detected with PCE only and might be involved in PceA maturation. The proteome of cells grown with pyruvate instead of formate as electron donor indicates a route of electrons from reduced ferredoxin via an Epsilonproteobacterial complex I and the quinone pool to PCE.
