Genome and proteome analysis of Pseudomonas chloritidismutans AW‐1^T that grows on n‐decane with chlorate or oxygen as electron acceptor

Abstract

Growth of Pseudomonas chloritidismutans AW-1 on C7 to C12 n-alkanes with oxygen or chlorate as electron acceptor was studied by genome and proteome analysis. Whole genome shotgun sequencing resulted in a 5 Mbp assembled sequence with a G + C content of 62.5%. The automatic annotation identified 4767 protein-encoding genes and a putative function could be assigned to almost 80% of the predicted proteins. The distinct phylogenetic position of P. chloritidismutans AW-1 within the Pseudomonas stutzeri cluster became clear by comparison of average nucleotide identity values of sequenced genomes. Analysis of the proteome of P. chloritidismutans AW-1 showed the versatility of this bacterium to adapt to aerobic and anaerobic growth conditions with acetate or n-decane as substrates. All enzymes involved in the alkane oxidation pathway were identified. An alkane monooxygenase was detected in n-decane-grown cells, but not in acetate-grown cells. The enzyme was found when grown in the presence of oxygen or chlorate, indicating that under both conditions an oxygenase-mediated pathway is employed for alkane degradation. Proteomic and biochemical data also showed that both chlorate reductase and chlorite dismutase are constitutively present, but most abundant under chlorate-reducing conditions.

Concurrent Haloalkanoate Degradation and Chlorate Reduction by Pseudomonas chloritidismutans AW-1T

“…S2). In line with the expression pattern of cld, a previous proteomic study showed an abundance of chlorite dismutase in strain AW-1 T even when chlorate was replaced by oxygen (19).…”

“…S1). Chlorite dismutase is a periplasmic enzyme (19,(33)(34)(35) and hence, utilization of the molecular oxygen derived from chlorite dismutation by oxygenases involved in the further oxidation of the dehalogenated haloalkanoates could be more efficient than using the oxygen from the extracellular environment. To this end, it should be noted that the solubility of chlorate in water (9.93 M at 25°C) is much higher than that of oxygen (0.000269 M at 25°C, under air), suggesting that exponentially growing cells of strain AW-1 T might be oxygen diffusion limited in the case of aerobic cultivation.…”

Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment

“…The only exceptions are the recently discovered 'intra-aerobic' anaerobes which apparently derive oxygen species from utilizing chlorate or nitrite to employ monooxygenases for attacking hydrocarbon substrates (e.g. during anaerobic growth of Candidatus Methylomirabilis oxyfera with methane [Ettwig et al, 2010], gammaproteobacterial strain HdN1 with n -hexadecane [Zedelius et al, 2011] and Pseudomonas chloritidismutans AW-1 T with n -decane [Mehboob et al, 2015]). Accordingly, anaerobic degradation of hydrocarbons involves a variety of intriguing biochemically unprecedented reactions, as indicated by previous microbiological and biochemical research on some model compounds.…”

Microbial respiration with chlorine oxyanions: diversity and physiological and biochemical properties of chlorate‐ and perchlorate‐reducing microorganisms

“…64 The clrABDC cluster of P. chloritidismutans is located on a 12-kb genomic island on the chromosome, and a transposase was found downstream of the clr genes. 13,65 There is only one insert containing the transposase gene, ISPa16, and the organization of cld with a downstream gene for cytochrome c553, an inverted repeat (ISPst12), clrABDC, and genes for an ATPase and a glycosyl transferase family protein are present, similar to Pseudomonas sp. PK.…”