Carbon-13 Nuclear Magnetic Resonance Study of Metabolism of Propionate by Escherichia coli

Abstract

We have evaluated the use of [1,2-13C2]propionate for the analysis of propionic acid metabolism, based on the ability to distinguish between the methylcitrate and methylmalonate pathways. Studies using propionate-adapted Escherichia coli MG1655 cells were performed. Preservation of the13C-13C-12C carbon skeleton in labeled alanine and alanine-containing peptides involved in cell wall recycling is indicative of the direct formation of pyruvate from propionate via the methylcitrate cycle, the enzymes of which have recently been demonstrated in E. coli. Additionally, formation of 13C-labeled formate from pyruvate by the action of pyruvate-formate lyase is also consistent with the labeling of pyruvate C-1. Carboxylation of the labeled pyruvate leads to formation of [1,2-13C2]oxaloacetate and to multiply labeled glutamate and succinate isotopomers, also consistent with the flux through the methylcitrate pathway, followed by the tricarboxylic acid (TCA) cycle. Additional labeling of TCA intermediates arises due to the formation of [1-13C]acetyl coenzyme A from the labeled pyruvate, formed via pyruvate-formate lyase. Labeling patterns in trehalose and glycine are also interpreted in terms of the above pathways. The information derived from the [1,2-13C2]propionate label is contrasted with information which can be derived from singly or triply labeled propionate and shown to be more useful for distinguishing the different propionate utilization pathways via nuclear magnetic resonance analysis.

Dual role of isocitrate lyase 1 in the glyoxylate and methylcitrate cycles in Mycobacterium tuberculosis

“…While acetyl‐CoA is produced from the β‐oxidation of even‐chain fatty acids, β‐oxidation of odd‐chain or branched‐chain fatty acids, as well as the branched chain amino acids, results in the production of propionyl‐CoA. High levels of propionate and propionyl‐CoA have been implicated in toxicity for bacteria and fungi (Textor et al ., 1997; London et al ., 1999; Brock et al ., 2000; Bramer and Steinbuchel, 2001; Horswill et al ., 2001; Bramer et al ., 2002; Claes et al ., 2002). There are several pathways for the metabolism of propionyl‐CoA, of which at least two putative pathways exist in M. tuberculosis , the methylmalonyl‐CoA pathway and the methylcitrate cycle.…”

Evaluation of small organic acids present in fast pyrolysis bio‐oil from lignocellulose as feedstocks for bacterial bioconversion

“…Propionic acid, also generated during fast pyrolysis of lignocellulosic biomass, is the third common small organic acid found in bio-oil with about 0.7 wt% (Table 1). Based on various studies, it is assumed that in most bacteria, yeast, and filamentous fungi, the 2-methylcitrate cycle is the main pathway used to oxidize propionate to pyruvate (Brock, Maerker, Schutz, Volker, & Buckel, 2002;Claes, Pühler, & Kalinowski, 2002;Horswill & Escalante-Semerena, 1999;London, Allen, Gabel, & DeRose, 1999;Miyakoshi, Uchiyama, Someya, Satoh, & Tabuchi, 1987;Pronk, Linden-Beuman, Verduyn, Scheffers, & Dijken, 1994;Tabuchi, Serizawa, & Uchiyama, 1974;Textor et al, 1997). As for acetate, propionate is first activated to propionyl-CoA by either ACS (encoded by acs) and propionyl-CoA synthase (encoded by prpE) or a sequential reaction of phosphorylation of propionate catalyzed by ACK and PTA ( Figure 1).…”

Alfa-oxidação de propionato está envolvida na redução da produção de plástico biodegradável em Burkholderia sacchari?

“…Ácido propiônico também pode ser produzido por fermentação de amido ou açúcar por Propionibacterium acidipropionici (Carrondo et al, 1988, Blanc & Goma, 1989, Raecker et al, 1992 (London et al, 1999). Em algumas bactérias a atuação simultânea de mais de uma via foi proposta para a sua transformação em acetil-CoA ou succinato (Evans et al, 1993).…”

“…Porém a proposta de funcionamento da via do metilmalonil-CoA foi unicamente baseada em experimentos nos quais se observava um aumento do consumo do propionato ou uma redução na fase lag, quando o meio era suplementado com vitamina B12 ou bicarbonato. Estudos mais recentes, utilizando propionato marcado em duas posições, demonstraram que não é necessário invocar a via do metilmalonil-CoA ou α-hidroxiglutarato para explicar o metabolismo de propionato em E. coli (London et al, 1999). London e colaboradores (1999) forneceram propionato 1,2-13 C 2 para análise do metabolismo de ácido propiônico, para distinguir entre as vias do metilcitrato e metilmalonato.…”

“…Este e outros resultados de Pereira (2007) propionato seria carboxilado a succinato ou oxidado a piruvato, sem no entanto indicar se última ocorreria por α-oxidação. Todos estes trabalhos se basearam em cultivos de bactérias em propionato marcado e análise dos metabólitos gerados, bem como na medida de atividade de diversas enzimas, que pode levar a resultados enganoso, como posteriormente comentado (London et al, 1999).…”