Publications

• Identification of lactaldehyde dehydrogenase and glycolaldehyde dehydrogenase as functions of the same protein in Escherichia coli.

  Caballero E., Baldoma L., Ros J., Boronat A., Aguilar J.

  Lactaldehyde dehydrogenase is an enzyme involved in the aerobic metabolism of fucose in wild type Escherichia coli, and glycolaldehyde dehydrogenase is an enzyme involved in the metabolism of ethylene glycol in mutant cells able to utilize this glycol. Both enzyme sources display oxidative activit ... >> More

  Lactaldehyde dehydrogenase is an enzyme involved in the aerobic metabolism of fucose in wild type Escherichia coli, and glycolaldehyde dehydrogenase is an enzyme involved in the metabolism of ethylene glycol in mutant cells able to utilize this glycol. Both enzyme sources display oxidative activity on either substrate with a constant ratio between these activities. We have found that both enzymatic activities present the same electrophoretic mobility when crude extracts were electrophoresed in polyacrylamide gels and the gels stained for enzyme activities. Furthermore, both enzymatic activities co-chromatograph in a DEAE-Sephadex column. If lactaldehyde dehydrogenase of wild type cells is purified near homogeneity and the purification procedure is screened for both aldehydes as substrates, only one enzyme is apparent, giving again a constant ratio between lactaldehyde and glycolaldehyde dehydrogenase activities. Genetic evidence of the fact that both activities are functions of the same protein is provided by the observation that mutation to thermosensitivity for the production of lactaldehyde dehydrogenase affected in the same way the production of glycolaldehyde dehydrogenase. Glycolaldehyde dehydrogenase from mutant cells is purified in a procedure coincident with the lactaldehyde dehydrogenase purification, yielding a single enzyme electrophoretically indistinguishable from the purified lactaldehyde dehydrogenase. Peptide mapping of the purified preparation after digestion with chymotrypsin or Staphylococcus aureus protease V8 gives an indistinguishable band pattern between both enzymes. << Less

  J. Biol. Chem. 258:7788-7792(1983) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• A new synthetic pathway for the bioproduction of glycolic acid from lignocellulosic sugars aimed at maximal carbon conservation.

  Lachaux C., Frazao C.J.R., Kraubetaer F., Morin N., Walther T., Francois J.M.

  Glycolic acid is a two-carbon α-hydroxy acid with many applications in industrial sectors including packaging, fine chemistry, cosmetics, and pharmaceutics. Currently, glycolic acid is chemically manufactured from fossil resources. This chemical mode of production is raising some concerns regardin ... >> More

  Glycolic acid is a two-carbon α-hydroxy acid with many applications in industrial sectors including packaging, fine chemistry, cosmetics, and pharmaceutics. Currently, glycolic acid is chemically manufactured from fossil resources. This chemical mode of production is raising some concerns regarding its use in health for personal care. Microbial production of GA stands as a remarkable challenge to meet these concerns, while responding to the increasing demand to produce bio-sourced products from renewable carbon resources. We here report on the design and expression of a novel non-natural pathway of glycolic acid in <i>E. coli</i>. The originality of this new pathway, termed "glycoptimus" relies on two pillars. On the one hand, it requires the overexpression of three naturally occurring <i>E. coli</i> genes, namely <i>kdsD</i> encoding a D-arabinose-5-P isomerase, <i>fsaA</i> encoding a class 1 aldolase that cleaves D-arabinose-5-P into glyceraldehyde-3-P and glycolaldehyde, and <i>aldA</i> coding for an aldehyde dehydrogenase that oxidizes glycoladehyde in glycolate. These three genes constitute the "glycoptimus module." On the other hand, the expression of these genes together with a reshaping of the central carbon metabolism should enable a production of glycolic acid from pentose and hexose at a molar ratio of 2.5 and 3, respectively, which corresponds to 50% increase as compared to the existing pathways. We demonstrated the '<i>in vivo</i>' potentiality of this pathway using an <i>E. coli</i> strain, which constitutively expressed the glycoptimus module and whose carbon flow in glycolysis was blocked at the level of glyceraldehyde-3-P dehydrogenase reaction step. This engineered strain was cultivated on a permissive medium containing malate and D-glucose. Upon exhaustion of malate, addition of either D-glucose, D-xylose or L-arabinose led to the production of glycolic acid reaching about 30% of the maximum molar yield. Further improvements at the level of enzymes, strains and bioprocess engineering are awaited to increase yield and titer, rendering the microbial production of glycolic acid affordable for a cost-effective industrial process. << Less

  Front. Bioeng. Biotechnol. 7:359-359(2019) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.