Discovery of a novel acrylic acid formation pathway in Gluconobacter oxydans and its application in biosynthesis of acrylic acid from glycerol

Heterologous Production of Acrylic Acid: Current Challenges and Perspectives

“…This is in accordance with the study by Arya et al [110] who concluded that the AA effect is specific on growth and not in the central carbon metabolism and that, consequently, a high concentration of AA can be tolerated under resting conditions. In addition, in [105], acrolein accumulation was not observed, which is positive due to its reported toxicity. This 3-step pathway allowed obtaining the highest concentration so far in batch fermentation.…”

“…Due to its toxicity to the cells, there are few organisms that are able to produce AA [105]. Usually, AA is present in a different form, as acrylyl-CoA (AA-CoA) that is an intermediate of 3-HP cycle in several organisms and it is then converted to propanoyl-CoA [106,107].…”

“…The first two steps of this pathway are based on the 3-HP cycle found in several organisms, such as C. aurantiacus, Acidianus brierleyi, Acidianus ambivalens, M. sedula, Megasphaera elsdenii, Sulfolobus sp. strain VE6 and Sulfolobus metallicus [105][106][107]. Some of these organisms have already been explored as a source of enzymes for this pathway, but there are still several enzymes than can be evaluated.…”

“…Recently, a new pathway from glycerol that produces acrolein as an intermediary was described (Figure 7d) [105]. This pathway is based on the pathway from Gluconobacter oxydans that is able to produce 3-HP and AA using acrolein as an intermediate.…”

“…Moreover, regarding AA production from β-alanine, the overexpression of more genes related to β-alanine accumulation would also help to increase the concentration (e.g., aspartate aminotransferase [40,104], phosphoenolpyruvate carboxylase [46]). Lastly, the elimination of competing pathways (e.g., deletion of yqhD) in the recent study by Zhao et al [105] would also probably allow improving AA production.…”