Microbial production of 4-hydroxybutyrate, poly-4-hydroxybutyrate, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by recombinant microorganisms

Abstract

4-Hydroxybutyrate (4HB) was produced by Aeromonas hydrophila 4AK4, Escherichia coli S17-1, or Pseudomonas putida KT2442 harboring 1,3-propanediol dehydrogenase gene dhaT and aldehyde dehydrogenase gene aldD from P. putida KT2442 which are capable of transforming 1,4-butanediol (1,4-BD) to 4HB. 4HB containing fermentation broth was used for production of homopolymer poly-4-hydroxybutyrate [P(4HB)] and copolymers poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-4HB)]. Recombinant A. hydrophila 4AK4 harboring plasmid pZL-dhaT-aldD containing dhaT and aldD was the most effective 4HB producer, achieving approximately 4 g/l 4HB from 10 g/l 1,4-BD after 48 h of incubation. The strain produced over 10 g/l 4HB from 20 g/l 1,4-BD after 52 h of cultivation in a 6-L fermenter. Recombinant E. coli S17-1 grown on 4HB containing fermentation broth was found to accumulate 83 wt.% of intracellular P(4HB) in shake flask study. Recombinant Ralstonia eutropha H16 grew to over 6 g/l cell dry weight containing 49 wt.% P(3HB-13%4HB) after 72 h.

Production and characterization of poly(3-hydroxypropionate-co-4-hydroxybutyrate) with fully controllable structures by recombinant Escherichia coli containing an engineered pathway

“…This demonstrated that the activity of PCS' on 4HB was much lower than that on 3HP. The gene orfZ from Clostridium kluyveri, putatively encoding a 4-hydroxybutyric acid coenzyme A transferase was found able to turn 4HB into 4HB-CoA effectively (Li et al, 2010;Zhang et al, 2009). Products derived from one metabolic precursor may be more efficiently produced using other carbon fixation pathways (Boyle and Morgan, 2011).…”

“…4HB-Coenzyme A transferase gene orfZ from Clostridium kluyveri was found able to turn 4HB into 4HB-CoA effectively (Hein et al, 1997;Song et al, 1999;Zhang et al, 2009). Genes dhaT and aldD were proven functional to synthesize 1,4-butanediol (BDO) or/and 1,3-propanediol (PDO) to 4HB or/and 3HP, the enzyme encoded by dhaT was mostly active with substrates containing two primary alcohol groups separated by one or two carbon atoms such as 1,3-propanediol or 1,4-butanediol, and 3HP or/and 4HB yield were affected by expression levels of these two genes ).…”

Poly(4-hydroxybutyrate) (P4HB) production in recombinant Escherichia coli: P4HB synthesis is uncoupled with cell growth

“…Several reports have described the P4HB synthesis and accumulation in E. coli [16,20,24]. However, neither physiological and cultivation conditions, nor the external factors that may influence P4HB accumulation have been studied yet in detail.…”

From Waste to Plastic: Synthesis of Poly(3-Hydroxypropionate) in Shimwellia blattae

“…This two-phase process has several benefits: (i) a higher cell dry weight can be achieved than in a completely anaerobic production process; (ii) NADH which accrues from the synthesis of poly(3HP) can be oxidized to NAD ϩ during aerobic respiration; and (iii) during aerobic poly(3HP) production, the precursor 3-hydroxypropionaldehyde is not converted back to 1,3-propanediol, since the native dhaT gene from S. blattae should not be expressed when oxygen is present (22). The interplay of DhaT Sb and DhaT Pp is important for the process, as it was shown previously that these isoenzymes exhibit different specific substrate preferences, preferring 3-hydroxypropionaldehyde (DhaT Sb ) (22,40) or 1,3-propanediol (DhaT Pp ) (24). Using the BLAST algorithm (41), a maximum amino acid identity of 38% was determined for the two isoenzymes.…”

“…We chose S. blattae for the synthesis of poly(3HP) from glycerol because it can naturally convert glycerol to 3-hydroxypropionaldehyde via catalysis by DhaB, thereby building an intermediate of the poly(3HP) biosynthetic pathway. In order to synthesize poly(3HP) from glycerol in S. blattae, we heterologously expressed the genes for (i) the 1,3-propanediol dehydrogenase DhaT, (ii) the aldehyde dehydrogenase AldD from Pseudomonas putida KT2442 (23,24), (iii) the propionate-coenzyme A (propionate-CoA) transferase Pct from Clostridium propionicum X2 (25)(26)(27), and (iv) the PHA synthase PhaC1 from Ralstonia eutropha H16 (28,29). By this synthetic pathway, 1,3-propanediol, which is produced by S. blattae under anaerobic conditions, is oxidized to 3-hydroxypropionaldehyde (DhaT).…”