Development of novel on-line capillary gas chromatography-based analysis method for volatile organic compounds produced by aerobic fermentation

Engineered Escherichia coli strains as platforms for biological production of isoprene

“…To increase the detection level of isoprene, a 1‐mL sample was injected into an Agilent J&W GC column (30 m × 0.53 mm internal diameter). We adopted the novel online monitoring system developed in our previous study using gas chromatography for the analysis of isoprene production during aerobic fermentation [15]. The temperature program used was 3 min at 50 °C followed by an increase to 150 °C for 10 min; the column was maintained at this temperature for 12 min before lowering to 50 °C again.…”

“…Isoprene has also been produced at a yield of 8.4 g·L −1 using E. coli BL21 engineered to express a truncated form of P. alba ispS along with a gene encoding two types of hydroxy‐2‐methyl‐2‐butenyl‐4‐diphosphate synthase ( ispG ) enzymes in fed‐batch cultivation [14]. We previously obtained 12.7 g·L −1 isoprene using E. coli DH5α with a two‐vector system of Populus trichocapa ispS and the MVA pathway [15]. Despite these numerous reports of enhanced isoprene production using several E. coli strains, all of these studies have focused on limited strains, including E. coli BL21, BL21 (DE3), BW25113 (DE3), Rosetta (DE3), and DH5α.…”

Production of Bio-Based Isoprene by the Mevalonate Pathway Cassette in Ralstonia eutropha

“…E. coli S17 and R. eutropha H16 harboring pTS-sPt-MVA were used in this study. The plasmid was obtained from pS-NA plasmid derived from pSTV28, as described previously [17] and contained the following: mvaS and hydroxymethylglutaryl-CoA reductase (mvaE) from Enterococcus faecalis; mevalonate kinase (mvaK1), phosphomevalonate kinase (mvaK2), and mevalonate diphosphate decarboxylase (mvaD) from Streptococcus pneumoniae; idi from E. coli; and ispS from Populus trichocarpa. ispS is an isoprene synthase gene to catalyze the formation of isoprene from DMAPP.…”

“…Isoprene hydrocarbons are a useful chemical product widely used as feedstock in fuel additives for gasoline or jet fuel as well as in the synthetic rubber industry [12][13][14]. The production of isoprenoids including isoprene is divided into two biosynthetic pathways, the mevalonate (MVA) pathway and the methylerythritol phosphate (MEP) pathway from isopentenyl diphosphate pyrophosphate (IPP) and dimethylallyl diphosphate (DMAPP), with each having been studied using engineered E. coli systems [15][16][17]. Several reports have also described bio-based isoprene production using novel engineered strains of Bacillus, cyanobacteria, and Saccharomyces cerevisiae species [18,19].…”

“…In our previous study, we achieved 12.7 g/l isoprene accumulation through heterologous co-expression of the Populus trichocapa ispS gene and MVA pathway genes using E. coli DH5α [17]. Despite the use of various hosts, genetic elements, and culture conditions in previous studies, the yield produced is still insufficient to meet the industrial demand for cost-effective productivity.…”