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Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality. However, the use of a single gene to impact several metabolic pathways is difficult. Here, we show that overexpression of the single gene SlMYB75 (SlMYB75-OE) is effective at improving multiple fruit quality traits. In these engineered fruits, the anthocyanin content reached 1.86 mg g−1 fresh weight at the red-ripe stage, and these SlMYB75-OE tomatoes displayed a series of physiological changes, including delayed ripening and increased ethylene production. In addition to anthocyanin, the total contents of phenolics, flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6, 4, and 1.2 times, respectively, compared to those of wild-type (WT) fruits. Interestingly, a number of aroma volatiles, such as aldehyde, phenylpropanoid-derived and terpene volatiles, were significantly increased in SlMYB75-OE fruits, with some terpene volatiles showing more than 10 times higher levels than those in WT fruits. Consistent with the metabolic assessment, transcriptomic profiling indicated that the genes involved in the ethylene signaling, phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits. Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC, AADC2 and TPS genes. The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.

A novel CO 2 -selective membrane with the facilitated transport mechanism has been synthesized to capture CO 2 from the industrial gas mixtures, including flue gas. Both mobile and fixed amine carriers were incorporated into the cross-linked poly(vinyl alcohol) (PVA) during the membrane synthesis. The membrane showed desirable CO 2 permeability (with a suitable effective thickness) and CO 2 /N 2 selectivity up to 170 °C. In the CO 2 capture experiments from a gas mixture with N 2 and H 2 , a permeate CO 2 dry concentration of >98% was obtained, using steam as the sweep gas. The effects of the feed flow rate and the sweep:feed molar ratio on the membrane separation performance were investigated. A one-dimensional isothermal model was established to examine the performance of a hollow-fiber membrane module composed of the described CO 2selective membrane. The modeling results show that a CO 2 recovery of >95% and a permeate CO 2 dry concentration of >98% are achievable from a 1000 standard cubic feet per minute (SCFM) (or 21.06 mol/s) flue gas stream with a 2 ft (0.61 m) hollow-fiber module that contained 980 000 fibers.

In this study, a water gas shift membrane reactor containing both a CO2-selective polymeric membrane and a commercial Cu/ZnO/Al2O3 catalyst was developed for hydrogen processing for fuel cells, especially for the proton-exchange membrane fuel cells (PEMFCs). The polymeric CO2-selective membrane was synthesized by incorporating fixed and mobile carriers in cross-linked poly(vinyl alcohol). The membrane showed good CO2/H2 and CO2/CO selectivities and high CO2 permeabilities at 110 − 170 °C. In the water gas shift (WGS) membrane reactor, the membrane removed CO2, one product of the WGS reaction, while the commercial Cu/ZnO/Al2O3 catalyst was used to catalyze the WGS reaction. By removing CO2 simultaneously, the reversible WGS reaction was shifted toward the products so that the CO concentration was converted and reduced significantly to less than 10 ppm, which met the purity requirement of hydrogen for PEMFCs. A one-dimensional model was used to simulate the reaction and the transport process in a rectangular flat-sheet membrane reactor with well-defined countercurrent gas flows. The modeling results agreed well with the experimental data. A CO concentration of less than 10 ppm and a H2 concentration of greater than 50% (dry basis) were achieved at various flow rates of a simulated autothermal reformate in the membrane reactor.

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