Enhanced Recombinant Protein Productivity by Genome Reduction in Bacillus subtilis

The emerging field of synthetic genomics is expected to facilitate the generation of microorganisms with the potential to achieve a sustainable society. One approach towards this goal is the reduction of microbial genomes by rationally designed deletions to create simplified cells with predictable behavior that act as a platform to build in various genetic systems for specific purposes. We report a novel Bacillus subtilis strain, MBG874, depleted of 874 kb (20%) of the genomic sequence. When compared with wild-type cells, the regulatory network of gene expression of the mutant strain is reorganized after entry into the transition state due to the synergistic effect of multiple deletions, and productivity of extracellular cellulase and protease from transformed plasmids harboring the corresponding genes is remarkably enhanced. To our knowledge, this is the first report demonstrating that genome reduction actually contributes to the creation of bacterial cells with a practical application in industry. Further systematic analysis of changes in the transcriptional regulatory network of MGB874 cells in relation to protein productivity should facilitate the generation of improved B. subtilis cells as hosts of industrial protein production

Emissions of volatile organic compounds (VOCs) from cooking and their speciation: A case study for Shanghai with implications for China

Cooking emission is one of sources for ambient volatile organic compounds (VOCs), which is deleterious to air quality, climate and human health. These emissions are especially of great interest in large cities of East and Southeast Asia. We conducted a case study in which VOC emissions from kitchen extraction stacks have been sampled in total 57 times in the Megacity Shanghai. To obtain representative data, we sampled VOC emissions from kitchens, including restaurants of seven common cuisine types, canteens, and family kitchens. VOC species profiles and their chemical reactivities have been determined. The results showed that 51.26% ± 23.87% of alkane and 24.33 ± 11.69% of oxygenated VOCs (O-VOCs) dominate the VOC cooking emissions. Yet, the VOCs with the largest ozone formation potential (OFP) and secondary organic aerosol potential (SOAP) were from the alkene and aromatic categories, accounting for 6.8–97.0% and 73.8–98.0%, respectively. Barbequing has the most potential of harming people's heath due to its significant higher emissions of acetaldehyde, hexanal, and acrolein. Methodologies for calculating VOC emission factors (EF) for restaurants that take into account VOCs emitted per person (EFperson), per kitchen stove (EFkitchen stove) and per hour (EFhour) are developed and discussed. Methodologies for deriving VOC emission inventories (S) from restaurants are further defined and discussed based on two categories: cuisine types (Stype) and restaurant scales (Sscale). The range of Stype and Sscale are 4124.33–7818.04 t/year and 1355.11–2402.21 t/year, respectively. We also found that Stype and Sscale for 100,000 people are 17.07–32.36 t/year and 5.61–9.95 t/year, respectively. Based on Environmental Kuznets Curve, the annual total amount of VOCs emissions from catering industry in different provinces in China was estimated, which was 5680.53 t/year, 6122.43 t/year, and 66,244.59 t/year for Shangdong and Guangdong provinces and whole China, respectively. Large and medium-scaled restaurants should be paid more attention with respect to regulation of VOCs

Vanillic Acid as a Promising Xanthine Oxidase Inhibitor: Extraction from Amomum villosum Lour and Biocompatibility Improvement via Extract Nanoemulsion

Gout is an oxidative stress-related disease. Food-derived vanillic acid, a promising xanthine oxidase inhibitor, could potentially be used as a safe, supportive, and therapeutic product for gout. The extraction of vanillic acid from a classic Chinese herbal plant Amomum villosum with ethanol was investigated in the study. The optimum conditions were determined as extraction time of 74 min, extraction temperature of 48.36 °C, and a solid-to-liquid ratio of 1:35 g·mL−1 using the Box–Behnken design (BBD) of response surface methodology (RSM). The experimental extraction yield of 9.276 mg·g−1 matched with the theoretical value of 9.272 ± 0.011 mg·g−1 predicted by the model. The vanillic acid in Amomum villosum was determined to be 0.5450 mg·g−1 by high-performance liquid chromatography–diode array detection (HPLC–DAD) under the optimum extraction conditions and exhibited xanthine oxidase (XO) inhibitory activity, with the half-maximal inhibitory concentration (IC50) of 1.762 mg·mL−1. The nanoemulsion of Amomum villosum extract consists of 49.97% distilled water, 35.09% Smix (mixture of tween 80 and 95% ethanol with 2:1 ratio), and 14.94% n-octanol, with a particle size of 110.3 ± 1.9 nm. The nanoemulsion of Amomum villosum extract exhibited markable XO inhibitory activity, with an inhibition rate of 58.71%. The result demonstrated the potential benefit of Amomum villosum as an important dietary source of xanthine oxidase inhibitors for gout

Unexpected fast radical production emerges in cool seasons: implications for ozone pollution control

Ozone is a crucial air pollutant that damages human health and vegetation. As it is related to the photo-oxidation of the nitrogen oxides and volatile organic compounds, the summertime reduction of these precursors is the primary focus of current ozone mitigation strategies. During ozone pollution episodes in eastern China, an observed accumulation of daily total oxidants (Ox=NO2+O3) in cool seasons (spring and autumn: 60 ppb and winter 40 ppb) is comparable to that in summer (60 ppb), indicating fast photochemical production of secondary pollutants including ozone over the year. Unrecognized fast radical primary productions are found to counteract the increased termination of hydroxyl radical and unfavorable meteorological conditions to maintain the rapid total oxidant formations in cool seasons. Elucidating and regulating the primary radical sources may be critical for the secondary air pollution control in cool seasons