Characterization of Two BAHD Acetyltransferases Highly Expressed in the Flowers of Jasminum sambac (L.) Aiton

Volatile benzenoid compounds are found in diverse aromatic bouquets emitted by most moth-pollinated flowers. The night-blooming Jasminum sambac is widely cultivated worldwide in the tropics and subtropics for ornamental and industrial purposes owing to its fragrant flowers. Benzylacetate is a characteristic constituent in jasmine scent which makes up to approximately 20–30% of the total emission in the headspace or extract, but the biosynthesis enzymes and the encoding genes have not yet been described. Here, we identify two cytosolic BAHD acyltransferases specifically expressed in the petals with a positive correlation closely to the emission pattern of the volatile benzenoids. Both JsBEAT1 and JsBEAT2 could use benzylalcohol and acetate-CoA as substrates to make benzylacetate in vitro. The recombinant GST-JsBEAT1 has an estimated apparent Km of 447.3 μM for benzylalcohol and 546.0 μM for acetate-CoA, whereas in the instance of the His-JsBEAT2, the Km values are marginally lower, being 278.7 and 317.3 μM, respectively. However, the catalytic reactions by the GST-JsBEAT1 are more efficient than that by the His-JsBEAT2, based on the steady-state kcat parameters. Furthermore, ectopic expression of JsBEAT1 and JsBEAT2 in the transgenic P. hybrida plants, driven by a flower-specific promotor, significantly enhances the biosynthesis of benzylbenzoate and benzylacetate, as well as the total VOCs.

China pollutant discharge permits as a link between total emission control and water quality: a pilot study of the pesticide industry

The deficiency of China's current pollution discharge permit system lies in the failure to improve the water quality effectively. This paper discusses the premise that the water quality of a water environmental functional zone (WEFZ) is mostly affected by industrial pollution sources. By reviewing the related policy, we noted the link between total emission control, effluent limitations and pollutant discharge permits to configure a practical framework for pollutant discharge permits based on water quality. China's pollutant discharge permit system provides an administrative foundation for reducing polluters' total emissions at the scale of the WEFZ, and it is best implemented through the imposition of limitations on polluters to identify the related treatment technology levels. Owing to the importance of limitations, the methodology of limitation classification and the related treatment technology classification are presented for the pesticide industry. Additionally, a comprehensive analysis of the pollutant reduction potential for the pesticide industry is conducted to determine the current level of sewage treatment. More importantly, this study offers an innovative way to investigate pollutant reduction potential and provides an example that may be useful to other key industries.

Gravitational and electromagnetic radiation from binary black holes with electric and magnetic charges: elliptical orbits on a cone

Extending the electromagnetic and gravitational radiations from binary black holes with electric and magnetic charges in circular orbits in Liu et al. (Phys. Rev. D 102:103520, 2020), we calculate the total emission rates of energy and angular momentum due to gravitational and electromagnetic radiations from dyonic binary black holes in precessing elliptical orbits. It is shown that the emission rates of energy and angular momentum due to gravitational and electromagnetic radiations have the same dependence on the conic angle for different orbits. Moreover, we obtain the evolutions of orbits and find that a circular orbit remains circular while an elliptic orbit becomes quasi-circular due to electromagnetic and gravitational radiations. Using the evolution of orbits, we derive the waveform models for dyonic binary black hole inspirals and show the amplitudes of the gravitational waves for dyonic binary black hole inspirals differ from those for Schwarzschild binary black hole inspirals, which can be used to test electric and magnetic charges of black holes.

Cropland Displacement Drives Carbon Emission of Grain Transport in China

Cropland displacement is a worldwide land-use phenomenon that involves replacing cropland occupied by urbanization with newly developed cropland in remote areas. Large-scale cropland displacement to some extent helps secure food supply to the growing urban population but also drives a great need for grain transport, which leads to rising energy consumption and carbon emission. Here we show a systematic evaluation of the carbon emission associated with grain transport at the prefecture-level in China in 1990 and 2015. We found that the total emission of grain transport in China more than doubled from 4.46 million-ton to 10.73 million-ton during this period. Cropland displacement contributed more than 60% of the increased carbon emission, while dietary change and population growth contributed 31.7% and 16.6%, respectively. In contrast, improvement of transport infrastructures offset 0.54 million-ton of the increased emission. Based on the research results, we provide policy suggestions on reducing grain transport carbon emission in China in terms of land use planning, grain-based value chain, as well as transport development.

Comparison of Carbonaceous Compounds Emission from the Co-Combustion of Coal and Waste in Boilers Used in Residential Heating in Poland, Central Europe

In this study, the effect of the addition of waste on the emissions from coal co-combustion was investigated. Coal was co-combusted with different additions of medium-density fiberboard and polyethylene terephthalate plastic (10 and 50%), in a low-power boiler (18 W). Polycyclic aromatic hydrocarbons, phenols, alkylphenols, phthalates, and biomass burning markers emissions were determined. Gas chromatography, coupled with a mass spectrometry detector, was used to analyze these compounds in particulate matter and gas phase, after extraction and derivatization. The emissions of polycyclic aromatic hydrocarbons were the highest among all the compounds determined. The total emission of these compounds was 215.1 mg/kg for coal, and 637.7 and 948.3 mg/kg for a 10 and 50% additive of polyethylene terephthalate plastic, respectively. For the 10 and 50% additive of medium-density fiberboard, the total emission was 474.2 and 464.0 mg/kg, respectively. The 50% addition of PET also had the highest emissions of phenols (638.5 mg/kg), alkylphenols (246.5 mg/kg), and phthalates (18.1 mg/kg), except for biomass burning markers, where the emissions were the highest for the 50% addition of medium-density fiberboard (541.3 mg/kg). In our opinion, the obtained results are insufficient for the identification of source apportionment from household heating.

Quantifying bubbling emission (ebullition) of methane from a rice paddy using high-time-resolution concentration data obtained during a closed-chamber measurement

Methane (CH4) produced in rice-paddy soil is transported to the atmosphere either via the rice plants or by bubbling events (ebullition); however, little is known about the frequency and intensity of bubbling CH4 emissions and the factors that affect them. We developed a method to quantify ebullition using high-time-resolution (~1 Hz) CH4 concentration data obtained by closed-chamber measurements. Field measurements were conducted in a Japanese rice paddy at different rice growth stages: panicle formation (PF), booting (BT), and heading (HD). A dataset of 132 chamber measurements was used to develop and evaluate the method. A scripting file written in R programing language was used to automatically determine CH4 emissions via the two pathways. Plant-mediated CH4 emission intensity was constant during chamber deployment and was reflected as a steady linear increase in chamber [CH4] with time or as a constant baseline in a flux time series. We found that the plant-mediated emission could be determined as the peak with the lowest flux intensity in the flux frequency distribution even if bubbling events occurred during the chamber deployment. The field measurement results in combination with established data processing protocols showed that at PF, ebullition contributed only 4% of the total emission, whereas it accounted for 32% and 60% of the total emission at BT and HD, respectively. In contrast, the plant-mediated flux variation among growth stages was smaller. Both ebullition and plant-mediated emissions correlated significantly with air temperature at HD, but the magnitude of the dependency was much higher for ebullition than for rice-mediated emission. These results demonstrate that ebullition occurs more frequently than has previously been thought, and the different transport pathways show varying degrees of dependency on plant phenological and environmental factors, thus underscoring the need to separately determine CH4 emissions via each transport pathway.

Integrated nutrient management - promising way to reduce carbon dioxide and methane emission in flooded rice ecosystem: A review

Climate change is an inevitable ruling issue caused by the increasing concentration of greenhouse gases (GHG’s) in the atmosphere worldwide. It will have a considerable impact on agriculture and its related fields like live stocks and fisheries. In India, the main sectors contributing to these emissions are industry, agriculture and waste, with a total emission of 334 MT CO2 eq. Besides, the major sources in agriculture are enteric fermentation (63.4%), rice cultivation (20.9%), agricultural soils (13.0%), manure management (2.4%) and on-field burning is the crop residue (2.0%). Thus, the crop productivity sector (rice cultivation, soil and field burning of crop residues) contributes 35.9% to the total emission from agriculture. Therefore, reducing GHG emissions and enhancing the C sequestration in soil and biomass has become challenging. However, the total GHG’s emission from all sectors of the country has decreased from 33% in 1970 to 18% in 2010. Cutting off GHGs emission from agriculture can be achieved by sequestering C and reducing methane emissions(CH4) and carbon dioxide(CO2) through various soil and crop management strategies. Integrated nutrient management (INM) practice ensures the Soil –plant –atmospheric continuum (SPAC) in a promising way, reducing the GHGs emission by sequestering more carbon to soil than emissions. A studious prominent INM solution can be identified to develop a mitigation strategy that helps in climate change adaptation and sustains soil health through soil carbon sequestration.

Performance evaluation of two pot raised mud improved cookstove

Biomass cookstove is widely used in the rural areas of Nepal for cooking and space heating. Its thermal and emission performance keeps importance environmentally, economically and socially. Chimney operated two pot raised mud Improved Cookstove (ICS) is one of Nepal’s most promoted cookstoves. The goal of this study is to evaluate the thermal and emission performance. Thermal and emission performance has been obtained by water boiling test and emission parameters have been measured by using Laboratory Emissions Monitoring System (LEMS). The thermal efficiency of cookstove has been improved from 17.99% to 24.7 % i.e. Tier 1 to 2 with the fabrication of appropriate material and accessories. Similarly total emission performance has been found in Tier 1 and fugitive emission performance has been found in Tier 5. Experimental results of thermal efficiency and fugitive emission complied with the performance target of the cookstove.