Biochemical characterization of glyceraldehyde-3-phosphate dehydrogenase from Thermococcus kodakarensis KOD1.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an essential role in glycolysis by catalyzing the conversion of D-glyceraldehyde 3-phosphate (D-G3P) to 1,3-diphosphoglycerate using NAD(+) as a cofactor. In this report, the GAPDH gene from the hyperthermophilic archaeon Thermococcus kodakarensis KOD1 (GAPDH-tk) was cloned and the protein was purified to homogeneity. GAPDH-tk exists as a homotetramer with a native molecular mass of 145 kDa; the subunit molecular mass was 37 kDa. GAPDH-tk is a thermostable protein with a half-life of 5 h at 80-90°C. The apparent K (m) values for NAD(+) and D-G3P were 77.8 ± 7.5 µM and 49.3 ± 3.0 µM, respectively, with V (max) values of 45.1 ± 0.8 U/mg and 59.6 ± 1.3 U/mg, respectively. Transmission electron microscopy (TEM) and image processing confirmed that GAPDH-tk has a tetrameric structure. Interestingly, GAPDH-tk migrates as high molecular mass forms (~232 kDa and ~669 kDa) in response to oxidative stress.

Renewable energy from biomass surplus resource: potential of power generation from rice straw in Vietnam.

Biomass, one of the renewable resources, is expected to play an important role in the world's energy future. In Asia, rice straw is an abundant agricultural surplus because rice is one of the leading staple food crops in the region. Often, rice straw is burned directly in the field via uncontrolled combustion methods that emit large amounts of short-lived air pollutants, greenhouse gases, and other pollutants. In Vietnam, the energy and environment protection sectors are facing great challenges because of rapid urbanisation and industrialisation. A national strategic choice is to exploit renewable energy, including biomass-derived energy, to achieve energy security and CO2 emission reduction. This study investigates the potential of rice straw as an energy source for power plants at a local scale in Vietnam using data derived from satellite Sentinel-1 images. The results show that Vietnam can produce 2,565 MW from rice straw, for which 24 out of 63 provinces have a potential capacity higher than 30 MW, and the Kien Giang province has the highest capacity (245 MW). The study also analyses limitations and obstacles overcoming which can promote the biomass energy sector in the country.

Emission inventories of rice straw open burning in the Red River Delta of Vietnam: Evaluation of the potential of satellite data.

Although rice straw open burning is one of the main sources of air pollution in Asian countries, problems remain in collecting the activity data needed to calculate emission inventories. In Vietnam, the results from traditional data collection methods, which are reported by the Vietnam General Statistics Office high levels of uncertainty. This is largely due to a lack of human and financial resources. To improve upon this, this study critically assessed the benefits of incorporating cultivation area data obtained by the Sentinel-1 Synthetic Aperture Radar (SAR) satellite in combination with crop production records during the period of 2015-2017. The results suggested that incorporating remote sensing data, especially satellite data, into a process-based crop model can improve the spatial distribution of yield estimates. Satellite data for 2018 were also applied to estimate emissions from rice straw open burning in the Red River Delta, Vietnam, for which official statistics are not otherwise yet available. The results show that a total of 3.24 Mt of burnt rice straw produced 3.82 Mt of CO2, 301 Gg of CO, 29.5 Gg of PM10, and 27 Gg of PM2.5. The estimated emission amounts for the common air pollutants SO2, NOx, and NH3 were 583 tonnes, 7.4 Gg, and 13.3 Gg, respectively. Hydrocarbon emissions were 31 Gg for CH4 and 22.7 Gg for NMVOC. The emission of BC, which is one of the main short-lived climate forcers, totalled 1.6 Gg. Based on these results, satellite data demonstrate great potential for estimating emissions from rice croplands, having the advantages of timely availability and cost competitiveness.