Mechanisms of inactivation of lipoxygenases by phenidone and BW755C.

Inhibition of soybean lipoxygenase (L-1) and potato 5-lipoxygenase (5-PLO) by the pyrazoline derivatives phenidone and BW755C only occurs after oxidation of these compounds by the peroxidase-like activity of the lipoxygenases. There is a clear relationship between this oxidation and the irreversible inactivation of L-1. The final product of phenidone oxidation by L-1, 4,5-didehydrophenidone, is not responsible of this inactivation, but the species derived from a one-electron oxidation of phenidone plays a key role in L-1 inactivation. In the absence of O2, inactivation of 1 mol of L-1 occurs after the oxidation of 34 mol of phenidone and the covalent binding of 0.8 mol of phenidone-derived metabolite(s) to L-1. In the presence of O2, inactivation of 1 mol of L-1 occurs already after oxidation of 11 mol of phenidone and only involves the covalent binding of 0.4 mol of phenidone-derived metabolite(s) to L-1. A mechanism is proposed for L-1 inactivation by phenidone, which involves the irreversible binding of a phenidone metabolite to the protein and the oxidation of an L-1 amino acid residue (in the presence of O2).     

Spatiotemporal Clusters and Trends of Pneumocystis Pneumonia in Korea

This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Joinpoint were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60–69 age group had the highest annual percentage change (APC 41.8) during 2014–2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60–69 age group had the most decrease (APC −17.6) during 2018–2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.     

Transgenic radish (Raphanus sativus L. longipinnatus Bailey) by floral-dip method – plant development and surfactant are important in optimizing transformation efficiency

Transgenic radish (Raphanus sativus L. longipinnatus Bailey) plants were produced from the progeny of plants which were dipped into a suspension of Agrobacterium carrying both the -glucuronidase (gusA) gene and a gene for resistance to the herbicide Basta (bar) between T-DNA border sequences. The importance of development of the floral-dipped plant and presence of surfactant in the inoculation medium were evaluated in terms of transgenic plant production. Plants dipped at the primary bolt stage of growth, into a suspension of Agrobacterium containing 0.05% (v/v) Silwet L-77 resulted in optimum transformation efficiency, with 1.4% from 1110 seeds. The presence of Pluronic F-68 or Tween 20 in the inoculation medium was beneficial towards transgenic plant output compared to treatments without surfactant. Putative transformed T1 plants were efficiently selected by spraying with 0.03% (v/v) Basta and all herbicide-resistant plants tested positive for GUS activity when analysed both histochemically and fluorometrically. Southern analysis revealed that both the gusA and bar genes integrated into the genome of transformed plants and segregated as dominant Mendelian traits. These results demonstrate that radish can be genetically modified for the improvement of this important vegetable crop.     

Flavin containing monooxygenase 3 exerts broad effects on glucose and lipid metabolism and atherosclerosis

We performed silencing and overexpression studies of flavin containing monooxygenase (FMO) 3 in hyperlipidemic mouse models to examine its effects on trimethylamine N-oxide (TMAO) levels and atherosclerosis. Knockdown of hepatic FMO3 in LDL receptor knockout mice using an antisense oligonucleotide resulted in decreased circulating TMAO levels and atherosclerosis. Surprisingly, we also observed significant decreases in hepatic lipids and in levels of plasma lipids, ketone bodies, glucose, and insulin. FMO3 overexpression in transgenic mice, on the other hand, increased hepatic and plasma lipids. Global gene expression analyses suggested that these effects of FMO3 on lipogenesis and gluconeogenesis may be mediated through the PPARα and Kruppel-like factor 15 pathways. In vivo and in vitro results were consistent with the concept that the effects were mediated directly by FMO3 rather than trimethylamine/TMAO; in particular, overexpression of FMO3 in the human hepatoma cell line, Hep3B, resulted in significantly increased glucose secretion and lipogenesis. Our results indicate a major role for FMO3 in modulating glucose and lipid homeostasis in vivo, and they suggest that pharmacologic inhibition of FMO3 to reduce TMAO levels would be confounded by metabolic interactions.     

Simulation of sequential batch reactor (SBR) operation for simultaneous removal of nitrogen and phosphorus

Modeling of the operation of sequential batch reactor (SBR) was performed to find out optimum design parameters for simultaneous removal of nitrogen and phosphorus in a small-scale wastewater treatment plant. The models were set up with material balances on SBR operation and Monod kinetics. The model parameters were obtained to best fit the experimental results in a small scale SBR. The models were useful in optimizing hydraulic retention time (HRT) and successfully simulated operations of SBR in a larger scale. Especially the model predicted well the reactions occurring in the filling period as well as the effect of dilution, and evaluated the performance of SBR process under diverse operating conditions.     

Genome sequencing of Bacillus subtilis SC-8, antagonistic to the Bacillus cereus group, isolated from traditional Korean fermented-soybean food

Bacillus subtilis SC-8 is a Gram-positive bacterium displaying narrow antagonistic activity for the Bacillus cereus group. B. subtilis SC-8 was isolated from Korean traditional fermented-soybean food. Here we report the draft genome sequence of B. subtilis SC-8, including biosynthetic genes for antibiotics that may have beneficial effects for control of food-borne pathogens.     

Enhanced spore production ofBacillus thuringiensis by fed-batch culture

Summary Fed-batch culture was carried out to increase cell mass followed by batch culture for spore production ofbacillus thuringiensis. High cell mass obtained by increasing the feeding glucose concentration in constant fed-batch culture which supported fast cell growth resulted in good sporulation during subsequent batch culture, and the maximum cell mass of 72.6 g/L and spore concentration of 1.25×10¹⁰ spores/mL could be obtained.