Improved 11α-hydroxycanrenone production by modification of cytochrome P450 monooxygenase gene in Aspergillus ochraceus

Eplerenone is a drug that protects the cardiovascular system. 11α-Hydroxycanrenone is a key intermediate in eplerenone synthesis. We found that although the cytochrome P450 (CYP) enzyme system in Aspergillus ochraceus strain MF018 could catalyse the conversion of canrenone to 11α-hydroxycanrenone, its biocatalytic efficiency is low. To improve the efficiency of 11α-hydroxycanrenone production, the CYP monooxygenase-coding gene of MF018 was predicted and cloned based on whole-genome sequencing results. A recombinant A. ochraceus strain MF010 with the high expression of CYP monooxygenase was then obtained through homologous recombination. The biocatalytic rate of this recombinant strain reached 93 % at 60 h without the addition of organic solvents or surfactants and was 17–18 % higher than that of the MF018 strain. Moreover, the biocatalytic time of the MF010 strain was reduced by more than 30 h compared with that of the MF018 strain. These results show that the recombinant A. ochraceus strain MF010 can overcome the limitation of substrate biocatalytic efficiency and thus holds a high potential for application in the industrial production of eplerenone

Assessing the reproducibility and validity of a food frequency questionnaire for pregnant women from the Chinese Miao ethnic group

BackgroundCurrently, no food frequency questionnaire is available to be administered exclusively to ethnic minorities in China. This study aimed to evaluate the reproducibility and validity of a culturally tailored semi-quantitative food frequency questionnaire (FFQ) designed for pregnant women belonging to the Miao ethnic group in China.MethodsA total of 74 questions in the FFQ were administered to collect dietary information from Miao women in China during their pregnancy. This study included 153 and 127 pregnant women, respectively, for testing the validity and reproducibility of the results. Baseline FFQ data (FFQ1) were collected initially, followed by the administration of a repeated FFQ 4–6 weeks later (FFQ2). Two 24-h recalls (24HR) were used as references to compare food groups and nutrient intake. Pearson/Spearman's coefficients were used to measure the validity and reproducibility of the FFQ. Quartile cross-classification, weighted kappa coefficients, and Bland–Altman plots were employed to assess the agreement.ResultsMost food groups and nutrient intake estimated by the FFQ were higher than those estimated by the 24HR. Food groups and nutrients' correlations for FFQ vs. 24HR after being energy-adjusted and de-attenuated, respectively, were 0.10 (vegetables) to 0.45 (grains/tubers) and 0.15 (iron) to 0.52 (riboflavin). Comparatively, correlation coefficients for FFQ1 vs. FFQ2 ranged from 0.41 (fruit) to 0.71 (vegetables) and from 0.45 (energy) to 0.64 (calcium). The percentage of pregnant women classified in the same or adjacent quartiles ranged from 64.08% (vegetables) to 95.29% (sour soup) and from 68.88% (vitamin E) to 78.81% (energy). Weighted kappa coefficients exceeded 0.2 for food groups and most nutrients, and Bland–Altman plots demonstrated acceptable agreement between the two tools.ConclusionsThis study provides novel information on the validation of FFQ. It demonstrates that the FFQ exhibits ideal reproducibility and acceptable validity in estimating and ranking the intake of food groups and most nutrients among pregnant women belonging to the Chinese Miao ethnic group

Effects of aroma quality on the biotransformation of natural 2-phenylethanol produced using ascorbic acid

Background: Natural 2-phenylethanol (2-PE) is an important flavoring that emits the aroma of roses. During biotransformation, the aroma quality of natural 2-PE is affected by its main by-products, which include butanol, isobutyric acid, butyric acid, and isovaleric acid. Thus, controlling undesirable by-product formation can reduce the effect of odor on 2-PE aroma quality. Results: 2-PE was produced through biotransformation using L-phenylalanine as a substrate and glucose as a carbon source. Ascorbic acid was added to the system to improve the redox reaction and suppress the generation of by-products. Principal component analysis of the aroma quality of 2-PE was performed using an electronic nose. Similarity analysis revealed that the effects of four by-products on 2-PE aroma quality may be ranked in the following order: isovaleric acid < butyric acid < isobutyric acid < butanol. The sample that exhibited the best similarity to the standard 2-PE sample (99.19%) was the sample to which ascorbic acid had been added during glucose metabolism. Conclusions: 2-PE produced through the addition of ascorbic acid exhibited the closest aroma similarity to the standard 2-PE sample

The Reform of China's Energy Policies

China's shift in energy policies has been broader, deeper and more successful than that of most other emerging economies, although the economic costs of this transition are tremendous because China is an over-industrialized country whose production is highly energy-intense and it depends on emission-intensive coal as main energy source. Factors that have influenced energy reforms, which focus on saving and conserving energy, developing renewable sources and nuclear power, are - on the international level - the impact of climate change on India, the desire to be recognized as a responsible power in the international community, China's dangerously growing dependence on energy imports, and the uncertain prospects of equity oil abroad for energy security. Domestic factors are the growing assertiveness of environmental NGOs, relatively effective sectorial governance, and the embedding of energy policies in a blueprint for industrial upgrading

Generation of flavors and fragrances through biotransformation and de novo synthesis

Flavors and fragrances are the result of the presence of volatile and non-volatile compounds, appreciated mostly by the sense of smell once they usually have pleasant odors. They are used in perfumes and perfumed products, as well as for the flavoring of foods and beverages. In fact the ability of the microorganisms to produce flavors and fragrances has been described for a long time, but the relationship between the flavor formation and the microbial growth was only recently established. After that, efforts have been put in the analysis and optimization of food fermentations that led to the investigation of microorganisms and their capacity to produce flavors and fragrances, either by de novo synthesis or biotransformation. In this review, we aim to resume the recent achievements in the production of the most relevant flavors by bioconversion/biotransformation or de novo synthesis, its market value, prominent strains used, and their production rates/maximum concentrations.We would like to thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, COMPETE 2020 (POCI-01-0145FEDER-006684), and BiotecNorte operation (NORTE-01-0145FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Synthesis of Ethylene/1-Octene Copolymers with Ultrahigh Molecular Weights by Zr and Hf Complexes Bearing Bidentate NN Ligands with the Camphyl Linker

Ultrahigh molecular weight polyethylene (UHMWPE) is a class of high-performance engineering plastics, exhibiting a unique set of properties and applications. Although many advances have been achieved in recent years, the synthesis of UHMWPE is still a great challenge. In this contribution, a series of zirconium and hafnium complexes, [2,6-(R1)2-4-R2-C6H2-N-C(camphyl)=C(camphyl)-N-2,6-(R1)2-4-R2-C6H2]MMe2(THF) (1-Zr: R1 = Me, R2 = H, M = Zr; 2-Zr: R1 = Me, R2 = Me, M = Zr; 1-Hf: R1 = Me, R2 = H, M = Hf; 2-Hf: R1 = Me, R2 = Me, M = Hf), bearing bidentate NN ligands with the bulky camphyl backbone were synthesized by the stoichiometric reactions of α-diimine ligands with MMe4 (M = Hf or Zr). All Zr and Hf metal complexes were analyzed using 1H and 13C NMR spectroscopy, and the molecular structures of complexes 1-Zr and 1-Hf were determined by single-crystal X-ray diffraction, revealing that the original α-diimine ligand was selectively reduced into the ene-diamido form and generated an 1,3-diaza-2-metallocyclopentene ring in the metal complexes. Zr complexes 1-Zr and 2-Zr showed moderate activity (up to 388 kg(PE)·mol−1(M)·h−1), poor copolymerization ability, but unprecedented molecular weight capability toward ethylene/1-octene copolymerization. Therefore, copolymers with ultrahigh molecular weights (>600 or 337 × 104 g∙mol−1) were successfully synthesized by 1-Zr or 2-Zr, respectively, with the borate cocatalyst [Ph3C][B(C6F5)4]. Surprisingly, Hf complexes 1-Hf and 2-Hf showed negligible activity under otherwise identical conditions, revealing the great influence of metal centers on catalytic performances

Biotransformation and Production from Hansenula Anomala to Natural Ethyl Phenylacetate

Ethyl phenylacetate can be widely applied in many industries, such as food, medicines, cosmetics and medicinal herbs. At the moment, the production of natural ethyl phenylacetate is very limited. However, the biotransformation production of natural ethyl phenylacetate has an very extensive application prospect. This paper is written by taking the phenylacetic acid tolerance and the esterifying enzyme activity as the two indexes for screening the HA14 strain of hansenula anomala mutagenic which is regarded as the microorganism of ethyl phenylacetate production through biotransformation. By optimizing the production condition of phenylacetic acid and the esterification condition of ethyl phenylacetate, the production of ethyl phenylacetate accomplished through biotransformation within 72 hours can reach 864mg/L which is 171% of that of the initial bacterial strain

Biotransformation and Production from

Ethyl phenylacetate can be widely applied in many industries, such as food, medicines, cosmetics and medicinal herbs. At the moment, the production of natural ethyl phenylacetate is very limited. However, the biotransformation production of natural ethyl phenylacetate has an very extensive application prospect. This paper is written by taking the phenylacetic acid tolerance and the esterifying enzyme activity as the two indexes for screening the HA14 strain of hansenula anomala mutagenic which is regarded as the microorganism of ethyl phenylacetate production through biotransformation. By optimizing the production condition of phenylacetic acid and the esterification condition of ethyl phenylacetate, the production of ethyl phenylacetate accomplished through biotransformation within 72 hours can reach 864mg/L which is 171% of that of the initial bacterial strain