Undesirable flavor caused by excessive higher alcohols restrains the development of the wheat beer industry. To clarify the regulation mechanism of the metabolism of higher alcohols in wheat beer ...brewing by the top-fermenting yeast
Saccharomyces cerevisiae
S17, the effect of temperature on the fermentation performance and transcriptional levels of relevant genes was investigated. The strain S17 produced 297.85 mg/L of higher alcohols at 20 °C, and the production did not increase at 25 °C, reaching about 297.43 mg/L. Metabolite analysis and transcriptome sequencing showed that the metabolic pathways of branched-chain amino acids, pyruvate, phenylalanine, and proline were the decisive factors that affected the formation of higher alcohols. Fourteen most promising genes were selected to evaluate the effects of single-gene deletions on the synthesis of higher alcohols. The total production of higher alcohols by the mutants Δ
tir1
and Δ
gap1
was reduced by 23.5 and 19.66% compared with the parent strain S17, respectively. The results confirmed that
TIR1
and
GAP1
are crucial regulatory genes in the metabolism of higher alcohols in the top-fermenting yeast. This study provides valuable knowledge on the metabolic pathways of higher alcohols and new strategies for reducing the amounts of higher alcohols in wheat beer.
In this paper, plasma silver (Ag) modified zinc oxide (ZnO) (AZO) was used to form AZO nanomaterials (including AZO nanofilms (NFm), AZO nanowires (NWs) and AZO nanoflowers (NFw)) in a ...two-step-controlled manner to investigate the effect of compounding different contents of Ag on the linear optical aspects of ZnO materials. The growth mechanism of the AZO nanomaterials with different strategies is discussed. If Ag nanoparticles (NPs) grow on the ZnO NFm surface, they first grow with ZnO as the core and then self-core into islands, which are undoubtedly influenced by factors such as the growth mechanism of ZnO as well as Ag. If Ag is grown on the surface of the ZnO NWs and ZnO NFw, it is more likely to self-core owing to factors such as the roughness of the ZnO NWs and ZnO NFw surfaces. The AZO nanomaterials have excellent optical properties based on the surface plasmon resonance, local electromagnetic field and charge transfer mechanism between Ag and ZnO. With the increase in Ag content, the absorption edges of AZO NFm are red-shifted, and the absorption edges of AZO NWs and AZO NFw are first blue-shifted and then red-shifted. The results show that AZO nanomaterials prepared using different methods not only have different growth morphologies, but also have different optical properties with potential for the preparation of optical devices.
The plasmonic AZO nanomaterials in a two-step-controlled manner to investigate the effect of compounding different contents of Ag on the linear optical aspects of ZnO materials.
Cold stress poses a serious threat to the survival and bloom of
. The enhancement of the cold tolerance of
is the central concern of our research. The WRKY transcription factor (TF) family was paid ...great attention to in the field of abiotic stress. The
gene was obtained from
. The
predicted protein contained two typical WRKY domains and two C2H2 zinc-finger motifs. Under cold stress,
in leaves was more greatly induced than that in stems and roots. The overexpression (OE) in
increased cold tolerance compared with wild-type (WT). Under cold stress, the OE lines possessed showed greater recovery after cold-treatment restoration ratios, proline content, soluble sugar content, and activities of antioxidant enzymes than WT; the relative electrolyte conductivity (EL), the accumulation of malondialdehyde (MDA), hydrogen peroxide (H
O
), and superoxide anion (O
) are lower in OE lines than that in WT. In addition, a series of cold-response genes of OE lines were compared with WT. The results revealed that
worked as a positive regulator by up-regulating transcription levels of cold-responsive genes. The genes above can contribute to the elevation of antioxidant activities, maintain the membrane stability, and raise osmotic regulation ability, leading to the enhancement of the survival capacity under cold stress. According to this work,
could serve as an essential gene to confer enhanced cold tolerance in plants.
Propylea japonica (Coleoptera: Coccinellidae) is a natural enemy insect with a wide range of predation in Chinese mainland and is commonly used in pest management. However, its genetic pattern (i.e., ...genetic variation, genetic structure, and historical population dynamics) is still unclear, impeding the development of biological control of insect pests. Population genetic research has the potential to optimize strategies at different stages of the biological control processes. This study used 23 nuclear microsatellite sites and mitochondrial COI genes to investigate the population genetics of Propylea japonica based on 462 specimens collected from 30 sampling sites in China. The microsatellite dataset showed a moderate level of genetic diversity, but the mitochondrial genes showed a high level of genetic diversity. Populations from the Yellow River basin were more genetically diverse than those in the Yangtze River basin. Propylea japonica has not yet formed a significant genealogical structure in China, but there was a population structure signal to some extent, which may be caused by frequent gene flow between populations. The species has experienced population expansion after a bottleneck, potentially thanks to the tri-trophic plant-insect-natural enemy relationship. Knowledge of population genetics is of importance in using predators to control pests. Our study complements existing knowledge of an important natural predator in agroecosystems through estimating its genetic diversity and population differentiation and speculating about historical dynamics.
A series of novel pyrazole carboxamide and niacinamide derivatives containing a benzimidazole moiety were designed and synthesized as antifungal candidate agents. All target compounds were ...characterized by FTIR, 1 H NMR, 13 C NMR, HRMS and elemental analysis techniques. The structure of compound T1 was further confirmed by single crystal X-ray diffraction analysis. The antifungal activities of the target compounds were evaluated in vitro against four phytopathogenic fungi (namely Botrytis cinerea , Rhizoctonia solani , Fusarium graminearum and Alternaria solani ) by the mycelium growth inhibition method. The bioassay results indicated that some of the compounds exhibited good antifungal activity against B. cinerea at 100 μg ML −1 compared to other three fungi. In order to better explore the structure–activity relationship (SAR), the EC 50 values of target compounds against B. cinerea were measured and assessed. Subsequently, a 3D quantitative structure–activity relationship (3D-QSAR) study was carried out using the comparative molecular field analysis (CoMFA) technique based on the inhibitory activities of tested compounds against B. cinerea . Molecular modelling results revealed fine predictive ability with cross-validated q 2 and non-cross-validated r 2 values of 0.578 and 0.850, respectively.
Abstract
Wax deposition is an important factor that influences oil production for high-wax crude oilfield. There are few studies on the formation damage by wax deposition, especially cold damage to ...the shallow low-temperature reservoir. With laboratory tests conducted on reservoir oil and cores of Changchunling Oilfield, this study aims to experimentally investigate the influence of temperature variations on characteristics of oil–water percolation and cold damage mechanisms, as well as the relative permeability of high-wax reservoirs. Experimental results show that seepage flow of high-wax crude is significantly sensitive to temperature-wax deposition evidently increases, whereas the cold damage such as the pore-throat radius and relative permeability sharply decrease with the decline in formation temperature. The research results can be applied to enhance oil recovery of high-viscosity or high-wax oilfields.
Apoplastic iron (Fe) in roots represents an essential Fe storage pool. Reallocation of apoplastic Fe is of great importance to plants experiencing Fe deprivation, but how this reallocation process is ...regulated remains elusive, likely because of the highly complex cell wall structure and the limited knowledge about cell wall biosynthesis and modulation. Here, we present genetic and biochemical evidence to demonstrate that the Cdi-mediated galactosylation of rhamnogalacturonan-II (RG-II) is required for apoplastic Fe reallocation. Cdi is expressed in roots and up-regulated in response to Fe deficiency. It encodes a putative glycosyltransferase localized to the Golgi apparatus. Biochemical and mass spectrometry assays showed that Cdi catalyzes the transfer of GDP-L-galactose to the terminus of side chain A on RG-II. Disruption of Cdi essentially decreased RG-II dimerization and hence disrupted cell wall formation, as well as the reallocation of apoplastic Fe from roots to shoots. Further transcriptomic, Fourier transform infrared spectroscopy, and Fe desorption kinetic analyses coincidently suggested that Cdi mediates apoplastic Fe reallocation through extensive modulation of cell wall components and consequently the Fe adsorption capacity of the cell wall. Our study provides direct evidence demonstrating a link between cell wall biosynthesis and apoplastic Fe reallocation, thus indicating that the structure of the cell wall is important for efficient usage of the cell wall Fe pool.
Apoplastic Fe in roots is essential to plant iron nutrition. This study establishes a link between cell wall modification and apoplastic Fe reallocation through functional characterization of Cdi, and reveals that Cdi-mediated galactosylation of rhamnogalacturonan-II is critical for apoplastic Fe reallocation.
Display omitted
•SBSE in combination with GC–MS was applied in Longjing tea aroma analysis.•A total of 151 volatile compounds were identified and quantified.•Fourteen compounds were distinguished as ...the most important key aroma compounds.•Dimethyl sulfoxide was first recognized as a key aroma compound in Longjing tea.
Longjing tea is the most famous premium green tea, and is regarded as the national tea in China, with its attractive aroma contributing as a prime factor for its general acceptability; however, its key aroma compounds are essentially unknown. In the present study, volatile compounds from Longjing tea were extracted and examined using stir bar sorptive extraction (SBSE) combined with gas chromatography-mass spectrometry (GC–MS). Data obtained from the present study revealed that 151 volatile compounds from 16 different chemical classes were identified by GC–MS analysis. Enols (8096 µg/kg), alkanes (6744 µg/kg), aldehydes (6442 µg/kg), and esters (6161 µg/kg) were the four major chemical classes and accounted for 54% of the total content of volatile compounds. Geraniol (6736 µg/kg) was the most abundant volatile compound in Longjing tea, followed by hexanal (1876 µg/kg) and β-ionone (1837 µg/kg). Moreover, 14 volatile compounds were distinguished as the key aroma compounds of Longjing tea based on gas chromatography-olfactometry (GC-O) analysis, odor activity value (OAV) calculations, and a preliminary aroma recombination experiment, including 2-methyl butyraldehyde, dimethyl sulfoxide, heptanal, benzaldehyde, 1-octen-3-ol, (E, E)-2,4-heptadienal, benzeneacetaldehyde, linalool oxide I, (E, E)-3,5-octadien-2-one, linalool, nonanal, methyl salicylate, geraniol, and β-ionone. This is the first comprehensive report describing the aroma characterizations and the key aroma compounds in Longjing tea using SBSE/GC–MS. The findings from this study contribute to the scientific elucidation of the chemical basis for the aromatic qualities of Longjing tea.
Psychotic major depression (PMD) is a subtype of depression with a poor prognosis. Previous studies have failed to find many differences between patients with PMD and those with non-psychotic major ...depression (NMD) or schizophrenia (SZ). We compared sociodemographic factors (including season of conception) and clinical characteristics between patients with PMD, NMD, and schizophrenia. Our aim was to provide data to help inform clinical diagnoses and future etiology research.
This study used data of all patients admitted to Shandong Mental Health Center from June 1, 2016 to December 31, 2017. We analyzed cases who had experienced an episode of PMD (International Classification of Diseases, Tenth Revision codes F32.3, F33.3), NMD (F32.0-2/9, F33.0-2/9), and SZ (F20-20.9). Data on sex, main discharge diagnosis, date of birth, ethnicity, family history of psychiatric diseases, marital status, age at first onset, education, allergy history, and presence of trigger events were collected. Odds ratios (OR) were calculated using logistic regression analyses. Missing values were filled using the k-nearest neighbor method.
PMD patients were more likely to have a family history of psychiatric diseases in their first-, second-, and third-degree relatives (OR 1.701, 95% confidence interval CI 1.019-2.804) and to have obtained a higher level of education (OR 1.451, 95% CI 1.168-1.808) compared with depression patients without psychotic features. Compared to PMD patients, schizophrenia patients had lower education (OR 0.604, 95% CI 0.492-0.741), were more often divorced (OR 3.087, 95% CI 1.168-10.096), had a younger age of onset (OR 0.934, 95% CI 0.914-0.954), less likely to have a history of allergies (OR 0.604, 95% CI 0.492-0.741), and less likely to have experienced a trigger event 1 year before first onset (OR 0.420, 95% CI 0.267-0.661). Season of conception, ethnicity, and sex did not differ significantly between PMD and NMD or schizophrenia and PMD.
PMD patients have more similarities with NMD patients than SZ patients in terms of demographic and clinical characteristics. The differences found between PMD and SZ, and PMD and NMD correlated with specificity of the diseases. Furthermore, allergy history should be considered in future epidemiological studies of psychotic disorders.
A large amount of foam is generated in the production of microbial oil and exopolysaccharide (EPS) by Sporidiobolus pararoseus JD-2, which causes low efficiency in fermentation. In this study, we ...aimed to reduce the negative effects of foams on the co-production of oil and EPS by controlling the formation of foams in broth. As we have found, the formation of foams is positively associated with cell growth state, air entrapment, and properties of broth. The efficient foam-control method of adding 0.03% (v/v) of the emulsified polyoxyethylene polyoxypropylene pentaerythritol ether (PPE) and feeding corn steep liquor (CSL) at 8–24 h with speed of 0.02 L/h considerably improved the fermentation performance of S. pararoseus JD-2, and significantly increased the oil and EPS concentrations by 8.7% and 12.9%, respectively. The biomass, oil, and EPS concentrations were further increased using a foam backflow device combined with adding 0.03% (v/v) of the emulsified PPE and feeding CSL at 8–24 h, which reached to 62.3 ± 1.8 g/L, 31.2 ± 0.8 g/L, and 10.9 ± 0.4 g/L, respectively. The effective strategy for controlling the formation of foams in fermentation broth reported here could be used as a technical reference for producing frothing products in fed-batch fermentation.
PDF
