Zeaxanthin, a vital carotenoid, is synthesized through a series of enzymatic reactions, with β-carotene hydroxylase serving as a key rate-limiting enzyme facilitating the conversion of β-carotene to zeaxanthin. This study aimed to investigate the feasibility of cloning and transferring the β-carotene hydroxylase gene (LpcrtR) from Limnospira platensis into Escherichia coli for the efficient production of zeaxanthin. Firstly, the LpcrtR gene was successfully extracted from the L. platensis genome, which contains 906 base pairs and encodes 301 amino acids. Through comparison, it was found that the LpCRTR protein shares high amino acid sequence homology with β-carotene hydroxylases from different species and possesses the "HXXXXH" and "HXXHH" motif structures. After constructing the gene expression vector pGEX-6p-1-LpcrtR, the recombinant plasmid was transformed into E. coli. The results of SDS-PAGE and Western blotting validated the expression of the LpcrtR protein (LpCRTR) in the bacterial system. Additionally, HPLC results revealed that LpCRTR can partially catalyze the conversion of β-carotene to zeaxanthin within E. coli. Notably, the zeaxanthin and β-carotene yield in recombinant E. coli were 81.7 ± 0.4

Diospyros lotus L., which belongs to the Ebenaceae family, is used in folk medicine for treating anemia, fatigue, insomnia, and hepatitis. In the present study, supercritical CO2 fluid extraction (SFE) was used to extract Diospyros lotus L. essential oil, and its antioxidant, antimicrobial, and cytotoxic activities were investigated. The chemical composition of the essential oil was investigated using GC/MS. The antioxidant capacity was evaluated via 1,1diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and hydroxyl radical scavenging. The minimum inhibitory concentration (MIC) using the broth microdilution method was applied to investigate antimicrobial activities. The cytotoxic activity of the essential oil was measured using a standard 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide (MTT) assay. The GC-MS analysis showed that Diospyros lotus L essential oil contained 25 components, mainly including 5-hydroxymethylfurfural (50.90%), 2-methylhexadecan-1-ol (19.97%), 2-cis-9-octadecenyloxyethanol (5.46%), dibutyl phthalate (4.84%), and n-hexadecanoic acid (4.20%). The IC50 values of the essential oil in the DPPH assay and hydroxyl radical scavenging activity were 46.46 +/- 1.70 mu g/mL and 0.551 +/- 0.0267 mg/mL, respectively. Furthermore, at concentrations below 50 mu g/mL, the evaluation of cell viability showed no cytotoxicity in the human embryonic kidney cell line 293T. The results show that Diospyros lotus L. essential oil has antimicrobial and antioxidant effects, and has no toxicity on 293T cells at low concentrations, indicating potential health benefits.

This study aimed to explore an effective, simple, and time-saving method for astaxanthin accumulation. Wild-type Saccharomyces cerevisiae as a bioreactor, the SpcrtR gene was first ligated with the signal peptide S to construct pYES2/NT-A-S-SpcrtR plasmid in Saccharomyces cerevisiae. The detection of SDS-PAGE and Western blotting protein proved that SpCRTR was successfully extracellular expressed in Saccharomyces cerevisiae. The target product astaxanthin was produced by co-fermentation of Spirulina platensis and recombinant Saccharomyces cerevisiae. The test results showed that after 18 h of fermentation, the astaxanthin concentration was highest in the mixed fermentation broth with 4% Spirulina platensis and recombinant Saccharomyces cerevisiae, and the content of astaxanthin was 0.25 ± 0.02 μg/mL. In addition, the source of astaxanthin was explored. During the fermentation process of the Saccharomyces cerevisiae strain, SpCRTR enzyme catalyzed the Spirulina platensis canthaxanthin, which almost completely converted into astaxanthin, providing a simple method for astaxanthin synthesis. Compared with culture of Haematococcus pluvialis, this culture route not only shortens culture time, but also eliminates the limitation of the conditions in the culture process.

Spirulina platensis protein hydrolysates were prepared by digesting protein extracts with papain, and the hydrolysates were separated into 30, 10, and 3 kDa weights using membrane ultrafiltration. The 0–3 kDa low-molecular-weight Spirulina peptides (LMWSPs) proved the highest chemical antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, hydroxyl radical (·OH) scavenging activities and total antioxidant capacity. Cellular antioxidant ability of LMWPs fractions against 2000 μg/mL H 2 O 2 induced oxidative damage of L02 cells were investigated. The MTT assay results displayed that LMWSPs at different concentrations (0–1000 μg/mL) had proliferation effect on the L02 cells and that treatment of the L02 cells with the 1000 μg/mL LMWSPs (0–3 kDa) significantly prevented H 2 O 2 -induced oxidative damage compared with control cells. Moreover, the 2′,7′-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe assay showed that the levels of ROS and NO were significantly lower in the experimental group that was treated with the peptides for 24 h than in the control group. Furthermore, using the corresponding kits, the treatment inhibited the reduction of SOD activity and the increase of MDA contents in the L02 cells. Therefore, LMWSPs (0–3 kDa) may have potential applications in antioxidant and liver health products.

This study aimed to investigate the protective effects of astaxanthin produced co-fermented by Spirulina platensis and Saccharomyces cerevisiae on H2O2 induced damages in mouse macrophage RAW 264.7 through cell viability, oxidative stresses and mRNA expression of apoptosis factors. The results showed that 40 mu M of astaxanthin increased the cell viability of damaged cells by 45.8% and decreased the ROS fluorescence intensity by 60.57%, almost returning to the level before oxidative damage. Simultaneously, astaxanthin at this concentration could also restore SOD activity and reduce its MDA activity by 61.78%, indicating that astaxanthin had a certain antioxidant effect on oxidatively damaged cells. Microscopic observation of the morphology of damaged cells and detection of apoptotic factors revealed that expression of cell morphology and apoptotic factor mRNA gradually recovered as the astaxanthin concentration increased. It was further confirmed that damaged cells treatment with astaxanthin inhibited cell apoptosis to achieve the goal of cell protection. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

从“盲评式党课”的基本概念入手,介绍了“盲评式党课”开展的背景及意义,并对开展“盲评式党课”应该注意的问题进行了阐述.“盲评式党课”将党课与教育教学活动紧密结合,党课聚焦教育大课题,却又超越了一般说教形式.参与党课的党员采用情景剧、雨课堂、朗读等形式,再现了日常生活和教学科研等活动中的真实案例,通过正确的点评,达到参与者受教育、受启发的目的,最大限度地发挥党课的教育及引领作用.

Diospyros lotus, a member of the Ebenaceae family, has long been used as a traditional sedative in China. In this study, the antioxidant and hypoglycemic effects of non-fermented and microorganism-fermented D. lotus were explored. The total phenolic and vitamin C contents of microorganism-fermented D. lotus for 24-72 h were less than those of non-fermented. High-performance liquid chromatography showed that the tannic, catechinic, and ellagic acid contents increased significantly upon fermentation for 24 h. D. lotus fermented with Microbacterium flavum for 24 h exhibited the highest DPPH radical scavenging activity (IC50 = 4.18 μg mL-1), and the highest ABTS radical scavenging activity was exhibited at 72 h of fermentation (IC50 = 29.18 μg mL-1). The anti-α-glucosidase activity of fermented D. lotus was higher (2.06-4.73-fold) than that of non-fermented one. Thus, fermented D. lotus is a useful source of natural antioxidants, and a valuable food, exhibiting antioxidant and hypoglycemic properties.

Elsholtzia ciliate is mainly used in folk medicine for the treatment of cold, fever, dysentery and digestion disorder. The aim of our study is to investigate the composition of supercritical fluid extract of Elsholtzia ciliate and to study its antimicrobial and antioxidant activity. In our research, the extract of Elsholtzia ciliate was extracted using the CO2 supercritical fluid extraction (SFE) and then its chemical constituents were analyzed by gas chromatography-mass spectrometry (GC-MS). Seventeen components were identified by GC-MS analysis which mainly include elsholtzia ketone (9.16 %), 9,12,15-octadecatrienoic acidethyl ester (13.74 %), 9,12-octadecadienoic acid (13.59 %), tetratriacontane (11.25 %), and octacosane (9.49 %). A good antibacterial effect of the extract has been proved by an experiment performed in an antibacterial assay with minimum inhibitory concentration (MIC) values and inhibition zone. Moreover, the extract showed low levels of antioxidant capacity in the DPPH assay, as well as slight inhibitory activity in a beta-carotene bleaching assay. The results of this research show that the extracts of Elsholtzia ciliata might be a natural potential source of food preservatives and antioxidants.

大学生党员的培养质量关系着国家的未来、民族的希望.做好大学生党员理论教育的同时,加强实践教育是当前高校党建工作者努力思考的问题.通过“红色理念辅导员工作室”开展的“建党员责任区、创党员先锋岗”活动,对大学生党员实践教育途径进行了有效的探索,提出了活动实施的4项基本原则,即强化全员参与原则、突出实践特色原则、加强分类指导原则、考核奖惩结合原则,以及3项要求,即“干部带头,做出表率”“探索创新,务求实施”“善于总结,形成机制”.分析了活动取得的效果、存在的问题,进一步提出了改进建议.

To assess the effect of corn peptides (CPs) as an antioxidant on ethanol (EtOH)-induced oxidative stress in HepG2 cells, the cells were preincubated with CPs for 4h before treated with EtOH. Methyl thiazolyl tetrazolium and flow cytometry assay were performed to detect the viability of CP-treated HepG2 cells and control cells. The activities of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by corresponding kits, respectively. The results showed that treatment with 300mmol/L EtOH for 24h resulted in a death of around 50% of the HepG2 cells. Pretreatments of appropriate concentrations of CPs (more than 5mg/mL, particularly at 20mg/mL) significantly prevented EtOH-induced cytotoxicity and reduced the increase of ALT, AST, LDH and MDA contents, as well as inhibited the reduction of SOD contents in the HepG2 cells, indicating that CPs protected the cells from oxidative damage induced by EtOH metabolism, and thus had a great application potential in hepatoprotective nutraceuticals.

<正>高校思想政治教育工作实施的难点在于如何使思想政治教育深入人心,使受教育者知行合一,这在价值取向多元化的社会大背景下显得尤为突出。深度辅导作为一种最基本也是最重要的大学生思想政治教育方式,成为高校学生和辅导员之间深度交流的新型互动模式,成为大学生思想政治教育一线工作者和学者共同不懈探索的重点。开展学生深度辅导,将思想政治教育工作层次化,针对不同阶段的大学生开展相适应的教育内容,将思想政治教育工作目标落到实处,是引导

<正>随着社会的快速变迁以及社会改革进程的加快,人们的日常生活观念、生活态度以及生活模式等都发生了深刻的改变。当代大学生是改革开放的完全受益者和信息时代的完全体验者,也是伴随着社会主义市场经济体制成长起来的一代。市场化、信息化和全球化等时代大背景使得当代大学生的消费观念、消费行为、消费结构等引起了社会的普遍关注,这从另一个侧面反应了现下大学生的生活状况。因此,如何解读消费生活所呈现出来的新特征,是我们认识首都大学