摘要：
A simple, selective, highly sensitive, and label-free electrochemical immunosensor for atrazine detection was developed by immobilizing gold nanoparticles (GNPs) on the gold electrode surface. The modified gold electrode exhibited good electrochemical activity. The high sensitive detection was achieved by increased the surface area of work electrode resulting in capturing more anti-atrazine monoclonal antibodies. The whole immunosensor fabrication process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with the use of ferricyanide as an electrochemical redox indicator, respectively. The signal was triggered based on the interaction between anti-atrazine monoclonal antibody and atrazine via differential pulse voltammetry (DPV). Under the optimal conditions, a limit of detection for atrazine as low as 0.016 ng/mL was obtained in buffer, and the linear working range was between 0.05 ng/mL and 0.5 ng/mL. The recovery of 95.5-119.8% was obtained in maize. The proposed immunosensor has acceptable stability and reproducibility, thus could be applied to other pesticides analysis of crop samples in practice. (C) 2013 Elsevier B.V. All rights reserved.
作者机构：
[Li, Ying; Liu, Xia; Lin, Zhao] College of Food Science and Technology, Hunan Agricultural University, Hunan Province Key Laboratory of Food Science and Biotechnology, Changsha 410128, China
关键词：
Fuzhuan brick-tea;Fungal community;Denaturing gradient gel electrophoresis;Eurotium cristatum;Debaryomyces hansenii;Anthraquinone
摘要：
Chinese Fuzhuan brick-tea is a unique microbial fermented tea characterized by a period of fungal growth during its manufacturing process. The aim of the present study was to characterize, both physicochemically and microbiologically, traditional industrial production processes of Fuzhuan brick-tea. Fermenting tea samples were collected from the largest manufacturer. Physicochemical analyses showed that the low water content in the tea substrates provided optimal growth conditions for xerophilic fungi. The fungal communities existing in tea materials, fermenting tea, and stored teas were monitored by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) targeting the D1 region of the 265 rRNA genes, followed by sequencing of the amplicons. Results revealed that the microorganisms were from, or closely related to, the genera Eurotium, Debaryomyces, Aspergillus, Verticillium, Pichia, Pestalotiopsis, Rhizomucor and Beauveria. This is the first report of Debaryomyces participating in the processing of Fuzhuan brick-tea. We concluded that the dominant genera Eurotium, Debaryomyces and Aspergillus are beneficial fungi associated with the fermentation of Fuzhuan brick-tea. The genus Beauveria was present in the stored Fuzhuan brick-tea, which may help protect tea products from insect spoilage. The remaining four genera were of minor importance in the manufacturing of Fuzhuan brick-tea. The predominant Eurotium species, a strain named Eurotium sp. FZ, was phenotypically and genotypically identified as Eurotium cristatum. High performance thin layer chromatography analysis of anthraquinones showed that emodin existed in all the dark tea samples, but physcion was only detectable in the tea fermented by E. cristatum. The PCR-DGGE approach was an effective and convenient means for profiling the fungal communities in Fuzhuan brick-tea. These results may help promote the use of microbial consortia as starter cultures to stabilize and improve the quality of Fuzhuan brick-tea products. (C) 2011 Elsevier B.V. All rights reserved.
作者：
Zhenhua Qiu;Pengjun Shi;Huiying Luo;Yingguo Bai;Tiezheng Yuan;Peilong Yang;Suchun Liu;Bin Yao
期刊：
Enzyme and Microbial Technology,2010年46(6):506-512 ISSN：0141-0229
通讯作者：
Yao, B.(yaobin@caas-bio.net.cn)
作者机构：
[Huiying Luo; Peilong Yang; Yingguo Bai; Zhenhua Qiu; Tiezheng Yuan; Pengjun Shi] Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, PR China;[Bin Yao] Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, PR China. Electronic address: yaobin@caas-bio.net.cn;[Zhenhua Qiu; Suchun Liu] Department of Nutrition and Food Hygiene, Hunan Agricultural University, Changsha, Hunan 410128, PR China
通讯机构：
[Yao, Bin] Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, PR China. Electronic address:
作者机构：
[Qin, Si; Hou, De-Xing] Core Research Program 1515, Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, China;[Qin, Si; Hou, De-Xing] Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China;[Hou, De-Xing] The United Graduate School of Agricultural Sciences, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan
通讯机构：
[Hou, De-Xing] Hunan Agr Univ, Coll Food Sci & Technol, Core Res Program 1515, Key Lab Food Sci & Biotechnol Hunan Prov, Changsha, Hunan, Peoples R China.;[Hou, De-Xing] Hunan Agr Univ, Hunan Coinnovat Ctr Utilizat Bot Funct Ingredient, Changsha, Hunan, Peoples R China.;[Hou, De-Xing] Kagoshima Univ, United Grad Sch Agr Sci, Fac Agr, Kagoshima, Japan.
摘要：
Keap1/Nrf2 system plays a critical role on cellular protection by regulating many antioxidant and detoxification enzyme genes through the antioxidant response element (ARE). Thus, it must work constantly to prevent the accumulation of reactive oxygen species (ROS) because excess ROS are associated with many diseases such as cancer, cardiovascular complications, inflammation, and neurodegeneration. Dietary phytochemicals widely distributing in fruits and vegetables have been considered to possess cancer chemopreventive potential through the induction of Keap1/Nrf2 system‐mediated antioxidant and detoxification enzymes in a variety of manners. The data are extensive and are not well classified on the molecular mechanisms. In this review, we first briefly introduce the current knowledge on Keap1/Nrf2 system regulation including Keap1‐dependent and Keap1‐independent cascades, and epigenetic pathway. Then, we summarize the molecular targets of Keap1/Nrf2 system by dietary phytochemicals, and finally review the crosstalk between Keap1/Nrf2 system and other cellular signaling pathways to regulate diverse chronic diseases by dietary phytochemicals. These comprehensive data will help us to understand the potential effects of dietary phytochemicals on the prevention of chronic diseases and maintenance of human health.
关键词：
Nisin-resistance;Cell wall;Membrane phospholipid;Two-component system
摘要：
Nisin is the most prominent lantibiotic and is used as a food preservative due to its high potency against certain Gram-positive bacteria. However, the effectiveness of nisin is often affected by environmental factors such as pH, temperature, food composition, structure, as well as food microbiota. The development of nisin resistance has been seen among various Gram-positive bacteria. The mechanisms under the acquisition of nisin resistance are complicated and may differ among strains. This paper presents a brief review of possible mechanisms of the development of resistance to nisin among Gram-positive bacteria.
通讯机构：
[Yin, Huaqun] Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Peoples R China.
摘要：
Response of biological communities to environmental stresses is a critical issue in ecology, but how microbial communities shift across heavy metal gradients remain unclear. To explore the microbial response to heavy metal contamination (e.g., Cr, Mn, Zn), the composition, structure and functional potential of sedimentary microbial community were investigated by sequencing of 16S rRNA gene amplicons and a functional gene microarray. Analysis of 16S rRNA sequences revealed that the composition and structure of sedimentary microbial communities changed significantly across a gradient of heavy metal contamination, and the relative abundances were higher for Firmicutes, Chloroflexi and Crenarchaeota, but lower for Proteobacteria and Actinobacteria in highly contaminated samples. Also, molecular ecological network analysis of sequencing data indicated that their possible interactions might be enhanced in highly contaminated communities. Correspondently, key functional genes involved in metal homeostasis (e.g., chrR, metC, merB), carbon metabolism, and organic remediation showed a higher abundance in highly contaminated samples, indicating that bacterial communities in contaminated areas may modulate their energy consumption and organic remediation ability. This study indicated that the sedimentary indigenous microbial community may shift the composition and structure as well as function priority and interaction network to increase their adaptability and/or resistance to environmental contamination.
关键词：
Fish gelatin;Acid pretreatment;Protein yield;Molecular weight distribution;Viscosity;Film
摘要：
Tilapia production is growing worldwide and to better utilize wastes from the processing industry, one important application is production of high quality fish gelatin to meet the needs of markets that are not amenable to beef or porcine gelatin. The extraction process from tilapia skin gelatin was optimized through the use of a combination of alkali (0.3 M NaOH) with different types and concentrations of acids before thermal hydrolysis. The effects of acid pretreatments on the protein yields and the physicochemical properties of tilapia gelatin were investigated. Acid concentrations (0.01-0.20 M) influenced gelatin protein recovery: 10.52%-22.40% for citric acid, 1.92%-21.55% for acetic acid, and 4.47%-24.35% for HCl. It was possible to increase gelatin yield for each of the tested acids by adjusting the acid concentration. Gelatin viscosity and the molecular weight distribution of gelatin proteins were related to the acid concentration used. Gelatin prepared using too low a concentration (e.g. 0.01 M acetic acid or HCl) or too high a concentration (e.g. >0.05 M HCl or citric acid) yielded an extract with a smaller ratio of large molecule components, such as beta-chains, and exhibited lower viscosity. The film forming properties of gelatins extracted from three acid-optimized pretreatments showed no significant difference in transparency, tensile strength and elongation at break; though the gelatin film made from 0.03 M citric acid pretreated gelatin had somewhat better water barrier property than those made with HCl or acetic acid. (C) 2013 Elsevier Ltd. All rights reserved.
期刊：
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES,2015年16(7):14511-14525 ISSN：1422-0067
通讯作者：
Jiang, BM
作者机构：
[Xiao, Xianzhong] Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha 410000, Hunan, China. xiaoxianzhong@csu.edu.cn;[Li, Yuanbin; Liu, Yanjuan] Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha 410000, Hunan, China. LYB820812@126.com;[Tong, Zhongyi] Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha 410000, Hunan, China. tongzhongyi2008@163.com;[Tong, Zhongyi] Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha 410000, Hunan, China. tongzhongyi2008@163.com;[Lv, Qinglan] Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha 410000, Hunan, China. lvqinglan2014@163.com
通讯机构：
[Jiang, Bimei] Cent S Univ, Xiangya Sch Med, Dept Pathophysiol, Changsha 410000, Hunan, Peoples R China.
摘要：
Doxorubicin (DOX) is an anthracycline drug with a wide spectrum of antineoplastic activities. However, it causes cardiac cytotoxicity, and this limits its clinical applications. MicroRNA-21 (miR-21) plays a vital role in regulating cell proliferation and apoptosis. While miR-21 is preferentially expressed in adult cardiomyocytes and involved in cardiac development and heart disease, little is known regarding its biological functions in responding to DOX-induced cardiac cytotoxicity. In this study, the effects of DOX on mouse cardiac function and the expression of miR-21 were examined in both mouse heart tissues and rat H9C2 cardiomyocytes. The results showed that the cardiac functions were more aggravated in chronic DOX injury mice compared with acute DOX-injury mice; DOX treatment significantly increased miR-21 expression in both mouse heart tissue and H9C2 cells. Over-expression of miR-21 attenuated DOX-induced apoptosis in cardiamyocytes whereas knocking down its expression increased DOX-induced apoptosis. These gain- and loss- of function experiments showed that B cell translocation gene 2 (BTG2) was a target of miR-21. The expression of BTG2 was significantly decreased both in myocardium and H9C2 cells treated with DOX. The present study has revealed that miR-21 protects mouse myocardium and H9C2 cells against DOX-induced cardiotoxicity probably by targeting BTG2.
摘要：
This work compares the polyphenolics composition, antioxidant activity and contents of selected nutrients in the leaves from seven cultivars of Moringa oleifera ('Tumu', 'Sunyaw', 'Kumasi', 'Techiman', 'China', 'Pakistan Black', and 'Pakistan White') representing the variety in Pakistan. Both the non-enzymatic (DPPH free radical and linoleic acid peroxidation inhibition assays) and enzymatic (superoxide dismutase, peroxidase, and catalase activities) antioxidant capacity was appraised. Regarding,the nutritional value, in terms of protein and minerals contents, minor differences were recorded among cultivars. HPLC-PDA-ESI-MSn analysis of the hydro-methanolic extracts of Moringa leaves revealed a wide range of phenolics, highlighting their content in kaempferol derivatives, caffeoylquinic acid, and feruloylquinic acid. The antioxidant capacity of the tested leaves was correlated with the individual phenolics composition in order to identify which compounds were responsible for this beneficial power. The varying (p < 0.05) concentration of phenolics together with the antioxidant capacity of the tested leaves established 'Pakistan Black' and 'Techiman' as the most nutritive cultivar among others to be grown in the local area. Moreover, these data support the relevance of genetic variability of Moringa for determining the aptitude as a source of beneficial phenolics and nutrients, allowing to identify the optima cultivars to be grown in southern Asia. (c) 2015 Elsevier B.V. All rights reserved.
期刊：
Food Research International,2013年54(2):1605-1612 ISSN：0963-9969
通讯作者：
Xiao, Q.(baby.qianxiao@gmail.com)
作者机构：
[Xiao, Qian] School of Food Science and Technology, Hunan Agricultural University, 410128 Hunan, China;[Tong, Qunyi] State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Jiangsu, China
关键词：
GAB;Guggenheim-Anderson-de Boer;M0;monomolecular layer moisture content;K;multilayer heat of sorption;C;monolayer heat of sorption;SEE;standard error of estimate;P;mean relative deviation modulus;qst;net isosteric heat of sorption;Qst;isosteric heat of sorption;heat of vaporization of pure water;∆H;differential enthalpy;∆S;differential entropy;∆G;Gibbs free energy;Tβ;isokinetic temperature;Thm;harmonic mean temperature;spreading pressure;∆Hin;net integral enthalpy;∆Sin;net integral entropy;aw*;geometric mean water activity at constant spreading pressure;Pullulan;Sodium alginate;Thermodynamic properties;Moisture isotherms;Enthalpy–entropy compensation theory
摘要：
Moisture sorption isotherms of pure pullulan, alginate and blend films were determined using the gravimetric method at 25, 35 and 45 degrees C. The five-parameter Guggenheim-Anderson-de Boer (GAB) model was used to fit the isotherm data from the experiments by nonlinear regression. Additionally, the experimental data were used to determine the thermodynamic parameters for pullulan-alginate based films. Net isosteric heat values for the films decreased exponentially with increasing moisture content, and approached to zero after around 025 g/H2O g dry basis. Pure pullulan films exhibited lowest differential entropy values at a high moisture content range, whereas pure alginate films showed the lowest differential entropy values with increasing moisture content from 0.05 to 0.17 g/H2O g dry basis. Net integral entropy values for pullulan, alginate and blend films were observed to decrease to each minimum value, and then increase with moisture content increases. Moreover, according to the enthalpy-entropy compensation theory, the sorption mechanism for all tested films was enthalpy-controlled. The thermodynamic information obtained from this study is essential for designing equipment and standardized drying process for pullulan-sodium alginate based edible films. (C) 2013 Elsevier Ltd. All rights reserved.
期刊：
Biosensors and Bioelectronics,2014年59:328-334 ISSN：0956-5663
通讯作者：
Liu, X.(liuxiaspr@gmail.com)
作者机构：
[Li, Lei; Liu, You-Qian; Yang, Yang; Li, Wen-Jin; Liu, Xia; Mao, Lu-Gang; Shi, Xing-Bo] College of Food Science and Technology, Hunan Agricultural University, Hunan Province Key Laboratory of Food Science and Biotechnology, Changsha 410128, China;[Liu, Xia] State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China
期刊：
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES,2014年15(5):9103-9116 ISSN：1422-0067
通讯作者：
Wang, RC
作者机构：
[Yi, Youjin] College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China. 13875946008@163.com;[Xiong, Xingyao] College of Horticulture and Landscape, Hunan Agricultural University, Changsha 410128, China. xiongxy@hunau.net;[Hu, Qiulong] College of Horticulture and Landscape, Hunan Agricultural University, Changsha 410128, China. huqiulongnet@126.com;[Guo, Yutong] State Key Laboratory of Sub-Health Intervention Technology, State Administration of Traditional Chinese Medicine, Changsha 410128, China. gytyjj@126.com;[Wang, Rencai] College of Horticulture and Landscape, Hunan Agricultural University, Changsha 410128, China. cavepeoper@gmail.com
关键词：
human colon cancer cells;apoptosis;mitochondria;caspase;MAPK
摘要：
Ganoderma lucidum polysaccharide (GLP) is a biologically active substance reported to possess anti-tumor ability. Nonetheless, the mechanisms of GLP-stimulated apoptosis are still unclear. This study aims to determine the inhibitory and apoptosis-inducing effects of GLP on HCT-116 cells. We found that GLP reduced cell viability on HCT-116 cells in a time- and dose-dependent manner, which in turn, induced cell apoptosis. The observed apoptosis was characterized by morphological changes, DNA fragmentation, mitochondrial membrane potential decrease, S phase population increase, and caspase-3 and -9 activation. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) by SP600125 led to a dramatic decrease of the GLP-induced apoptosis. Western blot analysis unveiled that GLP up-regulated the expression of Bax/Bcl-2, caspase-3 and poly (ADP-ribose) polymerase (PARP). These results demonstrate that apoptosis stimulated by GLP in human colorectal cancer cells is associated with activation of mitochondrial and mitogen-activated protein kinase (MAPK) pathways.
期刊：
CURRENT MICROBIOLOGY,2015年70(5):762-767 ISSN：0343-8651
通讯作者：
Wang, CT
作者机构：
[Liang, Jingru; Xiao, Xiao; Wang, Chengtao; Yin, Sheng; Lang, Tiandan] Beijing Technol & Business Univ, Sch Food & Chem Engn, Beijing, Peoples R China.;[Liang, Jingru; Wang, Chengtao; Yin, Sheng] Beijing Technol & Business Univ, Beijing Key Lab Flavor Chem, Beijing 100048, Peoples R China.;[Xiao, Xiao; Wang, Chengtao; Yin, Sheng] Beijing Technol & Business Univ, Beijing Lab Food Qual & Safety, Beijing, Peoples R China.;[Wang, Chengtao; Yin, Sheng; Lang, Tiandan] Beijing Technol & Business Univ, Beijing Engn & Technol Res Ctr Food Addit, Beijing, Peoples R China.;[Wang, Chengtao] Beijing Technol & Business Univ, Beijing Key Lab Flavor Chem, 11 Fu Cheng Rd, Beijing 100048, Peoples R China.
通讯机构：
[Wang, Chengtao] Beijing Technol & Business Univ, Beijing Key Lab Flavor Chem, 11 Fu Cheng Rd, Beijing 100048, Peoples R China.
摘要：
2-phenylethanol (2-PE) is an important aromatic compound with a rose-like fragrance widely used in food industry and cosmetic manufacture. In order to obtain "natural" 2-PE, the genetically modified budding yeasts were developed and applied for the 2-PE production. The gene ARO8 encoding transaminase and the gene ARO10 encoding decarboxylase in the Ehrlich pathway were expressed in Saccharomyces cerevisiae S288c. The activities of transaminase and decarboxylase were both enhanced in the corresponding recombinant strains. Consequently, the 2-PE yield in the recombinant strains with ARO8 and ARO10 were increased by 9.3 and 16.3 %, respectively, than that in the wild strain. A co-expression vector harboring ARO8 and ARO10 was then introduced into S. cerevisiae S288c, generating the recombinant strain SPO810. The fed-batch fermentation results indicated that the 2-PE yield in SPO810 reached 2.61 g L(-1) after 60 h of cultivation, which was 36.8 % higher than that in the wild strain. These results demonstrated that the 2-PE production was significantly improved by enhanced expression of the two key enzymes encoded by ARO8 and ARO10 in the Ehrlich pathway, providing new perspectives for enhancing "natural" 2-PE production in S. cerevisiae.
作者机构：
[Lim, Loong-Tak] Department of Food Science, University of Guelph, N1G 2W1 Ontario, Canada;[Xiao, Qian] School of Food Science and Technology, Hunan Agricultural University, 410128 Hunan, China. Electronic address: baby.qianxiao@gmail.com;[Tong, Qunyi] State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Jiangsu, China
关键词：
ATR-FTIR;attenuated total reflection Fourier transform infrared spectroscopy;2D;two-dimensional;HATR;horizontal attenuated total reflectance;AW-S;aggregated water with strong hydrogen bond;AW-M;aggregated water with moderately hydrogen;FW;free water;Pullulan;Drying process;ATR-FTIR;Two-dimensional correlation spectroscopy
作者机构：
[Huston, Wilhelmina M] School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia;[Liang, Zhao-Xun; Chakrabortti, Alolika] School of Biological Sciences, Nanyang Technological University, Singapore, Singapore;[Vu, Ngoc Minh Thu; Nhiep, Thi Hanh Nguyen; Waanders, Jennifer; Pham, Thi Huong; Turner, Mark S; Bansal, Nidhi; Zhu, Yan; Lo, Raquel] School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia;[Nielsen, Lars K; Marcellin, Esteban] Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia;[Pham, Thi Huong] University of Science and Technology, The University of Danang, Da Nang, Vietnam
摘要：
The second messenger cyclic‐di‐adenosine monophosphate (c‐di‐AMP) plays important roles in growth, virulence, cell wall homeostasis, potassium transport and affects resistance to antibiotics, heat and osmotic stress. Most Firmicutes contain only one c‐di‐AMP synthesizing diadenylate cyclase (CdaA); however, little is known about signals and effectors controlling CdaA activity and c‐di‐AMP levels. In this study, a genetic screen was employed to identify components which affect the c‐di‐AMP level in Lactococcus. We characterized suppressor mutations that restored osmoresistance to spontaneous c‐di‐AMP phosphodiesterase gdpP mutants, which contain high c‐di‐AMP levels. Loss‐of‐function and gain‐of‐function mutations were identified in the cdaA and gdpP genes, respectively, which led to lower c‐di‐AMP levels. A mutation was also identified in the phosphoglucosamine mutase gene glmM, which is commonly located within the cdaA operon in bacteria. The glmM I154F mutation resulted in a lowering of the c‐di‐AMP level and a reduction in the key peptidoglycan precursor UDP‐N‐acetylglucosamine in L. lactis. C‐di‐AMP synthesis by CdaA was shown to be inhibited by GlmMI154F more than GlmM and GlmMI154F was found to bind more strongly to CdaA than GlmM. These findings identify GlmM as a c‐di‐AMP level modulating protein and provide a direct connection between c‐di‐AMP synthesis and peptidoglycan biosynthesis.
