首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Today, the dramatic changes in types of food consumed have led to an increased burden of chronic diseases. Therefore, the emphasis of food research is not only to ensure quality food that can supply adequate nutrients to prevent nutrition related diseases, but also to ensure overall physical and mental-health. This has led to the concept of functional foods and nutraceuticals (FFNs), which can be ideally produced and delivered through plants. Metabolomics can help in getting the most relevant functional information, and thus has been considered the greatest –OMICS technology to date. However, metabolomics has not been exploited to the best potential in plant sciences. The technology can be leveraged to identify the health promoting compounds and metabolites that can be used for the development of FFNs. This article reviews (i) plant-based FFNs-related metabolites and their health benefits; (ii) use of different analytic platforms for targeted and non-targeted metabolite profiling along with experimental considerations; (iii) exploitation of metabolomics to develop FFNs in plants using various biotechnological tools; and (iv) potential use of metabolomics in plant breeding. We have also provided some insights into integration of metabolomics with latest genome editing tools for metabolic pathway regulation in plants.  相似文献   

2.
Brewers'' spent grain (BSG) is the most abundant by-product of beer-brewing. BSG is rich in nutrients such as protein, fiber, minerals, and vitamins, and therefore it is conventionally used as low-cost animal feed. On the other hand, alternative utilization of BSG has gained increased attention during recent years due to technological progress in its processing and the emergence of the concept of circular economy. The valorization of BSG through biotechnological approaches is environmentally friendly and sustainable. This review was focused on recent advancements in the conversion of BSG into value-added products, including bioenergy (ethanol, butanol, hydrogen, biodiesel, and biogas), organic acids, enzymes, xylitol, oligosaccharides, and single cell protein, via biotechnological approaches. In addition, the potential applications of BSG as immobilization matrices in bioprocesses have been reviewed.  相似文献   

3.
A rapid enzyme-linked immunosorbent assay (ELISA) for the detection of penicillin G in milk at concentrations of 6 ng/ml (0.01 IU/ml) was used to screen 1651 off-farm milk samples previously reported as containing no detectable levels of antimicrobial substances. Using a single-well per test format and a percent inhibition cut-off for the determination of positive/negative endpoint, 3.1% positives were obtained. Comparison with intra-assay standards lowered the numbers of positives to 0.42%. Analysis of 170 milk samples positive for antimicrobials confirmed 92.4% as containing penicillin G using the prescribed cut-off level and 87.6% when compared to standards. The ELISA, now available commercially in kit form, analyses between 1 and 48 samples in 15 minutes. It will detect 0.01 IU/ml to a level of confidence of 99% and 0.005 IU/ml with between 75 and 95% confidence.  相似文献   

4.
Milk antibiotic residues have been a public concern in recent years. The Grade A Pasteurized Milk Ordinance mandates that raw Grade A milk will test negative for beta-lactam antibiotic residues before processing. The purpose of this research was to investigate the ability of various levels of peroxide and heat to inactivate penicillin G in raw milk. Whole milk spiked to a mean of 436 +/- 15.1 (standard error of the mean) ppb of potassium penicillin G was treated with hydrogen peroxide at levels of 0.0, 0.09, 0.17, and 0.34%. Samples at each peroxide level (n = 6 per treatment) were treated as follows: 1) incubated at 54.4 degrees C for 3 h, 2) pasteurized at 62.8 degrees C for 30 min, 3) incubated and pasteurized as in treatments 1 and 2, or 4) received no further treatment. A beta-lactam competitive microbial receptor assay was used for quantification of penicillin G. Concentrations of penicillin in selected samples were determined by HPLC for a comparison of test methods. Treatments were evaluated relative to their ability to reduce milk penicillin G levels to below the safe level of 5 ppb. The 0.09% hydrogen peroxide level was ineffective for all treatments. Hydrogen peroxide at 0.17% lowered the mean penicillin G (+/- SEM) from 436 +/- 15.1 to 6 +/- 1.49 ppb using the incubated and pasteurized heat treatment. The 0.34% concentration of hydrogen peroxide was the most effective, inactivating penicillin G to a level well below the safe level of 5 ppb with the pasteurized heat treatment, with or without incubation.  相似文献   

5.
青霉素G酰化酶是一种重要的工业催化剂,每年催化制备20 000 t的6-氨基青霉烷酸,同时也用于β-内酰胺抗生素的合成.有效地回收和重复利用能够大大提高工业催化剂的应用性能,人们越来越关注青霉素G酰化酶的固定化研究.综述了青霉素G酰化酶的常用固定化方法,主要包括吸附法、包埋法、共价结合法、交联法等,以及该领域的最新研究进展.  相似文献   

6.
Penicillin G purposedly added to whole raw milk at concentrations from .05 to .20 IU/ml was removed to undetectable levels by a combination of ultrafiltrations and permeate washes. After penicillin removal, whole milk 3:1 vol/vol concentrated retentates were reconstituted to milk with antibiotic-free permeate with little change in composition and with very good to excellent flavor. Washing 3:1 vol/vol concentrated retentates from penicillin-contaminated milks with water also removed penicillin to an undetectable level but changed the composition of product, which displayed a flat flavor.  相似文献   

7.
The potential for antibiotic residues in calves from consuming milk containing penicillin G or amoxicillin was investigated. Six calves were fed milk replacer, 6% body weight twice daily, containing 0.293, 2.92, or 5.85 microg of penicillin/ml (ppm) G or 0.25, 1.0, or 2.0 microg of amoxicillin/ml for three consecutive feedings. Urine and blood samples were collected after each feeding. Serum and urine samples were tested with a microbial receptor assay and a microbial growth inhibition assay to indicate potential drug residues. Penicillin G and amoxicillin were detected in the serum and urine of several calves 3 h after drinking spiked milk replacer. Possible violative drug residues in the calves were detected by the microbial growth inhibition assay up to 15 h after drinking spiked milk replacer. Penicillin G, but not amoxicillin, could be detected in urine 24 h after the final feeding of spiked milk replacer. Subsequently, six calves were fed milk replacer containing 11.7 microg of penicillin G/ml (ppm) twice daily, 6% body weight per feeding. Calves were slaughtered 3 h after the final feeding. Mean (+/-SD) concentrations of penicillin G measured by high-pressure liquid chromatography in liver, kidney, muscle, and serum were 0.409 (+/-0.167) microg/g, 0.031 (+/-0.012) microg/g 0.008 (+/-0.002) microg/g, and 0.013 (+/-0.006) mg/ml, respectively. This study indicates that calves fed milk with amoxicillin or penicillin G could possibly have violative residues if slaughtered within 24 h after feeding. Violative drug residues in liver tissue were found in calves slaughtered 3 h after consuming milk replacer containing 11.7 microg of penicillin G/ml (ppm).  相似文献   

8.
Streptococcus thermophilus may be subjected to the effects of penicillin G in contaminated milk used for yogurt production. Sensitivity of this microorganism to penicillin G has been conventionally determined by the help of penicillin G-impregnated disks placed on solid media. It was observed that the bacteriostatic penicillin G concentration was much greater in liquid media than in solid media. The conventional disk method may not be appropriate for antibiotic sensitivity determinations if the microorganisms will be used in liquid culture. A simple mathematical model simulated the growth of S. thermophilus in liquid culture. Numerical values of this model's parameters were regarded as the measure of the antibiotic effect on the culture. In penicillin G containing fresh medium, small concentrations of antibiotic decreased the specific growth rate considerably. Increasing the antibiotic concentration caused only slight additional decline. Antibiotic shock, i.e., rapidly introducing penicillin G into an actively growing antibiotic-free culture, stopped growth of the penicillin G-resistant microorganisms, and no death was observed, but a fraction of the microorganisms were killed in the wild culture. Both the wild and the resistant cultures recovered from the shock in a few hours. Addition of penicillin G-resistant microorganisms together with the antibiotic dosage into the wild culture prevented death.  相似文献   

9.
文章综述了世界主要电脑圆纬机制造厂商近年来在技术和产品研发方面的动态,其中包括电子选针与选沉降片、电子多色调线、计件衣坯和嵌花编织技术等。  相似文献   

10.
国内外酒精行业发展近况   总被引:3,自引:0,他引:3  
傅其军 《广西轻工业》2005,(2):12-14,34
介绍了国内外酒精行业的发展近况。  相似文献   

11.
Halophilic micro‐organisms are able to survive in high salt concentrations because they have developed diverse biochemical, structural and physiological modifications, allowing the catalytic synthesis of proteins with interesting physicochemical and structural properties. The main characteristic of halophilic enzymes that allows them to be considered as a novel alternative for use in the biotechnological industries is their polyextremophilicity, i.e. they have the capacity to be thermostable, tolerate a wide range of pH, withstand denaturation and tolerate high salt concentrations. However, there have been relatively few studies on halophilic enzymes, with some being based on their isolation and others on their characterisation. These enzymes are scarcely researched because attention has been focused on other extremophile micro‐organisms. Only a few industrial applications of halophilic enzymes, principally in the fermented food, textile, pharmaceutical and leather industries, have been reported. However, it is important to investigate applications of these enzymes in more biotechnological processes at both the chemical and the molecular level. This review discusses the modifications of these enzymes, their industrial applications and research perspectives in different biotechnological areas. Copyright © 2012 Society of Chemical Industry  相似文献   

12.
生物技术在制革中的应用进展及趋势   总被引:2,自引:1,他引:2  
王睿  程海明 《西部皮革》2004,26(12):50-53
越来越严厉的全球环保制度正改变着皮革加工行业。制革工业80%-90%的污水来自鞣前准备和鞣制过程,并随之产生有毒气体,如硫化氢,还有固体废弃物,如石灰和铬泥。如今开发了多种酶制剂产品应用于制革的许多工段。酶在脱毛过程中减少硫化钠使用等方面起着越来越重要的作用。这篇综述主要讨论在皮革加工中新出现的生物技术方法,其中的一个重要部分是综述以生物处理为主的脱毛和松散纤维方法以减少有毒废弃物的产生。  相似文献   

13.
Self-help interventions for older smokers   总被引:1,自引:0,他引:1       下载免费PDF全文
OBJECTIVE: To evaluate the relative effectiveness of two self-help smoking interventions as adjuncts to a self-help manual and telephone support service (hotline) for older smokers. DESIGN: Subjects were stratified on baseline variables and randomised to one of two treatment conditions in a methods development study. SUBJECTS: 177 community- dwelling smokers aged 60 years and older. INTERVENTIONS: All subjects received a self-help manual and access to a smokers' telephone hotline. Subjects also received either mailings (Letters condition) or counselling telephone calls (Proactive condition) at four and eight weeks after enrollment. MAIN OUTCOME MEASURES: Use of the hotline and prevalence of abstinence lasting at least 48 hours (verified by a "significant other") were assessed at three and six months for the full sample. Seven-day abstinence was calculated for comparison with previous research. A subsample of 91 subjects was followed up at 12 months. RESULTS: Overall abstinence rates for the two conditions were in the range of typical self-help interventions. Men were more likely to be abstinent than women at follow up at three and six months. A significant gender x treatment interaction was found, with abstinence rates higher for men in the Letters condition, and women in the Proactive condition. Hotline use was high, with nearly half of subjects calling by 12 months. CONCLUSION: Both interventions appear promising for older smokers, but may be differentially effective for men and women. Older smokers will use a hotline; whether Letters and Proactive interventions can improve on manual and hotline effectiveness rates alone is being tested in a subsequent controlled trial.


  相似文献   

14.
Improving water use efficiency (WUE) in grapevines is essential for vineyard sustainability under the increasing aridity induced by global climate change. WUE reflects the ratio between the carbon assimilated by photosynthesis and the water lost in transpiration. Maintaining stomata partially closed by regulated deficit irrigation or partial root drying represents an opportunity to increase WUE, although at the expense of decreased photosynthesis and, potentially, decreased yield. It would be even better to achieve increases in WUE by improving photosynthesis without increasing water loses. Although this is not yet possible, it could potentially be achieved by genetic engineering. This review presents current knowledge and relevant results that aim to improve WUE in grapevines by biotechnology and genetic engineering. The expected benefits of these manipulations on WUE of grapevines under water stress conditions are modelled. There are two main possible approaches to achieve this goal: (i) to improve CO2 diffusion to the sites of carboxylation without increasing stomatal conductance; and (ii) to improve the carboxylation efficiency of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The first goal could be attained by increasing mesophyll conductance to CO2, which partly depends on aquaporins. The second approach could be achieved by replacing Rubisco from grapevine with Rubiscos from other C3 species with higher specificity for CO2. In summary, the physiological bases and future prospects for improving grape yield and WUE under drought are established.  相似文献   

15.
Improving water use efficiency (WUE) in grapevines is essential for vineyard sustainability under the increasing aridity induced by global climate change. WUE reflects the ratio between the carbon assimilated by photosynthesis and the water lost in transpiration. Maintaining stomata partially closed by regulated deficit irrigation or partial root drying represents an opportunity to increase WUE, although at the expense of decreased photosynthesis and, potentially, decreased yield. It would be even better to achieve increases in WUE by improving photosynthesis without increasing water loses. Although this is not yet possible, it could potentially be achieved by genetic engineering. This review presents current knowledge and relevant results that aim to improve WUE in grapevines by biotechnology and genetic engineering. The expected benefits of these manipulations on WUE of grapevines under water stress conditions are modelled. There are two main possible approaches to achieve this goal: (i) to improve CO2 diffusion to the sites of carboxylation without increasing stomatal conductance; and (ii) to improve the carboxylation efficiency of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The first goal could be attained by increasing mesophyll conductance to CO2, which partly depends on aquaporins. The second approach could be achieved by replacing Rubisco from grapevine with Rubiscos from other C3 species with higher specificity for CO2. In summary, the physiological bases and future prospects for improving grape yield and WUE under drought are established.  相似文献   

16.
近两年来,陕西掀起了发展红地球葡萄的热潮。据说,这一热源来自1998年的西安中西部经贸洽淡会,天津代表团建议在陕西中东部地区建立红地球葡萄商品基地。后来专家们论证了其可行性,认为陕西红地球葡萄商品基地的规模为20万亩,大约在6年内建成。主管部门据此在1998年底确定了《陕西省红地球葡萄产业开发试验示范工作方案》,其中明确了工作的指导思想、组织机构、工作任务、实施和管理办法等。全国葡萄栽培界的专家和政府主管部门为陕西经济发展寻求新的增长点的举措很快被精明的商家发现并大加炒作,众多民营农业开发企业和少数懂技术…  相似文献   

17.
The objective of this study is to demonstrate the use of new polyunsaturated fatty derivatives for cutaneous applications. These new compounds present an analogue structure of cutaneous lipid, stabilize the polyunsaturated fatty acids (face to oxidation) and demonstrate specific biological activities. Three molecules described are Omega 6 fatty acid stabilized compound (O6FASC), the O3FASC and the O9FASC. The derivatives are synthesized via the same biotechnological process. This work describes the choice of final structure, the design of the biotechnological process and the free solvent enzymatic synthesis used for the synthesis of these three cutaneous lipid analogues. The restructuring effect of such analogues has been demonstrated with an in vivo study on volunteers. The stabilization of the O3FASC and O6FASC, and the biological activities of these three compounds are presented. The O6FASC shows very good results in anti-inflammatory effects; the O3FASC has anti-stress activities, whereas the O9FASC presents interesting results in improving elasticity and firmness. All these activity tests are presented in this work.  相似文献   

18.
Immobilization of enzymes on nonporous supports provides a suitable model for investigating the effect of external mass transfer limitation on the reaction rate in the absence of internal diffusional resistance. In this study, deacylation of penicillin G was investigated using penicillin acylase immobilized on ultrafine silica particles. Kinetic studies were performed within the low-substrate-concentration region, where the external mass transfer limitation becomes significant. To predict the apparent kinetic parameters and the overall effectiveness factor, knowledge of the external mass transfer coefficient, k(L)a, is necessary. Although various correlations exist for estimation of k(L)a, in this study, an optimization scheme was utilized to obtain this coefficient. Using the optimum values of k(L)a, the initial reaction rates were predicted and found to be in good agreement with the experimental data.  相似文献   

19.
Incurred penicillin G, oxytetracycline, enrofloxacin and ciprofloxacin residues in bovine and porcine muscle and kidney samples were analysed by microbiological and chemical methods, the former using Bacillus subtilis BGA as a test organism on agar media of pH 6, pH 7.2 and pH 8 and the latter using liquid chromatography. Least squares fits between the logarithms of the chemically obtained concentrations of the antimicrobials and the widths of the inhibition zones were used to estimate the inhibition zone widths corresponding to the maximum residue limit concentrations. In vitro sensitivities were determined with standard antimicrobial solutions. The results indicate that if B. subtilis BGA is used as a test organism, muscle tissue cannot be used as test material for screening oxytetracycline, enrofloxacin and ciprofloxacin residues on the plates used in this study, while penicillin G can be screened from muscle tissue. Because of the numerous factors causing or increasing variation in the analysis, the inhibition zone caused by a given antibiotic concentration cannot be predicted precisely. Therefore, a positive agar diffusion test needs to be confirmed chemically. If a kidney sample gives a positive agar diffusion test result, the antimicrobial concentration in a muscle sample from the same carcass should be checked chemically.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号