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Antibiotic resistance is a growing problem in clinical settings as well as in food industry. Lactic acid bacteria (LAB) commercially used as starter cultures and probiotic supplements are considered as reservoirs of several antibiotic resistance genes. Macrolide–lincosamide–streptogramin (MLS) antibiotics have a proven record of excellence in clinical settings. However, the intensive use of tylosin, lincomysin and virginamycin antibiotics of this group as growth promoters in animal husbandry and poultry has resulted in development of resistance in LAB of animal origin. Among the three different mechanisms of MLS resistance, the most commonly observed in LAB are the methylase and efflux mediated resistance. This review summarizes the updated information on MLS resistance genes detected and how resistance to these antibiotics poses a threat when present in food grade LAB.  相似文献   

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Cao  Zhenhui  Pan  Hongbin  Li  Shijun  Shi  Chongying  Wang  Sifan  Wang  Fuyi  Ye  Pengfei  Jia  Junjing  Ge  Changrong  Lin  Qiuye  Zhao  Zhiyong 《Probiotics and antimicrobial proteins》2019,11(1):103-112
Probiotics and Antimicrobial Proteins - This study aimed to investigate the probiotic potential of lactic acid bacteria (LAB) strains isolated from De’ang pickled tea, a traditional food...  相似文献   

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Determination of the amount of lactic acid dehydrogenase in the blood has been demonstrated as a useful aid in the diagnosis of myocardial necrosis. The reliability of the test and the time element of the appearance and disappearance of the enzyme in the blood give it advantages over transminase determinations. In addition there appears to be a correlation of lactic acid dehydrogenase content with metastatic carcinoma. The levels of the substance correlate with the presence or absence of metastatic lesions and also with the extent of the metastasis. Few other clinical states are associated with increased levels of this enzyme, and in most instances the few that are can be excluded by other reliable criteria.  相似文献   

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The European Union in general and Germany in particular want to lead the way to substantially expand renewable energies for power production. Considering the extremely ambitious objectives of the German Federal Government, a strong, nationwide increase in cultivating energy crops can be anticipated. However, the expansion of biomass production, which is already in progress, has led to several environmental and ecological objections. Aside from competing for land, for food and feed production, the expansion of monocultures for biomass and biofuel production with a concentration on maize (Zea mays) and rapeseed (Brassica napus) can be problematic for biodiversity conservation. To face these challenges, the provision and cultivation of additional crop species and cultivars for biomass production would help to avoid these problems. The designated energy crop Miscanthus × giganteus represents an alternative species for extended biomass production. This giant grass is characterized by a broad range of possible applications and a high potential in producing and providing biomass in a sustainable way. In our study, we conducted a Geographic Information System (GIS)-based analysis of the cultivation potential of M. giganteus in Germany. As a result, we generated digital maps that display preferential regions for the cultivation of M. giganteus where a high productivity and quality of biomass is expected. Combining different climate- and soil-dependent scenarios, a total acreage potential of 4 million ha is predicted for Germany.  相似文献   

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In this study, an attempt has been made to predict the major functions of gramnegative bacterial proteins from their amino acid sequences. The dataset used for training and testing consists of 670 non-redundant gram-negative bacterial proteins (255 of cellular process, 60 of information molecules, 285 of metabolism, and 70 of virulence factors). First we developed an SVM-based method using amino acid and dipeptide composition and achieved the overall accuracy of 52.39% and 47.01%, respectively. We introduced a new concept for the classification of proteins based on tetrapeptides, in which we identified the unique tetrapeptides significantly found in a class of proteins. These tetrapeptides were used as the input feature for predicting the function of a protein and achieved the overall accuracy of 68.66%. We also developed a hybrid method in which the tetrapeptide information was used with amino acid composition and achieved the overall accuracy of 70.75%. A five-fold cross validation was used to evaluate the performance of these methods. The web server VICMpred has been developed for predicting the function of gram-negative bacterial proteins (http://www.imtech.res.in/raghava/vicmpred/).  相似文献   

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The Caulobacter crescentus bacteriophage phiCbK was studied with respect to the physical and chemical properties of both the phage and its deoxyribonucleic acid (DNA). Electron micrographs reveal the phage to be among the largest DNA bacteriophages reported, with head dimensions of 64 by 195 nm and a flexible tail 275 nm in length. The phage is composed of 57% DNA. This DNA is double-stranded as indicated by (i) the sharp increase in extinction coefficient over a narrow range of temperature increase, (ii) an increase in density in CsCl upon thermal denaturation, and (iii) the equivalence of guanine and cytosine as well as adenine and thymine, determined by chemical analysis. phiCbK DNA cosediments with Escherichia coli phage T2 DNA and has therefore been assigned an S(20,w) value of 63.5S. The size of the phage and its DNA and the percentage of DNA indicate that the phiCbK phage head is relatively loosely packed. The properties of the DNA from bacteriophage phiCbK are similar to those of host C. crescentus DNA with respect to buoyant density, thermal transition point, and guanine plus cytosine content.  相似文献   

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Determination of the ecotoxicity effect factor (EF) in life cycle impact assessment (LCIA) is based on test data reporting the total dissolved concentration of a substance. In spite of the recognised influence of chemical speciation and physico-chemical characteristics of the aquatic systems on toxicity of dissolved metals, these properties are not considered when calculating characterization factors (CFs) for metals. It is hypothesised that the main cause of the variation in reported EC50 values of Cu among published test results lies in different speciation patterns for Cu in the test media, and that the toxicity of Cu is predominantly caused by the free Cu2+ ion. Hence, the free Cu2+ ion concentration should substitute the total dissolved metal concentration when determining the EF.  相似文献   

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