ABSTRACT
Background: To investigate the effects of different media and media addition methods on the fermentation of tobacco. Methods: A plant extract and a bacterial agent are used for fermenting cigar tobacco leaves in a different order of addition. The chemical composition, cellulose, and pectin content, as well as changes in the microbial community, were measured. Results: The addition method of the fermentation medium affects the quality of fermented tobacco. The optimal medium formula and addition method involve first adding plant extracts and then microbial agents. The medium formula and addition method can significantly reduce cellulose in tobacco, with a reduction rate of 46%, and significantly increase the content of ß-carotene, thereby enhancing the aroma of cigarettes. There is an increase in aroma components, such as alcohols, alkanes, and olefins, in tobacco. By reducing the proportion of Aspergillus, it can alter the microbial community structure of tobacco. Conclusion: Adding plant extracts before introducing microbial agents can significantly improve the quality and alter the microbial community structure of Dexue No.1 tobacco.
ABSTRACT
Streptomycin-imprinted silica microspheres were prepared by combining a surface molecular-imprinting technique with the sol-gel method. A mixture of tetrahydrofuran, ethanol, and water (6:1:1, v/v/v) was selected as dispersing solvent while 3-aminopropyltriethoxysilane and triethoxyphenylsilane acted as functional monomers, and tetraethyl orthosilicate as a cross-linker. Characterization of the molecularly imprinted polymers was conducted using scanning electron microscope and dynamic binding experiments. As compared to the nonimprinted polymers, the imprinted polymers exhibited a higher degree of saturated adsorption volume up to 26.3 mg/g, and better selectivity even in an aqueous solution with interfering compounds, including dihydrostreptomycin, neomycin, and tetracycline. The adsorption ability and selectivity were observed to be influenced by the mole ratio of 3-aminopropyltriethoxysilane and triethoxyphenylsilane. Feasibility of the polymers to be used for actual application was also evaluated with spiked samples, indicating great potential for large-scale applications. Moreover, the streptomycin-imprinted polymers can be repeatedly used for 12 cycles without losing original performance, which is beneficial for commercial use.
Subject(s)
Anti-Bacterial Agents/chemistry , Polymers/chemistry , Streptomycin/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Anti-Bacterial Agents/isolation & purification , Microspheres , Molecular Imprinting , Polymers/chemical synthesis , Silicon Dioxide/chemistry , Streptomycin/isolation & purification , Water Pollutants, Chemical/isolation & purificationABSTRACT
This research amplified the phyA gene with the designed and synthesized primers specific for the phyA gene full-length coding sequence. The phyA gene was from Aspergillus niger F246 by the polymerase chain reaction(PCR), which is selected and identified in our laboratory. After sequncing the coding sequence, it was confirmed that the construction of cloning vector was succeeded. The phyA gene fragment was recovered from the pMD18T-phyA and ligated with prokaryotic expression vector pET30a+ to construct the recombinant expression plasmid pET30a+ -phyA. It was expressed with IPTG induction in E. coli for high efficiency. A new protein band with apparent molecular weight 50 kDa was detected in the lysate of the transformed cell by using SDS-PAGE. The amount of the soluble fusion protein was about 40% of large intestine bacillus soluble protein of transformed cells, estimated by absorbance scanning of SDS-PAGE and protein quantitation. It's phytase activity was eight times over the natural phyase. So this research provides the basis of the study on obtaining large and high active phytase and developmant of the new microbial ecologicalagent.
Subject(s)
6-Phytase , Genetics , Aspergillus niger , Genetics , Base Sequence , Cloning, Molecular , Escherichia coli , Genetics , Metabolism , Genes, Fungal , Genetic Vectors , Molecular Sequence Data , Recombinant Fusion Proteins , GeneticsABSTRACT
Biocompatibility has always been the focal point in the study of biomaterials applied to medical apparatus. But at present, the standard system hasn't formed completely to evaluate the biomaterials. In recent years scientists tend to use general standard of evaluation. In this article, based on the recalcification time, the adhesion of platelets as well as the total quantity of plasma protein and some other evidences, combining with the Analytic hierarchy process (AHP), the method of general evaluation on the biocompatibility of anticoagulant biomaterials was discussed.
Subject(s)
Humans , Anticoagulants , Biocompatible Materials , Reference Standards , Blood Proteins , Materials Testing , Methods , Reference Standards , Platelet AdhesivenessABSTRACT
Good anticoagulant biomaterials need good surface chemical properties, good mechanics performances and particularly good characteristics of biocompatibility, including tissue compatibility and hemocompatibility. In order to understand with greater clearness the anticoagulant biomaterial, we have to characterize them by different methods. In this paper, the approaches to assessing and displaying the characteristics of anticoagulant biomaterial are reviewed in three aspects, namely the surface chemical properties and structure, the mechanics performances the and the biocompatibility of anticoagulant biomaterial.
Subject(s)
Humans , Anticoagulants , Biocompatible Materials , Chemistry , Blood Coagulation , Materials Testing , Prostheses and Implants , Prosthesis Design , Surface PropertiesABSTRACT
The treatment of stained teeth has been one of the striking aspects of stomatology and esthetic dentistry. Based on detailed data and references, this article introduces the types of stained teeth and the main treatment methods including strong point, weakness, limitation of the usage, result, and the relevant mechanisms. It addresses the researches on problems in the treatment of stained teeth. Also in this paper is envisaged what will be done to treat the stained teeth in future.
Subject(s)
Humans , Dental Veneers , Tooth Bleaching , Tooth Discoloration , TherapeuticsABSTRACT
As a means to substitute the function of kidney, hemodialysis therapy has been applied to clinical therapy. The bio-compatibility of dialyser, which is the key of part of artificial kidney, is a determining factor for the therapy. This paper describes dialyser and the methods of improving bio-compatibility of dialyser.