共查询到19条相似文献,搜索用时 187 毫秒
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采用水性高分子异氰酸酯胶黏剂,以柞木、赛鞋木豆(乌金木)和橡胶木3种木材单板为表板制备杨木芯的三层实木复合地板.结果表明:赛鞋木豆(乌金木)和橡胶木的胶合性能良好,而柞木性能较差,分析认为与柞木木材表面性能以及胶合工艺等有关. 相似文献
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对我国进口的印茄木与甘巴豆木材从三个切面的微观构造特征上进行对比分析,找出它们的异同点,从而准确地鉴别。 相似文献
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对某番茄酱生产企业提供的辐照杀菌(辐照剂量≥15 kGy)的5 L无菌袋进行菌落计数、分离和鉴定。3 L无菌水反复漂洗,滤膜过滤后进行平板菌落计数,分离纯化后采用16S rDNA和dnaJ序列分析分别鉴定到属和种。结果表明,5 批次的样品中均有细菌检出,数量在5~132 CFU/袋,9 个典型菌落经过16S rDNA序列分析后,分别属6 个属,其中栖水菌属(Enhydrobacter)、不动杆菌属(Acinetobacter)和考克斯菌属(Kocuria)各1 株,微球菌属(Micrococcus)、微杆菌属(Microbacterium)和芽孢杆菌属(Bacillus)各2 株;dnaJ序列分析则将一株葡萄球菌C8-3鉴定到种-表皮葡萄球菌(Staphylococcus epidermidis)。辐照杀菌的无菌袋虽然微生物数量不高,但是依然残留了一些耐辐照的细菌,它们或多或少会给内装食品带来一定的食品安全隐患或影响食品保质期。 相似文献
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Blesa J Soriano JM Moltó JC Mañes J 《Critical reviews in food science and nutrition》2006,46(6):473-478
Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines. 相似文献
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以冷藏草鱼的优势腐败菌气单胞菌(Aeromonas spp.)为研究对象,利用报告菌株Chromobacterium violaceum CV026检测细菌的群体感应活性,通过染色法定量测定细菌的生物膜形成,并探究温度以及群体感应信号分子对气单胞菌生物膜形成的影响。结果显示,冷藏草鱼的气单胞菌属包含多个不同种,分离获得的20 株气单胞菌中90%能产生N-酰基高丝氨酸内酯。进一步分析生物膜形成量较强的2 株菌A. salmonia W41和A. salmonia W69,结果显示该2 株菌在30 ℃和8 ℃的生物膜形成量高于37 ℃。菌株W41和W69主要分泌N-丁酰基高丝氨酸内酯(N-butanoyl-L-homoserine lactone,C4-HSL)和N-己酰基高丝氨酸内酯(N-hexanoyl-L-homoserine lactone,C6-HSL)信号分子,50 μmol/L的C6-HSL显著促进W41生物膜的形成;而低浓度的C4-HSL和C6-HSL促进W69生物膜的形成,高浓度的C4-HSL和C6-HSL抑制W69生物膜的形成。可以看出,大多数气单胞菌属具有群体感应现象,气单胞菌属生物膜的形成受个体差异和温度的影响,同时群体感应信号分子的浓度和类型也是影响气单胞菌属生物膜形成的主要因素。 相似文献
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目的 了解徐州市某学校学生宿舍和食堂环境中克罗诺杆菌污染状况、分子分型及耐药特征,为预警食源性克罗诺杆菌病暴发提供参考。方法 采集徐州市某学校学生宿舍和食堂环境样品156份,分离并鉴定克罗诺杆菌,并利用基于O-抗原的血清分型和多位点序列分型(multilocus sequence typing,MLST)技术对分离株进行分子分型,采用纸片扩散法测定分离株的药敏性。结果 从11份环境样品中检出克罗诺杆菌,总检出率为7.1%(11/156),其中学生宿舍和食堂环境样品中克罗诺杆菌检出率分别为6.6%(8/121)和8.6%(3/35)。fusA基因序列分析将8株分离株鉴定为阪崎克罗诺杆菌(C.sakazakii),3株为丙二酸盐克罗诺杆菌(C.malonaticus)。MLST法将11株分离株分为5个序列型,其中ST500型为优势型别(54.5%,6/11)。11株分离株被鉴定为5种血清型,其中阪崎克罗诺杆菌血清型Csak O7为优势血清型(54.5%,6/11)。药敏性试验显示,11株分离株对头孢克肟、阿米卡星、环丙沙星、呋喃妥因、氯霉素和替卡西林/克拉维酸敏感,但部分菌株对头孢噻吩(63.6%,7/11)和美罗培南(27.3%,3/11)耐药。结论 学生宿舍和食堂环境中存在克罗诺杆菌污染风险,今后应加强对学校学生宿舍和食堂环境中克罗诺杆菌的流行病学监测。 相似文献
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Mark P McHenry 《Journal of the science of food and agriculture》2010,90(2):183-187
There is considerable interest in reliable and practical methods to sequester carbon (C) into agricultural soils to both reduce atmospheric greenhouse gas concentrations and improve conventional productivity. This article outlines a research methodology to refine the efficacy and economics of using long‐lived C species (biochars) as stock feed additives, produced from farm waste biomass, for ecologically delivered soil biosequestration, while generating renewable bioenergy. This article also draws attention to potential parallel outputs including annual feed use efficiency, fodder species expansion, soil nutrient retention, aquatic habitat protection, and forestry revegetation, using nitrogen‐fixing perennial fodder plant species. A methodology to generate parallel results including standing fodder tree C sequestration, optimised production of Acacia spp. biochar, animal growth on high‐tannin fodder with biochar feed additives, soil nutrient and stable C fractions, and economics of Acacia spp. bioenergy production. This form of research is contextually dependent on the regional agricultural production system, legislation, and surrounding ecosystem. Therefore, this article suggests the use of a scenario approach to include regionally specific levels of biochar integration with respect to the local prices for C, fossil fuels, meat and livestock, fertilisers, fodder, feed additives, water, renewable energy, revegetation and capital. Copyright © 2009 Society of Chemical Industry 相似文献
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一些根霉菌种产生毒素使其在发酵食品中的应用安全性受到了质疑.该文从毒素的研究进展和现状出发提出根霉菌可能存在的食品安全问题,并介绍文献资料在毒素研究过程中采用的一些新方法,希望从食品安全角度研究根霉菌的科学应用问题,为我国合理利用根霉菌发酵生产安全的发酵食品奠定基础. 相似文献
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Vadood Razavilar Constantin Genigeorgis 《International journal of food microbiology》1998,40(3):S53-157
The effects of concentration of NaCl (0.5 to 12.5%), methyl paraben (0.0 to 0.2%), sodium propionate (0.3%), sodium benzoate (0.1%), potassium sorbate (0.3%), pH (>5.9) temperature (4 to 30°C), storage time (up to 58 d) and inoculum (>105 to >10−2 per ml) on the log10 probability percentage of one cell of Listeria spp. to initiate growth in a broth system were evaluated in a factorial design study. At pH 5.96 and temperature ranging from 4 to 30°C the concentrations of sodium propionate, potassium sorbate, and sodium benzoate examined allowed growth of L. monocytogenes with lag phases at 4°C of 18, 27 and 21 days, respectively. For 0.1 and 0.2% methyl paraben growth of all Listeria spp. was initiated at 8°C and 30°C, respectively. At pH 6, concentration of 12% NaCl supported the growth of L. monocytogenes at 8 to 30°C, whereas 12.5% inhibited all Listeria species. Four regression equations were derived relating probability of growth initiation to temperature, concentrations of NaCl and preservatives storage time, and Listeria species specific effects. From these equations, the number of cells needed for growth initiation can be calculated. The impact of this type of quantitative study and its possible application on the development of microbial standards for foods is discussed. 相似文献