排序方式: 共有98条查询结果,搜索用时 0 毫秒
61.
研究了藻-菌混合培养(M)、添加NaHCO_3培养(C)以及二者的结合培养(MC)对栅藻生长和脂类合成的影响。将从栅藻培养液中分离的4种微生物与栅藻进行混合培养,筛选出对栅藻生长促进效果最佳的细菌B_1,并确定栅藻与B_1的最佳接种比例;确定添加NaHCO_3培养的最佳NaHCO_3质量浓度;按照确定的最佳参数进行M、C和MC实验,测定每种培养方式的生长指标和脂质合成指标,并与栅藻单独培养进行对比分析。结果表明:与栅藻单独培养相比,M、C和MC的生物量分别提高了68.3%、98.8%、195.1%,脂类含量提高35.6%、41.6%、50.4%,脂肪酸组成中的C18∶1总含量提高了17.0%、30.9%、47.4%。因此,MC比M和C更高效,是一种有潜在应用价值的生物柴油原料生产模式。 相似文献
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以斜生栅藻FACHB-12为原料,采用BG11、F/2和SE 3种培养基对其培养。通过对生物量、生长速率、油脂含量、油脂组分以及脂肪酸组成的测定,比较不同培养基对斜生栅藻生长和油脂积累的影响。结果表明:BG11培养基更有利于斜生栅藻的生长,而F/2培养基更适合油脂以及中性脂的积累;斜生栅藻在BG11培养基中比生长速率为0.095,培养15 d生物量为0.36 g/L,叶绿素a含量达到1.23 mg/L;而在F/2培养基中油脂含量可达细胞干重的24.75%,其中中性脂占总脂的36.64%,产率达0.98 mg/(L·d);并且在F/2培养基中斜生栅藻脂肪酸组成以C16∶0和C18∶1为主,含量分别占总脂肪酸的25.84%和54.47%,更适合作为制备生物柴油的原料。 相似文献
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Jayati Trivedi Neeraj Atray Deepti Agrawal 《European Journal of Lipid Science and Technology》2020,122(4)
Among various renewable energy sources, the production of biofuels derived from algal lipids holds bright prospects. One of the major roadblocks in the successful commercialization of microalgal biofuels is the existing energy‐intensive lipid extraction. In the present investigation, an attempt is made to assess aqueous lipid extraction strategies from oleaginous Scenedesmus obliquus at a high solid loading of 15% (w/v). In this study, four surfactants and five enzymes are evaluated for cell disruption of S. obliquus. It is the first report citing cetyl pyridinium bromide as the most suitable cationic detergent for surfactant‐assisted extraction, with a lipid recovery as high as 31.4%. However, during the evaluation of enzyme‐based cell disruption, neutral protease emerges as the best biocatalyst resulting in a lipid recovery of ≈75%. Total lipid extraction is accomplished using a two solvent system comprising of water‐immiscible ethyl acetate, followed by chloroform addition. The study revalidates the fact that the biochemical composition of Scenedesmus sp. plays a vital role while identifying and formulating an efficient and green process for microalgal cell disruption for enhanced lipid extraction under aqueous conditions. Practical Applications: The results of the present study demonstrate that if the biochemical composition of any oleaginous algal cell wall is known, aqueous enzymatic lipid extraction can be employed rather than taking up the conventional route of drying followed by Soxhlet extraction. The combination of using the cheap sources of enzymes and water‐immiscible green solvents like ethyl acetate can be lucrative downstream procedures for the lipid recovery from wet algal biomass when compared to traditional procedures. 相似文献
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Safety shoe designs are primarily based on safety requirements. But all-day comfort should not be luxury: Heel strike associated impact loads on joints need to be compensated by active muscular effort and safety shoes should support this protective function of muscle activation. In 10 healthy men, 12 trunk and leg muscles were analyzed with surface electromyography. Subjects walked on a walkway while wearing different safety shoes with the test shoes being equipped with exchangeable cushioning heel inserts according to individuals' body weight. While wearing the optimally cushioned shoes the cumulative muscle activity per distance travelled dropped clearly compared to the regular safety shoes, demonstrating reduced muscular effort. Also, the heel strike associated amplitude peak of back muscles occurred earlier within the stride while wearing the test shoes. Thus weight-balanced cushioning heel inserts in safety shoes proved able to reduce muscle strain, logically delaying muscular fatigue and extending muscular joint protection.Relevance to industryAdjustable heel inserts in safety shoes are suited to improve the health status of employees by reducing muscular effort so that active joint protection can be prolonged. 相似文献
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酮类化合物急性毒性的测定与评价 总被引:3,自引:0,他引:3
用生物检测的方法,测试酮类化合物抑制斜生栅列藻生长的半数有效浓度EC50值,依其毒性的大小确定毒性级别,评估18种酮类化合物对水生生物的安全性,同时预测环境安全浓度。实验结果表明:2,3-丁二酮毒性级别最高,丙酮毒性级别最低。 相似文献
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研究桦褐孔茵发酵胞外多糖的抗氧化活性。采用液体深层发酵培养桦褐孔菌,利用水溶醇沉法从发酵液中分离提取胞外多糖EPS,中性蛋白酶+Sevage试剂法对EPS去除蛋白分离得到多糖DEPS。DEPS经DEAE-52阴离子交换色谱和SephadexG-200凝胶色谱柱层析后得到三个多糖级份,其中,具有较高蛋白质和甘露糖含量以及具有较低分子量的级份DEPS2和DEPS3的抗氧化活性较好。表明桦褐孔菌胞外多糖的抗氧化活性与其蛋白质、甘露糖含量及分子量有关。 相似文献
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为研究大孔吸附树脂纯化桦褐孔菌三萜的工艺,筛选了适宜的大孔吸附树脂,并以吸附率和解析率为指标,利用最适的树脂进行对桦褐孔菌的静态吸附和解析的条件优化,研究了上样液体积、吸附时间、样液pH值、解析时间、解析液种类和解析液浓度的影响,确定纯化工艺参数。结果表明:在供试的5种大孔吸附树脂中,AB-8型大孔吸附树脂适合分离桦褐孔菌三萜。最佳分离条件为:样液在自然pH值条件下,按10mL/g树脂进行吸附12h后利用蒸馏水除去未吸附的样液后选择30%乙醇及70%乙醇进行依次解析12h,此时三萜的吸附率和解析率分别可达93%和80%以上。表明AB-8型大孔吸附树脂纯化桦褐孔菌三萜的效果较佳。 相似文献
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Fengyuan Lin Xiao Li Xiao Guo Xuechun Lu Xiao Han GuangYu Xu Peige Du Liping An 《Food Science & Nutrition》2023,11(1):191-203
The purpose of this study was to observe the effect of Inonotus obliquus polysaccharide (IOP) on blood lipids and its regulation on the intestinal flora in hyperlipidemia rats, and explore the modern biological connotation of IOP in reducing blood lipids. In this study, we obtained the crude IOP by the water extraction and alcohol precipitation method, and then classified it by DEAE ion-exchange chromatography to obtain the acidic I. obliquus polysaccharide (IOP-A). After the administration of the IOP-A, the serum TC, TG, and LDL-C levels were significantly lower, while the serum HDL-C levels were significantly higher. The expression of CYP7A1 protein was considerably increased, whereas the expression of SREBP-1C protein was considerably decreased in the rat hepatic tissue. In addition, the IOP-A could significantly alleviate the hepatocyte fatty degeneration in the liver lobule of rats. We believe that the IOP-A can affect the composition of intestinal flora by reducing the relative abundance of Firmicutes and increasing the relative abundance of Bacteroidetes. These findings indicated that the IOP-A can regulate the dyslipidemia of hyperlipidemia rats, and its mechanism may be through regulating the CYP7A1 and SREBP-1C expression in the metabolism of lipids, and correcting the imbalance of intestinal flora structure caused by a high-fat diet. 相似文献