响应面法优化工业大麻叶抑制金黄色葡萄球菌物质超声提取工艺

为提升工业大麻叶生理活性功能,研究工业大麻叶抑菌物质的最佳超声提取工艺。采用牛津杯法结合微量二倍稀释法比较工业大麻叶乙醇提取物对金黄色葡萄球菌、大肠杆菌、单核细胞李斯特菌、沙门氏菌的抑菌作用,并以抑菌效果最佳的金黄色葡萄球菌为供试菌,在单因素试验基础上,以抑菌圈直径为响应值,采用Box-Behnken响应面法优化超声辅助浸提工业大麻叶抑菌物质的工艺参数。结果表明,最佳提取工艺条件为液料比14∶1(m L/g),乙醇浓度88%,超声温度29℃,超声时间20 min,在该条件下,工业大麻叶提取物对金黄色葡萄球菌的抑菌圈直径达(19. 65±0. 20) mm,与理论最优值19. 68 mm接近。该工艺稳定可靠,适用于工业大麻叶中抗金黄色葡萄球菌物质的超声提取,可为工业大麻叶的高效利用及新型防腐剂的开发提供理论依据。     

3种辣椒超临界提取物的抑菌评价研究

以红辣椒、青线椒和黄灯笼辣椒的超临界二氧化碳提取物为原料,进行体外抑菌试验,比较分析以上3种辣椒油树脂对鸡的大肠杆菌、沙门氏菌和金黄色葡萄球菌的抑菌作用。试验结果表明：海南黄灯笼辣椒提取物对大肠杆菌和沙门氏菌的抑菌效果均优于青辣椒和红辣椒;对金黄色葡萄球菌的抑菌作用与红辣椒相当,但低于青辣椒。青辣椒提取物的丙酮溶液对大肠杆菌、沙门氏菌和金黄色葡萄球菌的最低抑菌浓度分别为0.75、0.6和0.9 mg/mL,最低杀菌浓度分别为0.9、0.75和1.2 mg/mL;海南黄灯笼辣椒提取物的丙酮溶液对大肠杆菌、沙门氏菌和金黄色葡萄球菌的最低抑菌浓度分别为0.6、0.45和1.2 mg/mL,最低杀菌浓度分别为0.75、0.6和1.5 mg/mL;红辣椒提取物的丙酮溶液对大肠杆菌、沙门氏菌和金黄色葡萄球菌的最低抑菌浓度分别为0.9、0.9和1.2 mg/mL,最低杀菌浓度分别为1.2、1.2和1.5 mg/mL。     

柳蒿不同溶剂萃取物抑菌活性研究

目的考察柳蒿不同溶剂提取物对大肠杆菌和金黄色葡萄球菌的抑菌效果。方法采用滤纸片固相扩散法和二倍稀释法研究了柳蒿水提取物、95%乙醇提取物、乙酸乙酯提取物对大肠杆菌及金黄色葡萄球菌的抑菌活性及最低抑菌浓度(MIC)。结果由抑菌直径可知,各提取液抑菌活性顺序为:乙酸乙酯提取液乙醇提取液水提取液,不同提取液对金黄色葡萄球菌、大肠杆菌的MIC分别为:乙酸乙酯提取液为50 mg/m L、3.125 mg/m L;乙醇提取液为100 mg/m L、12.5 mg/m L;水提取液为100 mg/m L、25 mg/m L。结论不同提取液抑菌效果不同,其中乙酸乙酯提取液抑菌效果最好。     

纳豆芽胞杆菌抑菌活性研究

为了研究纳豆芽胞杆菌高抑菌活性的最佳发酵条件,以苏云金芽孢杆菌和大肠杆菌为指示菌,采用滤纸片法,分别考察了培养时间、培养温度、培养基盐度、碳源、氮源及纳豆菌发酵粗提液浓度等因素对两种指示菌的抑制效果。结果表明：随着培养时间和粗提液浓度的提高,苏云金芽孢杆菌和大肠杆菌的抑菌圈直径先增后减;培养温度为37℃时苏云金芽孢杆菌的抑菌圈最大,42℃时大肠杆菌的抑菌圈最大;盐度为1%时,粗提液对苏云金芽孢杆菌和大肠杆菌的抑菌效果最好;碳源为牛肉膏时苏云金芽孢杆菌的抑菌圈最大,碳源为乳糖时大肠杆菌的抑菌圈最大;氮源为蛋白胨时苏云金芽孢杆菌的抑菌圈最大,氮源为硫酸铵时大肠杆菌的抑菌圈最大。正交法考察纳豆菌抑菌物质粗提液抑制两株指示菌的最优条件为培养时间36 h,粗提液浓度为100%,培养基盐度为1.5%。     

茶饮料的抗生活性研究

试验对酵母发酵的绿茶饮料抗生活性进行了研究。结果表明,采用平板法培养,发酵36小时的绿茶汁对大肠杆菌和金黄色葡萄球菌抑制率分别为98％和100％。液体培养法,发酵48～60小时绿茶汁对乳酸杆菌增生45．1％,对双歧杆菌作用不显著。另外,乙醇、茶多酚与有机酸对大肠杆菌和金黄色葡萄球菌均具有明显抑制作用;茶多酚对乳酸杆菌有一定促生效果。     

罗布麻茎叶粗提物及脱胶纤维的抑菌活性分析

文章研究了罗布麻茎叶粗提物对大肠杆菌、金黄色葡萄球菌和黄曲霉的抑菌活性和最小抑菌浓度,并定性分析了脱胶后的罗布麻纤维对上述类型微生物的抑制效果。结果表明,罗布麻茎叶粗提物对黄曲霉和金黄色葡萄球菌的抑制效果较为明显,对大肠杆菌抑制效果稍差,其中,罗布白麻和罗布红麻对黄曲霉菌的最小抑菌浓度分别为5、7.5 mg/mL,对金黄色葡萄球菌最小抑菌浓度均为7.5 mg/mL,而对大肠杆菌的最小抑菌浓度分别为10、15 mg/mL;定性分析发现,经脱胶后的罗布麻纤维仍对细菌类的金黄色葡萄球菌和大肠杆菌具有一定的抑制作用,但对霉菌类的黄曲霉无明显抑制作用。     

纳豆食品的研制

纳豆是以大豆为主要原料,经纳豆芽孢杆菌发酵而成,它具有溶血栓、抗肿瘤、助消化、预防骨质疏松等功效,但大豆经发酵后会产生难闻的氨味,颜色变暗,豆不成粒等现象,严重影响了产品的口味及外观,本实验为开发适合国人口味的新型纳豆食品,反复筛选了纳豆杆菌,对发酵条件进行了许多次探索,并加进了多种调味品,综合纳豆成品的外观及口味,最终确定:大豆浸泡时间为24h,接种量4%,加盐、糖比例为1:2,发酵时间为40h.     

油樟油抑制细菌生长的活性试验

为检测抑菌效果,对6种细菌的最低抑菌浓度(MIC)、最低杀菌浓度(MBC)和生长量进行了测定。实验结果表明,油樟油的MIC在12.5～3.13μL/ mL,MBC在25～3.13 μL/ mL,生长量在72 h内细菌生长仍受到抑制。抑制大肠杆菌效果最强,抑制金黄色葡萄球菌效果最弱。     

天然果皮洗涤剂的抑菌实验研究

目的:对新型洗涤剂的抑菌效果进行试验,为这种天然果皮洗涤剂的推广提供依据.方法:采用抑菌环法、二倍稀释法和悬液定量法进行抑菌实验.结果:大肠杆菌最小的抑菌浓度为25%,金黄色葡萄球菌最小的抑菌浓度为20%,沙门氏菌最小的抑菌浓度为25%.结论:这种天然果皮洗涤剂对大肠杆菌、金黄色葡萄球菌和沙门氏菌均有抑菌作用。     

玉米内生细菌YY1菌株高产抗菌物质的发酵条件优化

玉米内生细菌YY1菌株为枯草芽孢杆菌,对玉米大斑病菌(Setosphaeria turcica)有强烈的拮抗作用,通过产生抗菌物质发挥抑菌活性。以培养基的无菌滤液对玉米大斑病菌的拮抗活性为检测指标,确定其产生抗菌物质所需要的最佳碳源、氮源及无机盐,通过正交试验得到该菌株产生抗菌物质的培养基配方,并对其发酵工艺条件进行优化。结果表明,最佳培养基为可溶性淀粉3.0%,蛋白胨2.0%,KH2PO40.02%,MnCl20.01%。发酵工艺参数优化结果为培养基装液量30 mL/250 mL,接种量4%,培养基初始pH值为9.0,28℃条件下、120 r/min摇床振荡培养48 h。经发酵条件优化后,其抗菌活性有显著提高。     

豫北优质大豆产业发展策略

针对豫北地区的大豆生产现状，从气候、土壤、品种、生态因素及市场需求等方面提出了优质大豆的发展策略与途径。     

湖南沅陵4种绿茶品质成分分析

以长沙县高桥相同嫩度茶鲜叶原料采用卷曲形毛尖茶加工工艺制绿茶为对照,分别对沅陵县齐眉翠峰、凤娇碣滩茶、干发茶和军大坪茶4种绿茶的主要生化成分与感官品质进行初步分析。结果表明,沅陵4种绿茶的茶多酚总量28.76%~30.34%,游离氨基酸总量2.35%~3.22%,咖啡碱含量3.00%~3.63%,水浸出物含量37.26%~40.07%,可溶性糖总量5.46%~5.65%,可溶性蛋白含量1.50%~1.74%,类黄酮化合物总量1.16%~1.79%,叶绿素总量1.36%~2.01%,儿茶素总量13.53%~16.20%。与对照相比,4种绿茶的茶多酚、可溶性糖和儿茶素总量均高于对照,除齐眉翠峰外其余3种茶样水浸出物和叶绿素总量均高于对照,除干发茶外其余3种茶样类黄酮化合物总量均高于对照。     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。     

Comparisons of methods of scheduling irrigations of potatoes

Irrigation of Netted Gem potatoes was scheduled during three growing seasons by three methods: (a) when plants displayed first visual symptoms of moisture stress, (b) when indicated by a soil moisture budget involving estimated evapotranspiration, and (c) on the basis of tensiometer readings of soil moisture suction. When the tensiometer method of scheduling was used, the mean yields of tubers were 55.0 and 25.8 cwt/acre (6160 and 2890 kg/ha) higher than those obtained with the other two scheduling methods. Methods did not affect the specific gravity of potatoes. Method (a) scheduled irrigations least frequently. Scheduling by the budget method was not always adequate because it was based on the assumption that the crop extracted water from a constant 4 ft (1.2 m) profile from planting to full vegetative growth. In one year the budget method scheduled the first irrigation earlier than necessary and delayed the second irrigation during a critical period of crop growth. From full vegetative cover to harvest the irrigation schedules were alike for both the budget and tensiometer methods.     

吉林省平安农业科学院大豆所大豆研究工作报告

1　吉林省平安农业科学院大豆研究工作简介吉林省平安农业科学院大豆研究所 ,设在吉林省长春市西安大路种子大厦内。现有科技人员 6人 ,其中研究员 2人 ,农艺师 2人 ,技术员 2人 ,定向培养研究生 2人。大豆研究所的主要任务是选育稳产、高产、优质及抗病虫大豆新品种 ;同时密切     

Comparison of two methods of PCNB application for control of Rhizoctonia infection of potatoes

A broadcast application of PCNB (Terraclor) resulted in a reasonably uniform distribution of the chemical in the soil with the concentration decreasing in a linear fashion with increasing depth in the soil profile. A banded application resuluted in a considerably higher chemical concentration at the 4–6 inch depth than at the 0–2 or the 2–4 inch depths. The problem of the lack of uniformity of chemical distribution could probably be solved by altering nozzle placement and size and allow use of the band method of application to minimize grower cost. More complete disking in the case of the broadcast treatment would probably result in a relatively uniform distribution of the chemical but at higher cost to the grower. PCNB application rates of 10, 15 and 25 lbs per acre broadcast and 71/2, 10 and 121/2 lbs per acre in a band significantly reduced the severity ofRhizoctonia infection of Russet Burbank potatoes but did not increase potato yields significantly.     

Prediction of the digestibility of the diet of horses: evaluation of faecal indices

Data from in vivo digestibility trial with four to six horses fed twenty-seven forage-based diets are used to calculate prediction equations for the digestibility of dry and organic matter, based on the crude ash (CA), crude protein (CP) and crude fibre (CF) contents of diets and faeces. The most precise prediction of dry-matter digestibility (r.s.d. = 0.032, R²= 0.80) was derived from a multiple regression including faecal (CP, CF) and dietary parameters (CF). Among faecal parameters, CP was the best single predictor of both digestibility (r.s.d) = 0.040, r²= 0.63) and dietary CP content (r.s.d = 0.028, r²= 0.59). For biological reasons we propose a non-linear model that allows prediction of dry- and organic-matter digestibility from faecal CP Content with reasonable Precision (r.s.d = 0.038, 0.036, r²= 0.65, 0.74, respectively). This will be adequate for many studies, especially for free-living animals in rangelands.     

橡胶树丛枝病病原的抗血清制备与应用

以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为１：２０４８。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达３０％－３７％,可疑的褐皮病树检出率达８５．７％。