蛋清粉凝胶性与凝胶稳定性的研究   总被引：2，自引：1，他引：1  

胥伟  迟玉杰  孙强 《中国家禽》2012,34(2):22-24

研究蛋清粉在贮藏期间所成凝胶的质构、持水性以及微观结构的变化。结果显示,蛋清粉的凝胶硬度、弹性、粘结性、持水性分别为346g/cm2、0.905、0.382、52.00%,25℃下贮藏180d后,蛋清粉的凝胶硬度与粘结性较贮藏初期并无显著性变化(P>0.05),而凝胶弹性与持水性与贮藏初期相比差异性显著(P<0.05)。蛋清粉的溶解性随贮藏时间的延长呈下降趋势,但降幅很小,25℃下贮藏180d时与贮藏初期相比无显著性差异(P=0.154)。500倍扫描电镜(SEM)下观察蛋清粉所成凝胶,其结构空隙很大,分布疏松,随贮藏时间的延长无明显变化。研究结果表明,贮藏时间与温度对蛋清粉的溶解性影响很小,而对蛋清粉的凝胶性影响较大,含水量是影响蛋清粉凝胶稳定性的重要因素。  相似文献   

凝胶渗透色谱净化-气相色谱分离同时测定饲料中30种有机磷农药残留     

韩梅 《饲料工业》2012,33(5):51-54

文中建立了凝胶渗透色谱净化-气相色谱法同时测定饲料中敌敌畏、乐果等30种有机磷农药残留的方法。饲料样品用乙腈体系提取,采用凝胶色谱柱净化,毛细管色谱柱分离(DB-50+,30 m×0.25 mm×0.25μm),火焰光度检测器(FPD)检测,外标法定量。其方法检测限为5.6~54μg/kg,三水平添加回收率为71.3%~114.1%,RSD为0.3%~14.8%。方法简便、准确,并能满足饲料中多种有机磷农残测定的需要。  相似文献   

香蕉植株内生细菌群落的PCR-DGGE分析   总被引：1，自引：0，他引：1  

刘菲菲  李赤  刘勇勤  于莉 《果树学报》2012,(2):235-240

以健康香蕉植株和感染香蕉枯萎病菌Fusarium oxysporum f.sp.cubense(FOC)后的香蕉植株的根茎叶组织为材料,提取样品中的总DNA,扩增细菌的16S rDNA的V3可变区,对扩增产物进行DGGE电泳分析,并对其中18条优势条带进行切胶回收、克隆测序和系统发育分析。结果表明,香蕉健株与病株各组织中所含内生细菌的种群丰富度为根部>假茎>叶片;感病植株组织内生细菌种类比健康植株丰富;BLAST结果为大部分克隆序列与已知细菌16SrDNA基因序列的同源性较高(94%~100%),分别归属于蓝细菌门(Cyanobacteria)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、变形杆菌门(Proteobacterium)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和绿菌门(Chlorobi)7大类群;其中一个序列同源性较低(91%),可能代表新的分类单元。  相似文献   

混合农药对氟乐灵在固相表面光化学降解影响的研究     

岳永德陶庆会  刘根凤汤锋刘建兴  花日茂 《安徽农业大学学报》2005,32(4):411-414

以高压汞灯和太阳光为光源,研究氟乐灵在玻片、硅胶G、石英砂和膨润土表面的光化学降解.结果表明,在高压汞灯下,氟乐灵在玻片、硅胶G、石英砂和膨润土表面的光解半衰期分别为24.78、98.51、106.41和220.42 min.将7种农药分别与氟乐灵在硅胶G中以1:1混合,经太阳光照射,混合农药对氟乐灵均表现光敏化作用;剂量比为10:1时,表现为光猝灭效应;而1:5时,溴氰菊酯和氟氰菊酯仍为光猝灭作用,其余5种农药则表现为光敏化作用.在石英砂表面,丙烯菊酯使氟乐灵光解半衰期延长,氰戊菊酯则使氟乐灵在膨润土表面光稳定性增强,照光18 h后,氟乐灵单独处理降解率为27.05%,而与氰戊菊酯共存时,氟乐灵仅降解了5.41%.  相似文献   

HPAM/Cr3+弱凝胶调驱体系的室内研究   总被引：1，自引：0，他引：1  

罗跃  张艳芳  党娟华 《长江大学学报》2005,2(10):311-313

在室内研制了一种可供较高温度、高矿化度油藏深部调剖用的HPAM/Cr3 弱凝胶调驱体系.考察了聚合物浓度、交联剂浓度、稳定剂浓度、温度、矿化度以及pH值对成胶性能的影响.确定了HPAM/Cr3 弱凝胶体系的最佳形成条件:HPAM聚合物1200mg/L;铬交联剂J(以Cr3 计)浓度40mg/L;稳定剂W浓度40mg/L;体系pH值6～8;最佳使用温度70℃.HPAM/Cr3 弱凝胶体系可实现成胶时间可控,凝胶强度可调.  相似文献   

紫花苜蓿多叶型与三叶型品种同工酶的比较研究   总被引：7，自引：2，他引：5  

杜红梅  李志坚  周道玮  张维 《草业学报》2005,14(1):44-48

采用聚丙烯酰胺凝胶电泳技术,对国外2种多叶型苜蓿及国内外5种三叶型苜蓿幼苗的5种同工酶进行了测定,将酶谱数量化,应用SPSS统计软件求出各品种间的遗传一致度及欧氏遗传距离,并进行了聚类分析.结果表明:1)测定的5种同工酶中过氧化物酶(PER)、酯酶(EST)、淀粉酶(AMY)具有多态性,综合此3种酶酶谱可以鉴定供试的7个品种;2)2个多叶型品种具有一共同特征酶带PER-4,国内品种的过氧化物酶活性明显高于国外品种;3)品种间的遗传一致度为0.826～0.952,欧氏遗传距离为0.500～1.118,多叶型品种间遗传一致度为0.904,欧氏遗传距离为0.500;4)等级聚类分析结果为,以欧氏遗传距离0.400为分界,供试品种分为3类,2个多叶型品种为一类,其余的5种三叶型品种分为另两类.  相似文献   

Changes in the bacterial community and composition of fermentation products during ensiling of wilted Italian ryegrass and wilted guinea grass silages     

Yanbing Li  Naoki Nishino 《Animal Science Journal》2013,84(8):607-612

To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3‐Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre‐ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre‐ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre‐ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.  相似文献   

Susceptibility to Coolness at the Young Microspore Stage under High Nitrogen Supply in Rice (Oryza Sativa L.). Proteome Analysis of Mature Anthers     

《Plant Production Science》2013,16(3):212-218

Abstract

In vitro pollen germination experiment using agar plates showed that the growth under high nitrogen conditions enhanced the damage to pollen germination ability caused by the cooling at the young microspore stage. To clarify the physiological factors related to this damage to pollen germination, we performed the comparative proteome analysis of mature anthers and identified proteins that were changed by high nitrogen conditions or high nitrogen plus cooling conditions. Proteins were extracted from mature anther samples and separated by two-dimensional polyacrylamide gel electrophoresis. By comparing anther protein maps of the samples collected from the plants grown under standard nitrogen conditions, high nitrogen conditions and high nitrogen plus cooling conditions, we found 11 protein spots, which varied with the treatment. These protein spots were identified based on the rice proteome database and/or peptide mass fingerprinting (PMF) analysis after digestion with trypsin. Digested samples were analyzed by matrix-assisted laser desorption/ionization-time flight mass spectrometry to produce PMF data. Database searches using these PMF data revealed the identities of 9 proteins. Seven of these proteins were polypeptides involved in cell elongation, stress responses and sugar metabolism. The relation between the fluctuations of these proteins and the decrease in pollen germination are discussed.  相似文献   

Microbial composition and diversity of an upland red soil under long-term fertilization treatments as revealed by culture-dependent and culture-independent approaches   总被引：3，自引：2，他引：1  

Ji-Zheng He  Yong Zheng  Cheng-Rong Chen  Yuan-Qiu He  Li-Mei Zhang 《Journal of Soils and Sediments》2008,8(5):349-358

Background, aim, and scope  Fertilization is an important agricultural practice for increasing crop yields. In order to maintain the soil sustainability, it is important to monitor the effects of fertilizer applications on the shifts of soil microorganisms, which control the cycling of many nutrients in the soil. Here, culture-dependent and culture-independent approaches were used to analyze the soil bacterial and fungal quantities and community structure under seven fertilization treatments, including Control, Manure, Return (harvested peanut straw was returned to the plot), and chemical fertilizers of NPK, NP, NK, and PK. The objective of this study was to examine the effects on soil microbial composition and diversity of long-term organic and chemical fertilizer regimes in a Chinese upland red soil. Materials and methods  Soil samples were collected from a long-term experiment station at Yingtan (28°15′N, 116°55′E), Jiangxi Province of China. The soil samples (0–20 cm) from four individual plots per treatment were collected. The total numbers of culturable bacteria and fungi were determined as colony forming units (CFUs) and selected colonies were identified on agar plates by dilution plate methods. Moreover, soil DNAs were extracted and bacterial 16S rRNA genes and fungal 18S rRNA genes were polymerase chain reaction amplified, and then analyzed by denaturing gradient gel electrophoresis (DGGE), cloning, and sequencing. Results  The organic fertilizers, especially manure, induced the least culturable bacterial CFUs, but the highest bacterial diversity ascertained by DGGE banding patterns. Chemical fertilizers, on the other hand, had less effect on the bacterial composition and diversity, with the NK treatment having the lowest CFUs. For the fungal community, the manure treatment had the largest CFUs but much fewer DGGE bands, also with the NK treatment having the lowest CFUs. The conventional identification of representative bacterial and fungal genera showed that long-term fertilization treatments resulted in differences in soil microbial composition and diversity. In particular, 42.4% of the identified bacterial isolates were classified into members of Arthrobacter. For fungi, Aspergillus, Penicillium, and Mucor were the most prevalent three genera, which accounted for 46.6% of the total identified fungi. The long-term fertilization treatments resulted in different bacterial and fungal compositions ascertained by the culture-dependent and also the culture-independent approaches. Discussion  It was evident that more representative fungal genera appeared in organic treatments than other treatments, indicating that culturable fungi were more sensitive to organic than to chemical fertilizers. A very notable finding was that fungal CFUs appeared maximal in organic manure treatments. This was quite different from the bacterial CFUs in the manure, indicating that bacteria and fungi responded differently to the fertilization. Similar to bacteria, the minimum fungal CFUs were also observed in the NK treatment. This result provided evidence that phosphorus could be a key factor for microorganisms in the soil. Thus, despite the fact that culture-dependent techniques are not ideal for studies of the composition of natural microbial communities when used alone, they provide one of the more useful means of understanding the growth habit, development, and potential function of microorganisms from soil habitats. A combination of culture-dependent and culture-independent approaches is likely to reveal more complete information regarding the composition of soil microbial communities. Conclusions  Long-term fertilization had great effects on the soil bacterial and fungal communities. Organic fertilizer applications induced the least culturable bacterial CFUs but the highest bacterial diversity, while chemical fertilizer applications had less impact on soil bacterial community. The largest fungal CFUs were obtained, but much lower diversity was detected in the manure treatment. The lowest bacterial and also fungal CFUs were observed in the NK treatment. The long-term fertilization treatments resulted in different bacterial and fungal compositions ascertained by the culture-dependent and also the culture-independent approaches. Phosphorus fertilizer could be considered as a key factor to control the microbial CFUs and diversity in this Chinese upland red soil. Recommendations and perspectives  Soil fungi seem to be a more sensitive indicator of soil fertility than soil bacteria. Since the major limitation of molecular methods in soil microbial studies is the lack of discrimination between the living and dead, or active and dormant microorganisms, both culture-dependent and culture-independent methods should be used to appropriately characterize soil microbial diversity.  相似文献   

Eukaryotic communities associated with the decomposition of rice straw compost in a Japanese rice paddy field estimated by DGGE analysis     

Masashi?Hatamoto  Takanori?Tanahashi  Jun?Murase  Kazuo?Matsuya  Motoki?Hayashi  Makoto?Kimura  Susumu?AsakawaEmail author 《Biology and Fertility of Soils》2008,44(3):527-532

To estimate the succession and phylogenetic composition of the eukaryotic communities responsible for the decomposition of rice straw compost under flooded conditions during the cultivation period of paddy rice, denaturing gradient gel electrophoresis (DGGE) analysis targeting 18S rDNA followed by sequencing was conducted in a Japanese paddy field. The eukaryotic communities in rice straw compost incorporated into the flooded paddy field were influenced by the mid-season drainage and mainly composed of fungi (Ascomycota, Zygomycota, and Chytridiomycota) and protozoa (Ciliophora, Euglyphida, and Dactylopodida), most of which existed continuously during the cultivation period of paddy rice. The results indicated that these eukaryotic members were associated with the decomposition of rice straw compost in paddy field soil directly or indirectly.  相似文献