NaCl对足球菌ISK—1的发酵产物足球菌素ISK—1活性的影响

研究了足球菌ＩＳＫ－１发酵中ＮａＣｌ对足球菌素ＩＳＫ－１活性的影响。在ＭＲＳ培养基中添加８％的ＮａＣｌ，发酵２１￣２４ｈ，足球菌素ＩＳＫ－１活性达到最高，比无ＮａＣｌ时提高２５％。表明ＮａＣｌ具有提高足球菌素ＩＳＫ－１活性的作用。     

江米酒乳凝固特性研究

凝乳剂江米酒凝乳的最适温度范围为４０～４５℃;在ｐＨ值为５．５２～８．２范围内凝乳活力随ｐＨ值降低耐增大;江米酒大ｐＨ值为３．２５～４．７５范围内保证良好的稳定性（活力〉８０％;经７０℃、３０ｍｉｎ加热处理,凝乳活力损失８５％;Ｎａ＾＋、Ｋ＾＋、Ｃｕ＾２＋表现微弱的抑制作用,Ｍｇ＾２＋、Ｃａ＾２＋、Ｂａ＾２＋、Ｍｎ＾２＋、Ａｌ＾２＋、Ｆｅ＾２＋表现明显的促进作用;与皱胃酶、胃蛋白酶相比,江米酒具有     

高白度红麻皮浆制浆工艺的研究

采用添加表面活性剂的ＭＳＳ－ＡＱ法，在选用的蒸煮条件下，蒸煮液中Ｎａ２Ｓ／（Ｎａ２Ｓ＋Ｎａ２ＳＯ３）的摩尔比在０．０５至０．０８的范围内，所制得红麻皮粗浆硬度较低。与ＡＳ－ＡＱ法相比较，红麻皮ＭＳＳ－ＡＱ法浆硬度低８个Ｋ值单位。ＭＳＳ－ＡＱ法中添加０．２％表面活性剂可使硬度明显降低。采用新型的ＨＡＰ方式漂白，运用正交试验法，找到了Ｈ段用氯量５％，Ｐ段Ｈ２Ｏ２用量０．７％，可将白度４０．５％的未漂浆漂到白度８４．８％。漂白红麻皮浆在ＰＦＩ磨中打浆至３８．５°ＳＲ，手抄纸页裂断长可达７．１４Ｋｍ，透气度４５ｍｌ／ｍｉｎ。     

东台吉乃尔湖晶间卤水兑卤制取高品位钾镁混盐研究

本文依据Ｎａ＾＋，Ｋ＾＋Ｍｇ＾２＋∥Ｃｌ＾－，ＳＯ＾２－４－Ｈ２Ｏ五元水盐体系相图理论，通过兑卤改变东台吉乃尔湖晶间卤水组成的原始状态点，利用自然蒸发使卤水中的钠、钾得到有效地分离，获得含钠仅１．３２％的高品位的钾镁混盐，为制取硫酸钾提供了优越的条件。     

25℃Na^＋,K^＋∥Cl^—,SO^2—4—H3BO3—H2O体系相平衡研究

实验测定了２５℃Ｎａ＾＋,Ｋ＾＋∥Ｃｌ％－２,ＳＯ＾２－４－Ｈ３ＢＯ３－Ｈ２Ｏ五元体系的溶解度关对所绘相图进行了分析,讨论了硼酸的分离及其对硫酸钠转化制硫酸钾的影响。     

谈制丝用水的水质组成与茧层丝胶溶解性的定量关系

本文在前人研究的基础上结合生产实际，对制丝用水的水质组成与茧层丝胶溶解性的定量关系提出了新的表达式：Ｓ＝Ｓｏ．Ｋ＾Ｍ１Ｋ＾－Ｈ２（Ｋ１＞Ｋ２）。     

金属离子对桑椹红色素稳定性影响

研究了几种常见金属离子Ｋ＾＋、Ｎａ＾＋、Ｚｎ＾２＋、Ｍｇ＾２＋、Ｃａ＾２＋、Ｆｅ＾３＋、Ｓｎ＾２＋、Ｃｕ＾２＋等对桑椹红色素的稳定性的影响。     

黑芝麻色素的提取条件和稳定性研究

对黑芝麻色素的提取条件及其光谱特性和稳定性等进行了较系统的研究，结果表明：黑芝麻色素的最佳提取条件是以一定浓度的酸性醇溶液为溶剂，保持提取温度为８０℃，时间３ｈ，物料比为１：５０，黑芝麻色素呈天然黑褐色，对自然光，紫外光，温度（２５℃－１００℃，酸碱度（ｐＨ４－８），抗氧化剂（茶多酚），金属离子（Ａｌ＾３＋，Ｃａ＾２＋，Ｋ＾＋，Ｚｎ＾２＋，Ｍｎ＾２＋，Ｍｇ＾２＋），均表现较稳定，是一种优良的天然色     

扎仓茶卡盐湖卤水25℃等温蒸发实验

为了研究扎仓茶卡盐湖卤水蒸发时的相化学，确定钾盐，锂盐的结晶过程和结晶特性，在实验室内卤化进行了２５℃等温蒸发结晶过程的研究。实验结果与Ｎａ＾＋，Ｋ＾＋，Ｍｇ＾＋＋－／Ｃｌ＾－，Ｓｏ＾＝－Ｈ２Ｏ五元水盐体系介稳相图进行了比较与讨论。     

放大反应滴定法测定食品中的微量碘

依据Ｉ－的还原性的Ｉ２的氧化性原理，通过Ｂｒ２氧化样品中的微量Ｉ－为ＩＯ＾－３，而后煮沸除去Ｂｒ２，加过量ＫＩ并酸化，然后将反应生成的Ｉ２用ＣＨＣｌ３萃取，再用ｐＨ１１－１２碱液反萃取，再重复前述氧化反应等步骤，这时样品的微量碘已被放大了３６倍，最后用低浓度标准Ｎａ２Ｓ２Ｏ３溶液滴定，测出食品中微量碘的含量。     

Heterologous expression and functional analysis of the gene cluster for the biosynthesis of and immunity to the lantibiotic, nukacin ISK-1

Nukacin ISK-1 is a lantibiotic produced by Staphylococcus warneri ISK-1. The gene cluster of nukacin ISK-1 consists of at least nukAMTFEG, ORF1 and ORF7. In this study, we demonstrated the heterologous production of nukacin ISK-1 in Lactococcus lactis by the artificial polycistronic expression of nukAMTFEG-ORF7 under the control of the nisin-controlled expression (NICE) system. Consequently, the recombinant L. lactis showed antimicrobial activity. Mass analysis clarified the presence of nukacin ISK-1 produced in the culture supernatant. These results suggested that the recombinant L. lactis produced nukacin ISK-1 heterologously. Inactivation of nukA, -M or -T resulted in the complete loss of the nukacin ISK-1 production phenotype. This finding suggested that nukAMT are indispensably associated with the biosynthesis of nukacin ISK-1. To our knowledge, this is the first report of the heterologous production of lantibiotic using the NICE system.     

Physical mapping of a centromere-proximal region of chromosome IV-l defines the placement of genes USO1, MBP1, PSA1 and SLC1

A physical map of a 14·5 kb region close to the centromere on the left arm of chromosome IV of Saccharomyces cerevisiae is presented. This map has been constructed by restriction analysis of a clone from a YCp50 genomic library and by use of pre-existing and new sequence data from this region. The map reveals the following gene order (reading from the most centromere-distal to the most centromere-proximal locus): USO1/INT1–MBP1–PSA1–SLC1–YLA1 and defines the size of the open reading frames and intergenic regions.     

1-羧乙基氨基-1-脱氧-D-果糖在氦气中的热解产物分析

采用在线裂解GC/MS技术研究了1-羧乙基氨基-1-脱氧-D-果糖在300、500和800℃下于氦气中的热解产物。结果表明:①温度不同其热解产物亦不同,高温下热解产物较多;②热解产物大部分为杂环类化合物如吡嗪、甲基吡嗪、吡啶、呋喃酮、吡唑、吡咯和吡喃酮等,这些物质都是卷烟烟气中重要的致香成分。     

Origin and practical significance of the sticky dough factor in 1BL/1RS wheats

When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, β‐glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water‐soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non‐1BL/1RS doughs. Significant genotype–environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non‐1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high‐speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture. © 2002 Society of Chemical Industry     

Thermodynamic characterization of the PR-10 allergens Bet v 1, Api g 1 and Dau c 1 and pH-dependence of nApi g 1 and nDau c 1

Natural and recombinant Bet v 1, the major birch pollen allergen, and homologous allergens, Api g 1 and Dau c 1, from celery and carrot, respectively, were studied by CD spectroscopy under conditions of varying denaturant concentration, pH and temperature to determine fundamental thermodynamic parameters for conformational stability. Thermodynamic studies increase basic knowledge regarding differences between birch pollen-related allergens and are of importance in choosing processing conditions. The conformational stability determined from guanidine hydrochloride denaturation curves was similar for rBet v 1.0101 and rApi g 1.0101. Conformational responses to chaotropic salt were different for recombinant allergens from different species, but were similar for the natural isoform mixtures. The conformational stabilities of nApi g 1 and nDau c 1, were shown to be similar to rBet v 1.2801 at pH > 4.4 [Mogensen, J. E., Ipsen, H., Holm, J., & Otzen, D. E. (2004). Elimination of a misfolded folding intermediate by a single point mutation. Biochemistry, 43(12), 3357-3367], but nApi g and nDau c 1 were stable to heating at lower pH-values.     

甲型H1N1流感解读

2009年3月底墨西哥暴发了"人感染猪流感"疫情,该疫情迅速在全球范围内蔓延,对人类造成了巨大的威胁,引起了世界各国的重视。本文介绍了上世纪以来全球暴发的主要流感疫情,并对此次流感疫情的病原学、流行病学、防控以及治疗措施做了详细介绍。     

Suppression of sdh1 mutations by the SDH1b gene of Saccharomyces cerevisiae

Transformation of the respiratory-defective mutant (E264/U2) of Saccharomyces cerevisiae with a yeast genomic library yielded two different plasmids capable of restoring the ability of the mutant to grow on non-fermentable substrates. One of the plasmids (pG52/T3) contained SDH1 coding for the flavoprotein subunit of mitochondrial succinate dehydrogenase. The absence of detectable succinate dehydrogenase activity in mitochondria of E264/U2 and the lack of complementation of the mutant by an sdh11null strain indicated a mutation in SDH1. The second plasmid (pG52/T8) had an insert with reading frame (YJL045w) of yeast chromosome X coding for a homologue of SDH1. Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional. The expression of the two genes was compared by assaying the β-galactosidase activities of yeast transformed with plasmids containing fusions of lacZ to the upstream regions of SDH1 and SDH1b. The 100–500 times lower activity measured in transformants harbouring the SDH1b-lacZ fusion indicates that the isoenzyme encoded by SDH1b is unlikely to play an important role in mitochondrial respiration. This is also supported by the absence of any obvious phenotype in cells with a disrupted copy of SDH1b. © 1998 John Wiley & Sons, Ltd.