Ethylene Production by Albedo Tissue of Satsuma Mandarin (Citrus unshiu Marc.) Fruit

Isolated albedo tissue of Satsuma mandarin (Citrus unshiu Marcovitch, cv. Owari) fruit produced a large quantity of ethylene during incubation at 26 C in the dark. When sliced, albedo tissue began producing ethylene at an increasing rate until a maximum was reached after incubation for about 30 hours. Aged albedo discs which were capable of producing ethylene, actively converted l-[U-(14)C]methionine into both ethylene and carbon dioxide. In fresh tissue, almost no measurable conversion of radioactive methionine into ethylene took place. Conversion of labeled l-methionine into ethylene was totally inhibited by the addition of nonradioactive l-methionine or l-ethionine. It appears possible, from these findings, that methionine is a precursor of ethylene in the aged albedo discs. Ethylene synthesis in the aged albedo tissue was markedly reduced in the presence of cycloheximide, suggesting that there may be a rapid turnover of the ethylene-producing system, and that its formation involves protein synthesis. Actinomycin D exerted no effect.     

Fruit Malformation of Satsuma Mandarin (Citrus unshiu Marc.) Infected by Citrus Yellow Vein Clearing Virus

In 2013–2014, malformed young Satsuma mandarin (Citrus unshiu Marc.) fruits were found in Xunwu County, Jiangxi Province, China. Common disease symptoms include slightly curled and backward‐twisted spring leaves, cracked and deformed leaf edges, thickly grown spring twigs with twisted and slightly bent shoots, and malformed young fruits where groovelike depression forms from the upper portion and resembles a pumpkin. On the basis of the morphological characteristics, sequencing results and phylogenetic analysis of the infected plant, we identified the disease as citrus yellow vein clearing, which is caused by Citrus yellow vein clearing virus (CYVCV). To our knowledge, this study is the first to report CYVCV infecting Satsuma mandarin.     

超声波辅助提取褐藻糖胶活性成分优化研究

研究了超声波辅助提取褐藻糖胶的新工艺,以“硫酸根+多糖”质量分数作为产品的主要理化指标,得到优化的提取工艺。硫酸根和多糖质量分数分别达到22.49%和36.97%。     

Bacteriology of Spoilage of Fish Muscle: I. Sterile Press Juice as a Suitable Experimental Medium

A sterile raw fish muscle press juice, diluted 1:4 with saline, has been prepared. This dilution greatly facilitated Seitz filtration and affected the spoilage properties of the medium only negligibly. At 5.5 C, the spoilage pattern of naturally contaminated diluted juice was almost identical to that of naturally contaminated fillets. This was shown by comparing the quantitative and qualitative aspects of the bacterial flora on the two substrates and by measuring the production of volatile reducing substances (VRS) and of trimethylamine (TMA). With the sterile raw muscle press juice, some preliminary data showed that individual members of the genera Achromobacter and Pseudomonas differ markedly in their spoilage capabilities: some grew but did not produce spoilage detectable either organoleptically or chemically; others gave rise to strong off odors and to high levels of VRS and TMA.     

应用双水相萃取技术提取香菇多糖的研究

利用聚乙二醇(PEG)-硫酸铵双水相体系提取香菇多糖,研究了不同PEG-硫酸铵组成的双水相体系对香菇多糖分配比和收率的影响。结果表明:PEG分子量在6000时对香菇多糖的提取效果较好;PEG6000浓度在24%时、硫酸铵浓度在30%时组成的双水相体系提取香菇多糖的效果最好,此时香菇多糖的分配系数(K)可达到1.90,收率(Y)可达到57.42%。     

Trichophytin Extraction: Biological Comparison of Trichophytin Extracted from Trichophyton mentagrophytes Grown in a Complex Medium and a Defined Medium

The extraction of antigens (trichophytin) from Trichophyton mentagrophytes var. asteroides grown in both a complex medium and a defined medium proved to be reproducible and feasible. These extracts were first evaluated by skin testing in both infected and noninfected guinea pigs. Further evaluation and standardization was accomplished in selected humans by comparing these antigens to a trichophytin known to elicit allergic reactions to the dermatophytes. The trichophytins produced by this extraction procedure gave no false positive (or negative) skin test reactions. These antigens did, however, reliably elicit allergic sensitivity of both the immediate and delayed type. The potency of both complex and defined media antigen was shown to be equal to that of the standard trichophytin.     

Assessing the Intraoperative Accuracy of Pedicle Screw Placement by Using a Bone-Mounted Miniature Robot System through Secondary Registration

IntroductionPedicle screws are commonly employed to restore spinal stability and correct deformities. The Renaissance robotic system was developed to improve the accuracy of pedicle screw placement.PurposeIn this study, we developed an intraoperative classification system for evaluating the accuracy of pedicle screw placements through secondary registration. Furthermore, we evaluated the benefits of using the Renaissance robotic system in pedicle screw placement and postoperative evaluations. Finally, we examined the factors affecting the accuracy of pedicle screw implantation.ResultsThrough use of the Renaissance robotic system, the accuracy of Kirschner-wire (K-wire) placements deviating <3 mm from the planned trajectory was determined to be 98.74%. According to our classification system, the robot-guided pedicle screw implantation attained an accuracy of 94.00% before repositioning and 98.74% after repositioning. However, the malposition rate before repositioning was 5.99%; among these placements, 4.73% were immediately repositioned using the robot system and 1.26% were manually repositioned after a failed robot repositioning attempt. Most K-wire entry points deviated caudally and laterally.ConclusionThe Renaissance robotic system offers high accuracy in pedicle screw placement. Secondary registration improves the accuracy through increasing the precision of the positioning; moreover, intraoperative evaluation enables immediate repositioning. Furthermore, the K-wire tends to deviate caudally and laterally from the entry point because of skiving, which is characteristic of robot-assisted pedicle screw placement.     

Determination of Glycosyltransferase Specificities for the Escherichia coli O111 O Antigen by a Generic Approach

We describe a bacterial strain developed to facilitate the determination of glycosyltransferase (GT) specificities for O antigens of known structure and gene cluster sequence. For proof of principle for the approach, the strain was used to determine the specificity of the Escherichia coli O111 O-antigen GT genes.     

Proteomic analysis of leaves from a diploid cybrid produced by protoplast fusion between Satsuma mandarin and pummelo

Hypocotyls and cotyledons of three ramie (Boehmeria nivea Gaud.) cultivars (Zhongzhu No.1, Zhongsizhu No.1 and NC01), important plants for textile fiber, were pre-cultured on callus-inducing medium for 1 day before co-cultivation for 2 days with Agrobacterium tumefaciens strain LBA4404 harboring the plasmid pGBI4ABC carrying two insect resistance (CryIA and CpTI), gus, and neomycin phosphotransferase (npt II) genes. Calli were induced from both hypocotyl and cotyledon explants grown on a kanamycin selection medium. Regenerated shoots were obtained after two cycles of culture and transferred to rooting medium. Kanamycin-resistant plantlets were rooted in 2 weeks, and then transplanted to soil. Transgenic plants were subsequently confirmed by polymerase chain reaction, Southern blot hybridization, and GUS assays. More than 100 transgenic plants carrying insect-resistance genes were produced. A transformation frequency of 8.8 to 10.3% was obtained using hypocotyls as explants, which was higher than all previously reported transformation frequencies. The whole protocol, from transformation recovery of plants grown in soil, was completed within 2–4 months. Therefore, a simple, efficient, and robust Agrobacterium tumefaciens -mediated transformation system for ramie has been developed.     

白地霉Cryytococcus neoformans脂肪酶的双水相萃取

本文研究了不同无机盐的双水相体系对白地霉脂肪酶的萃取分离效果,对PEG/（NH4）2SO4成相系统进行了系统的研究,通过考察体系PEG分子量、不同的无机盐、PEG浓度、（NH4）2SO4浓度、离子强度、pH值及（NH4）2SO4浓度对反萃取的影响,并通过正交实验进一步优化了实验条件,初步确定在PEG浓度15%,（NH4）2SO4浓度22.5%,pH8.0,不加NaCl的条件下进行双水相萃取,脂肪酶分离系数和纯化倍数分别为6.8和7.5,比活力达到40.3 U/mg蛋白。     

Evaluation of Beef by Electronic Tongue System TS-5000Z: Flavor Assessment,Recognition and Chemical Compositions According to Its Correlation with Flavor

The aim of this study was to assess the ability of electronic tongue system TS-5000Z to evaluate meat quality based on flavor assessment, recognition and correlation with the meat chemical composition. Meat was sampled from eighteen beef cattle including 6 Wagyu breed cattle, 6 Angus breed cattle and 6 Simmental breed cattle. Chemical composition including dry matter, crude protein, fat, ash, cholesterol and taurine and flavor of the meat were measured. The results showed that different breed cattle had different chemical compositions and flavor, which contains sourness, umami, saltiness, bitterness, astringency, aftertaste from astringency, aftertaste from bitterness and aftertaste from umami, respectively. A principal component analysis (PCA) showed an easily visible separation between different breeds of cattle and indicated that TS-5000Z made a rapid identification of different breeds of cattle. In addition, TS-5000Z seemed to be used to predict the chemical composition according to its correlation with the flavor. In conclusion, TS-5000Z would be used as a rapid analytical tool to evaluate the beef quality both qualitatively and quantitatively, based on flavor assessment, recognition and chemical composition according to its correlation with flavor.     

双水相体系/溶剂反萃取法制备高纯天然烟碱

在探讨了硫酸铵对三种不同分子量聚乙二醇双水相体系的分相能力基础上,研究了聚乙二醇/盐双水相体系中烟碱的分配行为,同时考查了含盐量、pH值等因素的影响,并采用此体系处理废次烟草中烟碱提取液,利用溶剂反萃取法回收天然烟碱,结果显示:体系中含盐量、pH值对烟碱的回收率影响较大,确定含盐量25%、pH=9为体系的最佳分离萃取条件,回收率为96.7,纯度为99.87%.     

Inactivation of E. coli in Cranberry Juice by a High Voltage Pulsed Electric Field

The aim of this work was to study the effect of a high voltage pulsed electric field (PEF) on the inactivation of E. coli in cranberry juice to achieve the regulatory requirement of a 5‐log reduction in the microbial count. PEF processing involved the application of high voltage pulses to liquid or semi‐solid materials, placed between two electrodes at ambient, sub‐ambient, or supra‐ambient temperature. In this work, cranberry juice, inoculated with E. coli was subjected to 60 pulses in the voltage range of 5 to 40 kV/cm. The experiments were carried out at 20 °C. The temperature rise was less than 2 °C at the average treatment time of 80 s. PEF is an emerging non‐thermal technology for food preservation that retains the natural taste of food. It has mainly been applied to improve the shelf life of such foods as milk, liquid eggs and fruit juices.     

双水相同时提取次烟叶中茄尼醇和烟碱的研究

研究新型双水相体系同时从次等烟丝中提取茄尼醇和烟碱的可行性和工艺条件。新型双水相体系为丙酮-磷酸氢二钾双水相体系,主要研究了丙酮与水不同体积比、磷酸氢二钾的加入量、料液比、浸提温度、浸提时间、双水相体系pH值对茄尼醇和烟碱得率的影响,确定了最佳提取条件:丙酮与水的体积为5∶5,磷酸氢二钾的加入量为3.0 g,料液比为0.025 g/mL(0.5 g/20.0 mL),浸提温度为50℃,浸提时间为4 h,pH值为10。     

Preparation of Axenic Cultures of Algae by Use of a French Press

The differences in fragility of microorganisms when treated in the French press are useful for destroying bacteria and mold contaminants, and assist in the preparation of axenic cultures of Chlorella.     

Conversion of (+)-Dihydroquercetin to 3,4-cis-Leucocyanidin by a Reductase Extracted from Cell Suspension Cultures of Cryptomeria japonica

A soluble, NADPH-dependent reductase catalyzing the reductionof (+)-dihydroquercetin to 3,4-cis-leucocyanidin (5,7,3',4'-tetrahydroxyflavan-3,4-cis-diol)was demonstrated in an enzyme preparation from a cell suspensionculture of Japanese cedar (Cryptomeria japonica D. Don). TheK_m value for (+)-dihydroquercetin was 48µM. The enzyme,which was purified 26.2-fold, could also catalyze the reductionof (+)-dihydrokaempferol to 3,4-cis-leucopelargonidin (5,7,4'-trihydroxyflavan-3,4-cis-diol). The enzyme had a pH optimumof 7 and a molecular weight of 133,000. It was inhibited byCu²⁺ and iodoacetate, but not by p-chloromercuribenzoate. Duringthe growth stages of the cell suspension cultures, an increasein reductase activity proceeds an increase in procyanidin content,as might be expected. (Received November 25, 1987; Accepted April 11, 1988)     

Extraction of Zinc from Industrial Waste by a Penicillium sp

Zinc was extracted from a filter residue of a copper works (58.6% zinc) by a Penicillium sp. isolated from a metal-containing location. By isotachophoresis citric acid was identified as the leaching agent. Citrate was only formed when the leaching substrate was present. This production of citrate was different in several ways from that achieved by Aspergillus niger: glucose was utilized before fructose; the initial concentration of zinc was 50 to 500 times higher than usual in citrate fermentations with A. niger; citrate production stopped when 80 to 90% of the zinc was leached, although sufficient sugar for further synthesis was still present; and in synthetic media citrate production by A. niger needs an acidic environment (pH 2), while the formation of citric acid by Penicillium sp. occurred in a pH range of 7 to 4. Tests with different concentrations of waste material (0.5, 2.5, and 5%) showed that the highest yield of solubilized zinc occurred with a 2.5% substrate (93% zinc extracted after 13 days).     

超声集成双水相体系提取葡萄籽中的原花青素

采用响应面优化超声集成双水相体系提取葡萄籽中的原花青素最佳工艺条件.首先利用Plackett-Burmart(PB)实验设计对6个相关因素进行了筛选,结果表明,乙醇质量分数、硫酸铵质量分数和超声时间对葡萄籽中原花青素提取率影响较大.用最陡爬坡试验及Box-Benhnken设计进一步优化,利用Design-Expert软件进行二次回归分析,得出主要因素最佳条件为:按乙醇质量分数21.45％,硫酸铵质量分数23.46％配制双水相,在料液比1∶7,50℃温度下超声提取45.46 min,原花青素的提取率可达30.23％,分配系数可达11.5,提取率比优化前提高了6倍.     

Initial and Total Activity of Rubisco in Scenedesmus ecornis: is the French Press a Suitable Tool for Enzyme Extraction?

An enzyme assay was developed to measure the initial and CO₂-Mg²⁺activated forms of Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco) in the green microalga Scenedesmus ecornis. Comparisonswere made of extraction by mortar and pestle versus the Frenchpress, in the presence or absence of NADPH. Losses due to harvestingand extraction procedures decreased when the algae were collectedunder the same irradiance they had experienced during growth,and by adding NADPH to the extraction solution. Results arediscussed in relation to the possible interactions of effectorswith the enzyme. The suitability of the French press to obtaincatalytic competent extract is questioned. (Received June 5, 1992; Accepted December 9, 1992)