Improved elastase production by<Emphasis Type="Italic">Bacillus</Emphasis> sp. EL31410 —Further optimization and kinetics studies of culture medium for batch fermentation

An efficient culture medium producing a bacterial elastase with high yields was developed further following preliminary studies by means of response surface method. Central composite design (CCD) and response surface methodology were applied to optimize the medium constituents. A central composite design was used to explain the combined effect of three medium constituents, viz, glucose, K₂HPO₄, MgSO₄·7H₂O. The strain produced more elastase in the completely optimized medium, as compared with the partially optimized medium. The fitted model of the second model, as per RSM, showed that glucose was 7.4 g/100 ml, casein 1.13 g/100 ml, corn steep flour 0.616 g/100 ml, K₂HPO₄ 0.206 g/100 ml and MgSO₄·7H₂O 0.034 g/100 ml. The fermentation kinetics of these two culture media in the flask experiments were analyzed. It was found that the highest elastase productivity occurred at 54 hours. Higher glucose concentration had inhibitory effect on elastase production. At the same time, we observed that the glucose consumption rate was slow in the completely optimized medium, which can explain the lag period of the highest elastase production. Some metal ions and surfactant additives also affected elastase production and cell growth. Project (No. 300024) supported by the Natural Science Foundation of Zhejiang Province, China     

响应面法优化纳豆激酶液体发酵条件的研究

为了提高纳豆激酶的酶活力,本研究借助Minitab软件,采用Plackett-Burman试验设计方法和响应面分析方法对保存的枯草芽孢杆菌纳豆亚种（Bacillus subtlis natto。简称纳豆菌）-NT207进行了液体发酵条件的优化。首先通过Plackett-Burman方法对11个相关影响因素的效应进行评价,并筛选出有显著正效应的木糖浓度和有显著负效应的接种量、K2HP04浓度等三个因素,然后利用响应面分析方法确定了上述三个因素的最佳工艺参数。实验结果表明,在优化后的发酵条件下,纳豆激酶的产量为1504．51U／mL,比优化前提高了130．3％。     

Medium Optimization for Antifungal Active Substance Production from <Emphasis Type="Italic">Streptomyces Lydicus</Emphasis> Using Response Surface Methodology

Response surface methodology was used to optimize the medium for antifungal active substance production from Streptomyces lydicus E12 in flask cultivation. Initially, the component factors, which influence antifungal substance production, were studied by varying one factor at a time. Starch, soybean cake powder, K₂HPO₄·3H₂O and MgSO₄·7H₂O were found to have a significant effect on the production of antifungal substances by the traditional design. Then, a Box–Behnken design was applied for further optimization. A quadratic model was found to fit antifungal active substance production. The analysis revealed that the optimum values of the tested variable were starch 84.96 g/L, soybean cake powder 4.13 g/L, glucose 5 g/L, MgSO₄·7H₂O 1.23 g/L, K₂HPO₄·3H₂O 2.14 g/L and NaCl 0.5 g/L. The test result of 67.44% antifungal inhibition agreed with the prediction and increased by 14.28% in comparison with the basal medium.     

Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design

研究目的：优化获得血红密孔菌（P.sanguineus）的最佳培养基组成,提高耐热漆酶的产量。创新要点：获得了目前文献报道的最高水平的漆酶活力。研究方法：通过单因素试验研究了不同培养基（番茄汁、麦麸、麦芽提取物和葡萄糖细菌蛋白胨培养基）和不同组合诱导剂（大豆油、阿魏酸、没食子酸、二甲基苯胺、酸性蓝62和活性蓝19分别与硫酸铜组合诱导剂）对P.sanguineus产耐热漆酶的影响。在此基础上采用中心组合试验设计,进一步研究了番茄汁培养基结合硫酸铜和大豆油组合诱导剂对P.sanguineus产耐热漆酶的影响。利用SAS10.0和响应面分析方法对试验结果进行了统计分析和建立回归模型。重要结论：通过中心组合设计优化得出P.sanguineus产耐热漆酶的最优培养基条件：以36.8%番茄汁为培养基,以3 mmol/L硫酸铜和1%大豆油作为组合诱导剂。该条件下在10 L搅拌槽生物反应器中漆酶活力达到了143 000 IU/L（2,2＇-联氮双（3-乙基苯并噻唑啉-6-磺酸）为底物,pH值为3.0）。     

Preparation of AlN thin films for film bulk acoustic resonator application by radio frequency sputtering

Aluminum nitride （AlN） thin films with high c-axis orientation have been prepared on a glass substrate with an Al bottom electrode by radio frequency （RF） reactive magnetron sputtering. Based on the analysis of Berg＇s hysteresis model, the improved sputtering system is realized without a hysteresis effect. A new control method for rapidly depositing highly c-axis oriented AlN thin films is proposed. The N2 concentration could be controlled by observing the changes in cathode voltage, to realize the optimum processing condition where the target could be fixed stably in the transition region, and both stoichiometric film composition and a high deposition rate could be obtained. Under a 500 W RF power of a target with a 6 cm diameter, a substrate temperature of 450 ℃, a target-substrate distance of 60 mm and a N2 concentration of 25%, AlN thin film with preferential （002） orientation was deposited at 2.3 μm/h which is a much higher rate than previously achieved. Through X-ray diffraction （XRD） analysis, the full width at half maximum （FWHM） of AlN （002） was shown to be about 0.28°, which shows the good crystallinity and crystal orientation of AlN thin film. With other parameters held constant, any increase or decrease in N2 concentration results in an increase in the FWHM of AlN.     

Optimization of biotransformation from phytosterol to androstenedione by a mutant Mycobacterium neoaurum ZJUVN-08

Biotransformation of phytosterol(PS) by a newly isolated mutant Mycobacterium neoaurum ZJUVN-08 to produce androstenedione has been investigated in this paper.The parameters of the biotransformation process were optimized using fractional factorial design and response surface methodology.Androstenedione was the sole product in the fermentation broth catalyzed by the mutant M.neoaurum ZJUVN-08 strain.Results showed that molar ratio of hydroxypropyl-β-cyclodextrin(HP-β-CD) to PS and substrate concentrations were the two most significant factors affecting androstenedione production.By analyzing the statistical model of three-dimensional surface plot,the optimal process conditions were observed at 0.1 g/L inducer,pH 7.0,molar ratio of HP-β-CD to PS 1.92:1,8.98 g/L PS,and at 120 h of incubation time.Under these conditions,the maximum androstenedione yield was 5.96 g/L and nearly the same with the non-optimized(5.99 g/L),while the maximum PS conversion rate was 94.69% which increased by 10.66% compared with the non-optimized(84.03%).The predicted optimum conditions from the mathematical model were in agreement with the verification experimental results.It is considered that response surface methodology was a powerful and efficient method to optimize the parameters of PS biotransformation process.     

Application of Box-Behnken design in optimization of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa

Allelopathic effects of submerged macrophytes against algae are affected by many environmental factors which can only be measured one by one by traditional methods. Box-Behnken design of response surface methodology was used to optimize three environmental factors(temperature, light intensity and total dissolved solids) of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa at the same time. By solving the regression equation and analyzing the response surface contour plots, the optimal conditions of the relatively inhibitory rate of Microcystis aeruginosa were that the temperature was 23℃, the light intensity was 2,700,lx and the total dissolved solids were 4,415,mg/L. Under these conditions, the optimal value of relatively inhibitory rate of Microcystis aeruginosa was 81.9%. According to validation experiments, the results of analysis indicated that the experimental values fitted well with the predicted ones.     

Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue （MIL-C） by Streptoverticillium rimofaciens ZJU 5119

Cytosine-substituted mildiomycin analogue (MIL-C) was produced effectively by supplementing cytosine into the culture of Streptoverticillium rimofaciens. In order to improve the yield of MIL-C, statistically-based experimental designs were applied to optimize the fermentation medium for S. rimofaciens ZJU 5119. Fifteen culture conditions were examined for their significances on MIL-C production using Plackett-Burrnan design. The Plackett-Burman design and one-variable-at-a-time design indicated that glucose and rice meal as the complex carbon sources, and peanut cake meal and NH4NO3 as the complex nitrogen sources were beneficial for MIL-C production in S. rimofaciens ZJU 5119. The results of further central composition design (CCD)showed that the optimal concentration of glucose, rice meal and peanut cake meal were 18.7 g/L, 64.8 g/L and 65.1 g/L,respectively. By using this optimal fermentation medium, the MIL-C concentration was increased up to 1336.5 mg/L, an approximate 3.8-fold improvement over the previous concentration (350.0 mg/L) with un-optimized medium. This work will be very helpful to the large-scale production of MIL-C in the future.     

Effect of cultivating conditions on α-galactosidase production by a novel Aspergillusfoetidus ZU-G1 strain in solid-state fermentation

The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain ,Aspergillusfoetidus ZU-GI in solid-state fermentation （SSF）. Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 ℃ incubation temperature, 18^h cultivation period of seed, 10% inoculum volume, 5.0-6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2037.51 U/g dry matter near the 144th hour of fermentation.     

ZnS<Subscript>0.8</Subscript>Se<Subscript>0.2</Subscript> film for high resolution liquid crystal light valve

The structural characteristics and optical and electrical properties of molecular-beam-epitaxy (MBE) grown ZnS_0.8Se_0.2 thin films on indium-tin-oxide(ITO) glas substrates were investigated in this work. TheX-ray diffraction (XRD) results indicated that high quality polycrystalline ZnS_0.8Se_0.2 thin film grown at the optimized temperature had a prefered orientation along the (111) planes. The transmission electron microscopy (TEM) cross-sectional micrograph of the sample showed a well defined columnar structure with lateral crystal dimension in the order of a few hundred angstroms. Ultraviolet (UV) photoresponsivity as high as 0.01 A/W had been demonstrated and for wavelengths longer than 450 nm, the response was down from the peak response by more than 3 orders of magnitude. The thin ZnS_0.8Se_0.2 photosensor layer, with a wide energy gap and anisotropic electrical property, makes a transmission UV liquid crystal light valve (LCLV) with high resolution feasible. Project supported by the National Natural Science Foundation of China (No. 59910161981) and RGC grant from the Hong Kong Government Grant (No. NSFC/HKUST 35), China     

Improved elastase production by Bacillus sp.EL31410--further optimization and kinetics studies of culture medium for batch fermentation

An efficient culture medium producing a bacterial elastase with high yields was developed further following preliminary studies by means of response surface method. Central composite design (CCD) and response surface methodology were applied to optimize the medium constituents. A central composite design was used to explain the combined effect of three medium constituents, viz, glucose, K2HPO4, MgSO4@7H2O. The strain produced more elastase in the completely optimized medium, as compared with the partially optimized medium. The fitted model of the second model, as per RSM,showed that glucose was 7.4 g/100 ml, casein 1.13 g/100 ml, corn steep flour 0.616 g/100 ml, K2HPO4 0.206 g/100 ml and MgSO4@7H2O 0.034 g/100 ml. The fermentation kinetics of these two culture media in the flask experiments were analyzed. It was found that the highest elastase productivity occurred at 54 hours. Higher glucose concentration had inhibitory effect on elastase production. At the same time, we observed that the glucose consumption rate was slow in the completely optimized medium, which can explain the lag period of the highest elastase production. Some metal ions and surfactant additives also affected elastase production and cell growth.     

Improved elastase production by Bacillus sp. EL31410─further optimization and kinetics studies of culture medium for batch fermentation

INTRODUCTION Elastase is an enzyme that attacks and solubi-lizes elastin. As elastase can degrade elastin (Mori-hara, 1967) that other proteases cannot; it has broad applications in medical therapy, food processing and daily use chemicals industry. Considerable eff- orts were made to screen the elastase-producing strains, to study its pathogen effect and its charac-terizations (Tsuzuki and Oka, 1965; Tsai et al., 1988; Sharon et al., 1997; Ozaki and Shiio, 1975). Shiio, 1975). Reporte…     

Menaquinone-7 production from maize meal hydrolysate by <Emphasis Type="Italic">Bacillus</Emphasis> isolates with diphenylamine and analogue resistance

A menaquinone-7 (MK-7) high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK-7 high-producing strains via screening and mutagenesis by an atmospheric and room temperature plasma (ARTP) mutation breeding system. We isolated an MK-7-producing strain Y-2 and identified it as Bacillus amyloliquefaciens, which produced (7.1±0.5) mg/L of MK-7 with maize meal hydrolysate as carbon source. Then, an MK-7 highproducing strain B. amyloliquefaciens H.β.D.R.-5 with resistance to 1-hydroxy-2-naphthoic acid, β-2-thienylalanine, and diphenylamine was obtained from the mutation of the strain Y-2 using an ARTP mutation breeding system. Using strain H.β.D.R.-5, efficient production of MK-7 was achieved ((30.2±2.7) mg/L). In addition, the effects of nitrogen sources, prenyl alcohols, and MgSO4 on MK-7 production were investigated, suggesting that soymeal extract combined with yeast extract, isopentenol, and MgSO₄ was beneficial. Under the optimized condition, the MK-7 production and biomass-specific yield reached (61.3±5.2) mg/L and 2.59 mg/L per OD₆₀₀ unit respectively in a 7-L fermenter. These results demonstrated that strain H.β.D.R.-5 has the capacity to produce MK-7 from maize meal hydrolysate, which could reduce the substrate cost.     

Simplified method of designing FIR filter with controllable center frequency

A novel simplified method is presented to design FIR filter with controllable center frequency. The properties of transfer curves for all-phase filters are illustrated under 3 windowing conditions. By combining single-window all-phase filter design steps and double phase-shift combination, a series of design formulas for point-pass filter, notch filter, band-pass filter and band-stop filter are derived, thus the design computation complexity is greatly reduced. Experiments prove that the center frequency of all the filters can be accurately specified at arbitrary position by adjusting frequency parameters m and λ.     

虚拟现实技术在室内设计中的应用

在室内设计中运用虚拟现实技术可快速、高效、精确的获取客户需求,便于有效、经济、柔性地组织生产,实现设计作品的开发周期和成本最小化、设计质量的最优化、生产效率的最大化,从而达到最完美的室内空间设计效果。     

Sorption of wastewater containing reactive red X-3B on inorgano-organo pillared bentonite

Bentonite is a kind of natural clay with good exchanging ability. By exchanging its interlamellar cations with various soluble cations, such as quaternary ammonium cations and inorganic metal ions, the properties of natural bentonite can be greatly improved. In this study, hexadecyltrimethylammonium bromide （HDTMA）, CaCl2, MgCl2, FeCl3, AlCl3 were used as organic and inorganic pillared materials respectively to produce several kinds of Ca-, Mg-, Fe-, Al-organo pillared bentonites. Sorption of reactive red X-3B on them was studied to determine their potential application as sorbents in wastewater treatment. The results showed that these pillared bentonites had much improved sorption properties, and that the dye solutions＇ pH value had some effect on the performance of these inorgano-organo pillared bentonites. Isotherms of reactive X-3B on these pillared bentonites suggested a Langmuir-type sorption mechanism.     

Optimization of cultural conditions for thermostable β-1, 3-1, 4-glucanase production byBacillus subtilis ZJF-1A5

The optimization of cultural conditions for β-glucanase production byBacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanase production which maximized at optimal temperature of 37°C and decreased significantly when temperature was over 37°C. Charge quantity affected β-glucanase production significantly. Adding oxygen vector N-dodecane or acetic ether benefited β-glucanase production, but it depended on the concentration and charge quantity. The results of fractional factorial design showed that age and size of inoculum and shaking speed were the key factors affecting β-glucanase production and the cultivation time span to reach the highest β-glucanase activity. The optimal cultural conditions for β-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82% (v/v)), shaking speed 210 r/min, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37°C for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of β-glucanase, α-amylase and neutral protease produced byB subtilis ZJF-1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and increased significantly when cells entered the stationary phase. Project (No. B0608) supported by the National Natural Science Foundation of China and a grant (2001121B25) from Hangzhou Science and Technology Development Project of Zhejiang Province, China     

响应面法优化脐橙渣中类黄酮的提取工艺

为优化在超声波辅助条件下脐橙渣中类黄酮的提取条件,在单因素试验的基础上,采用Box-Behnken试验设计和响应面法,研究乙醇浓度、液料比、提取温度对类黄酮得率的影响,建立了各因子与类黄酮得率关系的回归方程.试验结果表明最佳提取条件为:乙醇浓度64%、液料比26 mL/g、提取温度70℃.此条件下类黄酮的得率为3.59%,与预测值3.67%接近.     

肝功能对意识消失时咪达唑仑血浆浓度和脑电双频谱指数的影响(英文)

研究目的:探索不同肝功能指数对镇静药咪达唑仑的敏感性以及脑电双频谱指数(BIS)的预测意识消失的影响。创新要点:明确不同肝功能状态的患者对中枢抑制药的敏感性以及BIS预测意识消失概率发生的敏感性。指导临床医生根据患者的肝功能状态合理使用中枢抑制药以及正确利用BIS预测镇定深度。研究方法:选择意识消失作为研究终点,以50%患者意识消失时的咪唑安定的浓度以及BIS值作为观察指标。重要结论:终末期肝病患者对中枢镇静药咪唑安定更敏感,该类患者在BIS预测意识消失概率发生的敏感性存在差异。     

Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells: 3-dimensional collagen matrix model

Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes, possibly due to proliferation of vascular endothelial cells (ECs) induced by mucoepidermoid carcinoma cells (MCCs) in their three-dimensional (3D) microenvironment. To date, no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model. In this context, the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs (MCMECs) conditioned by the microenvironment in the 3D collagen matrix model. We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs, and characteristics of tubule-like structures (TLSs) formed by induced MCMECs or non-induced MCMECs. The assessment parameters involved the growth curve, the length, the outer and inner diameters, and the wall thickness of the TLSs, and the cell cycle. Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model. A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture (t=5.00, P=0.001). The outer and inner diameters (t ₁=5.549, P ₁=0.000; t ₂=10.663, P ₂=0.000) and lengths (t=18.035, P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group. The TLSs were formed at the earlier time in the induction group compared with the control group. It is concluded that MCCs promote growth and migration of MCMECs, and formation of the TLSs. The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma.