Mutation Breeding of Lycopene-Producing Strain Blakeslea Trispora by a Novel Atmospheric and Room Temperature Plasma (ARTP)

To improve the fermentation efficiency of lycopene, a plasma jet, driven by an active helium atom supplied with atmospheric and room temperature plasma (ARTP) biological breeding system, was used as a new method to generate mutations in Blakeslea trispora (?). After several rounds of screening, a mutant A5 with high concentration of lycopene and dry biomass was isolated, which showed a maximum lycopene concentration (26.4?±?0.2 mg/g dry biomass) which was 55 % higher than the parent strain (16.9?±?0.3 mg/g dry biomass) in the production of lycopene. Compared with parent strain, B. trispora A5 required less dissolved oxygen (10 % less than that of parent strain) to reach maximum concentration in a 5-L stirred tank reactor batch fermentation.     

Screening,Growth Medium Optimisation and Heterotrophic Cultivation of Microalgae for Biodiesel Production

This article presents a study on screening of microalgal strains from the Peking University Algae Collection and heterotrophic cultivation for biodiesel production of a selected microalgal strain. Among 89 strains, only five were capable of growing under heterotrophic conditions in liquid cultures and Chlorella sp. PKUAC 102 was found the best for the production of heterotrophic algal biodiesel. Composition of the growth medium was optimised using response surface methodology and optimised growth conditions were successfully used for cultivation of the strain in a fermentor. Conversion of algal lipids to fatty acid methyl esters (FAMEs) showed that the lipid profile of the heterotrophically cultivated Chlorella sp. PKUAC 102 contains fatty acids suitable for biodiesel production.     

Conductive Cotton Prepared by Polyaniline In Situ Polymerization Using Laccase

The high-redox-potential catalyst laccase, isolated from Aspergillus, was first used as a biocatalyst in the oxidative polymerization of water-soluble conductive polyaniline, and then conductive cotton was prepared by in situ polymerization under the same conditions. The polymerization of aniline was performed in a water dispersion of sodium dodecylbenzenesulfonate (SDBS) micellar solution with atmospheric oxygen serving as the oxidizing agent. This method is ecologically clean and permits a greater degree of control over the kinetics of the reaction. The conditions for polyaniline synthesis were optimized. Characterizations of the conducting polyaniline and cotton were carried out using Fourier transform infrared spectroscopy, UV–vis spectroscopy, cyclic voltammetry, the fabric induction electrostatic tester, and the far-field EMC shielding effectiveness test fixture.     

A New α-Galactosidase from Thermoacidophilic Alicyclobacillus sp. A4 with Wide Acceptor Specificity for Transglycosylation

An α-galactosidase gene (gal36A4) of glycosyl hydrolase family 36 was identified in the genome of Alicyclobacillus sp. A4. It contains an ORF of 2,187 bp and encodes a polypeptide of 728 amino acids with a calculated molecular mass of 82.6 kDa. Deduced Gal36A4 shows the typical GH36 organization of three domains—the N-terminal β-sheets, the catalytic (β/α)₈-barrels, and the C-terminal antiparallel β-sheet. The gene product was produced in Escherichia coli and showed both hydrolysis and transglycosylation activities. The optimal pH for hydrolysis activity was 6.0, and a stable pH range of 5.0–11.0 was found. The enzyme had a temperature optimum of 60 °C. It is specific for α-1,6-glycosidic linkages and had a K _m value of 1.45 mM toward pNPGal. When using melibiose as both donor and acceptor of galactose, Gal36A4 showed the transfer ratio of 23.25 % at 96 h. With respect to acceptor specificity, all tested monosaccharides, disaccharides, and oligosaccharides except for D-xylose and L-arabinose were good acceptors for transglycosylation. Thus, Gal36A4 may find diverse applications in industrial fields, especially in the food industry.     

不对称双酸催化吲哚的Friedel-Crafts烷基化反应:抗衡阴离子调控对映选择性

研究了双酸催化剂对吲哚和β,γ-不饱和α-酮酸酯的不对称Friedel-Crafts烷基化反应.金属铟(III)盐和手性磷酸组成的双酸催化体系可以高效、高选择性地催化吲哚与β,γ-不饱和α-酮酸酯的Friedel-Crafts烷基化反应.简单改变铟(III)盐的抗衡阴离子从F-到Br-,就能使产物的构型发生反转,并同时获得相应的高产率(最高达98%)和高对映选择性(最高大于99%)的1,4-加成产物.     

Catalytic oxidation of NO over Mn–Co–Ce–Ox catalysts: effect of reaction conditions

Manganese–cobalt–cerium oxide (Mn–Co–Ce–Ox) catalysts were synthesized by the co-precipitation method and tested for activity in low-temperature catalytic oxidation of NO in the presence of excess O₂. With the best Mn–Co–Ce mixed-oxide catalyst, approximately 80 % NO conversion was achieved at 150 °C and a space velocity of 35,000 h^?1. The effect of reaction conditions (reaction temperature, volume fractions of NO and O₂, gas hourly space velocity (GHSV), and catalyst stability) was investigated. The optimum reaction temperature was 150 °C. Increasing the O₂ content above 3 % results in almost no improvement of NO oxidation. This catalyst enables highly effective removal of NO within a wide range of GHSV. Furthermore, the stability of the Me–Co–Ce–Ox catalyst was excellent; no noticeable decrease of NO conversion was observed in 40 h.     

聚丙烯光照老化下挥发性有机物的热解析-气相色谱谱质联用分析

改造了大体积顶空采样器,在其样品室上方加入氙灯用以模拟阳光照射,以采集聚合物样品在光照条件下逸出的挥发性有机物。使用Tenax吸附管收集某聚丙烯材料光照老化过程中产生的挥发性有机物,通过热解析-气相色谱/质谱联用仪分析挥发性有机物的种类和相对含量。随着光照时间的增加,挥发性有机物的强度有所变化,但物质种类并未改变。聚丙烯样品中的挥发性有机物主要是烷烃、烯烃、酮、醛等物质。     

纳米结构钛酸盐电极快速测定水体COD

分析了纳米结构钛酸盐电极快速测定COD的基本原理及COD标准物质定值方法。通过对纳米结构钛酸盐表征分析,钠型钛酸盐电极具有较高的灵敏度,外加0.7 V工作电位,测定COD溶液标准物质的线性相关系数大于0.995,误差在±8%以内;与国标方法比较,测量同一水样的误差在±15%以内。纳米结构钛酸盐电极可用于测量水体COD。     

Rational Design of the Metal-Free KBe2BO3F2⋅(KBBF) Family Member C(NH2)3SO3F with Ultraviolet Optical Nonlinearity

The first fluorosulfonic ultraviolet (UV) nonlinear optical (NLO) material, C(NH₂)₃SO₃F, is rationally designed by taking KBe₂BO₃F₂ (KBBF) as the parent compound. C(NH₂)₃SO₃F features similar topological layers as KBBF by replacing inorganic (BO₃)³⁻ with organic C(NH₂)₃⁺ trigonal units and BeO₃F with SO₃F⁻ tetrahedra. Therefore, C(NH₂)₃SO₃F is a metal-free UV NLO crystal. Benefiting from the coplanar configuration of the C(NH₂)₃⁺ cationic groups, it possesses a large SHG response of 5×KDP and moderate birefringence of 0.133@1064 nm. Besides, it has a short UV cutoff edge of 200 nm. The calculated results reveal the shortest SHG phase-matching wavelengths can reach 200 nm. These findings highlight the exploration of metal-free compounds as nontoxic and low-cost UV NLO materials as a new research area.     

A Non-Conjugated Polymer Acceptor for Efficient and Thermally Stable All-Polymer Solar Cells

A non-conjugated polymer acceptor PF1-TS4 was firstly synthesized by embedding a thioalkyl segment in the mainchain, which shows excellent photophysical properties on par with a fully conjugated polymer, with a low optical band gap of 1.58 eV and a high absorption coefficient >10⁵ cm⁻¹, a high LUMO level of −3.89 eV, and suitable crystallinity. Matched with the polymer donor PM6, the PF1-TS4-based all-PSC achieved a power conversion efficiency (PCE) of 8.63 %, which is ≈45 % higher than that of a device based on the small molecule acceptor counterpart IDIC16. Moreover, the PF1-TS4-based all-PSC has good thermal stability with ≈70 % of its initial PCE retained after being stored at 85 °C for 180 h, while the IDIC16-based device only retained ≈50 % of its initial PCE when stored at 85 °C for only 18 h. Our work provides a new strategy to develop efficient polymer acceptor materials by linkage of conjugated units with non-conjugated thioalkyl segments.