Chitinase family genes in grape differentially expressed in a manner specific to fruit species in response to Botrytis cinerea

Molecular Biology Reports - Chitinases (Chi), an important resistance-related protein, act against fungal pathogens by catalyzing the fungal cell wall, whereas are involved in different biological...     

Periplasmic expression and one-step purification of urease subunit B of Helicobacter pylori

UreB is one of the urease subunits of Helicobacter pylori and can be used as an excellent antigen candidate for H. pylori vaccination. Easy access to highly purified UreB protein, facilitate advances in therapeutic or preventive strategies. To achieve a simplified purification procedure, the present report represents a novel method of producing recombinant urease subunit B extracellularly. ureB gene from 26,695 standard strain was amplified by PCR and cloned into pET-26b(+) expression vector. UreB was expressed as a soluble, N-terminal pelB and C-terminal hexahistidine-tagged fusion protein (UreB-6His) and secreted into the periplasmic space of Escherichia coli. Expression of the recombinant UreB in E. coli BL21 (DE3) was induced by isopropylthio-β-d-galactoside (IPTG). Expression of UreB was confirmed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and western blot analysis using anti-His monoclonal antibody. UreB-6His protein was extracted from the periplasm by osmotic shock treatment and was purified in one step by Nickel affinity chromatography. In conclusion, the present protocol is easier to perform; more time effective and low cost than earlier methods.     

在玻璃表面上短时接触硅藻土和多杀菌素对四纹豆象的致死效应和亚致死效应（英文）

四纹豆象Callosobruchus maculatus (F.)是伊朗豇豆种子上的主要贮藏害虫。控制这一害虫时, 用生物杀虫剂比用常规杀虫剂更为合适。本研究评价了室内条件下在玻璃表面上硅藻土和多杀菌素对四纹豆象成虫的致死效应和亚致死效应。结果表明： 硅藻土处理24 h和48 h后, 对四纹豆象成虫的LC50 值分别为 1.47和0.2 g/m²; 多杀菌素处理24 h和48 h后, 对四纹豆象成虫的LC50 值分别为102.9 和68.8 mg ai/L, 说明两种化合物都对四纹豆象成虫具有较高的急性毒性。通过检测生物学参数, 研究了LC₂₀浓度的硅藻土和多杀菌素对四纹豆象的亚致死效应。LC₂₀浓度的硅藻土和多杀菌素使四纹豆象成虫的繁殖力分别比对照降低了71.5%和17.2%, 卵孵化率降低了57.5%和27.8%, 成虫寿命缩短了74.7%和17.1%。接触LC₂₀浓度的硅藻土和多杀菌素使这一害虫的蛹期分别比对照延长了4.8%和2.3%。亚致死效应研究表明, 硅藻土和多杀菌素对四纹豆象的生命参数均产生了负面影响。总之, 致死效应和亚致死效应综合显示, 硅藻土在防治四纹豆象上具有较大的潜力。     

MicroRNA-4731-5p delivered by AD-mesenchymal stem cells induces cell cycle arrest and apoptosis in glioblastoma

Glioblastoma multiforme (GBM) exhibits the most malignant brain tumor with very poor prognosis. MicroRNAs (miRNAs) are regulatory factors that can downregulate the expression of multiple genes. Several miRNAs acting as tumor-suppressor genes have been identified so far. The delivery of miRNA by mesenchymal stem cell (MSC) due to their ability to specifically target tumors is a new, hopeful therapeutic approach for glioblastoma. The objective of our study is the investigation of the effect of lentivirus-mediated microRNA-4731 (miR-4731) genetic manipulated adipose-derived (AD)-MSC on GBM. The downregulation of miR-4731 in human GBM tumor was detected using the GEO dataset. To evaluate the function of miR-4731, we overexpressed miR-4731 using lentiviral vectors in U-87 and U-251 GBM cell lines. The effects of miR-4731 on cell proliferation and cell cycle of glioma cells were analyzed by wound test and flow-cytometry assay. miR-4731 inhibited the proliferation of GBM cancer cells. Coculturing was used to study the antiproliferative effect of miR-4731-AD-MSCs on GBM cell lines. Direct and indirect coculture of GBM cell lines with miR-4731-AD-MSCs induced cell cycle arrest and apoptosis. Our findings suggest that AD-MSCs expressing miR-4731 have favorable antitumor characteristics and should be further explored in future glioma therapy.     

Characterization and optimization of extracellular alkaline lipase production by Alcaligenes sp. Using stearic acid as carbon source

The aim of this study was to improve the production of an extracellular alkaline lipase from Alcaligenes sp. (ATCC 31371) by optimization of the culture medium, for economic production of biodiesel from waste vegetable oil. A number of carbon sources including different types of starch, sugar, sugar alcohol, organic acids, and surfactants were investigated. Polyoxyethylene (20) sorbitan tristearate, whose side chain is stearic acid, was the most effective carbon source for lipase production. Box-Behnken experimental design was used for three factors (soy protein, sodium nitrate, and stearic acid) and the optimal composition for maximum lipase production (1.7-fold enhancement) was established as soy protein 4.07%, sodium nitrate 0.17%, and stearic acid 0.28% at 28°C with an agitation rate of 220 rpm for 24 h. The enzyme was purified to homogeneity and the recovery of the lipase activity was 7.8% with a 30-fold purification. The estimated molecular size of the protein determined by SDS-PAGE was 33 kDa. The optimum pH and temperature of the purified lipase was 8.5 and 40°C, respectively. The purified enzyme was stable in the pH range of 6.0 and 9.5 and in the temperature range of 20 and 50°C.     

Strain and plastic composite support (PCS) selection for vitamin K (Menaquinone-7) production in biofilm reactors

Menaquinone-7 (MK-7), a subtype of vitamin K, has received a significant attention due to its effect on improving bone and cardiovascular health. Current fermentation strategies, which involve static fermentation without aeration or agitation, are associated with low productivity and scale-up issues and hardly justify the commercial production needs of this vitamin. Previous studies indicate that static fermentation is associated with pellicle and biofilm formations, which are critical for MK-7 secretion while posing significant operational issues. Therefore, the present study is undertaken to evaluate the possibility of using a biofilm reactor as a new strategy for MK-7 fermentation. Bacillus species, namely, Bacillus subtilis natto, Bacillus licheniformis, and Bacillus amyloliquifaciens as well as plastic composite, supports (PCS) were investigated in terms of MK-7 production and biofilm formation. Results show the possibility of using a biofilm reactor for MK-7 biosynthesis. Bacillus subtilis natto and soybean flour yeast extract PCS in glucose medium were found as the most potent combination for production of MK-7 as high as 35.5 mg/L, which includes both intracellular and extracellular MK-7.