Thermococcus sp.B1001环糊精酶的重组表达及在麦芽七糖制备中的应用

成功构建pET-24a-tscd质粒,实现Thermococcus sp.Strain B1001来源的环糊精酶(TsCDase)在Es-cherichia coli BL21(DE3)中表达.通过热处理和镍柱分离对重组TsCDase进行纯化.酶学性质研究表明,重组TsCDase的比活为1 208.04 U/mg,最适温度为90℃、最适pH值为5.5.重组酶TsCDase在85℃、90℃、95℃条件下的半衰期分别为180、120、30min.酶转化研究表明,以80 g/L β-环糊精为底物,当酶转化温度为90℃、反应pH值为5.5～6.0,加酶量为25 U/g,反应时间为4 h时,麦芽七糖产率为81.19％和85.95％,七糖占产物麦芽寡糖的比例为95.24％和92.92％.本研究结果为工业化制备麦芽七糖奠定良好基础.     

Effect of volatiles emitted from wilted Populus nigra L. leaves on the mating and oviposition of Helicoverpa armigera (Hübner)

Wilted black poplar, Populus nigra ‘Italica’ L., leaves are very attractive to a vast number of noctuid moth species. This provides an opportunity for the development of effective trapping methods for the integrated management of pest species, such as Helicoverpa armigera, a major global and economically important insect pest.In the present study, we investigated the (1) nocturnal attraction patterns of H. armigera males and females to wilted P. nigra leaves; (2) effects of P. nigra volatiles on the mate-searching behavior of males through laboratory serial-chamber bioassays and field trapping; and (3) effects of P. nigra volatiles on the ovipositional choice and reproductive performance of females. Females and males, when tested alone, could be attracted by wilted P. nigra leaves, and the time periods of the first two attraction peaks were largely overlapped between sexes. Streams consisting of wilted P. nigra leaves and virgin females were not more attractive than virgin females alone, regardless of the stream sequence in a serial chamber. However, a stream of virgin females passed through wilted P. nigra leaves was more attractive than wilted P. nigra leaves alone. The addition of P. nigra extracts and its major aromatic components to the sex lure of H. armigera did not attract more moths than the sex lure alone. The volatiles from wilted P. nigra leaves were significantly more attractive to ovipositing females than those from cotton, tomato, and corn leaves, but equally attractive to tobacco leaves. Females exposed to volatiles from different leaves (P. nigra, cotton, and tobacco) showed similar fecundities. In summary, the attraction of moths to wilted P. nigra leaves may be attributable to multiple mechanisms, including the adsorption of sex pheromones, ovipostional attraction, and possible feeding attraction.     

Manipulation of host ecdysteroid hormone levels facilitates infection by the fungal insect pathogen,Metarhizium rileyi

Entomopathogenic fungi such as Metarhizium rileyi and Beauveria bassiana are widely used insect biological control agents. Little, however, is known concerning genetic or enzymatic factors that differentiate the mechanisms employed by these two fungal pathogens to infect target hosts. Infection by either of these organisms is known to increase levels of the growth and molting hormone, ecdysone, which also regulates the expression of a number of innate immune pathways. M. rileyi, but not B. bassiana, has apparently evolved an ecdysteroid-22-oxidase (MrE22O) that inactivate ecdysone. We show that deletion of MrE22O impaired virulence compared with the wild-type strain, with an increase in ecdysone titer seen in hosts that was coupled to an increase in the expression of antimicrobial genes. An M. rileyi strain engineered to overexpress MrE22O (MrE22O^OE), as well as trans-expression in B. bassiana (Bb::MrE220^OE) resulted, in strains displaying enhanced virulence and dampening of host immune responses compared with their respective wild-type parental strains. These results indicate that ecdysone plays an important role in mediating responses to fungal infection and that some insect pathogenic fungi have evolved mechanisms for targeting this hormone as a means for facilitating infection.     

A review of the botany,traditional uses,phytochemistry and pharmacology of Nepeta tenuifolia Briq.

Phytochemistry Reviews - Nepeta tenuifolia (N. tenuifolia) is a common aromatic herb that is widespread in East Asia. The aerial parts and spikes can be used as the traditional phytomedicines for...     

MiR-467a-5p aggravates myocardial infarction by modulating ZEB1 expression in mice

Journal of Molecular Histology - Myocardial infarction (MI) is a great threat to patients all over the word. MicroRNAs (miRNAs) are a group of non-coding RNAs and can regulate initiation and...     

稀土元素铈对花生幼苗生长与抗氧化保护酶系统的影响

采用溶液培养方法,研究不同浓度硝酸铈对花生(Arachis hypogaea)幼苗生长、开花数目及抗氧化酶过氧化物酶(POD)、超氧化物歧化酶(SOD)活性与丙二醛(MDA)含量的影响。结果表明,与对照相比,铈浓度低于20.0 mg·L–1能促进花生幼苗生长及开花,其中以10.0 mg·L–1铈的效果最为明显,其生物量和开花数分别约为对照的1.3倍和2.8倍;但高于20.0 mg·L–1则抑制花生幼苗生长,降低花朵数目;同时,低于20.0 mg/L铈可抑制花生幼苗过氧化物酶(POD)活性和降低其丙二醛(MDA)含量,其中以10.0 mg·L–1铈的抑制效果最明显,其POD活性和MDA含量约为对照的47.51%和20.76%;而低于20.0 mg·L–1铈能提高花生幼苗的超氧化物歧化酶(SOD)活性,其中以5.0 mg·L–1铈的促进效果最明显,其SOD活性约为对照的2.0倍。     

Silencing of FABP3 Inhibits Proliferation and Promotes Apoptosis in Embryonic Carcinoma Cells

Fatty acid–binding protein 3 (FABP3) facilitates the movement of fatty acids in cardiac muscle. Previously, we reported that FABP3 is highly upregulated in the myocardium of ventricular septal defect patients and overexpression of FABP3 inhibited proliferation and promoted apoptosis in embryonic carcinoma cells (P19 cells). In this study, we aimed to investigate the effect of FABP3 gene silencing on P19 cell differentiation, proliferation and apoptosis. We used RNA interference and a lentiviral-based vector system to create a stable FABP3-silenced P19 cell line; knockdown of FABP3 was confirmed by quantitative real-time PCR. Expression analysis of specific differentiation marker genes using quantitative real-time PCR and observation of morphological changes using an inverted microscope revealed that knockdown of FABP3 did not significantly affect the differentiation of P19 cells into cardiomyocytes. CCK-8 proliferation assays and cell cycle analysis demonstrated that FABP3 gene silencing significantly inhibited P19 cell proliferation. Furthermore, Annexin V-FITC/propidium iodide staining and the caspase-3 activity assay revealed that FABP3 gene silencing significantly promoted serum starvation–induced apoptosis in P19 cells. In agreement with our previous research, these results demonstrate that FABP3 may play an important role during embryonic heart development, and that either overexpression or silencing of FABP3 will lead to an imbalance between proliferation and apoptosis, which may result in embryonic cardiac malformations.     

Analysis of microbial diversity in tomato paste wastewater through PCR-DGGE

This study was conducted to evaluate the relationship between the flora and the changes in the microbial communities during tomato paste wastewater treatment. The bio-analytical techniques like Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), adenosine-triphosphate (ATP) analysis, and testing of mixed liquid and suspended solids (MLSS) were simultaneously conducted to analyze the dynamics of the microbial communities during tomato paste wastewater treatment process. The study suggests that the combined approaches of PCR-DGGE, ATP, and MLSS provided a simple and accurate method to evaluate the changes in microbial activity, microbial structure, and population size with the shift in contaminants in different treatment processes. The study also demonstrates that the structure and quantity of a microbial community are influenced by MLSS during the wastewater treatment process, which consequently determines the overall functionality of the system.     

Male and female Popillia quadriguttata (Fabricius) and Protaetia brevitarsis (Lewis) (Coleoptera: Scarabaeidae) response to Japanese beetle floral and pheromone lures

Popillia quadriguttata (Fabricius), and Protaetia brevitarsis (Lewis) adults were captured with Japanese beetle, Popillia japonica Newman, sex attractant and floral lures at Changchun, China during July–August 2012. The floral lure (phenethyl propionate:eugenol:geraniol, 3:7:3) was attractive to male and female P. quadriguttata (AV: 1.2 ± 0.9; 1.1 ± 0.3; total: 2.3 ± 0.8), and was similar in attraction to the combination of the sex attractant (SA) [(R, Z)-5-(1-decenyl) dihydro-2(3H)-furanone] plus the floral lure for male (1.60 ± 0.2), female (1.30 ± 1.1) and total captures (2.9 ± 3.0). However, the SA alone captured only males in much higher numbers than when combined with the floral lure (10.0 ± 6.4). In a separate earlier test, the greatest number of P. quadriguttata males (12.5 ± 3.0), female (12.2 ± 1.5) and total captures (24.7 ± 2.5) was in yellow, laboratory-made, bottle traps. The floral lure also attracted female Pro. brevitarsis (10.0 ± 3.4), while the SA attracted only few male beetles (1.0 ± 0.2). The combination SA + floral lure captured similar females (11.0 ± 2.0) and total (14.2 ± 2.2) Pro. brevitarsis as the floral lure alone. Two butterflies, Colias erate poliographus (Motschulsky) and Pieris rapae (Linnaeus), were also attracted to the floral lure. These studies indicate a potential for replacing pesticides by using the Japanese beetle lures for monitoring and control of several insects in China, and that they would be useful in monitoring and eradication of two potential scarab pests, P. quadriguttata and Pro. brevitaris, in the United States and Europe.