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Wu S.-P.,Northeast Forestry University | Sun L.-L.,Northeast Forestry University | Zhong H.,Northeast Forestry University | Yan S.-C.,Northeast Forestry University | And 3 more authors.
Open Life Sciences

As a target of insect growth regulators, the ecdysone receptor complex binds ecdysone agonists to regulate gene transcription, development, and growth. To understand the response of Lymantria dispar to methoxyfenozide, we studied receptor complex transcription profiles following larval exposure to methoxyfenozide, and observed important variations amongst post-embryonic stages. After the exposure of 2nd and 3rd instar larvae to LC5 and LC20 methoxyfenozide for 72 h, the transcription levels of ecdysone receptor complex genes were mainly upregulated in 2nd instar larvae, but downregulated in 3rd instar larvae. These results provide expression characteristics of the ecdysone receptor complex in L. dispar larvae after methoxyfenozide exposure. © 2015 Shao-ping Wu et al. 2015. Source

Dong Q.,Hubei Biopesticide Engineering Research Center | Yan X.,Wuhan University | Zheng M.,Hubei Biopesticide Engineering Research Center | Yang Z.,Hubei Biopesticide Engineering Research Center
Journal of Bioscience and Bioengineering

β-Galactosidase (lactase), which catalyzes the hydrolysis of lactose into glucose and galactose, is one of the most important enzymes used in dairy processing. In this study, a gene that encoded an extremely thermostable β-galactosidase from Pyrococcus furiosus (Pflactase) was cloned and expressed in Escherichia coli BL21. The recombinant enzyme was purified by heat treatment and Ni-NTA affinity chromatography. The enzyme displayed optimal activity at 90°C and pH 7.0 in phosphate buffer. The specific activity of the recombinant enzyme on o-nitrophenyl-β- d-galactopyranoside was 10.2U/mg at 0°C and 130.0. dU/mg at 90°C. The half-lives of the enzyme were 31423.4, 8168.3, 4017.7, 547.4, 309.6, and 203.5min at 70°C, 80°C, 85°C, 90°C, 95°C, and 100°C, respectively. The recombinant enzyme exhibited both β-galactosidase and β-glucosidase activity. The active inclusion bodies of β-galactosidase were easily isolated by nonionic detergent treatment and directly used for lactose conversion in a repetitive batch mode. More than 54% (90°C) or 88% (10°C) of the original enzyme activity was retained after 10 conversion cycles under optimum conditions. These results suggest that the recombinant thermostable β-galactosidase may be suitable for the hydrolysis of lactose in milk processing. © 2013 The Society for Biotechnology, Japan. Source

Dong Q.,Hubei Biopesticide Engineering Research Center | Yan X.,Wuhan University | Zheng M.,Hubei Biopesticide Engineering Research Center | Yang Z.,Hubei Biopesticide Engineering Research Center
Journal of Molecular Catalysis B: Enzymatic

In this paper, two genes that encoded two soluble type IV adenylyl cyclases (AC) from the hyperthermophilic archaeon Pyrococcus furiosus (PFAC I and PFAC II) were cloned and expressed in Escherichia coli (E. coli) BL21 (DE3). Amino acid sequence analysis of the two enzymes showed 29% homology. PFAC I and PFAC II were both Mn2+ activated enzyme. They were purified by His-trap chromatography and had a specific activity of 3.1 × 103 U/mg at pH 10.0, 95 °C (PFAC I) and 2.0 × 103 U/mg at pH 11.0, 95 °C (PFAC II), respectively. The Km and kcat of PFAC I was 1.38 mM and 1.11 s-1. The Km and kcat of PFAC II was 1.44 mM and 0.80 s-1. The thermostability of PFAC I and PFAC II were higher than the soluble type IV adenylyl cyclases from Yersinia pestis (YpAC-IV). All of the properties suggested that these two adenylyl cyclases may be useful for the industrial producing of cyclic adenosine 3′,5′-monophosphate (cAMP). © 2012 Elsevier B.V. Source

Dong Q.,Hubei Biopesticide Engineering Research Center | Yan X.,Wuhan University | Zheng M.,Hubei Biopesticide Engineering Research Center | Yang Z.,Hubei Biopesticide Engineering Research Center
Journal of Applied Polymer Science

This study focuses on the preparation and application of a recombinant thermophilic inorganic pyrophosphatase from the archaeon Pyrococcus furiosus on amino-functionalized silica beads. The amino-functionalized silica beads were prepared by coating with 3-aminopropyltriethoxysilane by silanization. The thermostable inorganic pyrophosphatase was rapidly and successfully immobilized onto the amino-functionalized silica beads with glutaraldehyde as a coupling agent (within 12 min, >95.4% protein was immobilized onto the support). The results show that the protein could be immobilized efficiently, with up to 1 mg of protein/g of support with 92.9% activity. Compared with the free enzyme, the immobilized enzyme displayed a high activity toward inorganic pyrophosphate, less sensitivity toward the pH, and increased thermal stability. The immobilized enzyme retained 56.9% of its initial activity after hydrolysis of the inorganic pyrophosphate after 12 consecutive cycles (total = 330 min) at high temperature; this indicated a high protein stability suitable for practical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40700. Copyright © 2014 Wiley Periodicals, Inc. Source

Huang D.,Hubei Biopesticide Engineering Research Center | Li J.,Beijing Plant Protection Station | Yao J.,Hubei Biopesticide Engineering Research Center | Cao C.,Hubei Biopesticide Engineering Research Center | And 4 more authors.
Journal of Pure and Applied Microbiology

Rhizoctonia solani Kuhn is one of the soilborne pathogenic fungi have been associated with damping-off. Protection of cucumber against this pathogen is important to maximize the crop field, plant growth-promoting rhizobacteria (PGPR) have been used to suppress the growth of this pathogen as well as enhance growth of several crops. In the present study, the endophytic bacterium Paenibacillus polymyxa strain NBF188 was evaluated as a biological control agent for cucumber Rhizoctonia rot. P. polymyxa strain NBF188 showed high inhibition activity in dual culture and inhibitory halos were observed Optical microscope study revealed deformation of hyphal and enlargement of cytoplasmic vacuoles. Furthermore, the strain NBF188 showed a broad antifungal spectrum on mycelium growth of numerous important plant pathogenic fungi. In the greenhouse, seed-soaking with NBF188 (108 CFU·ml-1) exhibited a better biological control effect on cucumber Rhizoctonia rot and plant growth promoting ability. The control effect was 76.67% and the plant height, root length and fresh weight have increased 53.48%, 49.84% and 37.57% respectively compared with the untreated control. Experiments reported here indicate that P. polymyxa NBF188 could be a promising agent in biocontrol cucumber Rhizoctonia rot. Source

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