排序方式: 共有49条查询结果,搜索用时 62 毫秒
11.
Taniguchi M Atiwetin P Hirai T Itoh M Harada S Hara S Kamei K 《Bioscience, biotechnology, and biochemistry》2006,70(5):1262-1264
Fungal protease inhibitor F (FPI-F) from silkworm inhibits subtilisin and fungal proteases. FPI-F mutants P(1) residues of which, Thr(29), were replaced with Glu, Phe, Gly, Leu, Met, and Arg, were prepared. The inhibitory activities of mutated FPI-F against subtilisin and other mammalian proteases indicated that FPI-F might be a specific inhibitor toward subtilisin-type protease. 相似文献
12.
13.
Panida?Prawitwong Rattiya?Waeonukul Chakrit?Tachaapaikoon Patthra?Pason Khanok?Ratanakhanokchai Lan?Deng Junjarus?Sermsathanaswadi Krisna?Septiningrum Yutaka?Mori Akihiko?KosugiEmail author 《Biotechnology for biofuels》2013,6(1):184
Background
Cellulases continue to be one of the major costs associated with the lignocellulose hydrolysis process. Clostridium thermocellum is an anaerobic, thermophilic, cellulolytic bacterium that produces cellulosomes capable of efficiently degrading plant cell walls. The end-product cellobiose, however, inhibits degradation. To maximize the cellulolytic ability of C. thermocellum, it is important to eliminate this end-product inhibition.Results
This work describes a system for biological saccharification that leads to glucose production following hydrolysis of lignocellulosic biomass. C. thermocellum cultures supplemented with thermostable beta-glucosidases make up this system. This approach does not require any supplementation with cellulases and hemicellulases. When C. thermocellum strain S14 was cultured with a Thermoanaerobacter brockii beta-glucosidase (CglT with activity 30 U/g cellulose) in medium containing 100 g/L cellulose (617 mM initial glucose equivalents), we observed not only high degradation of cellulose, but also accumulation of 426 mM glucose in the culture broth. In contrast, cultures without CglT, or with less thermostable beta-glucosidases, did not efficiently hydrolyze cellulose and accumulated high levels of glucose. Glucose production required a cellulose load of over 10 g/L. When alkali-pretreated rice straw containing 100 g/L glucan was used as the lignocellulosic biomass, approximately 72% of the glucan was saccharified, and glucose accumulated to 446 mM in the culture broth. The hydrolysate slurry containing glucose was directly fermented to 694 mM ethanol by addition of Saccharomyces cerevisiae, giving an 85% theoretical yield without any inhibition.Conclusions
Our process is the first instance of biological saccharification with exclusive production and accumulation of glucose from lignocellulosic biomass. The key to its success was the use of C. thermocellum supplemented with a thermostable beta-glucosidase and cultured under a high cellulose load. We named this approach biological simultaneous enzyme production and saccharification (BSES). BSES may resolve a significant barrier to economical production by providing a platform for production of fermentable sugars with reduced enzyme amounts.14.
15.
Duangkaew P Pethuan S Kaewpa D Boonsuepsakul S Sarapusit S Rongnoparut P 《Archives of insect biochemistry and physiology》2011,76(4):236-248
Cytochrome P450 monooxygenases are involved in insecticide resistance in insects. We previously observed an increase in CYP6P7 and CYP6AA3 mRNA expression in Anopheles minimus mosquitoes during the selection for deltamethrin resistance in the laboratory. CYP6AA3 has been shown to metabolize deltamethrin, while no information is known for CYP6P7. In this study, CYP6P7 was heterologously expressed in the Spodoptera frugiperda (Sf9) insect cells via baculovirus‐mediated expression system. The expressed CYP6P7 protein was used for exploitation of its enzymatic activity against insecticides after reconstitution with the An. minimus NADPH‐cytochrome P450 reductase enzyme in vitro. The ability of CYP6P7 to metabolize pyrethroids and insecticides in the organophosphate and carbamate groups was compared with CYP6AA3. The results revealed that both CYP6P7 and CYP6AA3 proteins could metabolize permethrin, cypermethrin, and deltamethrin pyrethroid insecticides, but showed the absence of activity against bioallethrin (pyrethroid), chlorpyrifos (organophosphate), and propoxur (carbamate). CYP6P7 had limited capacity in metabolizing λ‐cyhalothrin (pyrethroid), while CYP6AA3 displayed activity toward λ‐cyhalothrin. Kinetic properties suggested that CYP6AA3 had higher efficiency in metabolizing type I than type II pyrethroids, while catalytic efficiency of CYP6P7 toward both types was not significantly different. Their kinetic parameters in insecticide metabolism and preliminary inhibition studies by test compounds in the flavonoid, furanocoumarin, and methylenedioxyphenyl groups elucidated that CYP6P7 had different enzyme properties compared with CYP6AA3. © 2011 Wiley Periodicals, Inc. 相似文献
16.
Masahiko Isaka Panida Chinthanom Sumalee Supothina Suchada Mongkolsamrit 《Phytochemistry letters》2012,5(4):734-737
Two new hopane-type triterpenenes, 6α,15α,22-trihydroxyhopane (4) and 3β-acetoxy-6α,22-dihydroxyhopane (5), together with the known 6α,22-dihydroxyhopane (1, zeorin), 15α,22-dihydroxyhopane (2, dustanin), and 3β-acetoxy-15α,22-dihydroxyhopane (3) were isolated from the scale insect pathogenic fungus Aschersonia calendulina BCC 23276. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. 相似文献
17.
Sriamornsak P Asavapichayont P Nunthanid J Luangtana-Anan M Limmatvapirat S Piriyaprasarth S 《AAPS PharmSciTech》2008,9(2):571-576
The purpose of this study was to prepare wax-incorporated pectin-based emulsion gel beads using a modified emulsion-gelation
method. The waxes in pectin–olive oil mixtures containing a model drug, metronidazole, were hot-melted, homogenized and then
extruded into calcium chloride solution. The beads formed were separated, washed with distilled water and dried for 12 h.
The influence of various types and amounts of wax on floating and drug release behavior of emulsion gel beads of calcium pectinate
was investigated. The drug-loaded gel beads were found to float on simulated gastric fluid if the sufficient amount of oil
was used. Incorporation of wax into the emulsion gel beads affected the drug release. Water-soluble wax (i.e. polyethylene
glycol) increased the drug release while other water-insoluble waxes (i.e. glyceryl monostearate, stearyl alcohol, carnauba
wax, spermaceti wax and white wax) significantly retarded the drug release. Different waxes had a slight effect on the drug
release. However, the increased amount of incorporated wax in the formulations significantly sustained the drug release while
the beads remained floating. The results suggest that wax-incorporated emulsion gel beads could be used as a carrier for intragastric
floating drug delivery. 相似文献
18.
Unagul P Wongsa P Kittakoop P Intamas S Srikitikulchai P Tanticharoen M 《Journal of industrial microbiology & biotechnology》2005,32(4):135-140
Production of red pigments (naphthoquinones) by the insect pathogenic fungus Cordyceps unilateralis BCC 1869 was investigated in this study. Cultivation conditions, including temperature, intitial pH of medium, and aeration, were optimised to improve the yield of total naphthoquinones in shake-flask culture of C. unilateralis. The highest yield of total naphthoquinones (3 g L–1) was obtained from a 28-day culture grown in potato dextrose broth with an initial pH of 7.0, at 28°C with shaking-induced aeration at 200 rpm. An extraction process for isolation of the targeted naphthoquinone, 3,5,8-trihydroxy-6-methoxy-2-(5-oxohexa-1,3-dienyl)-1,4-naphthoquinone (3,5,8-TMON), from a culture of C. unilateralis, was also developed. The yield of 3,5,8-TMON obtained was about 1.2 g L–1 or 40% of total naphthoquinones. The stability of 3,5,8-TMON was very high, even upon exposure to strong sunlight (70,000 lx), high temperature up to 200°C, and acid and alkali solutions at concentrations of 0.1 M 相似文献
19.
Heng Mei Jay M. Campbell Cathy M. Paddock Panida Lertkiatmongkol Michael W. Mosesson Ralph Albrecht Peter J. Newman 《The Journal of biological chemistry》2014,289(30):20836-20844
PECAM-1 is a 130-kDa member of the immunoglobulin (Ig) superfamily that is expressed on the surface of platelets and leukocytes, and at the intracellular junctions of confluent endothelial cell monolayers. Previous studies have shown that PECAM-1/PECAM-1 homophilic interactions play a key role in leukocyte transendothelial migration, in allowing PECAM-1 to serve as a mechanosensory complex in endothelial cells, in its ability to confer cytoprotection to proapoptotic stimuli, and in maintaining endothelial cell junctional integrity. To examine the adhesive properties of full-length PECAM-1 in a native lipid environment, we purified it from platelets and assembled it into phospholipid nanodiscs. PECAM-1-containing nanodiscs retained not only their ability to bind homophilically to PECAM-1-expressing cells, but exhibited regulatable adhesive interactions that could be modulated by ligands that bind membrane-proximal Ig Domain 6. This property was exploited to enhance the rate of barrier restoration in endothelial cell monolayers subjected to inflammatory challenge. The finding that the adhesive properties of PECAM-1 are regulatable suggests novel approaches for controlling endothelial cell migration and barrier function in a variety of vascular permeability disorders. 相似文献
20.
Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production 总被引:1,自引:0,他引:1
Ana?s Dusotoit-Coucaud Nicole Brunel Panida Kongsawadworakul Unchera Viboonjun André Lacointe Jean-Louis Julien Hervé Chrestin Soula?man Sakr 《Annals of botany》2009,104(4):635-647