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1.
A. M. Abo-Shady S. M. Abou-El-Souod Abd El-Raheem R. El-Shanshoury Y. A. G. Mahmoud 《World journal of microbiology & biotechnology》1992,8(4):385-386
Protoplasts were obtained from the filamentous blue-green algaSpirulina platensis by treating the filaments with 0.05% (w/v) lysozyme in 0.03m phosphate buffer. The protoplasts regenerated cell walls and formed colonies when plated on a regeneration medium. The highest percentage of regeneration, 40% was obtained after 21 days. 相似文献
2.
Yada E Nagata H Noguchi Y Kodera Y Nishimura H Inada Y Matsushima A 《Marine biotechnology (New York, N.Y.)》2005,7(5):474-480
An arginine specific protease, Sp-protease, was purified by column chromatography from freeze-dried Spirulina platensis using a five-step process. Purified Sp-protease has a molecular weight of 80 kDa. It hydrolyzed the synthetic substrates
containing arginine residue in the P1 position but did not hydrolyze synthetic substrates containing other amino acid residues,
including lysine residue in the P1 position. Among the synthetic substrates tested, a substrate of plasminogen activator (Pyr-Gly-Arg-MCA)
was hydrolyzed most effectively with the enzyme (Km = 5.5 × 10−6 M), and fibrin gel was solubilized via activation of intrinsic plasminogen to plasmin with the enzyme. Activity was inhibited
completely with camostat mesilate (Ki = 1.1 × 10−8 M) and leupeptin (Ki = 3.9 × 10−8 M) but was not inhibited with Nα-tosyl-L-lysine chloromethyl ketone (TLCK). The optimum pH of the enzyme has a range of pH 9.0 to pH 11.0. The optimum temperature
was 50°C; the enzyme was stable at 0–50°C. 相似文献
3.
4.
C-Phycocyanin and allophycocyanin of Spirulina platensis are fractionated and purified using a non-chromatographic method namely, aqueous two phase extraction for the first time. Optimized process parameters of aqueous two phase extraction (PEG 4000/potassium phosphate of tie line length 18.64% with a phase volume ratio 1.45) resulted in pure C-phycocyanin and allophycocyanin with a purity of 3.23 and 0.74, respectively, in a single extraction. Multiple extractions (two) improved the purity of C-phycocyanin from 3.23 to 4.02. Integration of aqueous two phase extraction with membrane process not only facilitated the separation of phase forming components from the products and also increased the purity of allophycocyanin from 0.74 to 1.5. 相似文献
5.
Poly-beta-hydroxybutyrate has been identified in the cyanobacterium Spirulina platensis. The addition of reduced carbon compounds to the growth medium was not required for poly-beta-hydroxybutyrate accumulation. Poly-beta-hydroxybutyrate accumulated during exponential growth to 6% of the total dry weight and then decreased during the stationary phase. 相似文献
6.
Two ferredoxin-NADP+ reductases (FNRs I and II) [EC 1.6.7.1] were purified from a blue-green alga, Spirulina platensis, by (NH4)2SO4 fractionation, gel filtration on Sephadex G-100 and DEAE-Sephadex A-50 chromatography. FNRs I and II were both FAD-containing enzymes with molecular weights of 33,000, and could photochemically reduce NADP+ to the same extent in the presence of S. platensis ferredoxin, using FNR-depleted membrane fragments of S. platensis. They had similar physical and enzymatic properties, except for chemical properties such as the amino (N)-terminal sequences and the patterns of their peptide maps. The significance of the presence of two FNRs in S. platensis as as of the multiple forms found in other organisms is discussed. 相似文献
7.
Takashi Hirata Mikiya Tanaka Masaki Ooike Teppei Tsunomura Morihiko Sakaguchi 《Journal of applied phycology》2000,12(3-5):435-439
The antioxidative activity of phycocyanobilin fromSpirulina platensis was evaluated againstoxidation of methyl linoleate in a hydrophobic systemor with phosphatidylcholine liposomes. Phycocyanobilin as well as phytochemicals including-tocopherol, caffeic acid and zeaxanthin,effectively inhibited the peroxidation of methyllinoleate and produced a prolonged induction period.Oxidation of phosphatidylcholine liposomes was alsocontrolled markedly by adding phycocyanobilin or-tocopherol. Phycocyanobilin was distributedoutside in the liposomes to scavenge radicals fromAAPH and to prevent initiation of radical chainreactions. When the concentrations of phycocyanin andphycocyanobilin in the reaction mixture were adjustedequally on a phycocyanobilin basis, the activity ofphycocyanobilin was almost the same as that ofphycocyanin in the AAPH-containing reaction mixture.The antioxidizing action of phycocyanin prepared fromspray-dried Spirulina almost agreed with thatfrom fresh Spirulina in the AAPH-containingreaction mixture. These results suggest thatphycocyanobilin is responsible for the majority of theantioxidative activity of phycocyanin and may act asan effective antioxidant in a living human body. 相似文献
8.
Spirulina platensis is a multicellular edible blue‐green alga with abundant proteins (~60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze‐thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF‐7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5‐FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2‐CS) in food and pharmaceutical applications. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1230–1238, 2013 相似文献
9.
Søren Borg Henrik Brinch-Pedersen Birgitte Tauris Preben B. Holm 《Plant and Soil》2009,319(1-2):15-24
It has been reported that ground-penetrating radar (GPR) is a nondestructive tool that can be used to detect coarse roots in forest soils. However, successful GPR application for root detection has been site-specific and numerous factors can interfere with the resolution of the roots. We evaluated the effects of root diameter, root volumetric water content, and vertical and horizontal intervals between roots on the root detection of Cryptomeria japonica in sand using 900-MHz GPR. We found that roots greater than 19 mm in diameter were clearly detected. Roots having high volumetric water content were easily detected, but roots with less than 20% water content were not detected. Two roots that were located closely together were not individually distinguished. These results confirm that root diameter, root water content, and intervals between roots are important factors when using GPR for root detection and that these factors lead to an underestimation of root biomass. 相似文献
10.
Production and regeneration of spheroplasts from the cyanobacterium Spirulina platensis 总被引:2,自引:0,他引:2
Luisa Lanfaloni Renata Grifantini Anna Petris Claudio O. Gualerzi 《FEMS microbiology letters》1989,59(1-2):141-146
Abstract The development of a micro-method for the production and regeneration of spheroplasts starting from S. platensis trichomes is presented. The influence of the growth stage along with different treatments and conditions on the efficiency of spheroplast formation and regeneration are analyzed. 相似文献
11.
Phycocyanin (PC) prepared from a cyanobacterium Spirulina platensis by the DEAE-DE52 cellulose column chromatography that was developed by gradient elution of 50-250 mM phosphate buffer (pH 7.0) was stabilized by its subunits cross-linked covalently with formaldehyde. The single blue band that the chemically stabilized PC showed in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that the stabilized PC still maintained its trimeric aggregate form even after its incubation at 60 degrees C for 3h and at 100 degrees C for 10 min in the denatured buffer containing 5% (w/v) SDS. Moreover, the stabilized PC exhibited similar spectroscopic properties of absorption and fluorescence to those of the native PC, and showed adequate energy coupling with R-phycoerythrin (R-PE) after it was conjugated with R-PE via glutaraldehyde. 相似文献
12.
Purification and characterization of selenium-containing phycocyanin from selenium-enriched Spirulina platensis 总被引:1,自引:0,他引:1
A fast protein liquid chromatographic method for purification of selenium-containing phycocyanin (Se-PC) from selenium-enriched Spirulina platensis was described in this study. The purification procedures involved fractionation by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange chromatography and Sephacry S-300 size exclusion chromatography. The purity ratio (A620/A280) and the separation factor (A620/A655) of the purified Se-PC were 5.12 and 7.92, respectively. The Se concentration of purified Se-PC was 496.5 microg g(-1) protein, as determined by ICP-AES analysis. The purity of the Se-PC was further characterized by UV-VIS and fluorescence spectrometry, SDS-PAGE, RP-HPLC and gel filtration HPLC. The apparent molecular mass of the native Se-PC determined by gel filtration HPLC was 109 kDa, indicating that the protein existed as a trimer. SDS-PAGE of the purified Se-PC yielded two major bands corresponding to the alpha and beta subunits. A better separation of these two subunits was obtained by RP-HPLC. Identification of the alpha and beta subunits separated by SDS-PAGE and RP-HPLC was achieved by peptide mass fingerprinting (PMF) using MALDI-TOF-TOF mass spectrometry. 相似文献
13.
Cytochrome c-554 was purified from Spirulina platensis and someof its properties were studied. The cytochrome shows absorptionpeaks at 354, 410 and 529 nm in the oxidized form and at 318,416, 523 and 553.6 nm in the reduced form. The a peak at 553.6nm is slightly asymmetric with a shoulder around 550 nm. Theisoelectric point, midpoint redox potential and molecular weightof the cytochrome are 4.9, +0.35 V and 10,000, respectively.The cytochrome reacts fairly rapidly with Pseudomonas aeruginosanitrite reductase but does not react with cow cytochrome oxidase.The reactivities with the two enzymes of the S. platensis cytochromehave been compared with those of other algal c-type cytochromes. (Received August 22, 1977; ) 相似文献
14.
Monolayer films of phycobilisome-thylakoid membrane complexes isolated from Spirulina platensis were prepared at air/aqueous solution interface by using the Langmuir-Blodgett technique. The film preparation was optimized with 0.5 M phosphate buffer (pH 7.0) as sub-phase at 20 °C. The monolayer was transferred into grids and into mica surface for observing the surface image of the complexes by transmission electron microscopy and atomic force microscope, respectively. The shape of complexes was disk-like with the diameter of about 50 nm and the thickness of about 35 nm. The absorption and fluorescence spectra of the complexes in the monolayer were consistent with those in buffer solution, which suggests that the complexes in the monolayer preserve the basic functional groups of photosynthetic apparatus and can be used as a model to investigate the structural connection and functional association of the light-harvesting antenna with the reaction centres. 相似文献
15.
Converti A Scapazzoni S Lodi A Carvalho JC 《Journal of industrial microbiology & biotechnology》2006,33(1):8-16
Different concentrations either of ammonium chloride or urea were used in batch and fed-batch cultivations of Spirulina platensis to evaluate the possibility of substituting nitrate by cheaper reduced nitrogen sources in wastewaters biotreatment. The
maximum nitrogen concentration able to sustain the batch growth of this microalga without inhibition was 1.7 mM in both cases.
Ammonium chloride was limiting for the growth at lower concentrations, whereas inhibition took place at higher levels. This
inhibition effect was less marked with urea, likely because the enzymatic hydrolysis of this compound by urease controlled
the ammonia transfer into the cell. Fed-batch experiments carried out by pulse-feeding either ammonium or urea proved that
the use of these compounds as nitrogen sources can sustain the long term-cultivation of S. platensis, provided that the conditions for their feeding are accurately optimized. 相似文献
16.
Crystal structure of a light-harvesting protein C-phycocyanin from Spirulina platensis 总被引:2,自引:0,他引:2
Padyana AK Bhat VB Madyastha KM Rajashankar KR Ramakumar S 《Biochemical and biophysical research communications》2001,282(4):893-898
The crystal structure of C-phycocyanin, a light-harvesting phycobiliprotein from cyanobacteria (blue-green algae) Spirulina platensis has been solved by molecular replacement technique. The crystals belong to space group P2(1) with cell parameters a = 107.20, b = 115.40, c = 183.04 A; beta = 90.2 degrees. The structure has been refined to a crystallographic R factor of 19.2% (R(free) = 23.9%) using the X-ray diffraction data extending up to 2.2 A resolution. The asymmetric unit of the crystal cell consists of two (alphabeta)6-hexamers, each hexamer being the functional unit in the native antenna rod of cyanobacteria. The molecular structure resembles that of other reported C-phycocyanins. However, the unique form of aggregation of two (alphabeta)6-hexamers in the crystal asymmetric unit, suggests additional pathways of energy transfer in lateral direction between the adjacent hexamers involving beta155 phycocyanobilin chromophores. 相似文献
17.
Reddy CM Bhat VB Kiranmai G Reddy MN Reddanna P Madyastha KM 《Biochemical and biophysical research communications》2000,277(3):599-603
We report data from two related assay systems (isolated enzyme assays and whole blood assays) that C-phycocyanin a biliprotein from Spirulina platensis is a selective inhibitor of cyclooxygenase-2 (COX-2) with a very low IC(50) COX-2/IC(50) COX-1 ratio (0.04). The extent of inhibition depends on the period of preincubation of phycocyanin with COX-2, but without any effect on the period of preincubation with COX-1. The IC(50) value obtained for the inhibition of COX-2 by phycocyanin is much lower (180 nM) as compared to those of celecoxib (255 nM) and rofecoxib (401 nM), the well-known selective COX-2 inhibitors. In the human whole blood assay, phycocyanin very efficiently inhibited COX-2 with an IC(50) value of 80 nM. Reduced phycocyanin and phycocyanobilin, the chromophore of phycocyanin are poor inhibitors of COX-2 without COX-2 selectivity. This suggests that apoprotein in phycocyanin plays a key role in the selective inhibition of COX-2. The present study points out that the hepatoprotective, anti-inflammatory, and anti-arthritic properties of phycocyanin reported in the literature may be due, in part, to its selective COX-2 inhibitory property, although its ability to efficiently scavenge free radicals and effectively inhibit lipid peroxidation may also be involved. 相似文献
18.
FtsZ是与真核微管蛋白类似的原核骨架蛋白,能在细胞分裂位点聚合组装成环状结构而调控细胞分裂过程。为了研究钝顶螺旋藻(Spirulina platensis)FtsZ蛋白的功能,构建了钝顶螺旋藻FtsZ与绿色荧光蛋白GFP融合表达的质粒,并在大肠杆菌中进行了表达和定位研究,结果发现,表达融合蛋白GFP-FtsZ的大肠杆菌细胞由短杆状变为长丝状,且菌丝体长度与融合蛋白的表达量呈正比。在荧光显微镜下观察到融合蛋白GFP-FtsZ在长丝状体细菌中呈有规律的点状分布,这说明FtsZ蛋白功能高度保守,钝顶螺旋藻FtsZ蛋白能识别大肠杆菌分裂位点并装配成环状结构调控大肠杆菌细胞分裂,FtsZ蛋白的过量表达能抑制大肠杆菌正常的细胞分裂而导致长丝状体细胞的形成。 相似文献
19.
Probes derived from the tufA gene of Escherichia coli have been utilized to detect homologous sequences on Spirulina platensis DNA. A 6-kilobase-pair fragment of S. platensis DNA appears to contain two sequences homologous to the E. coli gene. Thus, as reported for gram-negative bacteria, the cyanobacterium presumably contains two tuf genes. 相似文献
20.
Optimization of phycocyanin extraction from Spirulina platensis using factorial design 总被引:5,自引:0,他引:5
Phycocyanin extraction from cyanobacteria Spirulina platensis was optimized using factorial design and response surface techniques. The effects of temperature and biomass-solvent ratio on phycocyanin concentration and extract purity were evaluated to determine the optimum conditions for phycocyanin extraction. The optimum conditions for the extraction of phycocyanin from S. platensis were the highest biomass-solvent ratio, 0.08 gmL(-1), and 25 degrees C. Under these conditions it's possible to obtain an extract of phycocyanin with a concentration of 3.68 mgmL(-1) and purity ratio (A(615)/A(280)) of 0.46. 相似文献