Isolation and characterization of six microsatellite markers in the large yellow croaker (Pseudosciaena crocea Richardson)

Six polymorphic microsatellite markers were isolated and characterized using an enriched library technique in the large yellow croaker (Pseudosciaena crocea Richardson, 1864), a commercially important marine fish in China. They showed PIC (polymorphism information content) ranging from 0.064 to 0.885 (average of 0.580) and allele numbers ranging from two to 13 (average of 7.5), which were useful for the studies on population genetics and selective breeding of the large yellow croaker.

Root zone microbial populations, urease activities, and purification efficiency for a constructed wetland

In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P < 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P < 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r = 0.8830, P < 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system, microorganism and urease activities in the root zones were very important factors.

Isolation and Characterization of a Methomyl-Degrading Paracoccus sp mdw-1

Methomyl, an extremely toxic pesticide, is widely used in agriculture. A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study. It could utilize methomyl as the sole carbon or nitrogen source. The optimal temperature and medium pH for its growth and methomyl biodegradation were 30 degrees C and 7.0, respectively. It was identified as a Paracoccus sp. according to its morphological features, physiological and biochemical characteristics, and phylogenetic analysis based on the sequence of 16S rDNA. Gas chromatography-mass spectrometry (GC-MS) analysis showed that methomyl could be completely transformed to S-methyl-N-hydroxythioacetamidate in 10 h of incubation with the isolate mdw-1.

Affinity membrane chromatography for the analysis and purification of proteins

Affinity chromatography is unique among separation methods as it is the only technique that permits the purification of proteins based on biological functions rather than individual physical or chemical properties. The high specificity of affinity chromatography is due to the strong interaction between the ligand and the proteins of interest. Membrane separation allows the processing of a large amount of sample in a relatively short time owing to its structure, which provides a system with rapid reaction kinetics. The integration of membrane and affinity chromatography provides a number of advantages over traditional affinity chromatography with porous-bead packed columns, especially with regard to time and recovery of activity. This review gives detailed descriptions of materials used as membrane substrates, preparation of basic membranes, coupling of affinity ligands to membrane supports, and categories of affinity membrane cartridges. It also summarizes the applications of cellulose/glycidyl methacrylate composite membranes for proteins separation developed in our laboratory. (C) 2001 Elsevier Science B.V. All rights reserved.

Isolation and extraction of total flavonoids from Epimedium Koreanum Nakai by supercritical fluid extraction

In the present paper is reported the method for the isolation and extraction of total flavonoids of Epimedium Koreanum Nakai by means of supercritical fluid extraction (SFE). By examining pressure, temperature. amounts of modifier and extraction time, the optimized condition of SFE is confirmed as 30 MPa and 60 degreesC. with 70% ethanol as the modifier. The samples were statically extracted for 30 min, followed by dynamic extraction for 120 min at a flow rate of 6 mL/min. The quantitative analysis of total flavonoids was performed by UV-Vis spectrophotometry. Compared with the conventional method, the SFE method is more efficient. more rapid and more friendly environmentally.

Isolation and X-ray crystallographic structure of cyclic tetramer based on bisphenol A and o-phthaloyl dichloride

The polycrystalline powder of the cyclic tetramer based on bisphenol A and o-phthaloyldichloride has been prepared by recrystallization from nitrobenzene and its crystal structure has been determined by Wide-Angle X-ray Diffraction (WAXD). The unit cell is orthorhombic and its dimensions a = 0.967 6 nm, b = 0.869 9 nm, c = 2.085 9 nm, Space group belongs to Pmmm, With two tetramers per unit cell,the crystal density is 1.36 g . cm(-3), Indices of crystal diffraction peaks are also detailed in the present work.

ISOLATION AND PROPERTIES OF MOLYBDENUM SERIES OF HETEROPOLY BLUE WITH KEGGIN STRUCTURE

The present paper reports the methods for preparing and isolating 8 kinds of 1:12 molybdenum series of heteropoly blue complexes KyHzXMo12O40 . nH2O (X=Si, P, As, Ge). The products were characterized by elemental analyses, potential titration, polarograms, cyclic voltammetry, IR spectra, visible-UV spectra, X-ray powder diffraction, XPS and P-31 NMR. The single crystal structure of 4-electron molybdenum-silicon heteropoly blue was measured and the positions of reduced molybdenum atoms were determined, i.e. they were located at Mo(3), Mo(7), Mo(8) and Mo(10). The experimental results show that the heteropoly blue remains Keggin structure. ESR spectra of heteropoly blue solids were first studied, from which it was found that the delocalization extent of 2-electron heteropoly blue and 4-electron heteropoly blue is smaller than that of 1-electron heteropoly blue. The study of thermal properties shows that the thermal stability increases with the increase of the reduction extent of heteropoly blue. The study of redox properties shows that the oxidizing power order of heteropoly blue changes in different mediums, and the polarographic half-wave voltage is found to be dependent on the electronegativity of the hetero atom linearly. It is found that the phosphorus heteropoly blue and arsenic heteropoly blue show a strong anti-acid property.

Isolation and characterization of microsatellites in yellow perch (Perca flavescens)

A total of 45 microsatellite loci from yellow perch, Perca flavescens, were isolated and characterized. Among the 45 microsatellite loci, 32 had more than two alleles. A wild population of P. flavescens (n = 48) was used to examine the allele range of the microsatellite loci. Mendelian inheritance of alleles was confirmed by examining the amplified products in pair-mated families. The number of alleles for the 32 polymorphic loci varied from two to 16, and observed heterozygosity ranged between 0.024 (YP79) and 0.979 (YP60). Cross-species polymorphic amplification in four other Percidae species was successful for 22 loci.

ISOLATION AND CHARACTERIZATION OF CHLORELLA SOROKINIANA GXNN01 (CHLOROPHYTA) WITH THE PROPERTIES OF HETEROTROPHIC AND MICROAEROBIC GROWTH

Heterotrophic and anaerobic microalgae are of significance in both basic research and industrial application. A microalga strain was isolated from a wastewater treatment pond and identified as Chlorella sorokiniana Shihira et W. R. Krauss GXNN01 in terms of morphology, physiology, and phylogeny. The strain grows rapidly in heterotrophic or mixotrophic conditions with addition of various carbon sources, and even in anaerobic conditions. The maximum growth rate reached 0.28 d(-1) when using D,L-malate as the carbon source, and the protein content of the microalgae was 75.32% in cell dry weight. The strain was shown to be capable of (1) utilizing D, L-malate only with light, (2) inhibiting photosynthesis in mixotrophic growth, and (3) growing in anaerobic conditions with regular photosynthesis and producing oxygen internally. This study demonstrates the influence of oxygen (aerobic vs. anaerobic) and metabolic regime (autotrophy, mixotrophy, heterotrophy) on the physiological state of the cell.

Isolation and characterization of microsatellite loci from mangrove red snapper Lutjanus argentimaculatus

Lutjanus argentimaculatus, also called mangrove red snapper, is a commercially important fish in East Asia. A proper understanding of population structure is primarily linked with the management of genetic resources in exploiting marine fisheries. Herein, seven microsatellite loci, which showed high polymorphism (observed heterozygosity per locus ranging from 0.3571 to 0.7857 and expected heterozygosity per locus ranging from 0.6236 to 0.8821), were isolated and characterized from L. argentimaculatus. Cross-species amplifications also indicate that primers designed for these loci may be useful for further studies about other closely phylogenetic species of the family Lutjanidae.

Scale-up of fermentation and purification of recombinant allophycocyanin over-expressed in Escherichia coli

Phycobiliprotein is a photosynthetic antenna pigment found in cyanobacteria, rhodophytes, cryptophytes and certain dinoflagellates, which has been found to have anti-oxidative and anti-tumour activities. In this paper, a recombinant allophycocyanin (rAPC) had been expressed in Escherichia coli for anti-tumour effect. E. coli cells were cultured using glucose fed-batch method to achieve high cell densities. The biomass of rAPC was up to 3.52 g/L broth. The rAPC was purified from soluble E. coli cell lysate employing hydrophobic interaction chromatographic (HIC) method developed at the bench scale using 20 mL column. The process was performed at the pilot scale using 500 mL column for evaluation of scale-up. An amylose affinity column was used to improve the purity of final product in pilot scale purification. The purification process resulted in greater than 98% pure product and yielded up to 2.0 g/kg wet cells at the bench scale and 1.2 g/kg wet cells at the pilot scale. Peptide mapping was used to prove the identity of rAPC purified from bench scale and pilot scale process. Purified rAPC at the pilot scale was found to have remarkable inhibition on S-180 carcinoma in mice. (c) 2005 Elsevier Ltd. All rights reserved.

Pilot-scale fermentation and purification of the recombinant allophycocyanin over-expressed in Escherichia coli

A recombinant allophycocyanin (rAPC), used for treatment of tumors, has been expressed in E. coli which was grown in glucose fed-batch culture in a 30 l fermentor. Recombinant allophycocyanin was purified from soluble E. coli cell lysate using hydrophobic interaction chromatography followed by chromatography using amylose affinity column. The purity of product was greater than 98% and yielded an average of 5.5 g kg(-1) dry cells. Recombinant allophycocyanin significantly inhibited H-22 hepatoma (p (0.01) in mice with inhibition rates ranging from 36% to 62% with doses from 6.25 to 50 mg kg(-1) d(-1).

One-step chromatography method for efficient separation and purification of R-phycoerythrin from Polysiphonia urceolata

Phycoerythrins have been widely used in food, cosmetics., immunodiagnostics and analytical reagents. An efficient one-step chromatography method for purification of R-phycoerythrins from Polysiphonia urceolata was described in this paper. Pure R-phycoerythrin was obtained with an absorbance ratio A(565)/A(280) of 5.6 and a high recovery yield of 67-33%, using a DEAE-Sepharose Fast Flow chromatography with a gradient elution of pH, alternative to common gradient elution of ionic strength. The absorption spectrum of R-phycoerythrin was characterized with three absorbance maxima at 565, 539 and 498 mum, respectively and the fluorescence emission spectrum at room temperature was measured to be 580nm. The results of native-PAGE. and SDS-PAGE showed no contamination by other proteins in the phycoerythrin solution. which suggests an efficient method for the separation and purification of R-phycoerythrins from Polysiphonia urceolata. (C) 2004 Elsevier B.V. All rights reserved.