Applied Mechanics and Materials Vols. 522-524

Abstract: A gene encoding a putative cysteine synthase was obtained by screening Monascus purpureus cDNA library. Bioinformatics analysis showed that this protein has Rhodanese Homology Domain in C-terminal, and Pyridoxal-phosphate dependent enzyme domain in N-terminal, and CBS-like structure. The deduced cysteine synthase protein of M. purpureus contained 517 amino acid, with molecular mass of 57,044Da. Sequence alignment analysis revealed that M. purpureus deduced cysteine synthase was closely related to cysteine synthase from Aspergillus, Ajellomyces and Paracoccidioides, and highly homologous to aforementioned and other known cysteine synthase. The structural model of the deduced cysteine synthase closely match the template with 100% confidence and 20-30% identity. The consistency of the comparison results of the primary structure, secondary structure and tertiary structure suggests that the dedued protein may well be cysteine synthase.

Abstract: The impact of inorganic anions on cadmium (Cd) fractions in soils was studied by experiment. The result showed that Cd exchangeable fraction contents in soils increased with the increase in soil salinity during soil saline process; Cd exchangeable fraction contents in soils increased with the increase Cl^- concentration of soil solutions, other fractions of Cd decreased with the increase of of Cl^- concentration; the changes of SO₄^2- concentration in soil solutions did not affect on Cd exchangeable fraction contents in soils, Cd carbonate fraction of increased, but the concentrations of Cd oxFe-Mn fraction and organic bound fraction decreased with the increase of SO₄^2- concentration; Cd exchangeable fraction content reduced significantly with the increase in HCO₃^- concentration of soil solutions, Cd carbonate fraction increased, and the concentrations of Cd oxFe-Mn fraction and organic bound fraction changed insignificant.

Abstract: The fluorescence intensity of double-stranded DNA (ds-DNA) hybridized by fluorescent 2-aminopurine (2-AP) oligonucleotide probe and different mismatched bases was studied by fluorescence spectra in this paper. The experiment designed and synthesised four oligonucleotide sequences with the bases of adenine (A), cytosine (C), guanine (G), thymine (T), and determined the fluorescence intensity of the mismatched double-stranded DNA. The results implied that the fluorescence intensity of oligonucleotide probe was varied due to different mismatched bases. And the fluorescence intensity was 546.9 with the ratio of 3.13, which showed a significantly increase as the mismatched base was A. While the mismatched base was T, the fluorescence intensity quenched to 43.26, as the ratio was 0.25. For C and G, the fluorescence intensity of 2-AP was 99.14 and 89.03, respectively, which showed a different degree of reduction.

Abstract: Seedlings of Atriplex centralasiatica Iljin were treated with Hoaglands solution containing 0, 200 and 400 mM NaCl respectively, after 2 weeks, Pn, Gs and Ci were measured. Besides, CO₂ compensation point, CO₂ saturation point, photorespiration rate, plant fresh weight and other physiological parameters were measured. The results showed that under 400 mM NaCl, the decrease of Pn was due to non-stomatal limitation factor. With the increase of NaCl concentrations, CO₂ compensation point and CO₂ saturation point did not show significant change. The photorespiration rate of the plants treated with 200 mM NaCl showed a little increase. However, under 400 mM NaCl, the increase of photorespiration rate was not that significant. As far as the carboxylation efficiency is concerned, it decreased with NaCl concrntration. At last, the fresh weight showed significant change under 400 mM NaCl treatment, which paralleled with the change of photosynthesis.

Abstract: The solubility of Na₂SO₄ mixed with K₂SO₄ and K₃PO₄ were investigated by a continuous kettle-reactor system at temperature within the range of 320°C to 420°C, 24MPa. The solubility of Na₂SO₄ showed a drastic reduce at a temperature of about 360°C. Ionic chromatography was used to determine the concentration of Na₂SO₄ in effluent. Among 355°C to 380°C, the presence of K₂SO₄ reduced the solubility of Na₂SO₄, due to common-ion effect. The addition of K₃PO₄ could inhibit the salts deposition in the supercritical water system, effectively. The variation degree is more remarkable as the addition of K₂SO₄ and K₃PO₄ increased.

Abstract: Aflatoxins (AFs) are a series of highly toxic and carcinogenic secondary metabolites. In order to eliminate AFs contamination, biological control is one of the more promising techniques. In this study, we describe the optimization of media nutrients for the selected biocontrol bacterium, Lysinibacillus xylanilyticus strain BPM1. The strain was isolated from the peanut hulls in Shandong Province, China and exhibited antagonistic activity against aflatoxins. Maltose and sucrose were identified as best carbon source, while soya peptone and yeast extract as nitrogen source led to the highest OD₆₀₀ observations. Medium composition was optimized using Plackett-Burman design, which was applied to find the key ingredients. The results revealed that the most significant two factors which were more effective in the fermentation of L. xylanilyticus BPM1 were soya peptone and yeast extract.

Abstract: Heavy metal contamination to Poyang Lake is increasingly severe. Bellamya aeruginosas, the dominant species of bellamya in Poyang Lake, was chosen in this project to carry out a proteomics study, because they obtain nutrients from sediments directly and have a strong heavy metal enrichment capability. To get a better knowledge of the contamination level of Poyang Lake and a better understanding of toxicity and bioavailability of heavy metals contamination, the main heavy metals of surface sediments were tested and a proteomics study was carried out on bellamya aeruginosa, the dominant species of bellamya in Poyang Lake. Results of heavy metal tests show, to Poyang Lake, the most contaminated heavy metal is Cu, the widest contaminated heavy metal is Pb, the most contaminated area is the south lake area, and the least contaminated area is the entrance of Xioushui River. Proteomics analysis shows the main significantly different proteins are keratins or similar substances. These proteins are higher expressed in the samples obtained from the most contaminated area, so they could be the responding biomarkers for monitoring heavy metal contamination of surface sediment in Poyang Lake.

Abstract: The present study was designed to determine the anti-hypoxia and anti-fatigue effects of Ganoderma lucidum polysaccharides (Gl-PS). The anti-hypoxia effects were evaluated by survival times of mice under anoxic condition of ordinary pressure. The anti-fatigue effects were evaluated by exhaustive swimming times of mice, and some biochemical parameters related to fatigue were measured. The results showed that Gl-PS could prolong survival and exhaustive swimming times, decrease blood lactic acid (BLA) and blood urea nitrogen (BUN) contents, and increase the liver and muscle glycogen contents of mice. Gl-PS had anti-hypoxia and anti-fatigue effects.

Abstract: The purpose of this study was to examine the effects of polysaccharides from Lycium barbarum fruits (LBP) on free radical metabolism of mice after exhaustive swimming exercise. The results showed that LBP supplementation could alleviate fatigue and enhanced the exercise tolerance. Furthermore, LBP supplementation effectively attenuates the exhaustive exercise-induced increased lipid peroxidation and elevates antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase) activities. LBP may have therapeutic role in preventing liver tissue damage during exhaustive exercise.

Abstract: The alkaloids contents were investigated by High performance liquid chromatography (HPLC) in Catharanthus roseus aseptic seedlings leaves, the expressions of terpenoid indole alkaloids (TIAs) biosynthesis pathway genes were detected by semi-quantitative RT-PCR. The plastic films treatment induces a low light condition. HPLC analysis shows, the contents of vindoline (VIN) and catharanthine (CAT) are slight increase first and significant decrease (p<0.05) under plastic films, the vinblastine (VBL) content increase and reach the maximum (0.028 mg g^-1±0.0051) on the 15th day of treatment. TIA biosynthesis pathway genes expression change under low light. The correlation analysis indicates, VIN accumulation is significantly correlated with the gene expression of desacetoxyvindoline-4-hydroxylase (D4h) and deacetylvindoline-4-O-acetyl transferase (Dat), and CAT accumulation is significantly correlated with strictosidine synthase (Str) gene expression (p<0.05). The low light treatment with plastic films accelerates the accumulation of VBL in C. roseus seedlings leaves.