Advanced Materials Research Vols. 343-344

Abstract: Astaxanthin, a main carotenoid pigment, has a strong antioxidant activity. A kinetics of astaxanthin fermentation by Xanthophyllomyces dendrorhous was studied in a batch fermentation system. The unstructured models were proposed using the Logistic equation for microbial growth, the Luedeking-Piret equation for astaxanthin production and Luedeking-Piret-like equation for glucose consumption. The production of astaxanthin was partly growth-associated. Compared with the experimental data and calculated data, most of errors were lower than 10 %, it showed that the proposed unstructured models were adequate to describe the fermentation bioprocess of astaxanthin by X. dendrorhous.

Abstract: Fructooligosaccharides (FOSs), as a mixture of 1-kestose, nystose, and 1F-fructofuranosylnystose oligosaccharides, exhibit lots of beneficial effects on our health and have been used as food ingredients. There have been a lot of reports on how to raise FOSs yield in different ways, but almost nobody did any deeply studies on the composition of FOSs—proportion of each component. However, different components may have different functions and some even show side-effects. In this research, we employed immobilized fructosyltransferase to produce FOSs and got a maximum yield of 56.12 %. Then we successfully produced FOSs of different components proportions by adjusting the reaction parameters—pH, temperature, and fermentation time. We designed six groups to investigate the relationship between reaction parameters and components proportions, and the results showed that pH condition mainly affects the yield while reaction time mainly affects components proportions. It is the first time that the components proportions of FOSs are systemically investigated, and we finally figured out six protocols for producing different FOSs. This is a basic investigation on the relationship between FOSs components proportions and reaction conditions. We hope this research can be helpful for other researchers who are interested in this area.

Abstract: In this pepar we investigated the developmental patterns of expression of growth hormone (GH) gene in pituitary tissue in pigs of different breeds and their effects on the carcass fat contents. 3 Jinhua gilts and 3 Landrace gilts were sampled at 35, 80 and 125 days of age, respectively. Carcass fat contents were determined. Pituitary tissue was sampled and total RAN was extracted to determine GH mRNA expression levels by semi-quantitative RT-PCR. The results showed that the contents of carcass fat increased with growth and showed significant differences (P﹤0.05) between different age groups in the two breeds. Furthermore, carcass fat contents in Jinhua gilts were higher than that in Landrace gilts during growth (P﹤0.05). GH mRNA expression levels decreased with age and displayed breed differences. Jinhua gilts showed lower abundance of GH mRNA compared with Landrace gilts at 35, 80 and 125 days of age (P﹤0.05). In addition, GH mRNA expression level was negatively related to carcass fat content in Jinhua and Landrace gilts (r = -0.790 (P = 0.01), r = -0.755 (P = 0.02), respectively).

Abstract: In this paper we compared growth performance, growth hormone (GH) pulsatile secretion and serum metabolites in growing Taihu and Landrace gilts at the same age. The results showed that compared with Landrace gilts, Taihu gilts decreased by 45.48% (P<0.05), 25.25% (P<0.05) in average daily gain and carcass muscle percentage, and increased by 52.44% (P<0.05), 69.50% (P<0.05) in feed/gain ratio and carcass fat percentage, respectively. While, average daily feed intake was not affected by breeds. Serum basal GH level, mean GH level and GH pulse amplitude were decreased by 26.67% (P<0.05), 20.00% (P<0.05) and 18.81% (P<0.05), respectively, but GH pulse frequency and pulse duration remained unchanged (P>0.05). Serum urea nitrogen concentration in Taihu gilts was 32.04% (P<0.05) higher, whereas, total protein level was 17.73% (P<0.05) lower than that of Landrace gilts.

Abstract: The study focused on the effect of four emulsifier ssl-csl, three monoesters, the single glyceride, the sugar ester for the quality of frozen dough steamed bread. We found the best percentage of additives through a single factor experiment and orthogonal experiment .The results showed that: the best formula was 0.2% ssl-csl, 0.25% three monoesters, 0.25% single glycerides, 0.5% sucrose ester. This compound emulsifier can improve the toughness of steamed bread, all indications were ideal.

Abstract: This work presents laboratory studies on the degradation of lambda-cyhalothrin. At first, a rapid quantitative determination method of lambda-cyhalothrin in food was developed by high performance liquid chromatography. Lambda-cyhalothrin-degrading bacterium F37 was isolated from the sewage of a pesticide factory outlet and was identified as Citrobacter braakii. The effects of environmental factors including carbon and nitrogen sources, initial pH, medium volume, incubating temperature and substrate concentration on the degradation rate were investigated. The addition of sucrose and yeast extract at the concentrations of 4.0 and 3.0 g/L, respectively, was the best for the degradation of lambda-cyhalothrin. F37 showed higher degradation activity at the range of moderate pH value (pH 6.5-8.0). After 72-h stirring culture, the degradation rates of lambda-cyhalothrin reached 81.1% at pH 7.0. The degradation dynamics analysis showed that the degradation half-life times of lambda-cyhalothrin in the culture liquid of F37 were only 5.7, 1.9 and 4.9 days at pH 9.0, 7.0 and 5.0, respectively. In addition, cypermethrin and triazophos could also be degraded by F37, showing that F37 was a broad-spectrum pesticide- degrading bacterium. Application of F37 on eliminating pesticide in vegetable showed that 68% of lambda-cyhalothrin was removed after treatment for 48 h. The results indicated that Citrobacter braakii F37 is effective in the elimination of pesticide and may provide a potent application in detergent industry and environmental restoration.

Abstract: In order to understand the structure and function of H-FABP gene, reveal the effect on the heart-type fatty acid-binding protein in goat, the cDNA of H-FABP gene was cloned and sequenced from heart of Tianfu goat （an emerging breed） by T-A clone techniques. The structure and function of H-FABP were analyzed by bioinformatics, and the gene expression profile in different tissues was examined by real-time PCR. The results showed that the full sequence of H-FABP cDNA is 650 bp, containing 402 bp coding region (CDS) encoding 133 amino acids. The isoelectric point (pI) of the protein is 6.11, and the molecular weight is 14.7 kDa. There were eight phosphorylational sites in this protein. The secondary structure of the protein was mainly α-helix, random coil and extended strand structure. The deduced amino acid sequence of H-FABP shared significant identity with the H-FABP from other mammals. The phylogenic tree based on H-FABP protein sequence was detected the closest relationship to cattle. A predicted 3D model was constructed by homology modeling. H-FABP mRNA is a broad-spectrum expression gene, which was detected in heart, liver, spleen, lung, kidney, longissimus muscle and leg muscle. In particular, high expression levels of H-FABP mRNA were detected in heart, longissimus muscle and leg muscle, but low expressions were observed in liver tissue.

Abstract: (R)-Ethyl 4-cyano-3-hydroxybutanoate is the key intermediate for the synthesis of liptor used for lowering high cholesterol and triglycerides. Firstly both enantiomers of ethyl 4-cyano-3-hydroxybu- tanoate were prepared by the enzymatic reduction of ethyl 4-cyano-3-oxobutanoate with two whole cells in high ee and high yield. The (R)-enantiomer was obtained in 89.8% yield and 98.5% ee in the catalysis of 20 mM substrate by the strain Bacillus pumilus Phe-C3; the (S)-enantiomer was achieved in 83.1% yield and 95.4% ee in the catalysis of 10 mM substrate by the strain Klebsiella pneumomiae Phe-E4. Preparative synthesis were carried out on 200-L scale.

Abstract: Newly discovered strain Baclicus lincheniformis JX010 was identified to enantioselective hydrolysis of racemic ethyl tert-leucinate for the synthesis of chiral L-tert-butyl leucine. In the hydrolysis of isopropyl tert-butyl leucinate, the L-tert-butyl leucine was synthesized in 99% ee and 48% conversion. The cells was immobilized on synthetic resin 0501 without pretreatment to increase the enzyme stability. A series of organic cosolvents were investigated the hydrolysis rate and 2% glycerol was considered as the optimized cosolvent. In the hydrolysis of 50 mM isopropyl tert-butyl leucinate, the immobilized cells remained 85%activity with L-tert-butyl leucine in 99% ee after 8 reaction cycles.

Abstract: Holiota nameko is an edible mushroom widely cultivated in the northeast of China. The cold water, hot water and ethanol extracts were prepared and their antioxidant properties were studied. At 2 mg/mL, the cold water extract showed a high reducing power of 1.502, whereas those of hot water and ethanol extracts were 0.868 and 0.159. With regard to the scavenging ability on DPPH free radicals, extracts were effective in the order: cold water > hot water > ethanol extracts. EC50 values for chelating ability on ferrous ions for cold water, hot water, and ethanol extracts were 1.461, 0.663, and 11.791 mg/mL, respectively. Based on EC50 values, the water extracts of P. nameko were effective antioxidants.