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A halophilic bacterium Halolactibacillus sp. SK71 producing extracellular glucoamylase was isolated from saline soil of Yuncheng Salt Lake, China. Enzyme production was strongly influenced by the salinity of growth medium with maximum in the presence of 5% NaCl. The glucoamylase was purified to homogeneity with a molecular mass of 78.5 kDa. It showed broad substrate specificity and raw starch hydrolyzing activity. Analysis of hydrolysis products from soluble starch by thin-layer chromatography revealed that glucose was the sole end-product, indicating the enzyme was a true glucoamylase. Optimal enzyme activity was found to be at 70°C, pH 8.0, and 7.5% NaCl. In addition, it was highly active and stable over broad ranges of temperature (0-100°C), pH (7.0-12.0), and NaCl concentration (0-20%), showing excellent thermostable, alkali stable, and halotolerant properties. Furthermore, it displayed high stability in the presence of hydrophobic organic solvents. The purified glucoamylase was applied for raw corn starch hydrolysis and subsequent bioethanol production using Saccharomyces cerevisiae. The yield in terms of grams of ethanol produced per gram of sugar consumed was 0.365 g/g, with 71.6% of theoretical yield from raw corn starch. This study demonstrated the feasibility of using enzymes from halophiles for further application in bioenergy production. © 2014 American Institute of Chemical Engineers. Source


Chen J.-L.,Life Science College | Wan X.-P.,Life Science College | Zhang H.,North Sichuan Medical College | Yang X.,Life Science College | And 6 more authors.
Procedia in Vaccinology | Year: 2010

A novel shuffled pig IL-2 gene and immunostimulatory sequences containing 11 CpG motifs were subcloned into the eukaryotic expression plasmid VR1020 and VR1012, respectively designated as the recombinant VRIL2S and VR1C, then they were encapsulated in chitosan nanoparticles (CNP) prepared by ionotropic gelation method. Forty 21-day-old piglets were divided into four groups and intramuscularly injected respectively with 0.5 mg VRIL2S-CNP, VR1C-CNP, VR1020-CNP and CNP along with the rabbit-attenuated swine fever virus vaccines. The bloods were weekly collected from the piglets after vaccination to detect the changes of immunoglobulins, specific antibodies, interleukins, IFN-γ and immune cells. The results were found that in comparison with the control VR1020-CNP and CNP group, the content of immunoglobulins, specific antibodies, IL-2, IL-6, IL-4 and IFN-γ significantly increased in the sera from the treated VRIL2S-CNP and VR1C-CNP group (P<0.05); the numbers of lymphocytes and monocytes also remarkably elevated in the treated groups (P < 0.05). Meanwhile, the levels of specific antibody, IgM, IgA and IgG in the VRIL2S-CNP group were significantly higher than those of VR1C-CNP group respectively from 7 or 28 to 56 days after vaccination (P < 0.05); so did the amount of IL-2 and IFN-γ in the VRIL2S-CNP group (P < 0.05). Moreover, the number of lymphocytes and monocytes rose to different degrees in the VRIL2S-CNP treated pilglets compared to those of VR1C-CNP group (P < 0.05). The average weight gain of in VRIL2S-CNP treated pigs was also obviously higher than that of the controls during the experimental period. These indicated that the humoral and cellular immunities of piglets were significantly promoted by VRIL2S-CNP and VR1C-CNP, and VRIL2S could provoked better immunities of piglets to Hog Cholera than VR1C-CNP, implying that the shuffled pig IL-2 gene entrapped with CNP is a safe and powerful adjuvant to boost the specific immunity of piglets against Hog cholera, facilitating the development of a novel effective adjuvant to improve the immunity of pig against Hog cholera. © 2010 Elsevier B.V. All rights reserved. Source


Wang M.,Life Science College | Wang Y.,CAS Kunming Institute of Zoology | Wang Y.,University of Chinese Academy of Sciences | Wang A.,Life Science College | And 10 more authors.
Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology | Year: 2010

While investigating antimicrobial peptide diversity of Amolops loloensis, five novel antimicrobial peptides belonging to two families were identified from skin secretions of this frog. The first family including two members is esculentin-2-AL (esculentin-2-ALa and -ALb); the second family including three members is temporin-AL (temporin-ALd to -ALf). The family of esculentin-2-AL is composed of 37 amino acid residues (aa); the family of temporin-AL is composed of 16, 13 and 10 aa, respectively. All of these antimicrobial peptides showed antimicrobial activities against tested microorganisms. cDNAs encoding precursors of esculentin-2-ALs and temporin-ALs were cloned from the skin cDNA library of A. loloensis. All the precursors share similar overall structures. There is a typical prohormone processing signal (Lys-Arg) located between the acidic propiece and the mature peptide. The antimicrobial peptide family of esculentin-2 is firstly reported in the genus of Amolops. Combined with previous reports, a total of four antimicrobial peptide families have been identified from the genus of Amolops; three of them are also found in the genus of Rana. These results suggest the possible evolutionary connection between the genera Amolops and Rana. © 2009 Elsevier Inc. All rights reserved. Source

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