Zhang Y.,University of Notre Dame |
Zhang Y.,Heilongjiang Academy of Agricultural science |
Mayfield J.A.,University of Notre Dame |
Ploplis V.A.,University of Notre Dame |
Castellino F.J.,University of Notre Dame
Biochemical and Biophysical Research Communications | Year: 2014
Cluster 2b streptokinase (SK2b), secreted by invasive skin-trophic strains of Streptococcus pyogenes (GAS), is a human plasminogen (hPg) activator that optimally functions when human plasma hPg is bound, via its kringle-2 domain, to cognizant bacterial cells through the a1a2 domain of the major cellular hPg receptor, Plasminogen-binding group A streptococcal M-like protein (PAM). Another class of streptokinases (SK1), secreted primarily by GAS strains that possess affinity for pharyngeal infections, does not require PAM-bound hPg for optimal activity. We find herein that replacement of the central β-domain of SK2b with the same module from SK1 reduces the dependency of SK2b on PAM, and the converse is true when the β-domain of SK1 is replaced with this same region of SK2b. These data suggest that simple evolutionary shuttling of protein domains in GAS can be employed by GAS to rapidly generate strains that differ in tissue tropism and invasive capability and allow the bacteria to survive different challenges by the host. © 2014 Elsevier Inc. All rights reserved.
Guo Z.-Y.,China Agricultural University |
Kong C.-H.,China Agricultural University |
Wang J.-G.,China Agricultural University |
Wang Y.-F.,Heilongjiang Academy of Agricultural science
Soil Biology and Biochemistry | Year: 2011
Despite an increase in the understanding of the soybean isoflavones involved in root-colonizing symbioses, relatively little is known about their levels in the rhizosphere and their interactions with the soil microbial community. Based on a 13-year experiment of continuous soybean monocultures, in the present study we quantified isoflavones in the soybean rhizosphere and analyzed the soil microbial community structure by examining its phospholipid fatty acid (PLFA) profile. Two isoflavones, daidzein (7, 4'-dihydroxyisoflavone) and genistein (5,7,4'- trihydroxyisoflavone), were detected in the rhizosphere soil of soybean plants, with the concentrations in the field varying with duration of mono-cropping. Genistein concentrations ranged from 0.4 to 1.2 μg g-1 dry soil over different years, while daidzein concentrations rarely exceeded 0.6 μg g-1 dry soil. PLFA profiling showed that the signature lipid biomarkers of bacteria and fungi varied throughout the years of the study, particularly in mono-cropping year 2, and mono-cropping years 6-8. Principal component analysis clearly identified differences in the composition of PLFA during different years under mono-cropping. There was a positive correlation between the daidzein concentrations and soil fungi, whereas the genistein concentration showed a correlation with the total PLFA, fungi, bacteria, Gram (+) bacteria and aerobic bacteria in the soil microbial community. Both isoflavones were easily degraded in soil, resulting in short half-lives. Concentrations as small as 1 μg g-1 dry soil were sufficient to elicit changes in microbial community structure. A discriminant analysis of PLFA patterns showed that changes in microbial community structures were induced by both the addition of daidzein or genistein and incubation time. We conclude that daidzein and genistein released into the soybean rhizosphere may act as allelochemicals in the interactions between root and soil microbial community in a long-term mono-cropped soybean field. © 2011 Elsevier Ltd.
Sun X.D.,Heilongjiang Academy of Agricultural Science
International Journal of Food Science and Technology | Year: 2011
Soy proteins are very important protein source for human being and livestock. Enzymatic hydrolysis of soy protein can enhance or reduce its functional properties and improve its nutritious value. Soy protein hydrolysates were primarily used as functional food ingredients, flavour and nutritious enhancers, protein substitute, and clinical products. Conditions for hydrolysis were usually mild, whereas recently high pressure treatment attracted more interest. Degree of hydrolysis (DH) was usually between 1% and 39.5%. The main problem associated with proteolytic hydrolysis of soy protein was production of bitter taste, hydrolysates coagulation and high cost of enzymes. Bitterness reduction can be achieved by control of DH, selective separation of bitter peptides from hydrolysates, treatment of hydrolysates with exo-peptidases, addition of various components [adenosine monophosphate (AMP), some amino acids, monosodium glutamate (MSG), etc.] to block or mask the bitter taste, and modification of taste signalling. Hydrolysates coagulation can be resolved by selecting appropriate enzymes and by applying immobilisation technology the production cost can be reduced. Enzymatic hydrolysis also enhances bioactivity of soy proteins through conversion of glycosides to aglycones, increasing antioxidant and immunoregulatory properties. Finally, future works have been discussed. © 2011 The Author. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.
Han G.,Heilongjiang Academy of Agricultural science
Acta Agriculturae Scandinavica Section B: Soil and Plant Science | Year: 2014
Modernization and effective management in modern Chinese agriculture are the key of future success in Chinese agriculture development and food production. Based on an analysis of the agriculture structure and adaptation of the industrial management experiences in China, this review addresses how to achieve an effective and dynamic management in agriculture in the future. Chinese agriculture is in the process being transformed from individual, small, family-based farmers to cooperate-based large-scale farmers with modern agriculture machinery. To permit a smooth advancement and transition of Chinese agriculture from primitive traditional agriculture to a modern and machine-based agriculture as well as to enhance the agricultural productivity when total area of arable land is declining, a dynamic and sufficient management is the basis. However, there are a number of challenges and limitations: (1) Chinese farmers have in general limited education, (2) the small family-based agriculture tradition and structure, (3) the lack of experience in agriculture and innovation, and (4) short-term profit-based mentality. This review will discuss those challenges and propose corresponding solutions to assure the successful agricultural development in China by effective and dynamic management. © 2014 Taylor & Francis.
Hu X.,Northeast Agricultural University |
Xiao Y.,Northeast Agricultural University |
Niu K.,Northeast Agricultural University |
Zhao Y.,Northeast Agricultural University |
And 2 more authors.
Carbohydrate Polymers | Year: 2013
An efficient system for hydrolysis of lignocellulosic materials to prepare reducing sugar in a series of functional acidic ionic liquids with low synthetic cost and excellent dissolved and catalytic activity was established. High yield of reducing sugar was obtained with the use of 1-H-3-methylimidazolium chloride ([HMIM]Cl). The use of ionic liquid under ultrasound irradiation greatly improved the yield of total reducing sugar. The optimum reaction conditions were as follows: ratio of water/sample was 5 (w/w), ratio of IL/sample was 25 (w/w), 70 °C, 120 min and the yield of reducing sugar was up to 53.27 mg from 0.2 g of soybean straw and 50.03 mg from 0.2 g of corn straw. © 2013 Elsevier Ltd.
Fan F.,Chinese Academy of Agricultural Sciences |
Yang Q.,Chinese Academy of Agricultural Sciences |
Li Z.,Chinese Academy of Agricultural Sciences |
Wei D.,Heilongjiang Academy of Agricultural science |
And 2 more authors.
Microbial Ecology | Year: 2011
The microbiology underpinning soil nitrogen cycling in northeast China remains poorly understood. These agricultural systems are typified by widely contrasting temperature, ranging from -40 to 38°C. In a long-term site in this region, the impacts of mineral and organic fertilizer amendments on potential nitrification rate (PNR) were determined. PNR was found to be suppressed by long-term mineral fertilizer treatment but enhanced by manure treatment. The abundance and structure of ammonia-oxidizing bacterial (AOB) and archaeal (AOA) communities were assessed using quantitative polymerase chain reaction and denaturing gradient gel electrophoresis techniques. The abundance of AOA was reduced by all fertilizer treatments, while the opposite response was measured for AOB, leading to a six- to 60-fold reduction in AOA/AOB ratio. The community structure of AOA exhibited little variation across fertilization treatments, whereas the structure of the AOB community was highly responsive. PNR was correlated with community structure of AOB rather than that of AOA. Variation in the community structure of AOB was linked to soil pH, total carbon, and nitrogen contents induced by different long-term fertilization regimes. The results suggest that manure amendment establishes conditions which select for an AOB community type which recovers mineral fertilizer-suppressed soil nitrification. © 2011 Springer Science+Business Media, LLC.
Yang X.,Northeast Agricultural University |
Li H.,Northeast Agricultural University |
Guan Q.,Northeast Agricultural University |
Liu D.,Heilongjiang Academy of Agricultural science
Genetics and Molecular Biology | Year: 2013
The Toll-like receptor 5 (TLR5) recognizes flagellin of Gram-positive and -negative bacteria and plays an important role in the host defense system. Here, we surveyed single nucleotide polymorphisms (SNPs) in the coding sequence of the porcine TLR5 gene in 83 individuals from five pig breeds, these including Chinese local populations and Western commercial pig breeds. A total of 19 medium polymorphic SNPs (0.25 < PIC < 0.5) were identified, three of which were missense mutations that clustered within the extracellular domain of TLR5. One of the non-synonymous SNPs fell within a 228-amino acid region which has been shown to be important for flagellin recognition. Four SNPs were only found with high frequencies in Oriental pig breeds. The 19 SNPs were found in 30 haplotypes, one of which segregated at high frequency in all samples. Compared with Western pig breeds, Chinese local populations had higher genetic diversity and more haplotypes. Tajima's test showed no evidence for deviation from neutrality. The data provide useful information for future genetic marker characterization by means of disease association analysis and/or stimulating the mutation carrier with relevant ligands. © 2013, Sociedade Brasileira de Genética. Printed in Brazil.
Meiyu Q.,Heilongjiang Academy of Agricultural science |
Liu D.,Heilongjiang Academy of Agricultural science |
Roth Z.,Hebrew University
Zygote | Year: 2015
An in vitro model of embryo production was used to examine the effects of insulin-like growth factor (IGF)-I on maturation and developmental competence of oocytes exposed to heat shock. Cumulus-oocyte complexes were matured at 38.5°C or exposed to acute heat shock (HS; 41.5°C), with or without 100 ng/ml IGF-I, for 22 h through in vitro maturation. The experimental groups were control (C), C + IGF-I, HS, and HS + IGF-I. Oocytes were fertilized at the end of maturation, and the proportion of cleaved embryos was recorded 44 h later. HS during maturation increased the proportion of TUNEL-positive oocytes (P < 0.05). HS did not have any effect on cortical granule translocation but impaired resumption of meiosis, expressed as a decreased proportion of oocytes with nuclei in metaphase I (P < 0.05) and metaphase II (MII; P < 0.05). HS decreased the proportion of oocytes that cleaved (P < 0.05), in particular those oocytes that further developed to 4-cell-stage embryos (P < 0.05). IGF-I alleviated, to some extent, the deleterious effects of HS on the oocytes as reflected by a reduced proportion of TUNEL-positive oocytes (P < 0.03). While not significant, IGF-I tended to increase the proportion of MII-stage oocytes (P < 0.08) and 4-cell-stage cleaved embryos (P < 0.06). Further examination is required to explore whether IGF-I also affects the developmental competence of oocytes exposed to HS. Copyright © Cambridge University Press 2014.
Sun X.D.,Heilongjiang Academy of Agricultural Science |
Holley R.A.,University of Manitoba
Comprehensive Reviews in Food Science and Food Safety | Year: 2012
The shelf life of packaged fresh red meats is most frequently determined by the activity of microorganisms, which results in the development of off-odors, gas, and slime, but it is also influenced by biochemical factors such as lipid radical chain and pigment oxidation causing undesirable flavors and surface discoloration. The predominant bacteria associated with spoilage of refrigerated meats are Pseudomonas, Acinetobacter/Moraxella (Psychrobacter), Shewanella putrefaciens, lactic acid bacteria, Enterobacteriaceae, and Brochothrix thermosphacta. The spoilage potential of these organisms and factors influencing their impact on meat quality are discussed. High O2-modified atmosphere (80% O2+ 20% CO2) packaging (MAP) is commonly used for meat retail display but vacuum packaging remains the major MAP method used for meat distribution. Two-step master packaging (outer anoxic-20% CO2+ 80% N2/inner gas-permeable film) is used for centralized MAP distribution, but CO use (0.4%) in low O2 packaging systems is limited by consumer uncertainty that CO may mask spoilage. Active packaging where the film contributes more than a gas/physical barrier is an important technology and has been studied widely. Its application in combination with MAP is very promising but impediments remain to its widespread industrial use. The influence of processing technologies including modified atmospheres on lipid oxidation and discoloration of meats are analyzed. Because both organic acids and antioxidants have been evaluated for their effects on microorganism growth, in concert with the prevention of lipid oxidation, work in this area is examined. © 2012 Institute of Food Technologists®.
Satoh T.,Hiroshima University |
Ohba A.,Hiroshima University |
Liu Z.,Heilongjiang Academy of Agricultural science |
Inagaki T.,Hiroshima University |
Satoh A.K.,Hiroshima University
eLife | Year: 2015
In eukaryotes, most integral membrane proteins are synthesized, integrated into the membrane, and folded properly in the endoplasmic reticulum (ER). We screened the mutants affecting rhabdomeric expression of rhodopsin 1 (Rh1) in the Drosophila photoreceptors and found that dPob/EMC3, EMC1, and EMC8/9, Drosophila homologs of subunits of ER membrane protein complex (EMC), are essential for stabilization of immature Rh1 in an earlier step than that at which another Rh1-specific chaperone (NinaA) acts. dPob/EMC3 localizes to the ER and associates with EMC1 and calnexin. Moreover, EMC is required for the stable expression of other multi-pass transmembrane proteins such as minor rhodopsins Rh3 and Rh4, transient receptor potential, and Na+K+-ATPase, but not for a secreted protein or type I single-pass transmembrane proteins. Furthermore, we found that dPob/EMC3 deficiency induces rhabdomere degeneration in a lightindependent manner. These results collectively indicate that EMC is a key factor in the biogenesis of multi-pass transmembrane proteins, including Rh1, and its loss causes retinal degeneration. © Copyright Satoh et al.