A cell line, SHK, was derived from the kidney of spotted halibut Verasper variegates. The cell line was subcultured more than 40 passages in minimum essential medium （MEM） supplemented with fetal bovine serum （FBS...A cell line, SHK, was derived from the kidney of spotted halibut Verasper variegates. The cell line was subcultured more than 40 passages in minimum essential medium （MEM） supplemented with fetal bovine serum （FBS） and 10 ng ml4 basic fibroblast growth factor （bFGF）. Cell morphology from primary culture and subculture was observed continuously by microscopy. The SHK cell line consisted predominantly of fibroblast-like cells. The cell line was able to grow between 20℃ and 30℃ with the optimum growth at 24℃ and with a reduced growth between 12℃ and 20℃. The growth rate of the cells increased as the proportion of FBS increased from 10% to 20% at 28℃ with optimum growth at the concentration of 20%. The doubling time of the cells was determined to be 44.8 h. Chromosome analysis revealed that 52% of the SHK cells maintained a normal diploid chromosome number （2n=46）. The cells were successfully transfected with green fluorescent protein （GFP） reporter plasmids and the expression of GFP gene in the cells indicated the possible utility of the cells in gene expression studies. The cells were infected by lymphosystis disease virus （LCDV） and found to be susceptible to the virus in cytopathic effect （CPE） observation. The infection was confirmed by PCR and electron microscopy experiments, which proved the existence of the viral particles in the cytoplasm of the virus-infected cells.展开更多
Yeasts represent an important category of microorganisms used in biocontrol of diseases affecting postharvest fruits or vegetables, food-born microorganisms being previously reported as also having important antimicro...Yeasts represent an important category of microorganisms used in biocontrol of diseases affecting postharvest fruits or vegetables, food-born microorganisms being previously reported as also having important antimicrobial activity against human pathogens. However, the action of yeasts against species with pathogen potential for plants or humans is less understood. Our research was conducted on three Metschnikowia pulcherrima yeast strains isolated from white grapes （SG1, SG2） and cherries （CPMI） from Romania. The screening tests performed on yeast peptone glucose （YPG） medium on isolates from human infections revealed reduced antimicrobial activity with narrow inhibition zones against strain M6 （Candidaparapsilosis）. In the presence of C3 （Candida albicans）, SGI was the most active forming wider halos, followed closely by SG2, while for CPM1, no activity was described. Improvement of antagonistic action was observed especially for mixtures of SG1 with 0.5% and 1% sodium bicarbonate （NaHCO3）, respectively, 1% and 2% calcium chloride （CaCI2）. Utilization of yeast malt extract agar （YMA） medium favoring mycelium formation in cultures representing potential sensitive substrates seemed to facilitate the antimicrobial action of SG1. When compared to reference M. pulcherrima MUCL 29874, the Metschnikowia strains isolated from fruits were better antagonists probably due to variation of gene regulation or existence of adaptative responses.展开更多
基金supported by grants from State 863High-Technology Rand Project of China(2006AA09Z406,2006AA10A401)Taishan Scholar Project of Shan-dong Province
文摘A cell line, SHK, was derived from the kidney of spotted halibut Verasper variegates. The cell line was subcultured more than 40 passages in minimum essential medium （MEM） supplemented with fetal bovine serum （FBS） and 10 ng ml4 basic fibroblast growth factor （bFGF）. Cell morphology from primary culture and subculture was observed continuously by microscopy. The SHK cell line consisted predominantly of fibroblast-like cells. The cell line was able to grow between 20℃ and 30℃ with the optimum growth at 24℃ and with a reduced growth between 12℃ and 20℃. The growth rate of the cells increased as the proportion of FBS increased from 10% to 20% at 28℃ with optimum growth at the concentration of 20%. The doubling time of the cells was determined to be 44.8 h. Chromosome analysis revealed that 52% of the SHK cells maintained a normal diploid chromosome number （2n=46）. The cells were successfully transfected with green fluorescent protein （GFP） reporter plasmids and the expression of GFP gene in the cells indicated the possible utility of the cells in gene expression studies. The cells were infected by lymphosystis disease virus （LCDV） and found to be susceptible to the virus in cytopathic effect （CPE） observation. The infection was confirmed by PCR and electron microscopy experiments, which proved the existence of the viral particles in the cytoplasm of the virus-infected cells.
文摘Yeasts represent an important category of microorganisms used in biocontrol of diseases affecting postharvest fruits or vegetables, food-born microorganisms being previously reported as also having important antimicrobial activity against human pathogens. However, the action of yeasts against species with pathogen potential for plants or humans is less understood. Our research was conducted on three Metschnikowia pulcherrima yeast strains isolated from white grapes （SG1, SG2） and cherries （CPMI） from Romania. The screening tests performed on yeast peptone glucose （YPG） medium on isolates from human infections revealed reduced antimicrobial activity with narrow inhibition zones against strain M6 （Candidaparapsilosis）. In the presence of C3 （Candida albicans）, SGI was the most active forming wider halos, followed closely by SG2, while for CPM1, no activity was described. Improvement of antagonistic action was observed especially for mixtures of SG1 with 0.5% and 1% sodium bicarbonate （NaHCO3）, respectively, 1% and 2% calcium chloride （CaCI2）. Utilization of yeast malt extract agar （YMA） medium favoring mycelium formation in cultures representing potential sensitive substrates seemed to facilitate the antimicrobial action of SG1. When compared to reference M. pulcherrima MUCL 29874, the Metschnikowia strains isolated from fruits were better antagonists probably due to variation of gene regulation or existence of adaptative responses.
