| 摘要 | 第1-8页 |
| Abstract | 第8-16页 |
| Chapter 1 Literature Review | 第16-46页 |
| ·Marine environment and marine yeast resources | 第16页 |
| ·Yeast distribution in marine environments | 第16-20页 |
| ·Deep sea hydrothermal vent | 第18-19页 |
| ·Mangrove ecosystem | 第19-20页 |
| ·Application of marine yeast | 第20-21页 |
| ·Killer yeast and killer phenomenon | 第21-25页 |
| ·Killer toxin and its classification | 第23-24页 |
| ·Molecular biology of yeast killer systems | 第24-25页 |
| ·Mechanism of action | 第25-33页 |
| ·Primary cell wall receptors | 第25-29页 |
| ·Secondary receptor | 第29-30页 |
| ·Inhibition of cell wall glucan and DNA synthesis | 第30页 |
| ·Increase of membrane permeability to ions | 第30-32页 |
| ·Cell cycle arrest | 第32页 |
| ·Apoptosis | 第32-33页 |
| ·Endonuclease | 第33页 |
| ·Characterization of killer toxins | 第33-36页 |
| ·Molecular weights | 第33-34页 |
| ·Optimal conditions for killer toxin activity | 第34页 |
| ·Optimal pH and Temperature | 第34-36页 |
| ·Optimal NaCl concentrations | 第36页 |
| ·Applications of killer yeast | 第36-40页 |
| ·Medicine: Antifungal and antimicrobial | 第37-38页 |
| ·Fermentation | 第38-39页 |
| ·Agriculture and food | 第39-40页 |
| ·Heterologous expression | 第40页 |
| ·Pathogenic yeast in mariculture | 第40-44页 |
| ·Killer yeast active against Metschnikowia bicuspidata WCY | 第44页 |
| ·Significance and objectives of the study | 第44-46页 |
| Chapter 2 Isolation, identification and screening of killer toxin producing yeast strain HN12-1 against pathogenic yeast in M. bicuspidata WCY crab | 第46-60页 |
| ·Introduction | 第46-47页 |
| ·Material and Methods | 第47-51页 |
| ·Sampling | 第47-49页 |
| ·Media | 第49页 |
| ·Isolation | 第49页 |
| ·Screening of killer toxin-producing yeasts | 第49-50页 |
| ·Identification | 第50-51页 |
| ·Results | 第51-56页 |
| ·Screening of killer yeasts against the pathogenic yeast M. bicuspidata WCY | 第51-52页 |
| ·Microscopic identification/Morphology | 第52-53页 |
| ·Yeast fermentative and assimilative ability for sugars | 第53-54页 |
| ·Molecular identification | 第54-55页 |
| ·Phylogenetic analysis | 第55-56页 |
| ·Discussion | 第56-60页 |
| Chapter 3 Production, purification and characterization of a novel killer toxin from Kluyveromyces siamensis HN12-1 | 第60-75页 |
| ·Introduction | 第60-61页 |
| ·Materials and methods | 第61-64页 |
| ·Yeast strains | 第61页 |
| ·Media | 第61页 |
| ·Production of killer toxin and preparation of crude killer toxin | 第61-62页 |
| ·Measurement of killer toxin activity | 第62页 |
| ·Purification of the killer toxin | 第62-63页 |
| ·SDS polyacrylamide gel electrophoresis | 第63页 |
| ·Mass spectrometry for protein identification | 第63-64页 |
| ·Effects of pH and temperature on killing activity | 第64页 |
| ·Killing activity spectra of the purified killer toxin | 第64页 |
| ·Results | 第64-71页 |
| ·The optimal conditions for production of the killer toxin | 第64-65页 |
| ·Purification of the killer toxin | 第65-66页 |
| ·Gel electrophoresis | 第66-68页 |
| ·The killer toxin identification by mass spectrometry | 第68-69页 |
| ·Effects of different temperatures, pHs and NaCl concentrations on killing activity of the purified killer toxin | 第69-70页 |
| ·Killing activity spectra of the purified killer toxin | 第70-71页 |
| ·Discussion | 第71-75页 |
| Chapter 4 Preliminary study of killer toxin mechanism of action | 第75-88页 |
| ·Introduction | 第75-76页 |
| ·Material and methods | 第76-79页 |
| ·Yeast strains | 第76页 |
| ·Media | 第76-77页 |
| ·Preparation of the purified killer toxin | 第77页 |
| ·Preparation of the yeast protoplasts and killing of the protoplasts | 第77页 |
| ·Competition assay | 第77-78页 |
| ·Fluorescence microscopy | 第78页 |
| ·Scan electron microscopy | 第78页 |
| ·Kinetics of Killer toxin | 第78-79页 |
| ·Results | 第79-85页 |
| ·Effect of Killer toxin on the protoplasts of sensitive cells | 第79-80页 |
| ·Competition assay | 第80-81页 |
| ·Fluorescence microscopy | 第81-82页 |
| ·Scan electron microscopy | 第82-83页 |
| ·Kinetics of the killer toxin | 第83-85页 |
| ·Discussion | 第85-88页 |
| Chapter 5 Effects of density of sensitive yeast cells and nutrient on cell growth and killer toxin production by the killer yeast Kluyveromyces siamensis HN12-1 | 第88-105页 |
| ·Introduction | 第88-89页 |
| ·Material and methods | 第89-91页 |
| ·Yeast strains | 第89页 |
| ·Media | 第89-90页 |
| ·Co-cultivation of the killer yeast and sensitive yeast | 第90页 |
| ·Determination of dead cells | 第90页 |
| ·Preparation of the crude killer toxin | 第90页 |
| ·Measurement of killer toxin activity | 第90-91页 |
| ·Determination of total protein concentration | 第91页 |
| ·Results | 第91-102页 |
| ·Effects of the density of the sensitive yeast and nutrients on cell growth of the killer yeast and sensitive yeast | 第91-95页 |
| ·Effects of the density of the sensitive yeast and nutrients on killer toxin production | 第95-97页 |
| ·Effects of the density of the sensitive yeast and nutrients on percentage of total dead cells in the co-culture | 第97-100页 |
| ·The changes in protein concentration during the co-cultivation | 第100-102页 |
| ·Discussion | 第102-105页 |
| Innovations | 第105-106页 |
| References | 第106-130页 |
| Appendix | 第130-132页 |
| Acknowledgement | 第132-133页 |
| Self Introduction | 第133页 |
| List of publications | 第133页 |
