The Effect of Saliva on Bacteria

The Effect of Saliva on Bacteria Mackenzie Abate 9th Grade

Problem • Does saliva have an effect on bacteria? • If so, what is this effect?

Research E. coli B. cereus Gram positive Facultative anaerobe Beta hemolysis Food-bourne illnesses Produces a emetic toxin: ETE; three enterotoxins: NBL, Nhe and EntK • Gram negative • Facultative anaerobe • Heterotrophic • Mixed acid fermentation: lactate, succinate, ethanol, carbon dioxide and acetate • Motile • Conjugation, transformation and transduction

Research S. mutans S. epidermidis Gram negative Non-motile Facultative anaerobe Grows on plastic objects in body Produces slime • Gram positive • Heterotrophic • Metabolizes sucrose to lactic acid • Allowed to grip to teeth because of receptors • Found mainly on teeth

Research Human Saliva Dog Saliva • 98% water • Digestion and disinfectants

Research Cat Saliva Amylase

Research Lysozyme

Hypothesis • If my research is correct, then ________ should be the most effective in killing bacteria

Types of Bacteria Bacillus cereus, Escherichia coli, Staphylococcus epidermidis and Streptococcal mutans Control: Amylase and Lysozyme Additional Materials: Innoculating loop (#) plates of agar (#) blank disks Autoclave Disposable gloves Safety Goggles Water (?) Materials

Procedure • Saliva will be extracted • 2 tabs will be soaked in each saliva type • 2 tabs will be soaked in amylase • 2 tabs will be soaked in water • 2 tabs will remain dry • 2 types of bacteria will be plated for each saliva type using sterile technique • The tabs will then be added to the bacterial plates • The plates will be sealed and stored at 37 degrees Celsius • Bacterial growth will be observed and measured over the period of 3 days • The zone of inhibition will also be measured

Procedure II • Saliva will be extracted • 2 tabs will be soaked in each saliva type • 2 tabs will be soaked in amylase • 2 tabs will be soaked in water • 2 tabs will remain dry • S. mutans and S. epidermidis will be plated for each saliva type using sterile technique • The tabs will then be added to the bacterial plates • The plates will be sealed and stored at 37 degrees Celsius • Bacterial growth will be observed and measured over the period of 3 days • The zone of inhibition will also be measured

Procedure III (?) • Each of the four types of bacteria will once again be plated using sterile technique • This time, eight disks will soak in a 20% (?) solution of lysozyme and water. • The tabs will then be added to the bacterial plates • The plates will be sealed and stored at 37 degrees Celsius • Bacterial growth will be observed and measured over the period of 3 days • The zone of inhibition will also be measured

Data

Conclusion

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The Effect of Saliva on Bacteria