Download presentation
Presentation is loading. Please wait.
Published byEustacia Morrison Modified over 9 years ago
1
Effects of physical, chemical and biological agents on bacteria Experiment 4
2
Outline Moist heatUV Chemical &biological agents Bacteria E.coli B.subtitis S.aureus E.coli Culture media BrothAgar plates Equipments Water bathUV light - Reagents Non 2% iodine 1% crystal violet 2% mercurochrome garlic paper disks of penicillin paper disks of streptomycin
3
Effect of moist heat BacteriaE.coil (liquid) (shake it)B.subtitis (slant) Temperature 100 ℃ RT 100 ℃ RT Time5min30minControl5min30minControl Tube number1#1# 2#2# 3#3# 4#4# 5#5# 6#6# Stand A Stand A Stand B Stand B Stand C Stand C 4 students / group
4
Effect of UV light Condition : expose UV light for 30min Bacterial strain : S.aureus Inoculation method : Streak plate (with cotton stick) UV 30min UV mark
5
Effect of chemical and biological agents Reagents: 1. 1% crystal violet 2. 2% mercurochrome 3. 2% iodine 4. garlic 5. paper disk of penicillin 6. paper disk of streptomycin Species : S.aureus 1 agar plate E.coli 1 agar plate 2 3 4 5 6 1 MarkManipulation Bring with me tomorrow !
6
Part 1. Effect of moist heat on bacteria; E.coli, B.subtitis Part 2. Effect of UV light on bacteria; S.aureus Part 3. Effect of chemical & biological agents on bacteria; E.coli, S.aureus Observation of results
7
Moist heat E.coli 1 # : 100 ℃, 5min 2 # : 100 ℃, 30min 3 # : RT, Control B.subtitis 4 # : 100 ℃, 5min 5 # : 100 ℃, 30min 6 # : RT, Control
8
Strains 100 ℃, 5 min 100 ℃, 30 min Control E. coli B. subtitis Record: Effect of moist heat on bacteria Clear: “-” or bacterial growth: “+” Surface growing / Turbidity / Precipitate growing;
9
UV radiation Covered part Radiated part UV Describe result:
10
Effect of chemical and biological agents Measure inhibition zone diameter or 2 radius
11
Effect of chemical and biological agents Inhibition zone diameter (mm)>15mm10~15mm<10mm 0mm susceptibility degree Extremely sensitive Medium sensitive Slight sensitive Resistant Cultures Diameter of Inhibition Zone (mm) 1% Crystal violet 2% Mercurochrome PenicillinStreptomycin2%IodineGarlic E.coli S.aureus Susceptibility degree Record:
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.