Fungal Growth with Czapek Dox Media

Section 2: Essential Nutrient Components for Fungal Growth

• Czapek Dox Media: Contains sucrose, sodium nitrate (source of N), sulfuric acid (source of S), potassium sulfate (source of K), ferrous sulfate (source of Fe)

Procedure for Fungal Growth

• Flask Preparation: One flask contains all components, others lack certain components. The flask with all components exhibits the best fungal growth.
• Sterilization: Sterilize the media in an autoclave at 121°C for 15-20 minutes.
• Cooling: Allow the sterilized media to cool.
• Pouring into plates: Pour the cooled media into pre-sterilized petri dishes.
• Solidification: Allow the media to solidify at room temperature.
• Inoculation: Introduce tested fungal specimens onto the plates.
• Incubation: Incubate the plates at 30°C for 7 days.
• Measurement: Measure the diameter of fungal growth.

Observation - Fungal Growth Comparison (Page 2)

• Fungal growth diameter decreases when comparing to the first plate/flask.
• Nutrient classification:
  • Macro nutrients (e.g., C, N, S, P, K): Needed in large amounts by fungi.
  • Micro nutrients (e.g., Cu, Co, Ca, Zn, Fe): Needed in small amounts by fungi.

Potassium (K+)

• Enzyme Activation: Potassium is a co-factor for enzyme activity.
• Toxicity Prevention: It helps to counteract negative charges that could negatively affect fungal growth.
• Permeability Regulation: Plays a role in regulating permeability within the fungi cell wall
• Metabolism regulation: Contributes to carbohydrate metabolism.

Effect of Temperature on Fungal Growth (Page 4)

• Procedure: Prepare Czapek Dox agar media, sterilize, pour into plates, allow to solidify, inoculate with tested fungi, and incubate at different temperatures (5°C, 15°C, 30°C, 45°C) for 7 days.
• Observation: Measure the diameter of fungal growth, record data.
• Minimum Temperature: The lowest temperature at which fungal growth is observed.

Optimum and Maximum Temperatures for Fungal Growth (Page 5)

• Optimum Temperature: The best temperature for fungal growth.
• Maximum Temperature: The highest temperature at which fungal growth is observed before it stalls.
• Fungal Types and Temperatures: Different fungal species (e.g., psychrophilic, mesophilic, thermophilic) are adapted to different temperature ranges.
• Low Temperature Impact: Low temperatures reduce the velocity (kinetics) of enzymes, limiting metabolic activity. Ice crystals formation in lower temperatures also affect fungal growth.
• High Temperature Impact: High temperatures denature enzymes, inhibiting growth. There is no absorption of nutrients.