L. 20 Microbes, Food and Nutrition Flashcards
L.O.
Understand:
- How microbes are involved in food production in both positive and negative ways and give 1 or 2 examples
- The types of relationships (pathogenic, mutualist, symbiotic) organisms have with microbes and give 1 or 2 examples
Briefly define:
- Zoonosis
- Fermentation in food production
- Difference between food spoilage and food poisoning and examples of microbes that cause food poisoning (infection and intoxication)
- Concept of One Health in food production Appreciate the importance of microbes in the gut microbiome and role in health
Food production and microbes
Production:
- Processed, distribution, retail, consume
Microbes have negative and positive impacts
Microbe pros
- Digestion
- Enhance plant growth
- Recycle waste into nutrients
- Fermemtation
- Fungi as food source
Microbe cons
- Pathogens
- Contamination
- Food poisoning
- Poor gutmicrobiota = poor health
Microbes in soil
Maintain soil health by:
- Fixing nitrogen
- Organic waste into inorganic nutrients
- Suppress pathogens by diversity
- Breakdown toxins (pesticides)
Microbes in animals
Enable animals to breakdown cellulose
- Cellulose = sugar polymer
Rumen of cow contains enzymes that can breakdown cellulose
Organic acids and microbial cells are then digested by animal as nutrients.
Microbes in plants
- Promote plant growth via mutualism
Mycorrhizal Fungi:
- Most plants, enhances water and nutrient uptake by creating more root systems, fungi gets sugar from plant
Phizobium Bacteria:
- In legume roots, fix nitrogen, receive sugars
Plant pathogens
- Fungi and virus are main problems
- Simple virus are mopst varient in plants
- Sigatoka fungi threaten banana survival gloabally
Animal pathogens
Can be virus, bacterial, fungi or protists
- Modern agriculture aggravate microbial problems
Animal pathogen examples
Foot and mouth disease virus (FMDV):
- Not in AUS
- Impacts cattle, causing fever, blisters, reduce milk and meat production
Salmonella Spp:
- In AUS
- Bacteria impacting poultry and pigs
- Causes gastro illness
- Large concern as easy transmitted to humans thorugh meat and eggs
Bovine Tuberculosis:
- Eradicated in AUS
- Bacterial infection
- Cattle and other animals transmitted to people
- Respiratory issues and weight loss
Avian Influenza Virus (HPAI):
- Viral infection
- Poultry
- Sudden death, respiratory, reduced egg production.
Zoonosis
Human infection arising from animals
- Microbes may be pathogenic to both animals and people (eg. rabies)
- Human Pathogen may be normal flora to animal or a vector for disease
- eg. Covid most likely had a zoonitic origin
Fermentation
Many meanings:
- Microbial transformation of foods by bacteria or fungi
- Anaerobic metabolism of sugars into alcohol, acids and CO2.
Saccharomyces (Beer yeast)
Fungus
- Important for food production
Microbial food spoilage
Due to growth of fungi or bacteria and/ or the enzymes secreted.
Prevention
- refridgeration
- Preservation
- Fermentation
Food poisoning
NOT same as food spoilage (different microbes)
Can occur from spoiled or fresh food
Food-borne infection:
- Microbes grow in the gut (salmonella)
Food-borne intoxication:
- Microbes make toxins in the food (Clostridium botulinum)
