Podcast
Questions and Answers
Which microorganism is commonly used for producing single-cell protein (SCP) and is also accepted for human consumption?
Which microorganism is commonly used for producing single-cell protein (SCP) and is also accepted for human consumption?
What is a key limitation of algal SCP regarding its digestibility?
What is a key limitation of algal SCP regarding its digestibility?
Which substrate is commonly used for bacterial SCP production?
Which substrate is commonly used for bacterial SCP production?
Which characteristic is NOT associated with the beneficial properties of SCP from fungi?
Which characteristic is NOT associated with the beneficial properties of SCP from fungi?
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What is a notable nutritional aspect of bacterial SCP compared to algal and fungal sources?
What is a notable nutritional aspect of bacterial SCP compared to algal and fungal sources?
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What is a key reason for the choice of microorganisms in producing Single Cell Protein (SCP)?
What is a key reason for the choice of microorganisms in producing Single Cell Protein (SCP)?
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What is the primary aim during the production of yeast biomass?
What is the primary aim during the production of yeast biomass?
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Which type of medium has predominantly replaced cereal grains in yeast production?
Which type of medium has predominantly replaced cereal grains in yeast production?
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During which process is aerobic respiration aimed to be maintained in yeast production?
During which process is aerobic respiration aimed to be maintained in yeast production?
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Single cell protein production began gaining traction during which major historical event?
Single cell protein production began gaining traction during which major historical event?
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What is the role of the ripening stage in yeast biomass production?
What is the role of the ripening stage in yeast biomass production?
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What is the expected protein yield from a 500 kg yeast culture over 24 hours?
What is the expected protein yield from a 500 kg yeast culture over 24 hours?
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Which microorganism is NOT mentioned as being used for Single Cell Protein production?
Which microorganism is NOT mentioned as being used for Single Cell Protein production?
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What is myco-protein primarily made from?
What is myco-protein primarily made from?
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Which of the following is NOT a benefit of consuming mushrooms?
Which of the following is NOT a benefit of consuming mushrooms?
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Which mushroom species is known for being the button mushroom?
Which mushroom species is known for being the button mushroom?
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What significant issue is associated with fungi in food production?
What significant issue is associated with fungi in food production?
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Which of the following diseases has been linked to mycotoxins?
Which of the following diseases has been linked to mycotoxins?
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What is the ideal temperature range for mycelial growth during mushroom production?
What is the ideal temperature range for mycelial growth during mushroom production?
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Which genera of mushrooms is specifically known for its immunomodulatory properties?
Which genera of mushrooms is specifically known for its immunomodulatory properties?
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What historical event brought attention to aflatoxins in feed?
What historical event brought attention to aflatoxins in feed?
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Study Notes
Agricultural Microbiology - MICR20010
- Course code: MICR20010
- Course name: Agricultural Microbiology
- Instructor: Dr. Tadhg Ó Cróinín
Practical MCQ Exam
- Exam date: Friday, Nov 22nd
- Exam time: 2:00 PM - 3:00 PM
- Exam format: Practical Online MCQ
- Instructions: Sample questions are available on Brightspace; refer to the e-mail for specific instructions. Separate e-mails for DSS students.
- Additional resources: Sample MCQ questions for the final exam in RDS are also available on Brightspace.
Remaining Lectures
- Lecture 10: Microorganisms and Disease
- Lecture 11: The Immune System
- Lecture 12: Pathogenic Bacteria
- Lecture 13: Pathogenic Fungi and Viruses
- Lecture 14: Antibiotic-Resistant Microorganisms
- Lecture 15: Microbiology in the Food Industry (including The Fungi)
- Lecture 16: Microbiology in the Food Industry (Fermentations)
- Lecture 17: The Nitrogen Cycle
Single Cell Protein (SCP)
- History: Originated in WWII to produce protein inexpensively using S. cerevisiae and Candida utilis.
- Development: Rapid growth in the 1960s and 1970s, resulting in the term "SCP".
- Application: Primarily used for animal feed, not widespread for human consumption.
- Production methods: Yeast from whey or Quorn production.
Production of Yeast Biomass
- Essential for high yield: Aeration is crucial to prevent fermentation.
- Affordable media: Historically, cereal grains; now mainly molasses.
- Gradual scale up: Transition from bench-top cultures to fermenters.
- Specialized feeding regimes: Necessary to avoid fermentation (fed-batch).
- Ripening stage: To encourage trehalose production and reduce protein production.
- Processing: Centrifugal separators before washing, drying, and packaging.
Yeast Production Process
- Stages: Stock culture, sterile medium, flask culture, seed culture, intermediate fermentor, production fermentor, concentration washing, cool storage, dewatering, compressing, packaging, cold storage.
Characteristics of Good Baker's Yeast
- High growth rates
- Good storage properties (including cryotolerance)
- Osmoresistance (to function in dough)
- Rapid maltose utilization (main dough sugar)
- High glycolytic activity ("gassing power")
SCP Production Methods
- Sources: Algae (spirulina), fungi, bacteria
- Methods: Submerged fermentation and solid-state fermentation
- Post-fermentation steps: Harvesting, washing, disrupting biomass, extracting protein.
Substrates for Microorganism Production
- Algae: CO₂ and sunlight
- Fungi: Waste materials providing carbon and nitrogen
- Bacteria: Industrial wastes or byproducts
- Specific examples: Molasses from sugar manufacture/starch hydrolysis, spent sulphite liquor, acid hydrolysates of wood, agricultural wastes, methane, methanol + ethanol, gas oil.
Nutritional Value of Microorganisms
- Algae: High in protein (40-60%), fats, vitamins (A, B, C, D, E), and minerals (7%).
- Fungi: Rich in B-complex vitamins, balanced amino acids (e.g., A. niger), thiamine, riboflavin, and biotin (in yeast).
- Bacterial SCP: High protein content, specific essential amino acids (e.g., methionine).
SCP Limitations
- Algal SCP: Cell walls are difficult for human digestion, production is weather-dependent.
- Fungal SCP: Potential for mycotoxins.
- Bacterial SCP: Expensive to produce, possible accumulation of uric acid (kidney stones, gout).
SCP in Nutrition and Food Production
- Application: Source of human and animal feed.
- Acceptable species (microorganisms): Saccharomyces cerevisiae, Candida utilis, Chlorella species
- Example: Quorn myco-protein, Fusarium graminearum species.
Mushrooms
- Types: Filamentous fungi forming fruiting bodies; edible varieties, like Agaricus bisporus (button mushroom), Lentinus edodes, Pleurotus spp (oyster mushroom) ~12,000 fungi species.
- Production process: Liquid culture inoculum preparation, bed preparation (composting), inoculation into compost, mycelial growth (25°C for 2-3 weeks), casing layer application (peat), fruiting bodies over ~4-6 weeks (multiple flushes).
- Benefits: Cheap to produce, excellent source of protein, easily harvested.
- Medicinal uses: Extracts from specific genera (e.g., Auricularia, Flammulina, Ganoderma, Hericium) are used immunomodulators, anti-cancer, and as a source for rare minerals/amino acids. Problems: Mycotoxins.
- Mycotoxins are secondary metabolites; some species produce mycotoxins which harm humans and animals. Examples include Aspergillus and Fusarium. Specific cases include Alflatoxins, first discovered in 1960 when 100,000 turkey poults died, and 14,000 ducklings died suddenly.
Additional Information
- Upcoming exam (Microbiology in the Food Industry - Alcohol, Dairy Industry, Vinegar): Next Monday.
- Previous exam reminder: Online Practical MCQ exam on Friday at 2 pm.
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Description
Prepare for the Agricultural Microbiology practical MCQ exam with this quiz. Cover essential topics including microorganisms and disease, the immune system, and antibiotic-resistant microorganisms. Make sure to review sample questions on Brightspace as you get ready for this important assessment.
