Microbial Nutrition and Classification
28 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main characteristic of a batch fermentation system?

  • It operates continuously without interruption.
  • It continuously removes nutrient solution while adding more.
  • It allows for real-time monitoring of biomass concentration.
  • It is a closed system with no additions during fermentation. (correct)

    • Which of the following statements best describes continuous fermentation?

  • It is a process that occurs in closed conditions.
  • An equivalent amount of nutrient solution is removed simultaneously. (correct)
  • Nutrient solution is added sporadically during the process.
  • It relies on periodic adjustments to environmental conditions.

    • What defines synchronous growth in a bacterial population?

  • All cells are at different stages of the cell division cycle.
  • Growth occurs only when environmental conditions are unstable.
  • Cells divide asynchronously and at different rates.
  • Every cell is physiologically identical and in the same stage of division. (correct)

    • How can a synchronous culture be achieved?

    <p>By changing temperature or adding fresh nutrients at specific times. (B)</p> Signup and view all the answers

    Which of the following is NOT typically added in batch fermentation?

    <p>Fresh nutrients throughout the fermentation (D)</p> Signup and view all the answers

    What percentage of cell weight do water and nutrients typically constitute in microbes?

    <p>70-80% (A)</p> Signup and view all the answers

    Which of the following elements is NOT considered a macronutrient needed by microorganisms?

    <p>Iodine (C)</p> Signup and view all the answers

    What type of microorganisms utilize organic compounds as their source of carbon?

    <p>Heterotrophs (B)</p> Signup and view all the answers

    What are trace elements primarily used for in microbial cells?

    <p>Part of enzymes for metabolic reactions (C)</p> Signup and view all the answers

    Which nutrients are classified as growth factors for microorganisms?

    <p>Vitamins and amino acids (B)</p> Signup and view all the answers

    Microorganisms that use light as a source of energy are known as:

    <p>Phototrophs (D)</p> Signup and view all the answers

    Which of the following macroelements is essential for the formation of nucleic acids in microorganisms?

    <p>Phosphorus (D)</p> Signup and view all the answers

    Which classification of microorganisms depends on inorganic substances for their energy needs?

    <p>Chemotrophs (B)</p> Signup and view all the answers

    Which type of organisms obtain energy by oxidizing inorganic molecules?

    <p>Lithotrophs (B)</p> Signup and view all the answers

    What is the primary means through which nutrients of low molecular weight enter the cell?

    <p>Facilitated diffusion (A), Simple diffusion (B)</p> Signup and view all the answers

    Which type of medium is specifically used for differentiating between bacterial species based on their metabolic activity?

    <p>Differential media (C)</p> Signup and view all the answers

    Which method of nutrient uptake requires cellular energy?

    <p>Active transport (A)</p> Signup and view all the answers

    What distinguishes enriched media from other types?

    <p>Contains nutrients and additives such as blood or plant extracts (A)</p> Signup and view all the answers

    Which of the following is NOT a characteristic of selective media?

    <p>Promotes the growth of all types of bacteria (D)</p> Signup and view all the answers

    Chemotaxis is observed in motile bacteria in response to which of the following?

    <p>Chemical gradients of nutrients like amino acids (B)</p> Signup and view all the answers

    What process do microorganisms use to break down complex compounds like cellulose?

    <p>Decomposing enzymes (A)</p> Signup and view all the answers

    How do microorganisms typically absorb food from their environment?

    <p>Absorption through cell membrane (C)</p> Signup and view all the answers

    Which nutrient transport mechanism uses specific proteins located in the plasma membrane?

    <p>Facilitated diffusion (C)</p> Signup and view all the answers

    What distinguishes maintenance media from other types of culture media?

    <p>Maintains continuous growth of microorganisms (D)</p> Signup and view all the answers

    Which of the following is a characteristic of organotrophs?

    <p>Obtain electrons from organic molecules (C)</p> Signup and view all the answers

    What is the main role of enzymes like Amylases in the digestion of complex compounds?

    <p>To break down complex compounds into smaller units (D)</p> Signup and view all the answers

    Which type of culture medium contains specific compositions to measure the presence of nutrients produced by microbial growth?

    <p>Assay media (A)</p> Signup and view all the answers

    Which of the following statements about permeability of compounds is accurate?

    <p>Low molecular weight compounds pass through without energy. (B)</p> Signup and view all the answers

    Study Notes

    Microbial Nutrition

    • Microbes require nutrients for biosynthesis, energy production, and growth.
    • Essential elements include carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus, potassium, calcium, magnesium, and iron (macroelements).
    • The first 6 elements (P, S, N, H, O, C) form sugars, fats, proteins, and nucleic acids.
    • Trace elements (zinc, cobalt, molybdenum, nickel, copper, iodine) are needed in smaller amounts and often part of enzymes.
    • Growth factors (vitamins, amino acids, nucleic acid components) are required for some microbes; they act as enzyme cofactors.
    • Microbes need carbon, hydrogen, oxygen, energy, and electrons.

    Nutritional Types of Microorganisms

    • Classified by carbon source:
      • Autotrophs use CO2.
      • Heterotrophs use organic compounds.
    • Classified by energy source:
      • Phototrophs use light.
      • Chemotrophs oxidize organic/inorganic compounds.
    • Classified by electron source:
      • Lithotrophs use inorganic molecules.
      • Organotrophs use organic molecules.

    Uptake of Nutrients by Cells

    • Microbes absorb nutrients from the environment.
    • Chemotaxis occurs in some motile bacteria, e.g., E. coli attracted to serine, repelled by leucine
    • Complex compounds (cellulose, proteins, fats) are digested externally by secreted enzymes.
    • Simple compounds enter the cell via various mechanisms:
      • Simple diffusion (no energy).
      • Facilitated diffusion (protein carriers, no energy).
      • Active transport (protein carriers, energy required).

    Culture Media

    • Media provide all nutritional requirements for microbial growth.
    • Microbial cultures can be:
      • In-vivo (living host).
      • In-vitro (artificial media). Types include:
        • Liquid (broth-based)
        • Solid (agar or gelatin added)
    • Specific media types cater to different microbial needs:
      • Enriched media (for certain heterotrophs) add blood, extracts.
      • Selective media (select for specific types) add chemicals hindering other growth.
      • Differential media (distinguishes based on reactions, like hemolysis).
      • Assay media (measuring metabolites, e.g., vitamins, antibiotics).
      • Enumeration media (counting specific bacteria).
      • Characterization media (isolating bacteria with specific functions).
      • Maintenance media (keeping cultures alive).
    • Media can be solid, semi-solid, or liquid.

    Microbial Culture Processes

    • Types of industrial fermentation processes include:

      • Batch fermentation (closed system, no addition after initial inoculation).
      • Continuous fermentation (open system with continuous inputs and outputs).
      • Fed-batch fermentation (a combination of batch and continuous).

    • Synchronous growth: all cells in the same stage of division at a specific time. Ways to achieve this include manipulating environmental conditions or by physically separating/filtering cells.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz tests your knowledge on microbial nutrition, including essential macro and trace elements required for microbial growth. Additionally, it covers the classification of microorganisms based on their nutritional types, such as autotrophs and heterotrophs. Enhance your understanding of how microbes obtain their nutrients and energy.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser