Chapter 6: Microbial Nutrition and Growth (Down to Effect of oxygen…)

What is an essential nutrient and what are the two categories of essential nutrients?

Essential nutrient: any substance that must be provided to an

organism (the organism cannot grow without them)

• The two categories include: Macronutrients and Micronutrients

What are Macronutrients role and examples of them? Are they in small or large quantities?

Macronutrients: roles in cell structure and metabolism (carbon, hydrogen, oxygen) (In large quantities)

What are Micronutrients role and what is it also known as? Provide examples and what do environmental conditions effect?

Micronutrients: enzyme function

• Also known as trace elements

• (manganese, zinc, nickel) (METALS)

• Environmental conditions also affect growth (salt, pH, temp., etc.)

What are the 4 nutritional classifications of microbes? What are the two subcategories of chemotroph?

1. Heterotroph

2. Autotroph

3. Phototroph

4. Chemotroph

• Organic or Inorganic

What are Heterotrophs and Autotrophs? The differences between the two are based on what?

• Heterotroph: an organism that must obtain its carbon in an organic form (organic sources = carbon must be bonded to hydrogen)

• Autotroph: an organism that uses CO2 as its carbon source (inorganic sources

• The differences between the two are based on the source of carbon

What are Phototrophs and Chemotrophs? The differences between the two are based on what?

• Phototroph: microbe that photosynthesizes and gets energy from sunlight (uses photosynthesis)

• Chemotroph: microbe that gets its energy from chemical compounds. Chemical compounds can be organic or inorganic

• The differences are based on the source of energy

What are the two types of chemotrophs and provide the examples of the compounds that make them up? What are the things that make organtic and inorganic unique (one each)?

1. Organic: Large polymers (carbohydrates, lipids, proteins, nucleic acids)

• Uses Respiration, fermentation, etc. as processes to harvest energy

2. Inorganic: Metals and their salts (magnesium sulfate, ferric nitrate, sodium phosphate), gases such as CO2

• The only cells that can use inorganic molecules for energy besides very specific bacteria

What are the two Main Nutritional categories of Microbes by Energy AND Carbon source? Name the subcategories of microbes the fall under the MAIN 2

1. Autotrophs

• Photoautotrophs and Chemoautotrophs (broken into Chemoorganicautotrophs and Chemolithoautotrophs)

2. Heterotrophs

• Photoheterotrophs and Chemoheterotrophs (broken into Saprobes and Parasites)

What is the energy source and carbon source of the Autotroph category's microbes?

1. Photoautotrophs: Sunlight and CO2

2. Chemoautotrophs

• Chemoorganicautotrophs: Organic compounds and CO2

• Chemolithoautotrophs: Inorganic compounds (minerals) and CO2

What is the energy source and carbon source of the Heterotrophs category's microbes?

1. Photoheterotrophs: Sunlight and organic compounds

2. Chemohererotrophs: Metabolic conversion of the nutrients from other organisms (organic)

• Saprobes: Metabolizing the organic matter of dead organisms and organic

• Parasites: utilizing the tissues, fluids of a live host and organic

Top hat Q: Which of the following terms describes an organism that derives its energy and carbon from organic molecules? Photoautotroph, chemoheterotroph, lithoautotroph, chemoautotroph, or photoheterotroph?

Chemoheterotroph

What are the three ranges of temperatures for the growth of a given microbial species? Which two are the extreme points and do microbes still grow at them?

1. Minimum temperature

2. Maximum temperature

3. Optimum temperature

• Minimum and Maximum are the extremes and microbes still grow at them but just very slowly

Explain the three ranges of temperatures and what happens to the cells/growth.

• Minimum temperature: the lowest temperature that permits a microbe’s continued growth and metabolism; below this temperature, its activities stop

• Maximum temperature: the highest temperature at which growth and metabolism can proceed before proteins are denatured

• Optimum temperature: an intermediate between the minimum and the maximum that promotes the fastest rate of growth and metabolism (best/fastest growth)

Does the temperature of bacteria go by Fahrenheit or Celsius? Are temperature numbers based on specific numbers or a range of numbers? Provide a example and what the optimum temperature usually is.

Celsius and they are based on a range (ex: microbe likes [0 degrees Celsius to 25 degrees Celsius] but optimum temperature is usually 10 degrees Celsius less than the max for best growth)

Do all bacteria grow at perfect human body temperatures?

No. Some bacteria can only grow in low temps in the human body and some are only at 98 degrees Fahrenheit

What are the 5 main types of microbial categories when dealing with temperature?

1. Psychrophiles

2. Psychrotrophs/Psychrotolerant

3. Mesophiles

4. Thermophiles

5. Extreme Thermophiles

What are the ranges of temperatures the main 5 types of microbial categories?

ask pierce if we have to remember these

What are psychrophiles and their natural habitats? Are they pathogenic? What do they love and where specifically do they grow the best?

• Natural habitats of psychrophilic bacteria, fungi, and algae are lakes, rivers, snowfields, polar ice, and the deep ocean

• Rarely pathogenic (hard to grow in humans)

• They love cold temperatures and grow the best in fridges b/c they are usually set at 4 degrees Celsius

What are two examples of Psychrotrophs/Psychrotolerants and where are they able to grow? What do they cause?

• Staphylococcus aureus and Listeria monocytogenes are able to grow at refrigerator temperatures and cause food-borne illness

Is freezing and the fridge effective ways of killing bacteria?

No

What are Mesophiles? What temperature do they like the best? Are they Thermoduric?

• Majority of medically significant microorganisms (majority human pathogens)

• They like the human body temp the best

• Some but not all are Thermoduric

What does thermoduric mean? Provide two examples of microbes that are thermoduric. What in-class example can they survive if it’s for a short time?

Thermoduric: Can survive short exposure to high temperatures, Examples are heat-resistant endospore formers such as Bacillus and Clostridium

• Can survive pasteurization if it’s for a short time

What are mesophiles common contaminants of?

• Common contaminants of heated or pasteurized foods

• Pasteurization doesn’t kill all bacteria it just makes it safe for consumption

What are themophiles? Most eukaryotic forms cannot survive above? Do they prefer low or high temps and would other bacteria usually die at these temps?

Live in soil and water associated with volcanic activity, compost piles (Most eukaryotic forms cannot survive above 60°C)

• They prefer high temps that other bacteria would usually die at

What are Extreme thermophiles?

Microbes that can grow above boiling temps