Cumulative Lab Test 1 LATEST 2022-2023
Cumulative Lab Test 1 Name: Mallory Nelson
1. Vibrio cholerae produces a potent toxin which is the causative agent of cholera. Describe the
Gram’s reaction, morphology, and cell arrangement of Vibrio cholerae. What is the most
likely habitat and mode of transmission of this bacterium. (5 pts.)
a. The gram reaction for Vibrio Cholerae is gram negative. It is a rod-shaped Bacteria that
has a long flagella and a thin cell wall that is a protective barrier. It lives in warm water
and can transport though the water by whipping its flagella to propel it through the
water.
2. Growth and survival of organisms depends on the environmental conditions including food
supply and pH. List and describe the physical (temperature and pH) and chemical
(carbon, nitrogen, sulfur, and phosphorus, trace elements, and oxygen) requirements for
microbial growth. (28 pts.)
a. There are 3 types of temperature organism groups:
i. Thermophiles which survive in the heat between 50-60 degrees C, the extreme
thermophiles can survive in heat upwards of 80 degrees C. Usually live in
sunlit soil and compost piles. Some can become heat resistant and become
endospores.
ii. Mesophiles which survive at temps between 25-40 degrees C. Many live in the
bodies of animals.
iii. Psychrophiles has the true Psychrophiles which survive at temps under 20
degrees C. Psychrotrophs survive at temps of 20-30 degrees C and cause
low temp food spoilage.
b. There are 3 types of pH organism groups:
i. Acidophilus which like pH between .1-5.4. Lactobacillus produces lactic acid,
tolerates mild acidity.
ii. Neutrophils which like pH between 5.4-8.5. Includes most human pathogens.
iii. Alkaliphiles which like pH between 7-12. Vibrio cholerae and Alkali genes
faecalis optimal pH 9
iv. Most bacteria prefer neutral pH. Yeast and Mold prefer a pH between 5-6.
c. Chemical groups:
i. Carbon
1. Makes up 50% of dry weight of cell. Structural backbone of all
organic compounds
ii. Nitrogen
1. Makes up 14% of dry weight of cell. Used to form amino acids, DNA,
and RNA.
iii. Sulfur
1. Used to form proteins and some vitamins (thiamin and biotin).
iv. Phosphorus
1. Used to form DNA, RNA, ATP, and phospholipids
v. Trace elements
1. Many are used as enzyme cofactors. Include iron, copper, zinc.
vi. Oxygen
1. Organisms that use molecular oxygen produce more energy
from nutrients than anaerobes
This study source was downloaded by 100000815611969 from CourseHero.com on 11-27-2022 01:06:26 GMT -06:00
https://www.coursehero.com/file/39733697/Cumulative-Lab-Test-1docx/
Cumulative Lab Test 1 Name: Mallory Nelson
1. Vibrio cholerae produces a potent toxin which is the causative agent of cholera. Describe the
Gram’s reaction, morphology, and cell arrangement of Vibrio cholerae. What is the most
likely habitat and mode of transmission of this bacterium. (5 pts.)
a. The gram reaction for Vibrio Cholerae is gram negative. It is a rod-shaped Bacteria that
has a long flagella and a thin cell wall that is a protective barrier. It lives in warm water
and can transport though the water by whipping its flagella to propel it through the
water.
2. Growth and survival of organisms depends on the environmental conditions including food
supply and pH. List and describe the physical (temperature and pH) and chemical
(carbon, nitrogen, sulfur, and phosphorus, trace elements, and oxygen) requirements for
microbial growth. (28 pts.)
a. There are 3 types of temperature organism groups:
i. Thermophiles which survive in the heat between 50-60 degrees C, the extreme
thermophiles can survive in heat upwards of 80 degrees C. Usually live in
sunlit soil and compost piles. Some can become heat resistant and become
endospores.
ii. Mesophiles which survive at temps between 25-40 degrees C. Many live in the
bodies of animals.
iii. Psychrophiles has the true Psychrophiles which survive at temps under 20
degrees C. Psychrotrophs survive at temps of 20-30 degrees C and cause
low temp food spoilage.
b. There are 3 types of pH organism groups:
i. Acidophilus which like pH between .1-5.4. Lactobacillus produces lactic acid,
tolerates mild acidity.
ii. Neutrophils which like pH between 5.4-8.5. Includes most human pathogens.
iii. Alkaliphiles which like pH between 7-12. Vibrio cholerae and Alkali genes
faecalis optimal pH 9
iv. Most bacteria prefer neutral pH. Yeast and Mold prefer a pH between 5-6.
c. Chemical groups:
i. Carbon
1. Makes up 50% of dry weight of cell. Structural backbone of all
organic compounds
ii. Nitrogen
1. Makes up 14% of dry weight of cell. Used to form amino acids, DNA,
and RNA.
iii. Sulfur
1. Used to form proteins and some vitamins (thiamin and biotin).
iv. Phosphorus
1. Used to form DNA, RNA, ATP, and phospholipids
v. Trace elements
1. Many are used as enzyme cofactors. Include iron, copper, zinc.
vi. Oxygen
1. Organisms that use molecular oxygen produce more energy
from nutrients than anaerobes
This study source was downloaded by 100000815611969 from CourseHero.com on 11-27-2022 01:06:26 GMT -06:00
https://www.coursehero.com/file/39733697/Cumulative-Lab-Test-1docx/
