Biology 2051 Brininstool Fall 2022 Lab Final

1) Lactobacillus and Streptococcus

2) Sacchromyces

1) two genus that produce lactic acid

2) genus that produces CO2 and alcohol

False. GROWTH DOES NOT MEAN SURVIVAL

Growth means survival (T/F)

Growth

The organism remains under subjected treatment conditions long enough to grow and divide.

Survival

The organism is exposed to the treatment for a limited time but not enough for division to occur, then removed to be assayed for subsequent growth.

Temperature and UV are for survival; pH and Osmotic Pressure are for growth.

What are the survival test procedures and what are the growth test procedures.

Pasteurization

gentle heating (71.5-74 Celsius for 15-30 seconds) was used to eliminate organisms that cause spoilage in a food product such as beer or wine.

Contains many species that produce endospores, and while vegetative cells are killed by boiling water, endospores may survive and later germinate at room temperature.

Describe the genus Bacillus

Extreme Thermophiles

grow at extremely high temps above 80 Celsius some with optimum temps at 100 Celsius

Thermophiles

grow at high temps (45 - 80 Celsius)

Mesophiles

grow well at temps comfortable for humans (20 - 45 Celsius) many with optimum growth at 37 Celsius

Psychrophiles

grow at low temps under 20 Celsius

Critical enzymes become denatured and thermal destruction of cellular structures, like the cell membrane, and molecules, such as nucleic acids occurs. Damage from heat is not reversible and will eventually kill the organism.

What happens when temps exceed the optimum?

The rate of cellular enzyme activity diminishes and lipids in the cell membranes begin to solidify, impairing membrane function. Lower than the optimum inhibits growth but may not cause death.

What happens when tempuratures go lower than the optimum?

Thymine dimers to form within the DNA, resulting in mutation or death of cells.

UV radiation in living cells causes...

colorless pigment production, because pigments can provide protection against UV (which causes mutation). Also it may provide beneficial characteristics for the organism.

Mutation in the gene(s) can cause...

Lethal Mutations

this mutation results in death of the cell because the damaged DNA cannot yield the RNA or protein production essential for cell survival.

Deinococcus radiodurans

a non-endospore forming microorganism that is resistant to UV radiation becuase of its highly efficient means of repairing the DNA damage. Halotolerant neutrophile.

Saccharomyces cerevisiae

Had a few colonies survive up to 4 minutes under UV light, halotolerant, acidophile

Acidophiles

grow at pH values below 6

Neutrophiles

grow at pH that is close to 7

Basophiles or Alkalinophiles

grow at pH that is above 7

Osmosis

describes the flow of water from areas of less solute to areas of more solute for equilibrium

Hypertonic

When the concentration of solute is greater outside the cell than inside it making it dehydrated

Plasmolysis

when the plasma membrane pulls away from the cell wall and causes a bacteriostatic condition

Bacteriostatic

the condition where the cell generally does not die but ceases to grow

Hypotonic

when the concentration of solute is lower outside of the cell than inside it, causing water to flow into the cell

The cell will swell until it bursts

What happens to cells that are hypotonic and lack a cell wall?

Isotonic

Water flows in and out of the cell but there is no net flow of water in one direction.

Enzymes

proteins that serve as biological catalysts

Extracellular enzymes

enzymes that degrade large molecules into units that are small enough to be transported across the cell membrane and into the cell

Endoenzymes

enzymes that degrade molecules into simpler molecules, releasing energy or synthesizing molecules that are needed by the cell

Inducible or Adaptive

enzymes that are produced only if the appropriate substrate is available

Constitutive

enzymes that are essential to the cell and are produced at all times

Substrate

The one substance that an enzyme can react with

Nosocomial infections

Life-threatening infections that are aquired in a health-care facility

Morphology vs physiology

The cell size, shape, and arrangement of a bacterium vs how the organism functions in an environment.

Catalase

breaks down hydrogen peroxide into water and molecular oxygen; a positive test results in bubbles

1) divide slide into sections and put 1 drop of H2O2 on each section

2) Aseptically transfercells from slant of Staph epi and Strepto mutans to their sections

3) mix and see if they produce bubbles

What are the steps of the catalase test?

True

Catalase is produced by essentially all microorganisms that use oxygen for respiration

True or False?

Staphylococcus epidermis

Streptococcus mutans

________ is catalase positive (bubbles)

________ is catalase negative (no bubbles)

the organism does Fermentation (Fermentative)

What does a negative catalase test indicate about an organism?

To confirm cytochrome c. oxidase presence

Oxidase Production PURPOSE?

1) get pre innoculated plate of Pseudomonas putida and E. coli

2) transfer 200 uL of oxidase reagent to each organism

3) within seconds, see if it turns blue/purple for cytochrome oxidase presence

What are the steps to the oxidase test?

Bright blue/purple immediately

if cytochrome oxidase is present, what does the positive oxidase test look like after adding the reducing agent?

Psudomonas putida (+) and E. coli (-)

Name the oxidase positive organism and oxidase negative organism used in the experiment

a protein of the membrane ETC that reduces molecular O2 to either H2O or H2O2 (toxic)

What is the function of cytochrome oxidase?

Carbohydrates

compounds composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio

Monosaccharides

single molecule of a sugar, usually with 5 (ribose) or six (glucose) carbons

Oligosaccharides

"few sugars"; two or more monosaccharides

Polysaccharides

larger polymers of monosaccharides that may serve as structural components (cellulose, chitin) or as important reserve carbon and energy sources (cellulose, dextran,glycogen, starch)

Amylase

enzyme that hydrolyzes starch into glucose to be transported into a cell for metabolism

Alpha (1-4) glycosidic bonds

Starch is a macromolecule composed of glucose molecules connected by _____________.

Starch agar (SA) plate

Used to test for ability to produce amylase

Amylase

can break down glycosidic bonds between the glucose subunits in starch and hydrolyze it into a smaller subunit

Iodine

reagent for the amylase test that reacts with the starch to make it look a dark brown color

Zone of hydrolysis

Means positive in amylase, caseinase, and gelatinase tests; clear area around colony.

Proteins

macromolecules composed of one or more polypeptides

peptide bonds

chains of of amino acids are held together by these which make up proteins

Protease

Enzymes that degrade proteins

Casein

protein present in milk

Milk Agar (MA)

Media for caseinase

Gelatin

protein extracted from the bones of animals that will gel (solidify) at temps below 26C, but is a sol (liquid) at temps above 28C

Gelatin Agar (GA)

Media for gelatinase

HCl, gelatinase

The addition of _________ makes the agar look white due to the precipitation of gelatin proteins which are hydrolyzed by ________ making a zone of hydrolysis

Bacillus subtilis

positive for amylase, protease caseinase, and gelatinase

Escherichia coli

Negative for amylase, protease caseinase, and gelatinase

1) Liquifies at incubation temperature

2) Microorganisms produce extracellular proteases that degrade it

Why is gelatin not suitable as a solidifying agent in bacteriological media? (2 reasons)

Heterotroph

requires an organic compounds of some sort as their sole source of carbon

Autotroph

obtains carbon from the carbon dioxide in the air

Phototroph

uses light as an energy source

Chemoorganotroph

uses chemically organic compounds as its energy source

Chemolithotroph

uses chemically inorganic compounds as its energy source

Durham tubes

Used to detect an organism's ability to ferment a certain sugar.

Collect gaseous by-products

Glycolysis

the process by which glucose is converted to pyruvic acid

Saccharomyces cerevisiae

The yeast that produces CO2 and ethyl alcohol from sugar and is used in the baking, beer brewing, and wine producing industry.

acids, alcohols, and gases

What are three types of fermentation products?

Amino acids

found in living cells; contain two important functional groups, a carboxylic acid and an amino group

Cysteine

an amino acid that contains a sulfhydryl group (-SH) that plays an essential role in protein structure by connecting amino acid chains

cysteine desulfhydrase

releases hydrogen sulfide (H2S) gas from cysteine, which is responsible for the rotten egg odor

Peptone iron agar deep

The test for cysteine desulfhydrase

Peptone- rich in cysteine

Ferric Citrate- indicator

Components of Peptone iron agar deep

Peptone iron agar

media in which ferric citrate reacts with hydrogen sulfide to form ferrous sulfide (FeS), a black insoluble precipitate

Hydrogen sulfide is extremely soluble in water

Why can't we use Durham tube for the cysteine desulfhydrase test?

Citrobacter freundii

organism that produces cysteine desulfhydrase and releases H2S

IMViC Series

a series of biochemical test that are used to identify bacteria within the coliform group

1% tryptone broth

Medium for indole test

tryptophan

Substrate for indole test

tryptophanase

enzyme for indole test

Indole

major product of breaking down tryptophan for indole test

Kovac's reagent

Reagent/indicator for indole test

MRVP broth with glucose

Medium for methyl red test

Mixed acid fermentation

Enzyme or procedure for methyl red test

Mix of acids

Product for methyl red test

methyl red pH indicator

Reagent/indicator for methyl red test

MRVP broth with glucose

Medium for Voges-Proskauer test

glucose

Substrate for Voges-Proskauer test

butanediol fermentation

Enzyme or procedure for Voges-Proskauer test

neutral products like acetoin

Major product for Voges-Proskauer test

alpha napthol and potassium hydroxide

Reagent/indicator(s) for Vognes-Proskauer test

Simmons' citrate agar slant

Medium for Citrate test