PPT 6 Lect.

What cellular division process produces the colony?

Binary fission

binary fission

Cloning division that makes 2 cells from 1

Enriched Functional Types

For Fastidious Microbes Have added growth factors, blood, hemoglobin, etc. Blood Agar

What happens if temp exceeds the maximum temp?

Growth drops rapidly

spectrophotometer

It calculates the absorbance bacterial suspension

"NORMAL GROWTH CURVE"

Lag, exponential (log), stationary, and death

MSA plate

Mannitol Salt Agar Differential

process for binary fission equation Nf = (Ni)2n

Nf = total # of cells Ni = starting amount of cells n = generation number

Passive Transport

No ATP is required A concentration gradient is used Ex: Diffusion of a variety of substances. Ex: Osmosis of water

complex

Non-Synthetic Chemical Composition Often are made from extracts, or ground up organisms Ex beef extrac

chemically defined

Synthetic Chemical Composition Ingredients of medium are put together w/ a precise formula & quantities of materials

Generation time

The time it takes for a cell to reproduce itself. As quick as 5/10 min. as long as days

GP Functional Types

Will grow a wide variety of microbes Most non-synthetic

colony

a collection of cells derived from a single cell

agar

a complex polysaccharide derived from a marine alga

culture medium

a nutrient material prepared for the growth of microorganisms in a lab

facultative anaerobes

ability to grow in both aerobe and anaerobe environment -can continue to grow without oxygen by using fermentation or anaerobic respiration -efficiency in producing energy reduces in the absence of oxygen

Halophiles

bacteria may thrive in salty conditions Fungi may also love salt These organisms have adaptations that allow them to live in salty environments.

why is osmotic pressure an important factor in microbial growth?

because it equalizes the pressure from its surrounding, thus helping preserve nutrients depending on the environment.

why is it difficult to define psychrophile, mesophile, and thermophiles?

because they're not rigidly defined. (ie: psychrophile are said to grow at 0degrees, but there other distinct groups capable of growing at that temp)

photoautothrophs

derive their carbon from carbon dioxide

Lag phase

intense activity preparing for population growth, but no increase in pop.

Acidophiles

love low pH (≈ pH = 1)

reducing media

media that contains sodium thioglycolate, that chemically combine with dissolved oxygen and deplete the oxygen in the culture medium

inoculum

microbes that are introduced into a culture medium to initiate growth

obligate aerobes

microbes that require oxygen for growth

Log phase

or exponential increase in microbe population

extreme/obligate halophiles

organisms that adapted to high salt concentrations and require it for growth

nitrogen, sulfur, and phosphorus

other elements that microorganisms need to synthesize cellular material -nitrogen(for amino acids) -sulfur (synthesize sulfur containing amino acids and vitamins) -phosphorus (synthesis of nucleic acids and phospholipids of cell memb.)

Stationary phase

period of equilibrium -microbial deaths balance production of new cells

death phase

population is decreasing at a log rate

Alkalinophiles

prefer high pH.

oxygen

required for aerobic respiration

how is pH used in preserving foods? what effects do they have on microbes

the acidity produced by bacteria preserves food from spoiling (ie: pickles, and most cheeses)

how is osmotic pressure used in preserving foods? what effects do they have on microbes?

the high salt or sugar concentrations draw water out of nay microbial ells that are present, preventing growth and preserving food

culture

the microbes that grow and multiply in or on a culture medium

psychrotrophs

the term that food microbiologists favor group of spoilage microorganisms do not grow well in low temp.

Intro Functional Types

used for isolation, culture maintenance, & experiments

minimum growth temp.

- the lowest temp. at which the species will grow

Thermophiles

-A group of Archae that thrive in very hot places. -heat-loving microbes -40 to 70 Celsius

Chemical requirement for growth:

-carbon (besides H2o, it is a requirement) -Nitrogen, sulfur, phosphorus -trace elements (small amounts of other mineral elements) -Oxygen (some microbes need a lot to none for growth) -Organic growth factors (compounds that an organism can't break down/synthesize)

chemoheterothrophs

-gets carbon from the source of their energy-organic materials such as proteins, carbohydrates, and lipids -carbon dioxide

What is meant by the optimum temperature?

-it means that its at the best temp for growth

what does it mean by "environment is hypertonic"?

-it means the concentration of the solute surrounding the cell is higher, thus forcing the water to leave the cell

what does it mean by "isotonic solution"?

-it means the solute concentration in the cell is equivalent to its surroundings.

nitrogen fixation

-many of the photosynthesizing cyanobacteria use gaseous nitrogen directly frm the atmosphere

Psychrophiles

-microbes that live in Cold temperature/cold-loving microbes - -10 to 20 Celsius

osmotic pressure

-microorganisms obtain almost all their nutrients in solution from surrounding water required for growth

mesophiles

-moderate-temp. loving microbes/body temp -10 to 50 Celsius -most common type of microbe -organisms that have adapted to live in the bodies of animals -optimum temp. for many pathogenic bacteria -they include most of the common spoilage and disease organisms

hyperthermophiles, thermophiles

-optimum growth in 80 Celsius or higher temp. -most organisms live in hot springs associated -sulfur important for metabolic activity

aerobic respiration

-organic compound that stripped hydrogen atoms, then combine with oxygen to make water -requires a lot of energy (atp) for this process -allows the neutralization of oxygen (toxic gas)

facultative halophiles

-organisms that don't require high concentration of salt but able to grow in it

what buffers are included in media to prevent interference of growth with the bacteria's own pH?

-peptones -amino acids -phosphate salts

other than controlling acidity, what is an advantage of using phosphate salts as buffers in growth media?

-phosphate salt is non toxic -provides phosphorus, which is an essential nutrient

pH

-refers to acidity or alkalinity of a solution

plasmolysis

-shrinkage of cell's cytoplasm (water shrinkage)

trace elements

-small amounts of mineral elements required by microbes -iron, copper, molybdenum, zinc

Carbon

-structural backbone of living matter -needed for all organic compounds that make up a living cell

Physical requirement for growth:

-temp. (ideally body temp./some at extreme temp.) -pH (usually best at neutral) -osmotic pressure (nutrients from surrounding water)

maximum growth temp.

-the highest temp. at which growth is possible

optimum growth temp.

-the temp. in which the species grows best

what are the 2 most important requirements for microbial growth?

-water -carbon

2 basic growth requirements for microbes?

1. Chemical 2. Physical

Active Transport

ATP is required Transport protein is used Substance moves against concentration gradient Ex absorption of simple sugars, amino acids, and ions. Endocytosis Ex: Phagocytosis