Estimating Bacterial Count

Question 1

computation of CFU

Answer 1

colony forming unit

Question 2

represent particular cell that have dividing capabilities

Answer 2

colony forming unit

Question 3

unit that we use for estimating the number of viable bacteria or the fungal cells in a sample

Answer 3

colony forming unit

Question 4

asexual reproduction by a separation of the body into two new bodies

Answer 4

binary fission

Question 5

– viable cells being computed utilizing hemocytometer

Answer 5

direct count

Question 6

increase in the number of cells

Answer 6

microbial growth

Question 7

 Depends on the nutrients of culture medium and the environmental requirements of the microorganisms

Answer 7

microbial growth

Question 8

parts of a growth curve

Answer 8

lag phase
log (exponential) phase
stationary phase
death (decline) phase

Question 9

introduction of microorganism to the culture medium

Answer 9

lag phase

Question 10

– phase where microorganisms increasese

Answer 10

exponential phase (log)

Question 11

phase where microorganisms reach their carrying capacity

Answer 11

stationary phase

Question 12

natural occurrence where organisms fight for limited resources

Answer 12

competition

Question 13

– represent that resources on the environment has been depleted

Answer 13

death phase

Question 14

general media used previously in midterms

Answer 14

nutrient agar

Question 15

time of gearing up for division following change in culture conditions

Answer 15

lag phase

Question 16

 Introduction of microbes in the environment

Answer 16

lag phase

Question 17

division at a constant rate (exponential)

Answer 17

log or exponential phase

Question 18

death rate = birth rate

Answer 18

stationary phase

Question 19

 Represents the carrying capacity of the environment

Answer 19

stationary phase

Question 20

 Shows the max number of microbes

Answer 20

stationary phase

Question 21

– constant per-capita death rate (exponential

Answer 21

death phase

Question 22

 Represents the competition

Answer 22

death phase

Question 23

used to determine how microorganisms grow, assess the foods and monitor industrial processes

Answer 23

microbial counts

Question 24

 An indicator of spoilage

Answer 24

microbial counts

Question 25

process through which the concentration of an organisms (ex. Bacteria) is systematically reduced through successive resuspension in fixed volumes of liquid diluent.

Answer 25

serial dilution

Question 26

 Usually the volume of __ is a multiple of 10 to facilitate logarithmic reduction of the sample organism

Answer 26

diluent

Question 27

a substance used to dilute something.

Answer 27

diluent

Question 28

counting methods (3)

Answer 28

direct count pour plate method (viable count) spread plate method (viable count)

Question 29

counting methods for viable counting

Answer 29

pour plate method spread plate method

Question 30

– include microscopic counts using a hemocytometer or a counting chamber

Answer 30

direct count

Question 31

 Dead cells are also counted

Answer 31

direct count

Question 32

technique when counting for direct count

Answer 32

L rule

Question 33

The central square is further subdivided into 0.05 x 0.05 mm (0.0025 mm2) squares.

Answer 33

nunbauer ruling

Question 34

is a tool used for manual cell countin

Answer 34

hemocytometer

Question 35

what quadrants are counted in hemocytometer

Answer 35

1, 5, 13, 21,25

Question 36

formula for direct count cells/mm^2

Answer 36

number of cells in 5 squares * 5

Question 37

formula for direct count cells/mm^3

Answer 37

cells/mm^2 *10

Question 38

cells / ml formula

Answer 38

cells /mm^3 x 1000

Question 39

dilution factor in computation

Answer 39

10^4

Question 40

formula for direct counting

Answer 40

(number of cells in 5 squares)(10)(1000)(DF)

Question 41

method used in cell culture to determine the number of living cells in a culture

Answer 41

viable count/plate count

Question 42

 This is different from other cell counting techniques because it makes a distinction between live and dead cells

Answer 42

viable count/plate count

Question 43

 Colony forming units are only considered

Answer 43

viable count

Question 44

consist of diluting a sample with sterile saline or phosphate buffer diluent until the bacteria are dilute enough to count accurately

Answer 44

standard plate count method

Question 45

– should have between 30 and 300 colonies

Answer 45

final plates

Question 46

– not acceptable for statistical reasons

Answer 46

<30

Question 47

<30 means

Answer 47

too few to count

Question 48

colonies too close to each other to be distinguished as distinct colony forming units

Answer 48

>300

Question 49

TNTC means

Answer 49

Too numerous to count

Question 50

view different number of colonies in ppt

Answer 50

+1

Question 51

an equipment that is designed to assist you when counting colonies on agar plates

Answer 51

colony counter

Question 52

colony counting can be done via (3)

Answer 52

pushbutton pen probe needle probe

Question 53

To look through the viewing area to assist with the counting of smaller colonies

Answer 53

magnifying glass

Question 54

A glass viewing area with a grid pattern drawn on it and a light to illuminate the agar plate.

Answer 54

ruled counting area

Question 55

pour plate method amount of innoculum

Answer 55

1.0ml

Question 56

spread plate method amount of innoculum

Answer 56

0.1mL

Question 57

formula for viable counting

Answer 57

(no of colonies)(total dilution factor)/volume of culture plated in ml

Question 58

what part of the growth curve represent the increase in population of certain organisms

Answer 58

log (exponential) phase

Question 59

loss of resources in a culture media what part of a growth curve

Answer 59

stationary phase or death (decline) phase

Question 60

which represents competition among organisms in growth chart

Answer 60

stationary phase