- 1 -

Chapter 6 [ , (, ), ]

2.

* .

* :

- , ,

* :

, , pH, ,

1)

:

- , , ,

- , ,

(Why : )

(autotrophs)

(heterotrophs) .

(auxotroph) :

(carbon sources)

- .

- , , Glucose, fructose, sucrose, maltose

.

- Lactose , .

- ( pectin) (amylase, pectinase)

ex) , ,

-

- : , ,

- :

- : (0.5-2%), (2-5%),

(10% )

- (), (DNA, RNA)

.

- (, )

- 2 -

- ,

.

- Peptone peptide

ex) Aspergillus, Penicillium(), Bacillus, Proteus ()

- , :

- : 0.1 0.5% N

- :

ex) , , , , ,

- : P, S, Mg, K, Na, Ca

- : Fe, Mn, Co, Zn, Cu, Mo, Cl

- , 2

- peptone, ,

.

-

ex) (Aspergillus niger) : Cu, Zn, Fe

Cu Penicillin, riboflavin

- Vit B1, B2, B6, pantothenic acid, p-aminobenzoic acid, B12, nicotin,

- , , :

- : ,

- , peptone,

(growth factor)

- , , (, , )

ex) : vit B

S. cerevisiae : pantothenic acid , biotin

-

-

-

2) (Moisture content)

, , pH , ,

,

- : ,

- 3 -

(water activity, aw)

- (aw) :

- aw 0.99, , , aw

- aw ,

aw .

- (P) > (P1) :

- aw(1.00 ) , aw

.

- (halophilic), (xerotolerant) aw .

aw

- aw : 0.98-0.99 ( )

p 127

Bacillus cereusEscherichia coliLactobacillusSallmonellaStaphylococcus

(halophilic)

0.90 - 0.91

0.92 - 0.95

0.94 - 0.97

0.90 - 0.96

0.93 - 0.96

0.83 - 0.92

0.71

(osmotolerant)

HansenulaDebaryomycesZygosaccharomyces rouxii

0.87 - 0.94

0.62 - 0.78

0.89 - 0.90

0.87 - 0.91

0.62 - 0.81

(xerotolerant)

AspergillusPenicillium

0.70 - 0.80

0.61

0.68 - 0.88

0.78 - 0.90

- .

- aw 0.95

- , , , aw 0.61

- aw 0.72

- .

.

- (60-70%), (45-50%)

.

- , aw 0.8

- 4 -

, 3% 0.98 aw .

- 2% NaCl

ex) NaCl : Clostridium botulinium(6.5-12%)

Staphylococcus aureus(15-20%),

: Zygosaccharomyces rouxii(18-20%)

3) pH : -log[H+]

pH :

- pH .

- .

- ,

- pH 4.2

- pH 4.6 ,

.

ex) Clostridium botulinum pH4.6

pH

(, )

7.6 - 9.5

5.3 - 6.4

6.8 - 8.0

6.8 - 5.1

5.3 - 6.3

3.0 - 4.2

1.8 - 2.0

pH

pH

pH

albumin pH : 7.6( )

- pH : 9.4 - 9.7

- pH : ,

- (pH 8.2 ) : CO2 ,

pH : (7.0 - 7.2)

- pH : 6.9 - 7.2 ( )

- 24 pH : 5.4 - 5.6 (glycogen )

- pH pH

.

ex) P seudomonas : pH 5.6 (5.6 )

pH

- pH : 7.0 - 8.0 ) Lactobacillus (pH 4.2), Vibrio (pH 8.6)

- 5 -

- pH : 5.0 - 6.0(2-8.5)

- pH : 4 - 6

pH

- pH :

- pH ,

pH : pH 3- 7

pH : pH 4.2

pH :

pH :

- Asp. oryzae : pH ( protease), ( protease)

pH

-

- pH (, )

- (why) : pH

ex) Salmonella, Staphylococcus, Bacillus cereus : pH 4.9 ( 0.04%)

Aspergillus niger : pH 4.1( 0.27%)

Saccharomyces cervisiae : pH 3.1( 0.59%)

Sauce, pickle : 1.5-2.0%

- 6 -

ex) (0.02N), (30) : tartaric acid>phosphoric acid>lactate> citrate)

:

Propion : .

ex) Swiss cheese : Propionibacterium shermannii

ropiness (Bacillus mesentericus) : Na, Ca-propionate (0.18-1.25%)

4) (p 135 )

*

(aerobes) : ex) Bacillus, Acetobacter

-

(anaerobes) : ex) Clostridium, Methanogen

-

(facultative anaerobes) : ex) Escherichia coli

-

(microaerophilic organism) : ex) Lactobacillus, Streptococcus

-

(aerotolerant anaerobes) : ex) Clostridium perfringens

-

:

- (thioglycolate)

* : (obligate aerobe)

* :

(ROS)

- ROS (superoxide,

peroxide)

- : O2*- H2O2

- : Superoxide dismutase(SOD), catalase

:

- 7 -

-

- : positive .

- : .

* : - ()

- ()

* : - ()

* Eh(-200), (ground meat) Eh(+200)

-

* : ,

-

ex) Eh(+300 +400) :

- 8 -

5)

* , , , , ,

.

* ,

.

:

(psychrophilic) : (10 30)

- 0 1-2

(psychrotroph) : (25 30)

- (5)

- , , ,

ex) Alcaligenes, Pseudomonas

- 9 -

(mesophilic) : (25 40)

- Salmonella, Staphylococcus, Clostridium, Shigella, Bacillus

-

(themophilic) : (45 65)

- Bacillus, Clostridium

-

- 10 15 .

ex) , : 60, 30 min

(Bacillus, Clostridium) : 100, 30min

(autoclave) : 121, 1.5 atm, 15min

:

- , , () , pH, , ,

.

-

- (pasteurization) : 61.7, 30min

- (HTST) : 71.7, 15

- (UHT) : 138, 2

- 10 -

-

- , pH

- ,

.

D :

90% ()

, , pH, , ( )

(D)

- (refrigeration) : 0 10

- (freezing) : 0

- (-10 )

- , :

: ,

0

- : Flavobacterium, Pseudomonas, Micrococcus

- : Penicillium, Cladosporium, Mucor

- : Candida

ex) : (-193) 40

6)

- 11 -

* (emission spectrum) : (700nm), (750-1000nm)

* : (200-320nm), (400-700nm), (750nm)

* .

-

.

- , .

- 260nm : , (DNA)

(Photoreactivation) :

- (310 -

400nm)

[X , (-ray), -ray]

- X, -

- 60Co caesium 137

(-ray)

- DNA RNA

- OH-, H+

- ,

- Gram :

- :

- : .

- : glycerol, cysteine, glutathione

- (sensitizer) : , SH

-

ex) E . coli

(gray, Gy)

- (Gy) : Kg 1 joule (rad 100)

- : 0.05 30Gy, ( 10kGy )

- : , (, )

- : DNA ,

* : ,

4-11

- 12 -

(kGy)

()

()

0.05 - 0.15

0.05 - 0.15

0.1 - 0.3

0.1 - 1.0

0.5 - 5

0.5 - 10

2 - 10

10 - 30

, ,

, ,

, ,

, ,

, , ,

,

7) ( )

(antimicrobial agent) : , , ,

- (antibacterial agent), (antifungal agent)

- (antivial agent)

Antimicrobial agent

- (bacteriocidal action), (bacteriolytic action)

- (bacteriostatic action)

Antimicrobial agent

- , , ,

- (sterilizers) :

- (disinfactants) :

- (antiseptics) :

- (food preservatives) :

:

- : (HgCl2). (AgNO3)

- : ,

- : ,

- : , ,

- (), ,

- , ,

: , ,

- : , , , phenol, alcohol

- : , , , NaOCl

- : ,

- : ,

- 13 -

* ,

* : , , dehydroacetic acid

, benzoic acid

Gram

()

Gram

()

Benzoic acid + + + + + + + , pH6

Sorbic acid ++ ++ + x x + + , pH7

Dehydroxy-

acetic acid++ ++ + o o + +

, ,

-Hydroxybenzoic

acid ester++ ++ ++ + + ++ +

pH

Propionic acid + x + x x o o

++; , +; , o; , x ;

8)

* : .

:

- : Lysozyme, ovomucoid

- Avidin (biotin ), Conalbumin( )

- pH

- :

- Lactoperoxidase : peroxidase

- Lactoferrin () : conalbumin

- Fatty acid :

:

- : ,

- : Tomatin(), anthocyanin , tannin

- , : thiosulfonate

- : Isoflavone

- 14 -

- :

[ Test] : disk-diffusion method

Fig. Evaluation of disinfectants by the disk-diffusion method

9) ,

*

* colony

(selective media)

-

ex) : citric acid agar

(differential media)

-

colony

ex) : proteinase, hemolysin

pH : EMB agar

ex) selective/differential : MacConkey agar

:

Lactose, pH : E. coli , Salmonella

(enrichment media)

-

ex) : , Shalmonella : selenite broth

- 15 -

Psedomonas agar P(PSP) medium Tellurite-glycine medium

[P seudomonas aeruginosa] [Staphylococcus aureus]

Eosin methylene blue (EMB) medium EMB medium

E scherichia coli E nterobacter aerogenes

(medium) : , ( + )

(synthetic medium) :

(complex medium) :

ex) yeast extract)

: , , ,

(batch culture) :

-

pH .

- .

- (4) .

(continuous culture) :

-

( )

: ,

.

, : 5, -20

- : , Deep freezer

- (-150-198) : +

* : 10% glycerol, , , sodium glutamate

- 16 -

- (lyophilization) :

- :

10) Colony counter

- 17 -