PPTH 103 Physiological and Biochemical Tests

Catalase Reaction

• Test for Oxygen Requirement

• Test for Starch Hydrolysis

• Tween 80 Hydrolysis

• H2S Production

• Acid Production from

Carbohydrates

Physiological and Biochemical Tests

Reactive

Oxygen

Species

are also

unavoidable

products of

plant

metabolism

“oxidative burst”

Pathogen infection can lead to a rapid increase in ROS level =

KatEs, KatGs, MnCats

Catalase Families:

Slide (drop) Method
Tube Method
Tube (slant) Method

Methods in catalase reaction

Obligate Aerobes
Facultative Anaerobes
Microaerophile
Aerotolerant Anaerobes
Obligate Anaerobes

Test for Oxygen Requirement

Starch

is a complex polysaccharide found abundantly in plant

amylose and amylopectin

starch Consists of two components:

Amylose:

consists of D-glucose units linked by α-1,4 glycosidic

bonds

Amylopectin:

branched polysaccharides α-1,4 glycosidic bonds and

α-1,6 glycosidic bonds

(α-amylase and oligo-1,6-glucosidase

exoenzymes

Tween 80

is a water-soluble long chain fatty acid ester

Cysteine

the

metabolic sulfide

donor for cellular

components

containing sulfur

Hydrogen Sulfide tests

when H2S is produced, it reacts with

lead ions from the lead acetate to form solid lead sulfide,

PbS (black solid).

Bromocresol purple

in acid production the indicator dye