What type of medium is Spirit Blue Agar?

What type of medium is Spirit Blue Agar?

Spirit blue agar is a nutrient medium with the dye spirit blue present. It also contains an emulsified lipid to serve as the target for the enzyme. For the test in this program, that emulsified lipid is assumed to be corn oil.

What color is spirit blue agar?

Spirit Blue Agar is used for the detection and enumeration of lipolytic microorganisms. Store prepared media below 8°C, protected from direct light. Store dehydrated powder in a dry place in tightly-sealed containers at 2-25°C. Appearance: Greenish yellow colored, homogeneous, free flowing powder.

How do you make spirit blue agar?

A satisfactory emulsion can be prepared by dis- solving 10 g gum acacia or 1 mL polysorbate 80 in 400 mL warm purified water, adding 100 mL cottonseed or olive oil and agitating vigorously to emulsify. Spirit Blue Agar contains peptone as a source of carbon, nitrogen, vitamins and minerals.

How do you make Tributyrin agar?

Dissolve 20 g in 1 litre distilled water. Sterilize by autoclaving at 121°C for 15 minutes. Let cool to 80°C and add 10g neutral Tributyrin (91010). Mix thoroughly to emulsify the Tributyrin completely.

What does spirit blue agar test for?

This agar is used to identify organisms that are capable of producing the enzyme lipase. This enzyme is secreted and hydrolyzes triglycerides to glycerol and three long chain fatty acids. These compounds are small enough to pass through the bacterial cell wall.

What is the function of spirit blue dye in spirit blue agar?

Spirit blue or Opal blue SS is a dye with formula C37H30ClN3. It is used as an indicator in agar for detection of lipase activity in bacteria.

What constitutes a positive result on Tributyrin agar?

Tributyrin agar is prepared as an emulsion so that the agar will appear opaque. When the plate is inoculated with a lipase-positive organism, clear zones will appear around the growth as evidence of lipase activity. If no clear zones appear, the organism is lipase-negative.

What is milk agar?

Skim milk agar is a differential medium that tests the ability of an organism to produce an exoenzyme, called casease, that hydrolyzes casein. Casein forms an opaque suspension in milk that makes the milk appear white.

What indicates a positive starch hydrolysis test?

Positive test:A clear zone around the line of growth after addition of iodine solution indicates that the organism has hydrolyzed starch. Negative test:A blue, purple, or black coloration of the medium (depending on the concentration of iodine).

What is the DNase test?

Principle. The deoxyribonuclease (DNase) test detects the degradation of DNA by bacterial species that produce DNase. The DNase test may be performed on plate media and is available in some commercial tests, e.g., QuadFERM+.

What does a positive lipase test look like?

Results. Positive test: A positive lipase test is noted by the appearance of an iridescent sheen (oil on water) immediately around colonies that can be seen when the plate is held at an angle to a light source. Negative test: A negative lipase test is indicated by the absence of an iridescent sheen.