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Micro Lab Part 1
Lab 12 Physiological Characteristics of Bacteria
Question | Answer |
---|---|
What is the function of bacterial exoenzymes? | Extracellular degradation of substances so that siimpler compounds can be taken into the cell as nutrient or energy resources |
Differentiate between anabolism and catabolism | Anabolism- energy driven synthesis of complex molecules from simpler ones. Catabolism is the energy-releasing degradatin of complex molecules into simpler ones |
Differentiate between fermentation and respiration | Fermentation metabolizes sugars in the absence of oxygen. Respiratin utilized oxygen. |
How are acids or alkalies detected in culture mediums? | By the use of pH indicators |
Name two tests for reactions that produce acid end products; | Sugar fermentation and fat hydrolysis |
Name two tests for reactions that produce alkaline end products | Urea hydrolysis, Citrate utilization, proteolysis (litmus milk & kligers iron agar) |
What types of gases can be produced as a result of sugar fermentation? | Carbon dioxide & hydrogen gas produced by fermentation |
How are gases detected in fermentation reactions? | In a durham tube as a trapped air bubble or as an air pocket in a stabbged solid medium eg Kligers Iron agar. |
Name a nonfermentative test in which gas production indicates a positive test result | Catalase test yields oxygen gas |
The tests for the hydrolysis of starch, casein and triglycerides are similar in terms of setup. How doe the methos for the detection of hydrolysis differ between them? | Casein-shows clear line of hydrolysisStarch Agar- iodine is added to form complexes and reveal clear zones of hydrolysis and Fat Hydrolysis- Spirit Blue agar contains pH indicator that reveals the release of fatty acids (by product of hydrolysis) |
In addition to the casein hydrolysis test, name two other tests that demonstrate hydrolysis of proteins, or proteolytic digestion | Litmus milk adn alkaline reaction in Kligers iron agar |
Kligers iron agar and SIM are multiple test media what test do these media have in common? | hydrogen sulfide production |
What components of the Kligers and SIM media are included for this test? | Cystein, ferrous salts |
Both Kligers and SIM are stabbed, but for different reasons; | SIM is stabbed to detect motility. Kliglers Iron Agar is stabbed to creat an aerobic environment to test for glucose. |
What does Kligers Iron Agar test for? | Carbohydrate fermentation and hydrogen sulfide production |
What does MR-VP broth test for? | 2,3 butanedoil fermentation |
What does phenol red lactose test for? | carbohydrate fermentation |
What does SIM Medium test for? | hydrogen sulfide production; tryptophan degradation and motility |
What does Simmon's citrate agar test for? | Citrate utilization |
What does skim milk agar test for? | Casein hydrolysis |
What does spirit blue agar test for? | triglyceride hydrolysis |
What does tryptone broth test for? | tryptophan degradation |
Match reagent alpha naphtol w/test | 2,3 butanediol fermentation |
Match reagent dimethyl-alpha-naphthylamine w/test | nitrate reduction |
Match reagent ferric chloride w/test | phenylalanine deamination |
Match reagent Gram's iodine w/test | starch hydrolysis |
Match reagent hydrogen peroxide w/test | catalase test |
Match reagent Kovac's reagent w/test | tryptophan degradation |
Match reagent methyl red with test | mixed-acid fermentation |
Match reagent NNNN with test | oxidase test |
Match reagent potassium hydroxide with test | 2,3 butanediol fermentation |
Match reagent sulfanilic acid w/test | nitrate reduction |
Match ezyme amylase w/reaction | starch hydrolysis |
Match cysteine desulfurase w/reaction | hydrogen sulfide production |
Match lipase w/reaction | triglyceride hydrolysis |
Match protease w/reaction | gelatin liquefaction, casein hydrolysis |
Match tryptophanase w/reaction | indole |
Match urease w/reaction | urea hydrolysis |
Match product 2.3 butanediol w/ reaction | Voges-Proskauer test |
Match product ammonia w/reaction | urea hydrolysis |
Match product fatty acids w/reaction | triglyceride hydrolysis |
Match product indole w/reaction | tryptophan degradation |
Match molecular oxygen w/reaction | catalase |
Match phenylpyruvic acid | phenylalanine deamination |