biochemical tests Flashcards
acetoin test
tests for presence of acetoin, an intermediate in the butanediolh fermentation pathway of glucose, use VP reagents
+:gradual appearance of red color
-:no color after 20-30 minutes
casein hydrolysis
test for caseinase which hydrolyzes casein->casamino acids
->use milk agar
+: pronounced zone of clearing in agar surrounding innoculum
-:no change in agar appearance
catalase test
test for presence of catalase which breaks down ROS, use H2O2
->found in aerobes and facultative anaerobes
+:formation of gas bubbles
citrate test
test for organisms ability to utilize citrate as carbon source
+:visible growth w/ or w/o blue color
-: no growth
fermentation test
test if organism can do fermentation
->growth is necessary
+:acid formation (A) or acid and gas (A/G)
-: no result
gelatin hydrolysis
capable of hydrolyzing gelatin->oligopeptides using gelatnase
->must refrigerate after pulling out
+:fluidity in gelatin tube
-:solid deep
indole test
Organism use tryptophanase to break down tryptophan
kovacs reagent
+: immediate formation of a pink layer
-: yellow brown top layer
methyl red test
Test for mixed acid fermentation
+: red ccolor
-: yellow or intermediate color
motility test:
Test if organism is motile or not via stab deeps
+:furry growth
-: no growth
nitrate reduction test
test if organism can reduce nitrate
+:color after adding reagents A/B(nitritr->nitrate) or no color after adding zn (nitrate->NH2 and O2)
-: color after adding zn
ornithine test
test for enzyme ornithine decarboxylase
+: purple color
-:no color
oxidase test
Test for enzyme cytochrome c oxidase
->aerobic respirers
+result: hot pink color on paper
starch hydrolysis
test if organism produces amylase to catalyze the hydrolysis of starch->glucose
+: yellowish-transparent halo of agar surrounding innoculum
-: no growth
