Everything Micro

Growth at Various Temperatures All four plates were inoculated with the same 4 organisms and incubated at the various temperatures (4, 25, 40 and 60 degree's C for 24 hours) on TSA agar: Upper left Quadrent:   Staphylococcus aureus                    Upper Right  Quadren t:   Bacillus  stearothermophilus, make sure to parafilm these plate's or they will dry out. Lower Left  Quadrent:  Pseudomonas   fluorescens, this bacteria is a slow grower at refrigerated temp's and can take a week plus to get good results. Lower Right Quadrent:   E. coli 4 Degree's C Psychrophiles (cold loving):  Bacterial species that will grow within a temperature range of -5 o C to 20 o C.  The distinguishing characteristics of all psychrophiles is they will grow between 0 o and 5 o C.  Capable of living and growing at cold temperatures they are responsible for food spoilage in refrigerators. 25 Degree's C Psychrotrophs :  Bacterial species tha

IMVIC Testing for E nterobacteriaceae The IMViC test consists of 4 tests: Indole, methyl red, Voges-Proskauer, and citrate untilization and is used to identify and differentiate between different Gram (-) lactose fermenting coliform bacteria or Enterobacteriaceae.   The presence of coliform bacteria indicates fecal contamination. SIM Three Tests In One: Hydrogen Sulfide, Indole, Motility (A)                            (B)                               (C)                                (D)                                 (E)                                 Sulfur-indole-motility test results from various microbes .  From left to right:  (A)  Escherichia coli , (B)  Staphylococcus aureus , (C)  Salmonella arizonae , (D)  Enterobacter aerogenes , and (E)  Proteus vulgaris.   After addition of Kovács reagent, a pink ring at the top of the tube indicates a positive indole result (A and E) .  Blackening of the media indicates hydrogen sulfide production (C and E) .  G

Oxygen Requirements:  Fluid  Thioglycolate Media A                             B                                C                                      D                                E    Organisms grown in Fluid Thioglycollate Media, a reducing media that uses sodium thioglycolate to chemically combine with dissolved oxygen to deplete the oxygen in the media. The top portion of the tube contains oxygen while the bottom of the tube is lacking molecular oxygen.  All organism except for  Neisseria sicca  were grown for 48 hours at 37 o  C. Neisseria sicca  was grown for 72 hours at 37 o  C for best results.  Note: Both  N. sicca  and  C. butrycium  were grow in supplemented Thioglycollate Media.  A calcium chip can be seen in the bottom of the tube for  N. sicca which is used as a buffer.  This media is aslo supplemented with vitamin K.   Note:  I buy prepared thioglycolate media and many times the media is "jostled" in shipping.  I will autoclave the tubes to d

Casein, Lipid, Starch and Gelatin agar:  Exoenyzme production Casein Plates (Milk Plates) contain the major milk protein found in milk and Lipid plates contain  Tributyrin.  If an organism can produce the exoenzyme protease/casease( hydrolyzes casein ) or lipase (hydrolyzes tributyriin) then a clear zone will be seen around the growing colony.  Both of these agars are considered differential media's since you can differentiate organisms by there exoenzyme ability.  Organisms that have    protease/casease break the casein down into smaller peptides, polypeptides and amino acids that are more easily transported into the cell for metabolism.  Similarly organism that break down  the fatty tributyrin, a triglyceride that is broken down to glycerol and fatty acids,   into smaller fragments that are more easily used in cellular processes. Organisms that have gelatinase using gelatin as the sources of carbon and can hydrolyse gelatin turning it form a solid to liquid state ate room te