Bacteria Description

Our unknown bacteria, L-25, is of the genus Serratia, and we believe of the genus marcesens. Here are descriptive qualities we have obtained through testing in the lab-

Morphological Characteristics
Cell shape: Bacilli
Size: Small
Spores: none
Gram's Stain: Negative
Motility: Motile
Capsules: none
Special stains: Acid-fast

Cultural Characteristics
Colonies: red
      Nutrient agar: red
      Blood agar:  white, partial lysis
Agar slant: red
Nutrient broth: pink
Gelatin slab: turbid
Oxygen requirements: facultative anaerobe
Optimum temperature: 25 degrees Celsius (but varies, also grows well at 37 degrees Celsius)

Physiological Characteristics
Fermentation

• Glucose: positive
• Lactose: partial
• Sucrose: positive
• Mannitol: negative

Hydrolysis

• Gelatin liquefaction: positive
• Starch: negative
• Casein: partial
• Fat: positive

iMViC

• Indole: positive
• Methyl Red: negative
• Voges-Proskauer (acetylmethylcarbinol): positive
• Citrate Utilization: positive
• Nitrate Utilization: positive
• Urease: negative
• Oxidase: positive

Litmus Milk

• Acid: no pH change
• Alkaline: no pH change
• Coagulation: soft curd formed

All of these characteristics indicate that our unknown bacteria is Serratia marcesens