CHARACTERISTICS

Below are given some characteristics that can distinguish Photobacterium from other organisms.

• Striaght and Plump Rods - imagine a corn dog ...
  
  
• Gram Negative - this gives an indication of the cell wall structure. A Gram-negative bacteria has a cellular membrane, followed by a thin layer called Peptidoglycan, and finally the outer membrane. The space between the inner and outer membranes is called the periplasm.
  
  
• Sodium Required for Growth - Salt is required because Photobacteria mostly occur in marine environments, where there is a high salt content.
  
  
• One to Three Polar Flagella; some Nonmotile - A polar flagella means that the flagella (or "tails") are located at one end or the other of the bacterium. This is opposed to Peritrichous, in which the flagella are all around the cell.
  
  
• Luminescent - Glow in the Dark!
  
  
• 40 - 44% GC - This is the percentage of the Gaunine and Cytosine ( nitrogen-containing molecules) part of DNA.
  
  
• Do not form Spores - this means Photobacterium cannot form resistant spores to avoid hard times like some other bacteria can.
  
  
• Diameter: 0.8-1.3 um; Length: 1.8-2.4 um - the size of the 'corndog' ...
  
  
• Facultatively Anaerobic - This means Photobacterium can live without oxygen by undergoing fermentation.
  
  
• Chemoorganotrophs - Photobacterium uses organic compounds for energy.
  
  
• Optimal Growth Temperatures Range from 18-25 C - This is a rather cool temperature range.
  
  
• Metabolism is Fermentative and Respiratory - Meaning Photobacterium can undergo fermentation or respire with oxygen.
  
  

Given in the table below are some carbon sources and whether Ph. angustum, Ph. leiognathi, and Ph. phosphoreum utilize these. Testing for use of these carbon sources can help distinguish between one species and another.