Safe Micro-Organisms for Education: Bacteria, Fungi, Algae, Viruses - excellent reference!

• Micrococcus luteus (yellow), Sarcina aurantiaca (orange-yellow), Rhodococcus rhodochrous (pink), and Vibrio fischeri (bioluminescent) are listed under "Junior High School and above"
• Chromobacteria are listed under "Model Organisms for Research Projects" - "may upon occasion may cause disease in compromised humans". (Note that Chromobacterium violaceum (purple) used to be available from many of the educational suppliers below, but is actually listed as BSL2 at ATCC!)

NRRL ARS Strain Collection - 24 strain per year FREE (+shipping)! Also has a large Patent collection not listed in the online catalog but which can be ordered if you have the NRRL number from a patent or paper.

American Type Culture Collection (ATCC) - private, not-for-profit biological resource center focusing on standard reference microorganisms, cell lines and other materials for life sciences research. Non-profit rates are typically around $300 for a strain, but some type strains are only around $50. That's still far more expensive than any of the following educational resource though:

Carolina

• Pigmented Bacteria Set: Micrococcus luteus (yellow) , Serratia marcescens D1* (red) , Sarcina aurantiaca (orange-yellow) , Rhodococcus rhodochrous (pink)
• Vibrio fisheri
• Slime Mold Cultures
• Plant Tissue Cultures 

EMPCO - specializes in the culture of marine and freshwater microalgae (No longer active?)

eNasco ("Live bacteria sold to schools only")

• Serratia marcescens
• Micrococcus luteus
• Haloferax volcanii 

Fischer Scientific

Flinn Scientific ("Orders may only be placed by certified science teachers and shipped to a certified school address.")

• Bacterial Pigmentation Set: Serratia marcescens (red), Micrococcus luteus (yellow), Micrococcus roseus (pink)
• Slime molds

Presque Isle Cultures ("All orders must be submitted on an official institutional purchase order")

Sargent-Welch ("can only be purchased by approved Shipping Accounts")

• Pigmented Bacteria Set (same as Ward's below): Kocuria rhizophila (yellow), Kocuria roseus (rose), Sarcina aurantiaca (orange), Serratia marcescens (pink-red)

Ward's Natural Science ("can only be purchased by approved Shipping Accounts" - we got one)

• Luminescent Bacteria Set: Azotobacter vinelandii and Vibrio fischeri
• Pigmented Bacteria Set:  Kocuria rhizophila (yellow), Kocuria roseus (rose), Sarcina aurantiaca (orange), Serratia marcescens (pink-red)

* Note: "S. marcescens D1" is strain Serratia marcescens NIMA ATCC 29632 (see http://www.faculty.virginia.edu/evolutionlabs/AmpResistanceBioscenev26-1p17-21.pdf); it is pathogenic for only immunocompromised individuals.