Strains and pouring medium
The Earth in the universe, life and the evolution of life
Cognitive objectives:
Show the effect of mutations on cellular metabolism and understand the role of the genome.

Proposed activity:
1) Comparison of the two types of cell division by microscopic observation.
2. Identification of the nutritional and energy needs of four strains of yeasts:
Four media differing by their carbon source will be used. Students will have a box of each medium divided into four equal quarters. Using a sterile inoculating loop, each strain will be seeded on one quarter of each of the four boxes.

Results obtained:
Growth or not of the strains depending on the media.
Division by scissiparity of Schizosaccharomyces pombe observable under the microscope.

Composition :
The kit is automatically composed of strains and media

• STRAINS:
  Saccharomyces cerevisae (wild strain)
  Saccharomyces cerevisae (rho-strain: unable to breathe)
  Saccharomyces cerevisae (sac-strain: unable to metabolise
  sucrose)
  Schwanniomyces castellii (has amylolytic activity)
  Schizosacharomyces pombe (divides by scissiparity)
  
• MEDIUM:
  NO. 5: Minimum media +glucose
  No.6: Minimum media + glycerol
  
  N°o. 7 : Minimum media + saccharose
  
  No. 8 : Minimum media + starch
  MATERIAL (for 40 students):
  
• 80 sterile inoculating loops
  
• 5 sterile spreaders
  
• 99 sterile Petri dishes - diameter 90mm
  
• 2 sterile droppers
  Technical and educational instructions available on our website.
  
  Conservation: 2 months at 4° C
  Transplanting the strains every month.