Team:Goettingen/week11-1

V07_09

• Experiment:
  M9 agar was prepared as usual. Afterwards, steril filtrated methionine and leucine solutions were added, to analyze their influence towards the swimming abilities of the bacteria. BL21 and ∆tar with a variety of containing plasmids (rfp, 18M, 18C, and 20E) were used. Trypton was used as a chemoattractant, soaked into whatman paper and plated in the center of the plates.

V07_10

• Experiment:
  According to previous test designs, the influence of two washing solutions (chemotaxis buffer and 1% NaCl solution) were tested. A variety of strains (DH10B and BL21) with a variety of plasmids (rfp, 18C, 18M, and 18O) were dropped onto M9 agar. As chemoattractant, 0.5% trypton or 100 mM aspartate solution were used.
• Observations & Results:
  It was no positive influence of the washing solutions and washing process detectable.

V07_11

• Experiment:
  A variety of strains (DH10B, BL21, and ∆tar) with different promotor strengths (empty vector, 18M, 18O, 18C) were dropped onto M9 minimal medium. The aim was the analysis of the influence towards swimming speed of the mentioned promoters. The whole approach was doubled and incatated both, 30° C and 37° C.
• Observations & Results:
  The constructs with 18C promoters showed the most swimming, whereas 37°C showed better results. Only strains DH10B and BL21 showed swimming, at all. The stronger the promoter, the stronger the swimming.

V07_13

• Experiment:
  Two versions of each of these three strains (BL21, DH10B, and ∆tar) were mixed in equal amounts. One with the rfp (empty) vector, and one with the 18C_tar vector. M9-agar were used for the plates: 1) M9-medium supplemented with methionine; Aspartate was used as chemoattractant in whatman paper. 2) M9-medium w/o any supplements; trypton as chemoattractant.
• Observations & Results:
  All BL21 and DH10B strains showed swimming, whereas ∆tar did not. 37°C showed greater swimming radii and the best overall swimming was performed by BL21 containing 18C plasmids.

• Experiment:
  see V07_09_1
• Observations & Results:
  BL21 and DH10B showed strong swimming and chemotaxis towards both, aspartate and tryptone. ∆tar showed swimming and chemotaxis only towards tryptone.