User:Trevor W. Gruen/Notebook/Biology 210 at AU

Lab 3: Microbiology and Identifying Bacteria 2 February 2016 Trevor Gruen

Hay Infusion Observations: Much of the water evaporated, and the thick moldy layer on top has largely dissipated. The smell of rot has become nearly undetectable. I would hypothesize that much of the organic matter that composed the thick top layer was food for the microorganisms in the jar, and they had consumed much of what had been there the prior week. This would explain why much of the matter and the smell were missing. Archaea likely won’t have grown on the agar plates since they prefer extreme environments, and the plate is not nearly extreme enough.

Plate Comparison:

Dilution	Agar Type	# Colonies on Plate	Conversion Factor	Colonies/ml
10^-3	Nutrient	5,900	10^3	5.9 x 10^6
10^-5	Nutrient	59	10^5	5.9 x 10^6
10^-7	Nutrient	1 (Very Large)	10^7	1.0 x 10^7
10^-9	Nutrient	1 (Average Size)	10^9	1.0 x 10^9
10^-3	Nutrient+Agar	61	10^3	6.1 x 10^4
10^-5	Nutrient+Agar	1	10^5	1.0 x 10^5
10^-7	Nutrient+Agar	0	10^7	0
10^-9	Nutrient+Agar	0	10^9	0

Comparing between the plates with and without antibiotic, the plates with Agar grew substantially less colonies. This indicates that the antibiotic is effective against some of the types of bacteria grown on the plates, but not all of them since some colonies grew in the higher concentration plates.

Function of Tetracycline: “Tetracyclines inhibit bacterial protein synthesis by preventing the association of aminoacyl-tRNA with the bacterial ribosome” (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC99026/). Being that protein synthesis is a necessary action for all life, tetracyclines will affect any bacteria that hasn’t developed a resistance to the antibiotic.

Colony Label	Plate Type	Colony Description	Cell Description	Gram Positive or Negative	Additional Notes
10^-3	Without Tet	Yellow and white colonies, mostly round with some undulate colonies, smooth, pulvinate.	Motile, round, coccus, bacillus, light blue.	Negative
10^-5	Without Tet	White Colonies, mostly round with some undulate colonies, smooth. pulvinate.	Nonmotile, round, coccus, bacillus, light blue.	Negative
10^-3	With Tet	Yellow and white colonies, round, smooth.	Motile, coccus, bacillus.	Positive	Cells taken from white colony.
10^-3	With Tet	Yellow and white colonies, round, smooth.	Motile, bacillus, filament.	Negative	Cells taken from yellow colony.

Lab 2: Hay Infusion January 28th 2016 file:///Users/trevorgruen/Downloads/Lab%20%232%20Hay%20Infusion/Lab%20%232%20Hay%20Infusion.html

Lab 1: Transect January 28th 2016 Biotic Factors: life in the pond, shrubs, trees, microorganisms in the dirt, flowers (dead for the winter). Abiotic Factors: Rocks, concrete, benches, Roper Hall, dirt. File:Roper transect.pdf