Soil Microorganisms and Antibiotics. December 6, 2004 Kenice Frank, Allison Johnson, Ruben Krantz, Hannah Wilbur. Habitats: Water films Need water for metabolic processes On surface of organic matter Need surface on which to grow In rhizosphere. Competition
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December 6, 2004
Kenice Frank, Allison Johnson, Ruben Krantz, Hannah Wilbur
Need water for metabolic processes
On surface of organic matter
Need surface on which to grow
Compete with surrounding bacteria and fungi
Production of antibiotics by competing bacteriaSoil bacteria
Soil environments are host to a great number of bacterial species
Methods and Materials
-We did a smear of the entire forest plate and the entire river plate because there were no identifiable, separate colonies
Agar plates showing areas of inhibition
Blood Agar Plate (BAP)
-3 forest plates
-2 river plates
-4 marsh plates
1.Bacillus- endospore staining, catalase test
2.Enterics- oxidase test, TSI test
Marsh A:Gram (+) & Gram (-) rods
Marsh B: Gram (+) rods
Marsh C: Gram (-) cocci
River A: Gram (-) cocci in clusters
River B: Gram (-) cocci in clusters
Forest A: Gram (-) rods
Forest B:Gram (+) ovals
Forest C: Gram (-) cocci in clusters
Glucose and 1 other sugar fermented
The first goal was to properly identify Streptomyacin, or other inhibiting agents produced by the bacteria in the soil that would supposedly combat against E. coli and S. aureus.
These attempts failed, as both species of bacteria sustained growth.
The experiment was also intended to isolate certain colonies from three different environments: forest, marsh, and river.
After single colonies of the first plating were isolated physically, a gram stain from the marsh indicated that bacillus and enteric species were present.
Tests resulted negative for enteric bacteria and positive for bacillus, however the endospore stain resulted negatively.
The procedure for isolating the bacteria should have been done using selective and differential media in order to eliminate any other contamination in the culture.
Other possibilities are that streptomyacin producing bacteria did not, in fact, reside at the chosen locations.Tests for Streptomyacin
Bacillus species are gram positive rods. They are endospore forming and are Catalase positive. They are also hemolytic.Bacterial Identification
The enteric tests showed Oxidase positive which is not a characteristic of enteric bacteria.
The tests for the Bacillus colonies were all correct, however the endospore stain did not show spore production. This could be because the bacteria was not in an environment that spore production was needed.
The second plating also should have been done using selective and differential agar to remove any contaminations.
The secong plating should have been inoculated from the same spot on the first petri dish.
Other possibilities are that these could be mutants.Bacterial Identification