Microbiology Unit 4 Microorganisms

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A total of four microorganisms were isolated from the sample brought back from Mars. To identify the microorganisms which were isolated from the sample brought back from Mars, an rDNA sequence analysis was required. Every sequence had an S_ab score of 1.000 meaning the sequence is identical to the microorganism that it was matched to. Before gathering phenotypic results, we gathered phylogenetic data for the four microorganisms which includes Micrococcus luteus, Citrobacter freundii, Hafnia alvei, and Staphylococcus epidermidis. Micrococcus luteus is a gram positive, coccus shaped microorganism that is nonmotile and unable to grow on glucose minimal media or simmons citrate agar (Kocur, 1972;). Citrobacter freundii is a gram negative, bacillus …show more content…
If the microorganism can use glucose as the sole carbon source, growth is seen. If glucose cannot be used as the sole carbon source, no growth is seen. It was observed that Micrococcus luteus does not grow on glucose minimal media, therefore it cannot grow when glucose is the sole source of carbon. Citrobacter freundii was observed to grow on glucose minimal media, therefore it can use glucose as the sole source of carbon. Hafnia alvei was observed to grow on glucose minimal media, therefore it can use glucose as the sole source of carbon. Staphylococcus epidermidis was observed to grow on glucose minimal media, therefore it can use glucose as the sole source of …show more content…
The broth will turn yellow if the microorganism can utilize carbohydrates, and an air bubble will get trapped inside the Durham tube if a gas by-product is produced. All the microorganisms were able to utilize lactose, so the focus will be on their lactose gas production instead. It was observed that the Micrococcus luteus Durham tube had no gas by-product, therefore there is no lactose gas production. It was observed that the Citrobacter freundii Durham tube had a gas by-product, therefore there is lactose gas production. It was observed that the Hafnia alvei Durham tube had no gas by-product, therefore there is no lactose gas production. It was observed that the Staphylococcus epidermidis Durham tube had no gas by-product, therefore there is no lactose gas

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