The Effect Of Microbial Growth On Different Soil Samples Essay

1439 Words Feb 9th, 2015 6 Pages
A comparison of microbial growth in different soil samples reveals that microbes are more abundant and diverse in dry soil sample.

Microbes are the most abundant organisms on Earth, and they are easily found in soil. To determine and compare the abundance and diversity of several types of microbes between environments, two soil samples from different environments were gathered and compared. One sample was obtained from a hot, dry environment while the other was obtained in an area of dense foliage and animal traffic near a large pond. These samples were tested using nutrient agar for “simple” soil bacteria, glycerol yeast extract agar for Actinobacteria, and Sabouraud dextrose agar with antibiotic for fungi. For the first step, dilutions were prepared. Next, these dilutions were plated onto the designated media. Then the plates were incubated at 37°C for one week and colonies were counted. Cell density (CFU/mL) was then calculated to determine abundance. Results suggested microbes were generally more abundant in the arid soil, and that the arid soil was a more suitable environment for both Actinobacteria and fungi. Through analyzing colony morphology, the arid soil sample also exhibited greater biodiversity than the damp soil sample.

Microbes are found all over the Earth. With only a microscope they can be observed on rocks, under the soil, and in other organisms, but they have also been found in more extreme environments such as miles into the…

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