Lab Report On Isolation Of Phototrophic Bacteria

A mixed culture of two unknown bacteria was provided by the instructor. The methods used for

The Gram stain was used to determine if the bacteria was gram positive or negative. A negative test shows a pink color and a positive test is a purple color. When a bacterium is negative it is because it has an outer membrane and a thin layer of peptidoglycan that is much harder to stain. A positive bacterium has a thick layer of peptidoglycan and no outer membrane that can be penetrated by crystal violet.

The next step of the project included preparing a Gram stain to discover the cell shape, arrangement, and if the bacteria is gram positive or

The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible

Table 3 shows Gram stain results that indicated C. Freundii as a gram negative bacterium in rod shapes scattered in singles and some in pairs. Each gram stain produced the same results. The Bartholomew and Mittwer method of endospore staining indicated that C. Freundii tested negative for endospore formation. Table 4 shows the biochemical test results of the unknown and the official test results for comparison.

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

15) Obtain the boiled chloroplast suspension, mix, and transfer 3 drops to cuvette 4. Immediately cover and mix cuvette 4. Insert it into the spectrophotometer's sample holder, read the percentage transmittance, and record it in Table 4.4. Replace cuvette 4 into the incubation test tube rack. Take and record additional readings at 5, 10, and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvtte 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

Prokaryotes are ubiquitous, successfully adapting to diverse environments as well as developing symbiotic relationships with host organisms (Lengeler, Drews, & Schlegel, 1999). Prokaryotes may have both autotrophic and heterotrophic characteristics. A cyanobacteria is photosynthetic, commonly called blue-green algae, and may produce toxins (Crayton, 1993). Bacteria are most commonly associated in the general

The bacteria that was contained within Unknown tube #12 is believed to be Pseudomonas aeruginosa, Figure 1. The bacteria tested to be Gram Stain negative, producing a pink, red color retained from the staining process. When the species of bacteria was plated on nutrient media, the cells produced an irregular and spreading configuration as shown in Figure 2. This same plating test provided the margins and elevation, lobate and hilly, respectively. The specimen was stabbed in a Fluid Thioglycollate Medium (FTM) tube using an inoculated loop of the bacteria. The results of this experimentation indicate the type of oxygen requirement of the bacteria. The test found the bacteria to be aerobic as colonies of the bacteria began to form along the top of the FTM tube (Manual 2017).

degrees Celsius for 48 hours. To identify my bacteria’s grouping and morphology, I gram stained my

The strategy used to determine the unknown organism was to first perform a gram stain to determine if the organism was either a gram negative or gram positive bacteria based on the color of cells. A TSA plate was inoculated to streak for isolation and purity. After colonies were incubated characteristics of colony morphology were recorded and a TSB broth and TSA slant were inoculated to determine characteristics of growth in broth and slant. Another TSA plate was inoculated to determine growth under anaerobic conditions. The next step was to look over the class results for biochemical test and create a dichotomous key to determine which test were useful and which were unnecessary to perform. The gram stain helped determine that the organism

The purpose of this lab was to observe how light is altered as it goes through a solution containing a visible dye. In doing so, we will understand the relationship between absorbance, concentration and light path length. We first created different concentrations of blue stock solutions through dilution. We made 4 dilutions, which gives us 5 solutions in total. Each diluted cup (A-D) had 20 g of stock solution to start with and then 10, 30, 30, 46 g of distilled water was added respectively.

These are gram positive bacteria which are found in acidic condition of pH 4 to 4.5 – acidophilic.

The highest count of heterotrophic bacteria was recorded for the concentration of 1000ppm. A large number of

Another purpose of this experiment is to stress the importance of knowing the identity of a microorganism. Knowing the species of microorganism present in a sample provides a