Characteristics Of Serratia Marcescens : History

Pseudomonas aeruginosa is a versatile gram negative bacterium that grows in soil, marshes, and coastal marine habitats, as well as on plant and animal tissues. People with cystic fibrosis, burn victims, individuals with cancer, and persons infected with HIV are particularly at risk of disease resulting from Pseudomonas aeruginosa.

The colonies were smooth, translucent, and had a white brownish color. The Gram stain resulted in Gram positive cocci. After the Gram stain was completed, the bacteria were streaked on a Mannitol-Salt Agar plate and a Catalase test was performed. After these test were completed a Phenol Red Dextrose Fermentation tube was inoculated, and a SIM Tube inoculated.

Unknown bacteria determined to be Alcaligenes faecalis because of its morphological, physiological and metabolic properties.

The temperatures tested were 4°C, 30 °C, and 60°C. The optimal growth and prodigiosin production

To improve the results from the experiment buffer solutions that were not whole pHs could have been used e.g. pH 4.5, 5.5 etc. This would have provided more reliable results as a wider range of results would have been produced. Using pHs with decimals would also help to more accurately determine the optimum pH as the optimum may have been above or below the pH stated in the hypothesis; 8. In this experiment however the optimum is taken at 8 because the graph does not rise again.

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 bacteria based on specific biochemical characteristics. Whether the tests performed identified specific enzymatic reactions or metabolic pathways, each was used in a way to help recognize those specifics and identify the unknown cultures. The differential tests used to identify the unknown cultures were oxidase, catalase, lactose and sucrose fermentation, Kugler/iron agar, nitrate reduction, gelatin hydrolysis, starch hydrolysis, manitol salt, MR-VP, citrate, bile esculin,

Purpose of Bergy’s Manual: based on ribosomal RNA sequences, which presumably reflect phylogenetic (evolutionary) relationships. Used for the identification of prokaryotes. 2nd edition on classification of prokaryotes.

“Dr. Ackerman, who had devoted his life’s work to resurrection medicine agreed to work with Rutherford in some lab experimentations with the bacterium. This was according to his journal. Dr. Ackerman wrote that he was under the impression given to him by Rutherford, that this bacterium was not at all a hot agent like Marburg or Ebola. Rutherford had informed him that USAMRIID had already classified this agent as a level zero bio safety.

A highly conserved gene will be used to identify a prokaryotic species isolated from the body. Fundamental lab techniques will be also explored and utilized, such as amplifying using PCR, cloning, and transforming the gene into a host cell. DNA electrophoresis and specific substrate plating will serve as analysis check points. The final product will be sequenced and compared to similar species to observe phylogenetic relationships.

"Aside from physical characteristics of the fossil bacteria that are similar to plague bacteria, their location in the rectum of the flea is known to occur in modern plague bacteria," said George Poinar, one of the researchers, in a news release. "And in this fossil, the presence of similar bacteria in a dried droplet on the proboscis of the flea is consistent with the method of transmission of plague bacteria by modern fleas."

The aim of this experiment is to follow the growth of Serratia marcescens in nutrient broth at 37oCby recording the changes in turbidity (cloudiness) by measuring the absorbance of visible light (600 nm) and also to prove that there is an increase in the cell number and not just in mass during the growth.

The analysis of the results by single type of mild stress (first analysis) as well as the analysis of the interactions (second analysis) indicates that the exposure to the OCC did not have a negative effect on the viability of Leuconostoc mesenteroides. In all the analysis performed by single type of mild stress (fist analysis) the same pattern was found; there were no significant differences between the negative and positive controls, low and medium levels of stress-agent within a given type of mild stress except for the highest levels of stress-agents which were significantly detrimental. In acid mild stress the survivability of Leuconostoc mesenteroides ranged from 103-63% the highest being the positive control and the lowest being exposure to pH 4.0 (Figure 4.1). Figure 4.2 shows that with the heat mild treatment no significant differences were found among both controls and all levels of mild heat stress (P > 0.05). The survivability ranged from 105- 100% (Figure 4.2). With ethanol, the survivability of Leuconostoc mesenteroides in the OCC was only different when exposed to 15% ethanol (v/v) (P < 0.05). The highest viability was obtained with the positive control which was 106% and the lowest with the 15% ethanol (v/v) with was 62%. (Figure 4.3). With the prior exposure to the oxidative stress, the viability in the OCC raged from 106-80% the highest being the positive control and the lowest being the 7.5 mM concentration of hydrogen peroxide which

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

The purpose of this assignment was to correctly identify an unknown bacterium, labeled #76, which was provided by the lab instructor. After a series of experiments and lab techniques were performed, the unknown sample was classified as Citrobacter Freundii (C. freundii). C. freundii was first discovered in 1932 by Werkman and Gillen (Collier, Balows, & Sussman, 1998). It is a facultative anaerobic gram-negative bacilli identified in the Enterbacteriaceae family (Holt, Kreig, Sneath, Staley, & WIlliams, 1994).

Warm stagnant water is the ideal environment where the bacteria grow. At temperatures between 78F-108 F the organism can multiply. The common types of water are of concern are whirlpool bath, faucets, water mist from cooling towers or evaporative condensers, misters, large plumbing system, and decorative fountains.