Differentiation of Microorganisms - Lab Report Example

Differentiation of Microorganism Physiological tests are important in differentiating between different types of microorganisms. Microorganisms are normally fastidious and they respire in various ways. The purpose of the five experiments was to comprehend and compare biochemical mechanisms and activities for the purpose of taxonomy. In culture media experiment, its purpose was to describe the function of ingredients in a typical medium of microbial growth. The secondary purpose was to differentiate the general selective, purpose, and differential media, and give illustrations in the form of examples, and describe the conditions under which they are useful. In enzymes experiment, its primary objective was to assay the culture of bacterial to find out if certain enzymes are developed or produced. The secondary objective was to use the tests to help in identifying bacteria. The experiment on fermentation, determined if a microorganism can make sugar ferment. Additionally, the primary objective of motility experiment was to determine if a bacteria is motile or not, the experiment used a motility agar and direct microscopic observation. The secondary objective of a motility test was to differentiate the motility from the Brownian motion. Finally, the experiment on differentiation of enteric bacteria had three objectives that listed the bacteria found in the gastrointestinal tract and differentiate non-pathogenic from pathogenic species. Consequently, the species defined terms such as enteric, coliform, and EnteroPluri-Test. It further interprets diagnosis results that are commonly used to differentiate enteric. Some of the microorganisms tested in the experiments include E. Cole, S. aureus, B. cereus, and P. aeruginosa. The microorganisms were used in testing for the enzymatic actions. Methods In culture media experiment the test included a synthetic medium, tryptic soy broth, SF broth, Macconkey Agar, and nutrient agar. The liquid media like the nutrient broth was used in the reproduction and isolation of organisms. MacConkkey Agar was a solid medium that examined colony morphology and the isolation of the organisms. Most of the culture media were complex; their chemical composition was unknown. Additionally, the culture media were selective. They selected certain microbe types by supplying the growth conditions. An example of this media was SF medium; it was designed to select Enterrococcus faecallis in warm blooded animals. In Enzymes experiment, the tests included the Caseinase which hydrolyzed casein to peptides to amino acids, gelatinase hydrolyzed gelatin, and Catalase protected the cells from the hydrogen peroxide. In addition Oxidase indicated the presence of cytochrome in the microorganisms, during oxidation the compounds turned red or blue. In fermentation experiment the fermentable compounds was sugar (glucose, sucrose, and lactose). Consequently, an indicator dye was used to change the color from red to a yellow color when the PH is below 7. In motility experiment flagellum was used a bacterial motility. The experiment used several ways to determine motility i.e. hanging drop and motility agar. In the course of the experiment, if the culture tested is strict aerobe, then growth will occur on the tube surface. The hanging drop slide was used in motility viewing when the oxygen is depleted. In the experiment that dealt with differentiation of enteric bacteria, most bacteria used were facultative anaerobes and anaerobes. The enteric bacteria used here encompassed facultative anaerobic rods, gram negative, and non-spore forming bacteria. The Coliforms were characterized by their fermenting ability. Other tests that were used to identify the enteric bacteria included H2S, KCN, MB agar, TSI agar, SS agar, and MacConkey agar. Discussion The culture media experiment used the following microorganism: Escherichis Coli, Enterococcus faecalis, and Pseudomonas aeruginosa. The two culture media in the experiment were synthetic medium and tryptic Soy Broth. The experiment examined the growth of the microorganisms in the two media. It was found out that the microorganisms had growth in the two culture media. Additionally, the culture media experiment examined the growth of microorganisms in SF Browth, Maccoonkey Agar and Color change, and Nutrient Agar and Glucose. The microorganisms used in these particular tests were Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica, Pseudomonas aeruginosa, Escherichia coli, and Bacillus subtillis. Of the microorganisms used, staphylococcus aureus and Enterococcus faecalis, had growth in SF broth. The microorganisms that had grown on Macconkey Agar and Color change were Pseudomonia aeruginosa and Escherichia coli. Escherichia coli exhibited a pink color change. Additionally, all the microorganisms grew on nutrient agar and glucose apart except staphylococcus aureus. The aim of enzyme experiment was to determine if the microorganisms can hydrolyze Oxidase, Amylase, Caseinase, Gelatinase, and Catalase. The organisms used in this experiment include Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus , Enterococcus faecalis, and Esherichia coli. All the organisms recorded a negative result with Oxidase except Pseudomonas aeruginosa. In amylase, all the organisms recorded a negative result except Bacillus subtilis. Additionally, Pseudomonas aeruginosa and Bacillus subtilis recorded positive results with Caseinase, Gelatinase, and Catalase. From the result, Staphylococcus aureus, reacted positively with Gelatinase and Catalase tests only. All the other tests were negative. Enterococcus faecalis , recorded a negative result in all the tests that were carried out in the experiment. Finally, Esherichia coli microorganism tested positive in Caseinase and Catalase, as negative tests were recorded in Oxidase, Amylase, and Gelatinase. In fermentation experiment, the following organisms were used; Escherichia coli , Enterobacter aerogenes, Salmonella enterica , Pseudomonas aeruginosa, Staphylococcus aureus , and Enterococcus faecalis. The three media were Glucose, Sucrose, and Lactose. All the microorganism exhibited growth in the three media except Salmonella enterica and Enterococcus faecalis which exhibited no growth in sucrose and lactose respectively. Additionally, the experiment tested the fermentation of Glucose, Sucrose and Lactose between 2 to 4 days and the results were recorded. In Glucose media Acid and gas were produced in Escherichia coli , Enterobacter aerogenes, and Salmonella enterica , no color change in Pseudomonas aeruginosa, while Staphylococcus aureus , and Enterococcus faecalis produced no acid. In Sucrose media Escherichia coli had no color change, Enterobacter aerogenes produced acid and gas, nothing happened in Salmonella enterica, there was a color change in Pseudomonas aeruginosa, while Staphylococcus aureus , and Enterococcus faecalis were not acidic in sucrose. In Lactose, Acid and gas were produced in Escherichia coli , Enterobacter aerogenes, and Staphylococcus aureus. There was no color change in Pseudomonas aeruginosa and Enterococcus faecalis. Motility experiment used the following Microorganism Bacillus Subtillis, Pseudomonas aerigunosa, and staphylococcus aureus. The organisms that recorded moving reaction (yes) on a wet mount, hanging drop slide and motility agar was Bacillus Subtillis and Pseudomonas aerigunosa. Meaning the two microorganisms were obligate and facultative aerobic respectively. However, staphylococcus aureus recorded a no moving reaction (No) on the hanging drop slide and wet mount. Meaning Stephylococcus aureus is anaerobic. In a motility agar, Stephylococcus aureus was not motile in a motility agar. The motility agar confirmed the slide observation. The discrepancies might have occurred in the reaction due to errors in accuracy. In the differentiation of enteric bacteria experiment, the microorganism that was used in the experiment include E. Coli,B. subtilis, C.glutamicum, S.aureus, E. faecalis, E. aerogenes, S. enterica, and P. aeruginosa. The tests include glucose, lysine, ornithine, H2S, Adonitol, Lactose, Arabinose, Sorbitol, Dulcitol, PA, Urea, and Citrate. In the experiment the following observations were made; Butt color and reaction, carbohydrate fermented, H2S was produced, and Slant color and reaction. The experiment helped in identifying the members of Enterobacteriaceae and their fermentation on carbohydrates. E. coli exhibited an acid slant and acid butt. Blackening was not seen, but the production of H2S was experienced. E. coli fermented Sucrose and Lactose. S. dysenteriae experienced an alkaline slant and acidic butt. The fermented carbohydrate was Glucose. S. typhiurium experiences an acidic slant and acidic butt. There was no blackening but H2S was produced. P. vulgaris has an acidic slant and acidic butt. Its carbohydrate was fermented to sucrose/lactose. P. aeruginosa presented an alkaline slant and acidic butt. And did not ferment any carbohydrate. A. faecalis presented an alkaline slant and weak alkaline butt. Neither blackening nor H2S production occurred. A. faecalis did not ferment carbohydrate. Conclusion The lab was very crucial. It enables us to learn the identification of organisms by various enzymatic activities. There were many tests, but the lab helped in narrowing down the microorganisms dramatically. The experiments were basics compared to other microbiology experiments. Much of the testing was to inoculate with a variety of media. It was beyond my imagination that there are very many media, and I guess there are a lot of unmentioned media that need testing. Reference Microbiology lab report differentiation of microorganisms - free eBooks download. (N.d.). Free books and manuals - GoBookee.org. Retrieved October 10, 2013, from http://www.gobookee.org/microbiology-lab-report-differentiation-of-microorganisms/ Read More