Introduction
Being the essential part of earth’s microbiota and their involvement in chemical, physical and biological transformations, bacteria are considered as a very important group of microorganisms. Those bacteria which cannot be grown easily on artificial nutrient media are referred as unculturables. The evidence for the presence of yet to be cultivated bacteria came from the molecular data. The capability to obtain DNA sequence information from an environmental sample by PCR manipulations and direct sequencing allowed identification of these phylogenetically important groups. When a sample is collected from environment, the total number of bacterial cells within sample is extremely high, which is not appropriate for isolation of uncharacterized bacteria. Few methods can be applied to reduce the number of microorganisms in mixed samples before cultivation. The majority of culture media are nutrient-rich. It is now thought that these conditions may favors the growth of faster growing bacteria at the expense of slow growing species, some of which grow in nutrient poor environments and may be inhibited by substrate-rich conventional media (Deming and Baross, 2000).
There are certain reasons behind the unculturability of microorganisms. It could be that the organism has a low prevalence or is particularly slow growing has been over looked in cultural analyses. Many genetically distinct phenotypes are phenotypically indistinguishable for example few bacteria are resistant to culture on conventional media. Certain bacteria have fastidious growth requirements including the need for specific physical conditions like pH conditions, incubation temperatures or oxygen levels in the atmosphere. There may be competition for nutrients a...
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After 48 hours of incubation the agar plates were viewed. Individual colonies were tested for successful isolation by gram staining and then viewing the stained bacteria under a microscope. Isolation was successful. One colony of each unknown bacteria was transferred to an agar slant for growth. The agar slants were stored at room temperature over the weekend so that they would not grow too much.
Streak plate technique was used to isolate pure culture for each bacteria (2). The Gram stain was used to determine Gram reaction and morphology of each bacteria (2) Selective and differential media such as, salt agar, MacConkey agar and blood agar were used for bacterial identification (2). Gelatin deeps were inoculated to detect production of gelatinase (2). Starch Agar plate were inoculated to detect amylase (2). Ocular reticle used to determine bacteria size (2). Motility deeps were inoculated to detect motility on bacteria (2). Thioglycollate broth used to determine oxygen requirements (2). Carbohydrate fermentation
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
The eighteenth exercise of the laboratory manual titled Unknown Identification and Bergey’s Manual is an experiment to identify an unknown bacterium. In this exercise, a student must randomly choose a numbered bacterium available to the class. The keys in Appendix H, located on the last pages of the book, are the major helpful tools in this exercise because it provides completed steps of tests that needs to be performed in order to distinguish certain bacteria. This means that in this exercise, various types of tests and techniques must be performed to identify the chosen unknown bacterium. The unknown bacterium that I selected was number thirty-nine in which I discovered as the Bacillus megaterium after conducting several tests.
The first step to the unknown is selecting an actual organism. The best way to select a culture is based on a high-quality distribution. Equally important, shaking up the broth tube facilitates in the distribution. Upon selection, a gram check for purity is performed. Step by step instructions for this procedure can be found in Benson’s, Microbiological Applications p. 99. Furthermore, an aseptic technique must be performed for this test and the entire tests following the unknown. The purpose of this test is to differentiate between gram positive and gram-negative bacteria. The key indicator of gram-positive bacteria is a purple stain and a pink stain for gram-negative bacteria. A slide is viewed with a microscope under oil immersion. Equally
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
The scientific techniques that were mainly used in the conduction of our investigation were the identification of bacteria through the use of a microscope, putting together a Simple Distillation Kit, treating Petri Dishes with Agar on them with the boiled, distilled or radiated water and calculating the coverage of bacteria on the amount of area treated on the Petri Dish. All of these scientific techniques were a crucial part of our investigation. Without all of these techniques we wouldn’t have been able to conduct such a successful experiment.
The eradication of species numbers average at a toll close to one hundred percent of earths total living creatures. “It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct” (Sahney, and Benton 759). Not only where marine and terrestrial species effected but this catastrophic event is the only recogni...
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test.
"Ocean Pollution." MarineBio Conservation Society ~ Marine Biology, Ocean Life Conservation, Sea Creatures, Biodiversity, Research... Web. 19 May 2014.
Oceans are such so vast that people underestimate the impact their actions —seeming so insignificant— have on them. Humans have by and large taken the oceans for granted; not considering how important a healthy ocean is to our survival. A popular mind-set is that the oceans are a bottomless supply of fish, natural resources, and an infinite waste dump. There are myriad reasons why the oceans should be saved and the most obvious one is marine life. With 71% of the Earth being covered by water, it is obvious that sea creatures are predominant form of life, making up 80% of the species of life on Earth. However, as important as marine life is, that is not the only reason why saving the oceans is crucial. The ocean floor provides natural resources such as, oil, natural gas, petroleum, minerals, medications, and ingredients for foods and products. The economic benefits of the oceans are huge and significant, as well. Fishing and fish products have provided employment to 38 million people and have generated about $124 billion in economic benefits. However, oceans are on the verge of crisis, marine life, natural resources, transportation, the economy, and important ingredients are at risk due to overfishing, pollution, and acidification. Thus, in this essay I will argue that, oceans are not impervious to human activity and threatening the health of the ocean threatens the health of humanity, since oceans key to our survival.
Toufexis Anastasia, Andrea Dorfman, Eugene Linden, and Edwin M. Reingold. "The Dirty Seas Threatened by Rising Pollution, the Oceans Are Sending out an SOS." Time 132.5 (1988): 1-8. MasterFILE Complete. Web. 16 Apr. 2014.
Raiskin, Judith L., ed. Wide Sargasso Sea: Backgrounds, Criticism. New York: W.W. Norton, 1999. Print.
These results agree with the hypothesis that our “untouched and super-productive world” is affecting marine life ecosystems (Vannela, 2012). All of these results combined confirm the overall hypothesis that pollution is getting worse in the ocean and more marine life ecosystems are being affected, but there
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