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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...iotechnology, 3, 301–308.
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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.
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
Dinoflagellates are one of the four main types of phytoplankton, which are photosynthetic, single celled and free living organisms in the ocean. Dinoflagellates cause the Harmful Algal Blooms (HAB) also known as the red tide effect (Hackett et al 2004). Toxicity persisting at upper levels of the food chain is detected in them from the ones which are toxic, but not all such blooms are toxic. Enhanced detection capabilities may in part contribute to observed high frequency and severity of toxic blooms. As they are also important in the health of coral reefs their study has gained significant interest. Species are often selected for genome sequencing based on their importance as a model organism or relevance to human health, such as the HAB case.
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.
Eastfield College Microbiology Laboratory Manual, 1st edition, Oliver, T. D. (Book Must Be Purchased New from Eastfield Bookstore and Cannot Be Sold Back to Bookstore at the End of the Semester), Kendall Hunt Publishing, 2013, Dubuque, IA. ISBN 9781465223784.
Coli. Each culture was grown in an M9 medium. One culture utilized glucose as a carbon source, while the other utilized succinate as a carbon source. Two other treatments of E. Coli were also tested, one without succinate and one without glucose. These two treatments were added as a baseline to compare how much succinate and how much glucose actually helped the E. coli grow. The two treatments were covered with parafilm and for the purposes of this experiment, will be called blanks. These cultures remained within their assigned group all day to measure the growth of E. Coli. The following process was repeated by all groups throughout the day. A cuvette was labeled with the sample that was being tested. The writing was at the top of the cuvette to prevent light from being disturbed and affecting results. 3 mL of the tested sample were placed in a flask using a sterilized 1 mL pipet. The spectrophotometer was then rezeroed with the corresponding blank inside. This was so that only growth would be measured. After recording measurements the flasks were returned to the incubator and the pipets were disposed of in a red biohazard bag. The contents of the cuvette were poured into 50% bleach to kill any E. coli. The cuvette was rinsed with distilled water. This process was repeated every 30 minutes over the course of eight and a half hours. Measurements at 12:00, 12:30, and 15:30 were missed due
Microorganisms play an important role in our life: helps us to process our nourishment, break down squanders and take an interest in different life cycles. They are various and have adjusted to occupy distinctive situations including outrageous conditions, for example, hot vents under the sea to ice tops. In “Bugged” by Rinku Patel aims that we know little about microbes, however there is a big part of unknown and we should learn more about these microbes that could benefit our health wise. Therefore, the author tries to emphasize on the effect of microbes in our life while engaging the reader to see things through the advantages of microbes, the disadvantages and defining useful bacteria.
The purpose of the study was to identify what are unknown bacteria by applying all the methods that we have learn in microbiology for the identification of are unknown. We apply the different test and be able to recognize the different characteristic of are unknown. Each test has its own purpose to help identify the bacteria by the reaction.
Istiblennius lineatus (Rockskipper Blenny) will be collected from three different tide pools across the island of Mo’orea, French Polynesia in May 2017. Fish will be caught with nets and stored in tanks at UNC Berkley’s Gump Field Station before transport back to Atlanta for use in the lab manipulative portion. Two algal species that The Rockskipper Blenny uses as food sources will also be collected. The algae species collected will be the same for each of the three tide pools and are preferably from two different families of algae. Initial samples from each fish and alga, as well as water samples will be taken in field for 16s gene sequencing to determine the microbial composition. Samples will be stored in RNA and frozen prior to DNA extraction and sequencing. Water samples will be stored in ethanol. The initial fish gut and algae sample will be used to compare the effect of isolation on fish gut microbiome. The water sample will be used to determine differences in water microbial composition between tide pool
One type of bacteria from the mixed culture plate is placed on a separate plate of media for testing. That one parent cell will multiply itself through a process called binary fission producing bacteria with the same DNA. The pure culture will be used for further study of the bacteria. The unknown species KK appeared to contain a pure culture because all of the colonies on the petri dish were similar in color and shape after incubation.
Guinotte, J. M. and Fabry, V. J. (2008), Ocean Acidification and Its Potential Effects on Marine Ecosystems. Annals of the New York Academy of Sciences, 1134: 320–342. doi: 10.1196/annals.1439.013
The purpose of the microbiological experiment was to applying different types of techniques and methods learned in microbiology lab to a bacteria so that it may be accurately and precisely identified. “The words accurately and precisely are not the same in microbiology, accurately has the meaning of if repeated the same answer continues to be the result, precisely has the meaning of the correct answer.” “Microbiological experimentation often involves test that determine the ability of an organism to use or produce some chemical, or to determine the presents or absence of a specific organism in a sample.” The scientific methods that were performed aided in the precise identity of the bacteria.
The purpose of this study was to isolate, characterize, and identify an unknown species of bacteria collected from soil in Flagstaff, Arizona. The environmental isolate (EI) was found to be non-motile, this limits the bacteria from spreading across an area without outside forces. The EI had a positive reaction to the catalase test this indicates that the bacteria can convert harmful hydrogen peroxide into water and free oxygen (Shand and Fitchett 2017). It was also discovered that the EI was a strict aerobe which is significant because it cannot live without oxygen. This limits the area the bacteria can survive in. It was discovered that the EI was predominantly arranged in clusters and had the ability to produce a biofilm. This
Microbes are everywhere in the biosphere, and their presence invariably affects the environment in which they grow. The effects