Materials All the chemicals used for synthesis purposes were of AR grade, purchased from Sigma Aldrich chemicals, and for spectral analysis spectral grade solvents were used. Double distilled water was used for preparing solutions. The test strains, Escherichia coli (E. coli) gram-negative, Staphylococcus aureus (S. aureus) gram-positive bacteria and Pseudomonas aeruginosa (P. aeruginosa) were purchased from IMTECH, Chandigarh, India. Yeast extract, tryptophan and bacterial-grade agar–agar were purchased from Hi-media Laboratories, Mumbai, India. Synthesis of 2-[(4-methoxy-phenyl)iminomethyl]-4-nitrophenol (SB) The Schiff-base, 2-[(4-methoxy-phenyl)iminomethyl]-4-nitrophenol, (C14H12N2O4) was synthesized by using p-Anisidine in methanol …show more content…
In a separate beaker, 10-3 M of synthesized SB was dissolved in 10 ml DMF. The two solutions were mixed together under stirring and resulting yellow precipitate solution was transferred to a sonochemical bath. After 60 minutes of sonochemical treatment, the resulting CdS precipitate was collected, filtered, washed with double distilled water and absolute ethanol several times to remove the unreacted chemicals, and finally dried in an oven at 80oC for 5hours. Similar procedure was adopted to synthesize uncapped CdS …show more content…
Elemental mapping over the selected regions of the CdS NPs was conducted by Energy-dispersive X-ray spectroscopy (EDX). The UV–visible diffuse reflectance spectra (UV-vis DRS) were obtained on the spectrophotometer of Shimadzu UV-3600 equipped with an integrating sphere accessory (BaSO4 was used as a reference). Fluorescence spectra were recorded on a Shimadzu RF-5301PC spectrofluorometer. The FT-IR spectra were recorded on a Shimadzu spectrophotometer. The powder X-ray diffraction (XRD) analysis was made with an X’pert Pro diffractometer. Zeta potential measurements were determined with the Zeta sizer Nano Z (Malvern,
The purpose of this lab report is to employ a myriad of skills, tools and, methods learned throughout this semester to perform the appropriate tests for the identification of the assigned unknown bacteria. Add more background information here!!! The most important tools and techniques used during this identification include aseptic technique, microscopic examination and, the use of selective and differential media. Aseptic technique is an important tool for microbiologists. It is imperative that aseptic technique is maintained throughout the length of any test to avoid any cross-contamination that may lead to inaccurate results.
I expect to learn the biochemical differences in bacteria from this lab. Also, how to identify different species of bacteria. Material & Methods For the first day of the practical, an unknown specimen was provided
Gram-negative bacteria also have a negative charge but get the charge from lipopolysaccharides (Bacterial Morphology). For this experiment, biochemical tests were utilized to help determine which of the following four bacteria were in the unknown test tube number 16: E. coli, E. aerogenes, K. pneumoniae, and S. typhimurium. The unknown bacteria was also inoculated and placed on a TSA plate using the T-Streak method to verify that isolated colonies could be obtained. The biochemical tests that were used were the Citrate test, Methyl Red test, Voges-Proskauer test, Urease test, Sulfur Indole Motility test, and Triple Sugar Iron Agar test.
Therefore, acid fat, lactose fermentation, mannitol fermentation were not needed to be performed, because they are selective to a specific thing. As a result, Unknown bacteria “W” was concluded to be gram stain positive, endospore positive, bacilli shape (rod shape), and arranged in chains (strepto-). Test Purpose Reagents Observation Results Gram Stain To determine gram reaction of bacteria.
Materials and Methods To start with, the unknown bacteria # 710 broth had to be successfully isolated on an EMB and MAC agar plate. Using aseptic technique by sterilizing the wire loop with Bunsen Burner between inoculations and flaming the opening of the test tubes before inserting in the loop with the bacteria. The streaking technique used was to isolate the colonies on the agar plates. In addition, the streak plates had to be incubated in a upturned position for 24 hours in a hot temperature incubator at 37 degree Celsius. Bacteria need a favorable condition to grow in.
In the laboratory, identification of an unknown bacterium is often necessary. In the lab, a random sample consisting of three different bacteria was selected. The sample contained one gram-positive, one gram-negative paracolon, and one gram-negative coliform. The purpose of the experiment is to identify each of the three species that the mixture contained. After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates.
When given an unknown bacteria there are a multitude of steps one must go through to be able to correctly identify what bacteria was given. It is important to correctly identify the bacteria because some bacteria are more harmful than others. The gram stain is the first test that should be performed because it helps narrow down the possibilities by telling one whether the bacteria is gram positive or gram negative. After this test is performed, one shall place bacteria on/in Mannitol Salt agar, MacConkey agar, Eosin Methylene Blue agar, Urea agar, Simmon’s Citrate, Purple Beef broth with Lactose and finally Purple Beef broth with Sucrose. A streak plate should also be made up, this helps one identify the morphology of the colonies.
The six bacteria used in this lab were, Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes, Staphylococcus epidermis, Enterococcus durans, and Escherichia coli. Citrobacter freundii is a Gram-negative rod shape bacteria. The MSA plate will grow Citrobacter freundii, Bacillus subtillis, Enterobacter aerogenes and will have a yellow color change while Staphylococcus epidermis will not grow nor have a color change to yellow. The MacConkey agar will have growth with Escherichia coli, Enterococcus durans, but not Staphylococcus epidermis and Bacillus subtilis since it is a Gram-positive.
Gram-Positive bacteria that are inhibited with MacConkey agar due to crystal violet and bile salt presence . “3. What ingredient(s) makes MacConkey agar differential?” MacConkey agar are inhibited by a pH indicator (neutral red), and a disaccharide ( Lactose) “4.
A positive and negative control for each reagent (Biuret, Ninhydrin, Benedict’s, Lugol’s reagents) was produced using 5 mL of water, glucose, albumin, starch, and glycine solutions. One milliliter of Benedict’s reagent was tested on every solution and it was heated to sixty-five degrees Celsius for five minutes before we observed the color change. Moreover, one milliliter of Ninhydrin was also added to another set of solutions and they were heated to eighty degrees Celsius for five minutes. Additionally, two milliliters of the Biuret reagent and one milliliter of the Lugol’s reagent were added to the other two sets of solutions at room temperature. Similarly, each protein brand sample was treated with the above reagents using an equivalent procedure and
The possible explanations and changes to make are similar to the previous questions. Conclusion and Future Experiment 18. The identity of the product and unknown were 4-tert-butylbenzyl phenol ether and tert-butyl phenol respectively. The key to making this discovery was the melting point and TLC results!
After a gram stain was done unknown #257 was identified as a gram positive organism because when observed under the microscope the organism appeared purple with cocci in clusters. The organism was also catalase positive which means that it produced enzyme catalase and bubbled when hydrogen peroxide was added to it. Three test were conducted based on the result of the gram staining procedure. Blood agar with a Novobiocin disk was chosen as well as DNase (DNA) and Mannitol Salts (MSA) agar. The Blood agar is a bright red, opaque plate and the streaking or the inoculation technique was a modified streaking for isolation with a heavy quadrant one.
The element Cadmium symbol on the periodic table is known as Cd, it has an atomic number 48, atomic weight 112.411, density 8.69, and it is classified as a metal. This metal is found naturally in the Earth’s crust and it is rare to find in its pure form, however, it can be found coupled with other elements in a variety of compounds, including with some toxic elements, which Cadmium can be toxic itself. Cadmium in its pure form is of a bluish silvery white color and does not change color when heated up, however, impure cadmium when heated up can change color. Friedrich Stromeyer, and Karl Samuel Leberecht Hermann, simultaneously discovered the metal both in Germany in 1817, as an impurity zinc carbonate. The element Cadmium’s name derived from
The different types of nitrate precursors was used to preparation of the catalyst and they are dried at 120°C for 12 hr in an oven and then calcination at 300oC for 2hr in a furnace. The calcination of the precursors is done just before the activity measurement of the catalyst. The calcination of different nitrate precursors was carried out in three ways;
Furthermore, the use novel starter strains with industrially important functionality can provide the development of microbiologically safe new products with enhanced nutritional, sensory and health