Gram-negative bacteria

DISCUSSION: Pseudomonas aeruginosa was selected to study their antimicrobial activity due to the production of pyocyanin, an antimicrobial phenazine pigment. For this study different clinical specimen were collected and from these P. aeruginosa was isolated. To isolate good pyocyanin producing P. aeruginosa, repeated plating of all the isolates on cetrimide agar helped in final selection of the 5 isolates. To examine the antimicrobial activity of those isolates, in vitro inhibition by cross…

In this experiment, three strains of tetracycline resistant E. Coli were tested. First, the bacteria were diluted via serial dilution in order to more accurately count and quantify the bacteria. To ensure that the three different strains of bacteria are not cross contaminated, label everything either Farm A, Farm B, or Farm C depending on what is being tested. There are six agar plates for each farm, three of the plates are tetracycline plates (which are labeled) and three are unlabeled. For…

Hankin performed an interesting experiment to test if the antibacterial ‘substance’ in Ganges and Jamuna was volatile in nature. He heated the Ganges and Jamuna water in an open and a hermatically sealed tube (Hankin, 1896 and Hankin 2011- this is the English version of the original French paper translated by gangagen.com). He found that the antibacterial activity was retained when the water was heated in the sealed tube, but was lost in the open tube. Although the exact temperature and the…

Water and Iodine. The procedure of the lab for the first day involved our group acquiring a cotton swab and using the swab to gather the Propionibacterium acnes (P. acnes) bacteria from various spots around our face, we then grabbed a Petri dish filled only with a thin layer of agar. We proceeded to swab the P. acnes bacteria off of the cotton swab (gently to not break the agar) into the Petri dish. Once we had completed swabbing the P. acnes over the agar we closed the Petri dish, taped over…

Throughout the course of the semester we have learned how different variables in an environment can affect the growth, change, and behavior of an organism. Using this research as a guide we set out to design an experiment that would show a particular variable’s effect on brine shrimp eggs. After much debate we decided to use light wavelengths as the variable being tested. We wanted to see the difference in development in the brine shrimp eggs and the development after hatching when…

evaluated for their anti-microbial activity using the agar diffusion technique . The tested compounds were evaluated against, Gram +ve bacteria , Gram -ve bacteria, Yeast and Filamentous Fungus. Minimum inhibitory concentration (MIC) was made in vitro for compounds which showed antimicrobial activity. Compound 3b has broad spectrum activity against Gram +ve bacteria, Gram -ve bacteria, Yeast and Filamentous Fungus with MICs 150, 150, 75, 312, 625 and 625 µg/mL against (Bacillus subtilis…

uncountable. To ensure a countable plate, serial dilutions of a solution containing an unknown amount of bacteria are plated. The total number of bacteria in the original sample can be determined by counting the colony forming units and dividing them by the product of the dilution factor and the volume of the plated diluted suspension. This formula helps us to calculated the number of bacteria per mL present in the original solution.…

There are bacteria everywhere. Bacteria is on everything that we touch, eat, and is in our own bodies. We cannot see them with just the naked eye, it takes a microscope to be able to see them. Even though they are visible through a microscope, it is not possible to tell what they are. Two ways that we can identify bacteria is by using agars and staining. The agars that are used in this lab are eosin methylene blue agar (EMB), mannitol agar, and nutrient agar. Mannitol agar is used for…

of a body part effect the bacteria population present on the said part? What has more bacteria the inside of a person's mouth or a person's index finger? My biology class is learning how to conduct experiments, and last week for our experiments we were broken into groups and given instructions to swab any two different objects. After swabbing our two objects, we were then suppose to wipe each swab onto a divided petri dish in order to see which object had more bacteria. My group could have…

The aim of this experiment is to identify and classify of an unknown bacterial isolate. Morphological and Biological test were preformed to identifiy the isolates characteristics. The following characteristics were tested: gram-stain, motility, morphology, hemolysis, lactose fermetation, mannitol fermentation, osmotolerance, aesculin hydrolysis, starch hydrolysis, gelatine hydrolysis, amino acid decarboxylation, lipid hydrolysis, lactose fermetation, casein digestion, catalase enzyme production,…