Gram-negative bacteria

Gram positive: First, the bacteria sample is placed on a glass slide and heated only to the point of rendering it innocuous in terms of being infectious to the handler. Next, the bacteria sample is treated with a gentian violet-iodine solution for up to sixty seconds. The slide is then gently rinsed under clean water and the Gram solution is applied, which is a mixture of iodine and potassium iodide diluted in water. This step triggers a reaction to the gentian violet compound. Initially, the reaction produces a dark blue colour. However, a subsequent rinse with ethyl alcohol leads to the colour in some bacteria samples to bleed out, but not in others. A final dye solution is applied that uses a different colour, usually a variation of red. A sample that accepts this counter stain will appear pink, and is…

The purpose of the unknown experiment is to understand and identify a gram positive and a gram negative. Bacteria can be very helpful in clinical uses and many pharmaceutical drugs are based on the organism. Knowing how a bacterium works and how it is structured can be crucial to determine how it affects each individual. Several biochemical tests were performing to separate and determine the identities of the microorganisms. Broth tube number 31 containing unknown microorganisms. One of the…

containing peptidoglycan. When bacteria divide, holes actually appear in their cell walls that must be filled with peptidoglycan. However, penicillin inhibits proteins that are needed to link the peptidoglycan together. So when bacterial cells try to divide when penicillin is present, the holes in the cell wall cannot be filled in with peptidoglycan. The bacterial cell will eventually burst as solutes from the environment rush into the cell through these holes (Yocum, Rasmussen & Strominger,…

After gram staining both the gram positive and gram-negative bacteria, the groupings were observed. For the unknown gram-positive bacteria, the cells were arranged in a cocci cluster, while in the gram-negative bacteria, the cells were arranged in a rod cluster. Both the gram negative and gram-positive bacteria exhibit a small yellow colony on the TSA plate. After 48 hours, the MSA plate was observed. Individual isolated colonies were found throughout the plate, with a yellowish color. The…

The objective of this lab was to isolate and identify an unknown Gram positive and Gram negative bacteria through the use of various microbiological techniques. The identification of the genus and species for the unknown culture should be obtained based on the characteristics for Gram positive and Gram negative bacteria. Bacteria are prokaryotic microorganisms that lack a nucleus and therefore all its genetic information is stored in the cytoplasm of the cell. The bacterial cell envelope…

Introduction: Bacteria create an enormous domain of prokaryote microorganisms that are diverse and abundant in most habitats on Earth. In fact, bacterial cells drastically outnumber somatic cells just on the external part of the human body compared to somatic cells within the whole body of a single individual. Bacteria are found just about anywhere on earth and are usually alongside other microorganisms including: mold spores or yeast cells, creating some difficulty when trying to distinguish…

bacterium was also plated on a MAC plate, which is both selective for gram-negative bacteria and differential as well. On the NA plate, bright red colonies were present; on the MAC plate there was bacterial growth as well, but no color change was observed. This lack of color change on the MAC plate indicated that the bacteria did not ferment lactose. A Gram stain was then performed to confirm that bacteria #12 was indeed gram-negative and also showed that it was rod shaped. Following the…

Type IV pili are a family of appendage protein filaments that are assembled on the surfaces of many different microorganisms, such as bacteria and archea. The wide range of diverse microorganisms within the type IV pili family indicates that there must be both a common evolutionary origin, as well as a versatile functionality (Giltner, Nguyen and Burrows 2012). The formation of type IV pili occurs when the enzyme PilD, first recognized in the bacterial species Pseudomonas aeruginosa, catalyzes…

Antibiotic creams, also known as topical ointments are preparations designed to fight bacteria on the skin. The main difference between antibiotic creams and ointments is the oil to water ratio. For instance, ointments contain an average of 80% oil and 20% water while creams contain a relatively lower oil to water ratio. This is why ointments tend to feel greasier and stickier than creams. We have chosen three antibiotic creams and three antibiotic ointments in order to find out which…

In microorganisms metal resistance character is regulated by genes which are organized in operons. Commonly, the heavy metal resistance genes are found on plasmid carried by metal resistant bacteria. In the presence of specific metals in the vicinity of bacterial niche the heavy metal resistance genes are expressed and induced. The regulation of expression of metal resistant gene is specific for each heavy metal and is dependent upon metal species concentration. The promoter and regulator genes…