1. What is a microbial colony? (/3) • A microbial colony is a group of cells that you can see with

Most micro-organisms need most of the things you and I need to flourish and grow - moisture, warmth and a source of nutrition - some (usually the most dangerous such as those responsible for some types of gangrene) can do without oxygen (anaerobic bacteria). They need a mode of spread (usually the unwashed or poorly washed hands of people or badly cleaned equipment/facilities or badly stored food) and a vulnerable person to invade.

An Aerotolerant Anaerobe- can grow in oxygen if present, but does not use oxygen. If it was in a test tube there would be equal growth throughout the broth, While a Facilitated Anaerobe uses oxygen, it can grow without it. In a test tube there would be more growth at the top of the broth that anywhere else.

This organism is positive in oxidation because bacteria use oxygen to use lactose. The lactose tube turns from red to yellow without the mineral oil on top of the solution. Negative result for oxidation is no color change without the mineral oil. Fermentation also positive because color change from red to yellow with the mineral oil on top of solution. This mean the bacteria can use lactose without oxygen.

Bacteria groups or species can be differentiated by the fermentation patterns. The end-product of carbohydrate fermentation is an acid or acid with gas production and is dependent on the organism involved in the fermentation process. The carbohydrate fermentation tests detect if an organism is able to utilize glucose, lactose and sucrose. Phenol red is used as a pH indicator because it can indicate a change in pH when acid products are formed. Bacteria can utilize certain sugars resulting in an alkaline by-product which changes the color of the carbohydrate broth from red to yellow. Bubbles trapped within the Durham tube indicate the production of gas. The Phenol red carbohydrate fermentation tests determine that my organism E. coli can utilize glucose, lactose and sometimes sucrose but can only produce gas in glucose and lactose. (Phenol red carbohydrate fermentation lab

The science of identifying these organisms based on known characteristics is termed bacterial taxonomy. Where each species is assigned to a genus which then follows a level of hierarchy using ranks (family, suborder, order, subclass, class, division/phyla,

Thus we inoculated lactose broth, glucose broth and tryptophone broth with our organism. At our final lab meeting, we observed that the lactose broth was still phenol red in color, glucose tube had turned yellow with a bubble present in Durham tube, and the oily ring in our Indole test was colorless. Taking all the results into consideration and rechecking all of our steps against the guidelines and steps to ensure all required tests had been performed, we concluded that our organism belonged to Group IX genre, Proteus, Providencia, and Morganella. We then proceed to consult with our instructor.

For this experiment we will be testing four different bacteria with four different tests, using glucose, lactose, and sucrose. Hopefully we will use the information from those test to be able to identify the organisms in each of the samples from the case studies. We will use the results from the four different tests along with the information of how different bacteria react to match up to the case scenario and identify the bacteria, then check to see if our guess was correct. The findings are that we were able to identify, by process of elimination, the four different test bacteria.

8.) Combine the results and information from the previous tests and establish the identity of the

Fermentation test are used to detect the use of substrates and sugars to identify the unknown bacteria. Hence, bacteria that ferment sugar with the production of acid or acid and gas and bacteria that do not ferment sugar can be differentiate. For example, Phenol Red fermentation broth are used to determine if the bacteria ferment sugars such as glucose, lactose, or sucrose, and phenol red is the pH indicator added to detect or trap the acid or gas. Other fermentation broths are used such as, Methyl Red- Voges Proskauer(MR-VP) broth or Voges Proskauer (VP); which determine ability oxidize glucose to pyruvic acid to strong acid( lactic, acetic, formic) and

Prokaryotes are ubiquitous, successfully adapting to diverse environments as well as developing symbiotic relationships with host organisms (Lengeler, Drews, & Schlegel, 1999). Prokaryotes may have both autotrophic and heterotrophic characteristics. A cyanobacteria is photosynthetic, commonly called blue-green algae, and may produce toxins (Crayton, 1993). Bacteria are most commonly associated in the general

In order for growth to occur microorganisms need to obtain energy. One of those ways is by either the use of oxygen or not using oxygen. Microorganisms that require oxygen are obligate aerobes. It is essential for

Amphibacillus xylanus has the capabilities to be both anaerobic and aerobic depending on the environmental setting (Niimura et al. 1990). The EI is an obligate aerobe and grown on a TSA agar plate. Amphibacillus can become aerobic when grown on a TSA plate (Niimura and Suzuki 2015). Both the EI and Amphibacillus xylanus were negative for oxidase and catalase test (Table 4). The indicating factor for this species is its habitat. The EI and A. xylanus were each isolated from the soil (Table 4). This trait sets this species apart from the rest considering the other two species were from aquatic environments. A. xylanus motility indicated a difference from the EI. The EI was shown to have no motility and A. xylanus does have motility. Depending

Escherichia is a genus of aerobic gram-negative rod-shaped bacteria of the family Enterobacteriaceae that form acid and gas on many carbohydrates, such as dextrose and lactose, but not acetone, which include occasional pathogenic forms, including some strains of E. coli which are normally present in the human intestine as well as other forms which typically occur in soil and water (Webster). Escherichia coli is a gram-negative bacilli that rarely varies in shape and size and when stained often resemble safety pins because the ends of some bacilli stain more densely than does the middle; which is a characteristic called bipolar staining which is common in enteric gram-negative bacilli (ASM). Gram negative cells have a thin cell wall layer and will stain red to pink. The staining process is the same as Gram positive, requiring four steps: applying a primary stain, adding a mordant, then rapid decolorization and completing with a counter stain. Applying the alcohol for decolorization dissolves the outer membrane and leaves small holes in the thin peptidoglycan layer through which the crystal violet-iodine diffuse. The gram-negative bacteria is colorless after the decolorization; therefore adding safranin

Determination of the bacteria being a lactose fermenter or non fermenter is done through the growth on the MacConkey agar. Knowing this allow for the student to perform the necessary tests to determine which lactose fermenter was present in the sample. The Indole test allows for the determination of whether the unknown bacteria is Escherichia coli because this genus and speices is the only lactose fermenter that will produce a positive result here. Moving onto the Methyl red test this indicates glucose fermentation, more specifically microbes that produce mixture of acids as a result of fermentation. The Voges-proskauer tests for glucose fermentation, specifically organisms whose acid is converted to acetoin. The Citrate test differentiates an organism’s ability to use citrate as its only carbon source. The urea broth culture detects the enzyme urease, which allows break down of urea producing acid, which causes a noticeable change in color. The final test is the motility test to determine if the bacteria has the capacity of movement beyond the point of

The effect of environmental factors such as temperature, osmotic pressure, oxygen concentration and pH on microbial growth and survival