MacConkey agar

the Genus theyre working with. This indicates which tests to perform next. The MacConkey agar is a selective medium that only allows the growth of gram positive bacteria confirming the results received from the gram staining procedure. The NaCl growth test indicates whether or not the organism is able to

MacConkey Agar plate Extremely similar to Eosin Methylene Blue Agar, MacConkey Agar is a selective and differential media used to isolate organisms based on their lactose fermentation ability. It contains lactose, bile salts, neutral red, and crystal violet (Leboffe, A Photographic Atlas for the Microbiology Laboratory). Just like the Eosin Y and Methylene Blue dyes in the EMB plate, the bile salts and crystal violet in the MacConkey plate encourage the growth of Gram-negative bacteria while preventing

ferment lactose, sucrose, and/or glucose and if Hydrogen Sulfide was produced by the bacteria. The TSI agar was stabbed with the pale pink bacteria and the slant was streaked. Following incubation, the slant was red in color (alkaline) and the butt yellow (acidic.) This meant that the bacteria were only able to ferment glucose. This was consistent with the initial finding from the MacConkey agar, that the bacteria were not lactose fermenters. The next step was to conduct an MIO test. After incubation

contributes to the biogeochemical cycle and without bacteria and fungi we could not continue our existence on our planet “earth. METHODS AND MATERIALS MATERIALS 1 Becker 1 Nutrient agar plate 1 pair plastic gloves 1 Potato agar plate 1 Staining tray 100ml of distilled water 2 MacConkey Agar Plates 3 Blank slides 3 plastic cups 6 pipettes 95% Grams alcohol Bibulous paper Boat & Scale Bunsen Burner & Flint Crystal-violet Grams Iodine Incubator of

local grocery store or farmer’s market, submerged in 100 ml of sterile, distilled water. (Any other food or beverage item may be substituted for alfalfa sprouts) -Graduated pipettes (sterile) -Pipettor -5 tubes containing 9 ml of sterile water -5 MacConkey Agar plates -Glass hockey stick -Jar of alcohol -Bunsen burner -Flint striker -Microscope slide & Glass coverslips Method: 1. Make a wet mount (Ex 12) of a small sample of the alfalfa water. Examine at 1000X total magnification using high contrast

Project Title: Examination of bacterial content of sea water samples from selected sites in South East England Introduction Over the past few years coastal beaches across the UK has seen lavished with recognition for their cleanliness, by sections of the media and various organisarions. Majority of these beaches have been awarded the Blue flag award in recognition for meeting set criteria on various standard including cleanliness, water quality, environmental management and environmental education

27). Microbiological Media: a) Nutrient Agar (NA) Composition of Nutrient Agar • 0.5% peptone • 0.3% beef extract/ Yeast extract • 1.5% agar • 0.5% NaCl • Distilled water pH is adjusted to neutral (7.4) at 25°C Preparation of Nutrient Agar • Suspend 28g of nutrient agar powder in 1L of distilled water. • Heat this mixture while stirring to fully dissolved all components • Autoclave the dissolved mixture 121°C for 15 minutes • Pour nutrient agar into each plate and leave plates on the sterile

Nutrient Agar To observe the colony morphology, the original unknown culture was streaked for isolation on nutrient agar using the quadrant streaking technique, inverted, and incubated at 37° C for 48 hours. This allowed for observation of the colony morphology. Separation of Gram-positive and Gram-negative The original unknown culture was streaked for isolation on Columbia CNA agar and MacConkey agar using a quadrant streak, inverted, and placed in a 37° C incubator for 48 hours. CNA agar contains

Results Observing under 1000X magnification, the gram stain depicts pink bacilli, as seen in Figure 1. Figure 2 depicts the growth of a brown bacteria on a MacConkey Agar plate. Figure 3 depicts the growth of a similarly brown bacteria surrounded by a very thin clear area on a blood agar plate. As seen in Figure 4, the slant of gram-negative isolate appears mainly clear, with a slight green tint. Figure 5 shows the methyl red test, which produced no color change. Figure 6 shows the Voges-proskauer

this lab. Find each section and complete the “Preparing for Class” sections. Preparing for class - Day 1 Read in your lab manual about the following agar mediums: Blood Agar (pg 168), EMB Agar (pg 170), Mannitol Salt Agar (MSA)(pg 172) ), MacConkey Agar (pg 174), and PEA Agar (pg 176) to answer the following: 1. What does the blood agar select for?