Viruses, bacteria, fungi, protozoa and some algae | Microorganisms |
Microbiological, chemical, physical, allergenic | Types of Hazards (4) |
Vet drugs, cleaning materials, food additives, pesticides | Chemical Hazard Examples |
Infectious bacteria, toxin producing organisms, spoilage bacteria, yeasts, moulds | Microbiological Hazard Examples |
Metal, glass, dead insects, hair | Physical hazards examples |
Milk, Eggs, Peanuts, Nuts (almond, brazil, pistachio, macadamia, pecan etc.), Fish, Crustaceans (Inc. prawns and lobster), Molluscs (Inc. squid, snails, mussels), Lupin, Sesame, Soya, Wheat/Gluten, Celery, Mustard, Sulphur Dioxide. | Allergens List (14) |
1µm (micrometre) = 10-3 mm | Unit of Measurement for bacteria |
Cocci (spherical), Bacilli (rod shaped), Spiral bacteria (twisted) | Three shapes of bacteria |
1 µm Spherical | Cocci bacteria |
Rod shaped, 0.5-1 µm width, 1-4 µm long | Bacilli |
Twisted shape 1-3 µm in length, 0.3-0.6 µm width | Spiral bacteria |
Can assume several shapes | Pleomorphic bacteria |
Diplococci | Cocci that remain in pairs after dividing |
Streptococci | Cocci that remain in chains after dividing |
Tetrads | Cocci that divide in two planes and remain in groups of four |
sardinae | Cocci that divide in three planes and remain in groups as a cube of 8 |
Staphylococci | Cocci that divide in multiple planes- grape like clusters |
Bacilli that appear in pairs after division | Diplobacilli |
Appear in chains after division | Streptobacilli |
Short and fat so appear like cocci | Coccobacilli |
Spiral bacteria that look like curved rods | Vibrio |
Helical shape and rigid bodies | Spirilla |
Helical shape and flexible bodies. Move by means of axial filaments (which look like flagella) | Spirochetes |
Cell wall, cell membrane, cytoplasm, nuclear material | Essential stricture of bacteria (4) |
Capsule, flagella, pili, spore | Other structures of bacteria (4) |
highly resistant, dormant structures (i.e. no metabolic activity) formed in response to adverse environmental conditions. | Spore |
is a long, whip-like structure that helps some single celled organisms move | Flagella |
is a very large structure of many bacteria.[1] It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell | Capsule |
Cell walls contain many layers of peptidoglycan and contain teichoic acids | Gram Positive bacteria |
Multiple layers found in gram positive bacteria. Single of thin layer in gram negative. | Peptidoglycan |
Only found in gram positive bacteria | Teichoic acids |
Have a lipopolysaccharide-lipoprotein-phospholipid outer membrane surrounding a thin/single peptidoglycan layer. | Gram negative bacteria |
thread like structures that make up moulds | hyphae |
Mass of hyphae | Mycelium |
Grow by extending length of hyphae (apical or intercalary growth) | Mould growth |
Mould growth, hyphae extends at the tip | Apical growth |
Mould growth, hypha extend within their length | Intercalary Growth |
Cross walls in hyphae, presence of which used in identification | Septate |
Mycotoxins and aflatoxins | Mould toxins |
Sexual spores are thick walled resting spores called zygospores | Zygomycetes |
Spores borne internally in sac called and ascus | Ascomycetes |
Spores borne externally on a club-shaped structure called a basidium | Basidiomycetes |
Have no known sexual state in their life cycle | Deuteromycetes or fungi Imperfecti |
Larger than bacteria. Oval or rod shaped. | Yeasts |
How yeast multiply (asexual reproduction) | Budding |
Making beer, wine, spirits, bread and fermented foods. Produces carbon dioxide, alcohol and/or organic acids | Yeast use in food production |
Pathogenic fungi have 2 forms. Moulds at ambient temperatures and yeasts and body temperatures. | Dimorphism |
1.Bacteria have the shortest generation time compared to yeasts and moulds. 2. Some bacteria more heat resistant than Y&M 3.Y&M can grow at low pH and low Aw and under high osmotic pressure | Differences between bacteria, yeasts and moulds (3) |
the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane | Osmotic Pressure |
Acellular, obligate intracellular parasites (need a ‘host’), no ATP generating system, no ribosomes or means of protein synthesis. | Viruses (4 points) |
DNA or RNA (never both), Capsid (coat protein). Some viruses: envelope or enzymes | Virus Structure (2 main, 2 optional) |
>50% | The Peptidoglycan layer accounts for what percentage of the dry weight of cell wall in many gram-positive bacteria. |