bacteria

tiny, single-celled microorganisms found everywhere, they can either be helpful or harmful and cause diseases

• temperature • PH level • presence / absence of oxygen • adequate nutrients

• helps control and prevent infections • manage sterilisation • reduce harmful bacteria

• controlling bacteria growth • preventing disease outbreak • protecting food supplies • reducing risk of infection

• safe food storage, preservation and preparation

• research • vaccine production • antibiotic testing

• lag phase • log (exponential) phase • stationary phase • death phase

bacteria that require oxygen for survival and reproduction. they use oxygen for aerobic respiration - this produces ATP for the cell

• can’t survive in the presence of oxygen as its toxic to them due to lacking the enzymes to break down harmful oxygen by-products. • rely on anaerobic respiration or fermentation to generate energy.

• can survive and grow both with or without oxygen • prefer aerobic respiration but can do that or anaerobic respiration / fermentation too

• culturing bacteria • preventing infections • choosing the right antibiotic

• too cold = slows enzyme activity so bacteria grow slowly or stop growing • too hot = enzymes and proteins might break down so the bacteria may die. • 37° is optimal

• 6.5 - 7.5 usually optimal • if environment is wrong ph bacterial enzymes can be damaged or growth can be slowed down or stopped some types are adapted to specific levels

• need nutrients to build cells, make energy and reproduce • without enough carbon, nitrogen, minerals or vitamins they cant grow / multiply if there is limited nutrients growth can be slowed or there may be early entry into stationary or death phase

circular, irregular or have filamentous (thread like) edges

smooth, rough or jellylike

a polysaccharide, often derived from red seaweed. its used as a solidifying agent in growing microorganisms. it form a gel like matrix that supports the growth of microorganisms by providing nutrients

agars that contain substances that inhibit unwanted bacteria and allow only specific types to grow. This helps focus on bacteria of interest and reduces contamination.​

agars that include indicators that cause visible changes based on bacterial metabolism or activity. helps identify bacteria by distinguishing their characteristics.

provides a stable, non-digestible matrix for microbes to colonize and grow.

added to nutrient broth, agar itself isn’t a nutrient but it holds other nutrients

• growth or no growth • colour • changes in media colour • patterns in blood agar • colony shape or size

MacConkey Agar Mannitol Salt Agar Blood Agar Eosin Methylene Blue (EMB) agar