Bacteria Revision PDF

Bacteria  mmmmres of bacteria staininggram : Small...

Bacteria  mmmmres of bacteria staininggram : Small celled positive and gram negative batraise · , single microorganisms. prokaryotic irregular placed single circular DNA chromosome : ,. Gram positive Thick peptidogly can = cell wall retains , crystal No membrane bound organelles. violet stain. (Streptococcus mutans ) Basic functions ; procreate/reproduce) , metabolise. Gram negative = Thin peptidogly can layer with thick lipopolysaccharide layer , doesn't retain crystal violet, appearing pink (porphyromonas gingivalis) (Endotoxins). · Mizearrangement tor periodontal disease + cares a mmmonmental ~ requirements : moisture : required for metabolic processes. most thrive in moist environments , though some can survive in · dry conditions by forming spores. Oxygen a) Anaerobes : - do not need oxygen may , even harm it. settle at bottom where oxygen is lowest. · (Porphyromonas gingivalis). b Aerobes - require oxygen for survival found near surface where oxygen is highest. , ) microderophiles - grow optimally in lower oxygen environments but still requires some 6) facultative anaerobes > adapts and lives within range of different oxygen levels. (Streptococcus mutans) - carbon dioxide capnophiles need increased co2 to grow but most can grow with normal atmospheric co2 levels. : · , Temperature : 1. Psychrophiles - cold , Optimum 5-15 %.. 2 mesophiles - moderate , optimum 30-40 %.. Thermophiles 3 high optimum 60-70 % - , 4. Hyperthermophiles extremely high 90-1000. -> , PH : 1. Acidophiles z. neutrophils 3. Alkaliphiles Light : · High intensity visible light can kill bacteria , low power visible and near infrared can promote bacterial growth. Osmotic effect : 1. Halophiles -> grow and develop in high salt concentration areas. mechanical stress : Some can withstand pressure/agitation by forming biofilms or protective structures (spores/capsules)·  Classification of organisms g of bacteria · : Kingdom Procaryote Systematic classification of organisms into groups called TAXONOMY. Division Firmicutes name classically comes from last 2 ranks ; Genus and species. Subdivision Low DNA content species doesNot begin with Capital , name usually in italics. Family Streptococcaceae (e g. S salivarius.. Genus Streptococcus Species Streptococcus salivarius mmmmria With dentistry ass : · Periodontal disease : · Porphyrinomonas gingivalis (gram- anaerobic inflammation tissue destruction) , , + Aggregatibacter actinomycemcomitans (gram- facultative localised aggressive periodontitis ) · , ,. Temponema denticola (spirochete anaerobic invades and damages aggressive form). , , , caries : Streptococcus mutans (gramt facultative digests sugar to produce. , , acide stores polysaccharides , continue producing acid) Lactobacilli. (gramt facultative micro-aerophiles or acid producing thrive in sugar presence ) · , , ,.