BACTERIAL NOMENCLATURE & GROWTH Flashcards
CLASSIFICATION SYSTEMS
Numerical taxonomy
Phylogenetic classification
Phenotypic classification
• Compuer taxonomy
Basis: frequency of trait-sharing (phenetics)
Numerical Taxonomy
Basis: Genetic similarity and evolutionary relatedness
• Phylogenetic Classification
Basis: overall similarities (microscopic and colony morphology)
• Phenotypic Classification
group of “level” of classification
Taxon
Hierarchical system within domains:
King philip came over for good spaghetti
Kingdom
Phylum/Division
Class
Order
Family
Genus
Species
“basic unit” of taxonomy
SPECIES
represents a specific, recognized type of organism
Identified by comparison with known “type strains” (pure cultures)
Species
(ATCC)
American Type Culture Collection
• A population of microbes descended from a single individual or pure culture
• Different ___ represent genetic variability within a species
STRAIN
: Ureaplasma urealyticum
based on biochemical and physiological qualities
Biovars
: Corynebacerium diphtheria
Mitis, intermedius, and gravis
Morphology
Morphovars
: Salmonella enterica (typhi)
Serology/antigenic properties
Serovars
(Systematic name)
Scientific name
• Are italicized or underlined
• Are “latinized” and used worldwide
• May be descriptiv or honors a scientist
Scientific name (Systematic name)
In scientific name
• _____name is never abbreviated
• A_____ name may be used alone to indicate a group
• A____ name is never used alone.
Species
genus
species
a manual that aids in identification of unknownns
Bergey’s Manual of Determinative Bacteriology
Main resource for determining the identity of bacteria species, utilizing every characterizing aspect
Uses successive “key” features to narrow down identification
Bergey’s Manual of Determinative Bacteriology
PHYSICAL AND NUTRITIONAL GROWTH
REQUIREMENTS OF BACTERIA
Major Elements:
• Carbon
• Oxygen
• Nitrogen
• Hydrogen
• Phosphorus
• Sulfur
• Potassium
• Magnesium
• Calcium
• Iron
PHYSICAL AND NUTRITIONAL GROWTH
REQUIREMENTS OF BACTERIA
Trace Elements:
MangaZin CuCoMo
• Manganese
• Zinc
• Copper
• Cobalt
• Molybdenum
act as co-factors for enzymatic reactions
only small amounts
need not be added to culture media
Elements
TYPES OF ORGANISMS BASED ON PHYSIOLOGIC REQUIREMENTS
Phototroph
Chemotroph
Autotroph
Heterotroph
Energy source: Light
Phototroph
Energy source: Chemical
Chemotroph
Energy source:
Inorganic
Organic
Chemolithotrophs
Chemoorganotrophs
Carbon source: CO2
Capnophiles (Autotroph)
Carbon source: Organic compounds
Heterotroph
essential substances that the organism
is unable to synthesize from available nutrients
required in small amounts by cells
GROWTH FACTORS
Categories of Growth Factors
Purines, pyrimidines -> nucleic acid
Amino acids -> proteins
Vitamins -› coenzymes. enzymes
Fastidious
Organisms tend to require a variety of growth factors
Only aerobic growth:
oxygen required.
Growth occurs only where high concentrations of oxygen have diffused into the medium
Obligate Aerobes
Both aerobic and anaerobic growth; greater growth in presence of oxygen
Growth is best where most oxygen
is present, but occurs throughout tube
Facultative anaerobes
Only anaerobic growth; ceases in the presence of oxygen
Growth occurs only where there is no oxygen
Obligate Anaerobes
Only anaerobic growth; but
continues in presence of oxygen
Growth occurs evenly: oxygen has no eefect
Aerotolerant Anaerobes
Only aerobic growth; oxygen required in LOW concentration
Growth occurs only where a low concentration of oxygen has diffused into medium
Microaerophiles
Requires elevated conc. of carbon dioxide
Easily cultivated in a candle jar
CAPNOPHILES
3 common enzymes produced by microbes
Superoxide dismutase
Catalase
Peroxidase
Obligate aerobes, most facultative
anaerobes
(e.g. Enterics)
Superoxide dismutase
Catalase
Most aerotolerant anaerobes (e.g.
Streptococci)
Superoxide dismutase
Peroxidase
Require O2- final electron acceptor in aerobic respiration
Obligate Aerobes
Can interchange between aerobic and anaerobic type of metabolism
If O2 present = switches to aerobic
respiration
Facultative Anaerobes
Does not require oxygen - it is toxic for them
Lives by anaerobic respiration, fermentation, bacterial photosynthesis or methanogenesis
Obligate Anaerobes
Interchanges between anaerobic to aerobic type of metabolism
If under anaerobic conditions, grows by fermentation or anaerobic respiration
Facultative Aerobes