Microbiology

Autotrophs

• utilize inorganic source of carbon

• primary producers

Heterotrophs

• derive nutrients from other organisms

Phototrophs

• Use light as energy source via pigments

Chemotrophs

• Obtain energy from chemical compounds

Organotrophs

Acquire electrons from same organic molecules that provide them carbon and energy

Lithotrophs

Acquire electrons from inorganic substance (H2, H2S)

Chemoorganotrophs

Obtain energy from organic compounds

Extremophiles

Organisms inhabiting extreme environments

Methods of Culturing Microorganisms (Five “I” s)

• Inoculation

• Incubation

• Isolation

• Inspection

• Identification

Cell

– basic and fundamental unit of life

Mycoplasma

bacteria with no cell wall (0.1-0.5 micrometers)

Mycoplasma cell

membrane

stabilized by sterols and resistant to lysis (process of cell

destruction)

Pleomorphism

property of extreme shape variation

Mycoplasma pneumoniae

adheres lung cell causing pneumonia to humans

Protoplast

gram-positive cell wall losing itself completely from lysosome or penicillin contact

Peptidoglycan

–polymer of 2 monosaccharides subunit

▪ Fully permeable to ions, aa, and sugar

Gram Stain

– staining technique by Hans Christian Gram delineating two

major groups of bacteria

Gram-positive

o Thick layer of peptidoglycan

o Negatively charged teichoic acid on surface

o Regulate cation movement

o Polysaccharides provide antigen

Gram-negative

o Thin peptidoglycan

o Outer membrane

o Periplasmic space

o Lipid A acts as endotoxin

o O polysaccharides antigens for typing

o Less sensitive to medication

Nucleoid

nuclear region containing DNA

Plasmids

small, non-essential, and circular DNA

Ribosomes

intercellular structure made of both RNA and protein

Inclusion Bodies

granules containing nutrients, monomers, Fe compounds

(magnetosomes)

Mesosome

internal folds by cell membrane in cytoplasm

Cytoplasm or Cytoplasmic Matrix

• dense, gelatinous solution surrounded by cell membrane

• Hold internal structures of bacteria

• 70-80% of water serving as solvent to many complex mixtures of nutrients

Chemical pool

site for many biochemical and synthetic activities