华中农业大学：《食品微生物学》课程PPT教学课件（Food Microorganism）Chapter 3 The Prokaryotes

Chaper 3 The Prokaryotes Section 1 Bacteria Section 2 Actinomycetes Section 3 Cyanobacteria Section 4 Archaeobacteria Section 5 Other prokaryotes

Chaper 3 The Prokaryotes Section 1 Bacteria Section 2 Actinomycetes Section 3 Cyanobacteria Section 4 Archaeobacteria Section 5 Other prokaryotes

Size, Shape, and Arrangement of Bacterial Cells Most bacteria fall within a range from 0.2 to 2.0 μm in diameter and from 2 to 8μm in length. They have a few basic shapes-spherical coccus (plural, cocci, meaning berries), rod-shaped bacillus (plural, bacilli, meaning little staffs), and spiral. Cm = 10-2 meter mm = 10-3 meter μm = 10-6 meter nm = 10-9 meter Bacteria

Size, Shape, and Arrangement of Bacterial Cells Most bacteria fall within a range from 0.2 to 2.0 μm in diameter and from 2 to 8μm in length. They have a few basic shapes-spherical coccus (plural, cocci, meaning berries), rod-shaped bacillus (plural, bacilli, meaning little staffs), and spiral. Cm = 10-2 meter mm = 10-3 meter μm = 10-6 meter nm = 10-9 meter Bacteria

Representative Cell Shapes(Morphology)in Prokaryotes Coccus Budding and appendaged bacteria

The thousands of species of bacteria are differentiated by many factors, including morphology (shape), chemical composition (often detected by staining reactions), nutritional requirements, biochemical activities, and source of energy (sunlight or chemicals). How to identify an unknown bacterial species ?

The thousands of species of bacteria are differentiated by many factors, including morphology (shape), chemical composition (often detected by staining reactions), nutritional requirements, biochemical activities, and source of energy (sunlight or chemicals). How to identify an unknown bacterial species ?

Arrangement of Spherical Bacterial Cells diplococci streptococci tetracocci sarcinae staphylococci Spherical coccus

Arrangement of Spherical Bacterial Cells diplococci streptococci tetracocci sarcinae staphylococci Spherical coccus

The Micrococcaceae The family Micrococcaceae contains gram-positive cocci, 0.5-2.5 μm in diameter, that divide in more than one plane to form regular or irregular clusters of cells. All are aerobic or facultatively anaerobic. The peptidoglycan di-amino acid is L-lysine. The three most important genera are: Micrococcus Staphylococcus Streptococcus

The Micrococcaceae The family Micrococcaceae contains gram-positive cocci, 0.5-2.5 μm in diameter, that divide in more than one plane to form regular or irregular clusters of cells. All are aerobic or facultatively anaerobic. The peptidoglycan di-amino acid is L-lysine. The three most important genera are: Micrococcus Staphylococcus Streptococcus

Micrococcus – aerobic, gram-positive, catalase positive, cell arranges mainly in pairs, tetrads, or irregular clusters, nonmotile. They are often yellow, orange or red in colour

Micrococcus – aerobic, gram-positive, catalase positive, cell arranges mainly in pairs, tetrads, or irregular clusters, nonmotile. They are often yellow, orange or red in colour

Staphylococcus - facultatively anaerobic, gram￾positive, usually form irregular clusters, nonmotile, catalase positive but oxidase negative, ferment glucose anaerobically. staphylococci staphylococci

Staphylococcus - facultatively anaerobic, gram￾positive, usually form irregular clusters, nonmotile, catalase positive but oxidase negative, ferment glucose anaerobically. staphylococci staphylococci

Streptococcus - facultatively anaerobic or microaerophilic, catalase negative, gram-positive, Cell arranges in pairs or chains, usually nonmotile, A few species are anaerobic rather than facultative

Streptococcus - facultatively anaerobic or microaerophilic, catalase negative, gram-positive, Cell arranges in pairs or chains, usually nonmotile, A few species are anaerobic rather than facultative

Bacilli divide only across their short axis, so there are fewer groupings of bacilli than of cocci. Rod-shaped bacteria Diplobacilli streptobacilli Single bacillus Coccobacillus

Bacilli divide only across their short axis, so there are fewer groupings of bacilli than of cocci. Rod-shaped bacteria Diplobacilli streptobacilli Single bacillus Coccobacillus