Micro organisms Micro-organisms • Study of organisms too • Study of organisms too small to be clearly seen by the unaided eye (i.e., micro- organisms) • Size < ~1 mm (microscopic organisms) • Mainly single-celled organisms • Lack organs and true tissue • Some multi-celled organisms have primitive tissues V ht • Very heterogeneous group
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1 Micro-Organisms Morphology.ppt [Read-Only]Micro-organisms • Study of organisms tooStudy of organisms too small to be clearly seen by the unaided eye (i.e., micro-organisms) •
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Micro organismsMicro-organisms
• Study of organisms too• Study of organisms too small to be clearly seen by the unaided eye (i.e., micro-organisms)
• Size < ~1 mm (microscopic organisms)
• Mainly single-celled organisms
• Lack organs and true tissue
• Some multi-celled organisms have primitive tissues
V h t• Very heterogeneous group
Micro organismsMicro-organismsCan be divided into:
Procaryotes (lack a true membrane-delimited nucleus)
1. archaea or archaeobacteria2. bacteria or eubacteria
--------------------------------Eucaryotes (have a membrane-enclosed nucleus, are more complex morphologically and aremorphologically and are usually larger than procaryotic cells)
3 algae Eukaryotes have organelles!3. algae4. fungi5. protozoa
--------------------------------
6. viruses (obligate parasites)
Examples of the importance of micro-organisms
• The oldest and most common form of• The oldest and most common form of life
• Mineralization (biogeochemical c cles bioremediation compostingcycles, bioremediation, composting, water purification, etc.)
• Useful to macro-organisms (nitrogen fi i i i bi i lfixation, nutrition, symbiosis, normal flora, photosynthesis etc.)
Bacilli or rods:Bacilli or rods:Cylindrical shape, diam 1 µm, length 2-5 µm
Escherichia coli Bacillus subtilis
Vibrions: a twisted bacillusVibrions: a twisted bacillus
Spirillaspiral bacilli with flagellae, 6-15 µm long
Spirochetspiral bacilli with an axial filament
Micelle-forming bacteriaMicelle-forming bacteria
The genus Streptomyces includes about 500 species.Constitutes 1-20% of the cultivable earth flora.Forms geosmin or earth smell and a large number of antibioticsForms geosmin, or earth smell, and a large number of antibiotics.