| Bacterial Type | Characteristics |
|---|---|
| Acetic acid bacteria | Mostly rod-shaped, gram-negative, aerobic; highly tolerant of acidic conditions; generate organic acids |
| Actinomycete (mostly) | Rod-shaped or filamentous, GRAM-POSITIVE, aerobic; common in soils; essential to growth of many plants; source of much of original antibiotic production in pharmaceutical industry |
| Coccoid (mostly) | Spherical, sometimes in clusters or strings, GRAM-POSITIVE, aerobic and anaerobic; resistant to drying and high-salt conditions; Staphylococcus species common on human skin, certain strains associated with toxic shock syndrome |
| Coryneform | Rod-shaped, form club or V shapes, GRAM-POSITIVE,aerobic; found in wide variety of habitats, particularly soils; highly resistant to drying; include Arthrobacter, among most common forms of life on earth |
| Endospore-forming (mostly) | Usually rod-shaped, can be GRAM-POSITIVE or gram-negative; have highly adaptable, heat-resistant spores that can go dormant for long periods, possibly thousands of years; include CLOSTRIDIUM and BACILLUS |
| Enteric(mostly) | Rod-shaped, gram-negative, aerobic but can live in certain anaerobic conditions; produce nitrite from nitrate, acids from glucose; include Escherichia coli,Salmonella (over 1000 types), and Shigella |
| Gliding(mostly) | Rod-shaped, gram-negative, mostly aerobic; glide on secreted slimy substances; form colonies, frequently with complex fruiting structures |
| LACTIC ACID (mostly) | Rod-shaped or cocci, GRAM-POSITIVE, facultative anaerobic or microaerophilic; produce lactic acid through fermentation; include: LACTOBACILLUS, essential in dairy product formation, and STREPTOCOCCUS (common in humans), BIFIDOBACTERIA ; Catalase negative |
| Mycobacterium | Pleomorphic, spherical or rod-shaped, frequently branching, no gram stain, aerobic; commonly form yellow pigments; include Mycobacterium tuberculosis, cause of tuberculosis |
| Mycoplasma | Spherical, commonly forming branching chains, no gram stain, aerobic but can live in certain anaerobic conditions; without cell walls yet structurally resistant to lysis; among smallest of bacteria; named for superficial resemblance to fungal hyphae (myco- means 'fungus') |
| Nitrogen-fixing | Rod-shaped, gram-negative, aerobic; convert atmospheric nitrogen gas to ammonium in soil; include Azotobacter, a common genus |
| Propionic acid | Rod-shaped, pleomorphic, GRAM-POSITIVE,anaerobic; ferment lactic acid; fermentation produces holes in Swiss cheese from the production of carbon dioxide |
| Pseudomonad | Rod-shaped (straight or curved) with polar flagella, gram-negative, aerobic; can use up to 100 different compounds for carbon and energy |
| Rickettsia | Spherical or rod-shaped, gram-negative, aerobic; cause Rocky Mountain spotted fever and typhus; closely related to Agrobacterium, a common gall-causing plant bacterium |
| Sheathed | Filamentous, gram-negative,aerobic; 'swarmer' (colonizing) cells form and break out of a sheath; sometimes coated with metals from environment |
| Spirillum(mostly) | Spiral-shaped, gram-negative,aerobic; include Bdellovibrio, predatory on other bacteria |
| Spirochete(mostly) | Spiral-shaped, gram-negative,mostly anaerobic; common in moist environments, from mammalian gums to coastal mudflats; complex internal structures convey rapid movement; include Treponemapallidum (cause of syphilis) |
|
Sulfate- and Sulfur-reducing |
Commonly rod-shaped, mostly gram-negative, anaerobic; include Desulfovibrio, ecologically important in marshes |
|
Sulfur- and iron-oxidizing |
Commonly rod-shaped, frequently with polar flagella, gram-negative,mostly anaerobic; most live in neutral (nonacidic) environment |
| Vibrio(mostly) | Rod- or comma-shaped, gram-negative,aerobic; commonly with a single flagellum; include Vibrio cholerae (cause of cholera), and luminescent forms symbiotic with deep-water fishes and squids |
Reference: Bacteria.Dr. Sayeed Ahmad D. I. Hom. (London)
Taber's Online Medical Dictionary
http://www.scienceclarified.com/As-Bi/Bacteria.html#ixzz2JqhuVa1t
