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Eubacteria can be spherical (cocci), spiral (spirilla), tightly coiled (spirochaetes) or rod-shaped (bacilli) and 0.5 to 5 micrometers long.
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Eubacteria can be found as individual cells or in the large colonies shaped like tight coils, grape-like clusters, filaments and thin biofilms.
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Some Eubacteria are equipped with cilia and flagella which are used for movement.
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Eubacteria do not have nucleus and cell organelles. They have single circular DNA and numerous plasmids (small circular pieces of DNA) in cytoplasm and cell wall made of chains of peptidoglycan. Additional layer of lipids and sugar around the cell wall can be found in Gram negative bacteria (term "negative" refers to their inability to absorb Gram stain that is used for dyeing of bacteria). This type of bacteria is harmful for humans and animals due to potent toxin (endotoxin) incorporated in the lypopolysaccharide layer.
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Eubacteria can be autotrophic (able to produce food on their own) or heterotrophic (they consume organic compounds produced by other organisms).
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Some Eubacteria metabolize ("digest") remains of plants and animals and release valuable nutrients into the ground.
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Nitrogen-fixing Eubacteria absorb atmospheric nitrogen and convert it into nitrates, plant-friendly form of nitrogen.
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Eubacteria are used in the manufacture of cheese, curd, yogurt, soy sauce, vinegar and wine and for pickling.
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Eubacteria in the human guts play important role in digestion of food and synthesis of vitamin K. They also protect human body from harmful bacteria.
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Some Eubacteria can induce serious diseases such as tuberculosis, meningitis, anthrax, leprosy, cholera and tetanus.
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Antibiotics disrupt normal functioning of bacterial ribosomes or synthesis of the cell wall and prevent further multiplication of bacteria in the body.
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Most species of Eubacteria can survive either in aerobic or anaerobic conditions, while some species tolerate atmosphere both with and without oxygen.
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Eubacteria reproduce asexually, via binary fission (separation of daughter and mother cells via cell wall). They exchange DNA material via hair-like projection called pili (in a process called conjugation), absorb DNA from their environment (in a process called transformation) and alter existing DNA by incorporating bacteriophage into the chromosome (in a process called transduction).
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Under optimal conditions Eubacteria can produce 4 generations in 20 minutes.
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Some Eubacteria form endospores under unfavorable environmental conditions. Endospores can last millions of years (until conditions improve).
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