The only organisms in the Kingdom Monera are bacteria. They are the most prevalent
microorganisms. Bacteria are found practically everywhere. A small amount of soil contains
hundreds of bacteria. In addition, they inhabit harsh environments where few other life forms
can thrive, like deep oceans, deserts, snow, and hot springs. Many of them are parasites that
reside in or on other species.
Based on their shapes, bacteria are divided into four groups: the spherical Coccus (pl.: cocci),
the rod-shaped Bacillus (pl.: bacilli), the comma-shaped Vibrio (pl.: vibrio), and the spiral
Spirillum (pl.: spirilla).
Despite having a relatively minimal structure, bacteria exhibit highly sophisticated behaviors.
Bacteria exhibit the greatest metabolic diversity among all species when compared to many
others. Because they synthesize their nourishment from inorganic materials, some bacteria are
autotrophic.
Both chemosynthetic and photosynthetic autotrophs are possible.
The great majority of bacteria are heterotrophs, meaning they rely on dead organic matter or
other living things for sustenance.
1 Archaebacteria
They are unique because these bacteria inhabit some of the harshest environments, including
marshy places (methanogens), hot springs (thermoacidophiles), and extremely salty places
(halophiles). Archaea can survive in harsh environments because of a unique cell wall
construction that sets them apart from other bacteria. Methanogens, which are found in the guts
of many ruminant animals, including cows and buffaloes, are in charge of turning the feces of
these animals into methane as biogas.
2 Eubacteria
Eubacteria, or "real bacteria," come in thousands of varieties. They are distinguished by the
presence of a flagellum if they are motile and a hard cell wall otherwise. The cyanobacteria, also
called blue-green algae, are photosynthetic autotrophs with chlorophyll similar to that of green
plants. Cyanobacteria are either freshwater/marine, terrestrial, unicellular, colonial, or
filamentous algae. Typically, a gelatinous coating envelops the colonies.