Bacteria Definition and Types of Bacteria

The bacteria comes from the word "bakterion" (Greek) which means stick or rod. The term is now widely used bacteria for each single-celled microbes. The bacteria was first discovered by a Dutch scientist named Anthony van Leewenhoek. Leeuwenhoek then publishes a variety of bacterial shapes picture in 1684. Since then, the study of the bacteria began to thrive.
The study of bacteria is called bacteriology.
Bacteria are organisms that are the most numerous and widespread to other living things. Have hundreds of thousands of species of bacteria that live in the desert sand, snow or ice, to ocean.

Understanding Bacteria

For humans, there are beneficial bacteria and no adverse. Bacteria have characteristics that distinguish it from other living beings. Bacteria are unicellular organisms, prokaryotic, and generally do not have chlorophyll. Bacterial body size varies, from a diameter of 0.12 microns to hundreds of microns in length. Bacteria can be viewed using light microscopy and electron microscopy. Most bacterial organism is Mycroplasma size of 0.12 microns. Conversely biggest bacterium is Thiomargarita measuring 200 microns. Basic forms of bacteria varied, ie cocci (round), bacilli (rods) and spirilia (spiral). The types of bacteria are distinguished based on how to obtain food and how to obtain oxygen.
By way of obtaining food, the kinds of bacteria in question is :

Bacteria Heterotroph.
Heterotrophic bacteria are bacteria that food in the form of organic compounds from other organisms. Heterotrophic bacteria are divided into saprophytic bacteria and bacterial parasite.

Autotrophs Bacteria.
autotrophic bacteria are bacteria that can make its own food. Bacteria autotrof divided into two groups based on the origin of energy to synthesize food, namely bacterial fotoautotrof and kemoautotrof. Based on how to obtain oxygen, the types of bacteria are divided into :

Aerobic Bacteria
Aerobic bacteria are bacteria which require free oxygen to obtain energy. Examples of aerobic bacteria is Nitrosomonas, Nitrosococcus, and Nitrobacter.

Anaerobic Bacteria
anaerobic bacteria are bacteria that do not require free oxygen to obtain energy. Energy derived from the reform process of organic compounds without using oxygen is called fermentation. anaerobic bacteria can be divided into 2, obligate anaerobic and facultative unaerobic.

Bacteria cell on diagram:
-

-

-

-

-

So the description of Bacteria Definition and types of bacteria, may be useful.