Bacteria 102

Chapter 1


Bacteria are a group of microscopic, single-celled organisms that inhabit virtually all environments, including soil, water, organic matter, and the bodies of multicellular animals. 

Bacteria, because of their unique structure, are classified as neither plant nor animal but have their own Domain. Bacteria are generally harmless, relatively few are pathogenic, but many are beneficial and critically essential to the balance of nature. 

In an aquatic environment, the foremost group of beneficial bacteria is the nitrifying bacteria. This group of bacteria contains the Ammonia oxidizers (Nitrosomonas et. al.) and the Nitrite oxidizers (Nitrobacter et. al.). Working in tandem, these bacteria convert Ammonia, which is a highly toxic compound produced by fish respiration and organic waste decomposition, into Nitrite (also highly toxic) which is in turn converted into Nitrate, an essential nutrient for all plant life. 

Bringing up a close second in importance are the heterotrophic bacteria. Their primary role is the reduction of organic waste. They are commonly marketed as ‘sludge busters’. Although they have the ability, under certain conditions, to oxidize Ammonia, their efficiency level is minuscule compared to the true nitrifying bacteria. 

All water contains both groups of bacteria at some level. This population level is ultimately determined by the availability of the respective energy sources and the surface area available for colonization.