Bacteria’s Basic Function

In spite of their tiny size, bacteria function as the planets second biggest agent for the decomposition of organic material. Fungus is the primary decomposers since they are able to handle tougher, complex ligdin fibers. But without bacteria, the world would be choked in waste materials. Using carbon (carbohydrates) as an energy source, bacteria break down plant materials in an effort to ingest nitrogen and other nutrients. Nutrients will be then kept fixed but “immobilized” within the bacteria’s body. Their consumed nutrients will be discharged and “mineralized” only once the bacteria is eaten or simply dies.

What is a Bacteria

The term/name bacteria was used for all prokaryotic (no membrane-enclosed nucleus) microbes. However now, there are 2 groups of prokaryotes. Things change as we develop our understanding of life. The size and lack of a nucleus in the new classification, both types possess. But everything else about them is different. The updated classification divides bacteria into these two groups:

  • Bacteria; (also known as Eubacteria)
  • Archaea; (also known as Archaebacteria)

The Archaebacteria are very different from the true bacteria. Eubacteria.  These two microbes had a different evolutionary history since life began here on Earth. Archaea bacteria are thought to be the fountain of all higher life forms on the planet.

Bacteria The First Life Form

The Bacteria evolved some 3 billion years ago. Nature considers them the basic building block of all life. It could be said that all life component parts, including you and me, are made up of bacteria. When more complex living “things” began to evolve, they where composed, like building blocks, of different forms, shapes and parts of bacteria. Before DNA sequencing, bacteria were grouped based on shape alone. The old classification included  coccus (oval), bacillus (rods), and spiral (cork-screw). Now they are classified in 5 major clades: Proteobacteria, Chlamydias, Spirochetes, Gram-positive Bacteria, Cyanobacteria.

Classification of Bacteria (Eubacteria)

Classification is done by their different traits:

  • shape
    • bacilli: rod-shaped
    • cocci: spherical
    • spirilla: curved walls
  • spore formation or not
  • different ways of energy production… glycolysis for anaerobes, cellular respiration for aerobes
  • Gram stain ( the ability to hold certain dies)

The Gram stain is named after Hans Christian Joachim Gram ( 1853-1938) who developed it.

  • cells are stained with a purple dye called crystal violet.
  • preparation is treated with alcohol or acetone.
  • crystal violet washes the stain out of gram-negative cells.
  • To see them now requires the use of a counter-stain of a different color.
  • Bacteria that are not decolorized by the alcohol/acetone wash are gram-positive.

Although the Gram stain technique could be viewed as an arbitrary trait for bacterial taxonomy, in fact, it does distinguish between two entirely different types of bacterial cell walls which is a natural division among the bacteria.

Of special interest to us is the endophytic bacterium. An endophyte bacteria (or fungus) is an endosymbiont that lives within a plant for at least part of its life without causing apparent disease. Rhyzobium Bacteria and Gluconacetobacter diazotrophicus are two very good examples of beneficial endophytic bacterium.

Bacteria Reproduction

Bacterias reproduce extremely fast by single cell division. One single bacteria can reproduce itself 5 billion fold in a half day if supplied with sufficient warmth, water, sugars and nutrients. They seldom die-off of old age. Bacterias typically are ingested by another microorganism or wiped out by environmental shifts. Once dead they are eaten by another microorganism, decomposing them to release their nutrients, the most important one being nitrates.

Today, bacteria are classified in the kingdom Procaryotae. This term refers to the fact that bacteria consist of prokaryotic cells. This is a class of cells that do not contain a nucleus. It free floats in his cytoplasm. The nucleus is the first thing to divide during cell division.

Bacterial Environmental Needs

The environmental need for fast reproduction and life of a bacteria is moisture. Water is the medium for mobility, the up take of nutrients and the release of waste. Moisture is also needed for bacteria to move about and to transport enzymes they use to break down organic matter. We all know our compost pile sits there dormant until it is watered. Whenever soils or compost come to be too dry, the bacteria go dormant, but normally do not die.