Difference between Eubacteria and cyanobacteria
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Eubacteria vs cyanobacteria
Bacteria are the greatest kingdom amongst micro organisms. Eubacteria are also known as “true bacteria” and are typically microscopic unicellular prokaryotic organisms without a nucleus and without cellular organelles like mitochondria, ribosomes, etc. Cyanobacteria are blue green colored bacteria which are endowed with a nucleus but modified slightly due to their functioning. Cyanobacteria are a type of eubacteria.
Cyanobacteria are a sub group of eubacteria which obtain energy through photosynthesis. The most important and characteristic feature of this type of bacteria is that they produce oxygen as a byproduct of photosynthesis. Cyanobacteria perform photosynthesis to obtain energy for their own functions and as a result they produce oxygen. In this complicated process they convert the nitrogen from the atmospheric air into ammonia and nitrates. They effectively make these nitrogenous products available in the soil for the utilization of plants. To perform all these tasks, cyanobacteria have growth of specialized cells called as heterocysts. Heterocysts are special cells which are customized to convert nitrogen from air; even if there are scarce amounts of nitrogen, they manage to convert it into ammonia in the soil. Basically, heterocysts are nitrogen fixing cells formed by the cyanobacteria in case of scarcity of nitrogen in the air. They perform this conversion of nitrogen into ammonia in the presence of an enzyme called nitrogenase. Even the converted nitrogen is utilized by the cells of the cyanobacteria. Under regular conditions, the enzyme nitrogenase remains inactivated by the presence of oxygen in the surrounding air.
Thus, in order to have it work, cyanobacteria need to create an environment of anaerobic (lack of oxygen) conditions. Cyanobacteria create these anaerobic conditions by producing multiple cell walls that prevent oxygen from entering the bacterial cell completely. Also, they set up a mechanism by which any traces of oxygen left in the cell are used up and depleted. Thus, cyanobacteria are a farmer’s friends as they help provide vital nitrogen to the crops. Some cyanobacteria are used in the production of health supplements due to their high protein content.
Eubacteria are the commonest form of bacteria. Eubacteria kingdom is divided into five phyllums called as spirochetes, chlamydias, gram positive bacteria, cyanobacteria and proteobacteria. Technically speaking, eubacteria are bacteria which lack nucleus. Eubacteria lack mitochondrions and chloroplasts and possess a rigid cell wall made of proteoglycans. These eubacteria divide by binary fission which is simply put, division of the chromosomes into two halves. It is an asexual method of reproduction. All eubacteria are either spiral shaped, rod shaped or spherical in nature. They form spores which are resistant to dehydration and extreme temperatures and hence, make the eubacteria resistant and tough. The cell membrane is composed of bilayer phospholipids which do not contain cholesterol and steroids. They obtain their nutrition by photoautotroph, chemoautotroph, photoheterotroph or chemoheterotroph mechanisms depending upon the energy source. The source of energy may either be light, organic or inorganic chemicals. Eubacteria are extremely useful in the industries as they are used in the production of certain medical drugs, wine, cheese and even dairy products. Certain eubacteria are also used at waste water plants to treat and cleanse water.
Summary: Eubacteria as well as cyanobacteria are extremely important for their industrial uses. Eubacteria is a larger kingdom which is further divided into five subgroups and cyanobacteria is one of the subgroups. The characteristics of the group always apply to the subgroup as well. Hence, we conclude that all cyanobacteria are a form of eubacteria, but all eubacteria are not blue-green and thus cannot be called as cyanobacteria.