Types of Bacteria

There are different types of bacteria that can be divided into harmful bacteria and helpful bacteria. Some helpful bacteria are as follows;

Fermentation is necessary to taste cheese or yogurt. Helpful bacteria like brevibacterium give carbon dioxide during the process of fermentation. Helpful bacteria are responsible for the complexity and acidity in beer.

Pseudomonas Syringae is a type of bacterium found in leaves and grass and produces protein for frost formation. Now the protein from this type of bacterium is sold in a brand name to enhance the formation of snow.

Caulobacter Crescentus is another helpful bacterium which has long sticky sugar molecules. They are better than glues and therefore natural and non toxic adhesive are made from these bacteria.

There are billion types of bacteria around us. Most of them are helpful bacteria and they are very important for our survival. Yet there are some few harmful bacteria that cause diseases.

Harmful types of bacteria are as follows;
Streptococcus bacteria are one of the harmful bacteria that may cause disease in human and animals particularly mammals. They cause some small infections like strep throat and some dreadful diseases like pneumonia. Some harmful streptococci may even cause death. These bacteria are highly contagious and can spread easily through air.

Group A and B bacteria are more harmful streptococcus bacteria than any other bacteria strain. They may cause scarlet fever, rheumatic fever etc. They may also cause problems in female reproductive system. However they are controllable through vaccines and antibiotics.

Yet there are some harmful bacteria ha may cause gum bleeding and other teeth problems. As they progress rapidly, steps must be taken to prevent them in the early stage itself. However there are some harmful bacteria that are highly resistant to drugs.

Bacteria can be classified into 3 types based on the shape. The rod shaped bacteria, Sphere shaped bacteria and Spiral bacteria are the three types of bacteria. There are some bacteria that are in different shapes and so it is difficult to classify tem according to shape.

Some bacteria require oxygen for their survival while others do not. On the basis of oxygen requirement they are classified as aerobic and anaerobic bacteria.


On the basis of Gram staining method bacteria are classified into two types. They are Gram positive bacteria and Gram negative bacteria. Bacteria are also classified according to their growth and reproduction. Such classification includes Autotrophic bacteria and heterotrophic bacteria. Autotrophic bacteria take the required carbon from carbon dioxide by itself. Some types of autotrophs will use sunlight to transform carbon dioxide to sugar. While heterotrophic bacteria will take sugar or carbon from the environment they live.

Scientists have classified various types of bacteria according to the phyla. Each phylum then again corresponds to various species of bacteria. The bacteria can be classified according o the environment they live also. Sweet water bacteria, ocean water bacteria are some of the types of bacteria classified according to their environment. Some types of bacteria can survive in extremely hot or cold temperature.