Tag: bacteria

Bacterias like Azotobacter and Azospirillum fix atmospheric Nitrogen while free living in soil, thus enriching Nitrogen content of soil.

Azotobacter is free-living aerobic non-photosynthetic nitrogen fixing bacterium which have wide variety of metabolic abilities, they fix atmospheric nitrogen as they produce nitrogenase enzyme and convert it to ammonia. They are free living in soil and do not associate as symbionts. 

Azospirillum is a nitrogen-fixing bacterium that is commonly associated with the roots of grasses and cereals, including paddy (rice) fields.

Many micro - organisms grow water bodies and decrease their oxygen level. This is harmful to the other organisms living in those water bodies.

Thermococcus, Methanococcus, and Methanobacterium are Archaea whose histones are shorter than eukaryotic histones and are assembled in tetramers.

Amoebic dysentery is caused by Entamoeba histolytica, a protozoan parasite.  Arthritis is an inflammation of joints. It is caused by attack on immune system, injury or metabolic abnormalities. Beriberi is a disease caused by a vitamin B$ _1$ deficiency. Diphtheria is an infectious disease caused by the bacterium Corynebacterium diphtheriae. 

Cyanobacteria are also called myxobacteria. In which flagella one completely absent but the movement occurs in some genera by special gliding motion. Such movement are connected with the secretion of mucilage.

Tetanus is also called as lockjaw. It is a disease caused by bacterium Clostridium tetani. It affects the nerves that control the muscle movements. Symptoms include difficulty swallowing, difficulty breathing, muscle spasm. Polio is a contagious disease caused by a poliovirus. It attacks the nervous system. It mainly affects the small children. Filaria is a parasitic disease caused by nematode parasites of the order Filariidae. It spreads by mosquitoes and black flies. Malaria is a disease is caused by Plasmodium protozoa. It is transmitted through the bite of the Anopheles mosquito. Symptoms include fever, aches, nausea.

Sterilization by autoclaving is carried out to kill bacteria and other pathogens present in the nutrients, equipment, and materials. In bacterial/ tissue culture, glassware and nutrients are sterilized through autoclave. In this, a pressurized steam is applied with the heat of 121$^0$C for around 15–20 minutes to kill bacteria, spores, and other pathogens.

Crown gall disease is a plant disease that is caused by the bacterium Agrobacterium tumefaciens. It results in the overgrowth appearing as knobbly swellings or galls on stems, roots, trunks, and branches. It affects mostly woody shrubs and herbaceous plants like grapes, raspberries, blackberries, and roses.