Cholera is caused by Vibrio cholerae which is a Gram-negative, comma-shaped bacteria.

Azotobacter vinelandii is a free-living N₂ fixer which is capable of producing numerous phytohormones and vitamins in the soil. It is diazotroph. It is used to study nitrogen fixation.

It is a rod-shaped, Gram-positive, endospore forming bacteria. It is generally employed as a soil inoculant in horticulture & agriculture.

Staphylococcus is a Gram-positive bacteria. They are arranged in form of grape-like bunches.

All these three diseases are causes by bacteria.

It is a Gram-negative bacillus bacterium species, and an obligate anaerobe of the gut.

It is a self-perpetuating lipoprotein complexe. It is present in form of grains, rods, or threads in the cytoplasm of most cells. It is supposed to function in cellular metabolism and secretion. So, it is the site of respiration in aerobic bacteria.

These are the bacteria with a single flagellum at each end.

Salmonella is a rod-shaped, Gram -ve non spore-forming, absolutely motile enterobacteria. Fresh meat is putrefied by salmonella. It enters the human body through the digestive tract and must be ingested in large numbers to cause disease in healthy adults.

acetobutylicum is better famed as Weizmann organism. It was first used by Chaim Weizmann to develop acetone and biobutanol from starch.

Nitrogen fixation is the natural process, in which the atmospheric nitrogen (N₂) is converted into ammonia. Rhizobium is a soil bacteria which has the capacity to fix atmospheric nitrogen.

These bacteria can produce organic compounds from inorganic raw materials by using energy generated from the oxidation of inorganic substances.

Leghemoglobin is a red coloured pigment produced by certain leguminous plants in response to the roots being infected by certain nitrogen-fixing bacteria known as rhizobium, as part of the symbiotic interaction between plant and bacterium. It acts as a nitrogen or oxygen carrier.

Streptomyces olivaceus are Gram positive bacteria with high GC content and are characterised by a complex secondary metabolism. They produce over two-thirds of the clinically useful antibiotics of natural origin. Cyanocobalamin is synthesised by utilising Streptomyces olivaceus.

These are a group of coccoid or rod shaped bacteria much smaller than other classical bacteria. They are non-motile and reproduce by fission. Most of them are obligate parasites. Some familiar examples are Rickettsia prowazeki which causes typhus fever.

Agamogenesis is the process of reproduction which does not include the fusion of gametes. It is the primary form of asexual reproduction in bacteria.

Most filamentous cyanobacteria develop piercing dormant structures in adverse condition. These structures are larger than the vegetative cells, equipped with thick walls, and are called akinetes. When favourable conditions return, they germinate and produce new filaments.

These bacteria are found in the alimentary canal of human beings. They keep a check on the growth of harmful putrefying bacteria in the gut of the human beings. They also release vitamins K and B₁₂ which are necessary for blood components. In return human host provides shelter and food for these bacteria. So, they are symbiotic bacteria.

Listeria is a gram-positive bacteria. It causes listeriosis which affects primarily pregnant women, newborns, adults with crippled immune systems.

These are intensely minute hair-like structures present mainly in male cells. They are consisted of protein subunits called pili. They participate in the formation of conjugation tube. They are therefore called sex pili.

It is found as a commensal on human skin, but has also been involved in infections of the bloodstream, urinary tract, bones and joints.

Corynebacterium granulosum is a bacterium which provokes the immune system to fight against cancer.

Selman Waksman was an American biochemist and microbiologist .He discovered about twenty antibiotics & also coined the same.

It is an anaerobic, motile, gram-positive bacterium. It plays significant role in the fermentation process for second generation biofuels.

It is a facultatively aerobic, Gram +ve coccus-shaped bacteria. It is commonly found in the human oral cavity. It causes tooth decay in humans.