Tag: useful and harmful bacteria

Escherichia coli  is a Gram-negative bacteria. It plays an important role in the field of biotechnology, where it has served as a host organism in recombinant DNA technology. The bacterium can be grown and cultured easily. One of the first useful application of recombinant technology was the manipulation of E.coli to produce human insulin.
Rhizobium meliloti is a Gram-negative, nitrogen-fixing bacterium. It is a symbiotic bacteria lives in the association with legumes. The bacteria possesses nif genes, responsible for the nitrogen fixation.
Bacillus thuringensis is a soil dwelling bacteria. It has been used as a biological pesticide. During spore formation, the bacteria produces crystal proteins called as endotoxins which have insecticidal action.
Crude oil is a complex mixture of hydrocarbons. Several strains of bacterium Pseudomonas putida were known to produce enzymes that degrade these hydrocarbons, i.e., the bacteria ate the hydrocarbons, nourishing themselves and reproducing.

Rickettsial or viral vaccines are produced by cultivating microorganisms in living tissues of animal bodies, such as chick embryos. It is possible in some cases to reduce these effects by harvesting only proteins of the infected tissues. E.g., allantoic fluid of chick embryo. These viruses can be killed or inactivated with formaldehyde, phenol etc. 

Bacteria like E. coli have very short generation times. Combined with the high copy number of plasmid they produce, they duplicate the plasmid with pretty good fidelity for other uses. Agrobacterium tumefaciens is capable of transferring a particular DNA segment of the tumour-inducing (Ti) plasmid into the nucleus of infected cells where it is subsequently integrated into the host genome. 

• pBR322 is a widely-used E. coli cloning plasmid vector. 
• It was created in 1977 in the laboratory of Herbert Boyer at the University of California San Francisco. The p stands for " plasmid " and BR for "Bolivar " and " Rodriguez ", researchers who constructed it. 
• By using  pBR322 plasmid of E.coli Insulin, interferons and somatostatin can be synthesized through the genetic engineering procedure.
• So, the correct answer is 'Escherichia coli'.

The genus Pseudomonas are adapted to very different environments. This capability to thrive in various habitats coincides with an enormous metabolic capacity of this genus to use recalcitrant compounds as carbon source as well as to produce a wide range of secondary metabolites and biopolymers. Environmental applications of various Pseudomonas species in biodegradation of recalcitrant pollutants as well as biocontrol agents in plant growth promotion is very common.

Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are classified as Archaea, a domain distinct from bacteria. They are common in wetlands, where they are responsible for marsh gas. Cyanobacteria are often called as blue-green algae. Cyanobacteria are a photosynthetic nitrogen fixing group that survive in wide variety of habitats, soils, and water. Mycoplasma refers to a genus of bacteria that lack a cell wall. Mycoplasma can survive without oxygen.

AIDS (Acquired Immunity Deficiency Syndrome) is a sexually transmitted disease. It is caused by HIV virus. Syphilis is a serious disease caused by spirochete Treponema pallidum. It is also a sexually transmitted disease. Gonorrhoea is a sexually transmitted infection caused by bacteria Neisseria gonorrhoeae. Urethritis is inflammation of the urethra. It is caused by bacterial infection caused by Neisseria gonorrhoeae or Chlamydia trachomatis.

Anthrax is a bacterial disease caused by the bacterium Bacillus anthracis. It can occur in four forms: skin, lungs, intestinal, and injection. It commonly affects grazing animals like sheep, pigs, cattle, horses, goats. However, it rarely affects humans as well. Tick fever is a disease spread by the bite of an infected tick. It is caused by spirochete species like Borelliahermsii, Borelliaparkerii. Symptoms include fever, headache, muscles pains, rash. Coccidiosis is a disease of the intestinal tract of animals caused by coccidian protozoa. Symptoms include droopiness, loss of appetite, pale combs and wattles, blood or mucus in the feces, diarrhea, dehydration. Rinderpest is a disease of cattle caused by a paramyxovirus. Symptoms include fever, dysentery, inflammation of the mucous membranes.

a) Treponema pallidum is a spirochaete bacterium that causes syphilis. Syphilis is a sexually transmitted disease.