Biotechnology and its Applications Test - 11

During bio-gas formation, digestion of cellulose is slow (rate-limiting) and most of the lignin is not decomposed. After cellulose lignin is the most abundant plant polymer. It forms 20 to 30% of the wood of the tree, lignin is a complex polymeric molecule, made up of phenyl propanoid units. Cellulose is a large chained polymer of glucose molecules which are linked with each other by glycosidic bonds. Hemicellulose are branched polymers of glucose, xylose, galactose, mannose and arabinose.

The term 'antibiotics' was first time used by SA Waksman in 1945. Antibiotics are the substances which are produced by microorganisms such as fungi or bacteria. These substances are harmful to the growth of other microorganisms, example of some of the antibiotics are penicillin, streptomycin, chloramphenicol, etc.

According to union petroleum minister, 5% of alcohol (ethanol) will be mixed in petrol for meeting energy needs.

Biogas is an econimically friendly and clean renewable energy source. The gas can be utilized to meet several energy services, such as lighting and space heating, generation of electricity, and fuel for cooking. "Biogas is produced under anaerobic conditions; the process is denominated as anaerobic digestion. The major constituent of biogas is methane (55-70%), CO2 (30-45%) and some traces of gases such as H2S and ammonia. Common digester feedstock (feeding material) is cow, buffalo, and pig manure".

Anabaena is a free-living nitrogen fixing cyanobacterium which can form symbiotic association with water fern Azolla. The alga Tolypothrix belongs to class-Cyanophyceae. Some forms of Chlorella form symbiotic association in lichens and in certain invertebrates such as Hydra, Paramecium and sponges. Some species of Nostoc have been reported to fix atmospheric nitrogen and tend to maintain fertility of paddy fields.

Bacillus thuringiensis strains have been used for designing bio insecticidal plants. A gene from this bacteria have insecticidal property which is transferred to cotton plants to produce Bt cotton which is resistant I to bollworm insect which is a major pest of cotton. Similarly insects affecting maize; cabbage, Sunflower etc., are also controlled by mutant strains of Bacillus thuringiensis bacteria.

Transgenic Brassica napus seeds are being used to produce the anticoagulant hirudin. Bt in "Bt Cotton'' stands for Bacillus thurengiensis. This is naturally occurring soil bacterium. Somatic hybridization involves fusion of protoplast of two cells. "Flavr savr" is genetically engineered tomatoes which express delayed softening by insertion of an additional copy of PG endociding gene. PG is poly galacturonase enzyme which is responsible for the breakdown of cell wall pectin.

They are actually the insect-resistant transgenic type of plants that contain the gene from the thuringiensis. 

This helps in the production of a protein which can help in the process of crystalline which can be inclusive in the strains of bacteria.

In 1983 an American company Eli Lily produced the first genetically engineered insulin by first synthesizing two DNA sequences corresponding to A and B insulin chains. The two DNA sequences or genes were made to fuse with plasmids of Escherichia coli and later allowed to form Insulin chains. Rhizobium is a Gram negative, aerobic, motile, non-spore forming symbiotic nitrogen-fixing bacterium. It can fix nitrogen only when they are present inside the root nodules. Mycobacterium tuberculosis causes tuberculosis in man. It is an acute bacterial infection of the lungs, lymph and meninges.

Saccharomyces cerevisiae is known as Baker’s yeast and Saccharomyces ellipsoidens is wine yeast and these are used in baking and brewing industry respectively.

Modern detergents contain enzymes preparation of alkaliphiles. Detergents represent the largest industrial application of enzymes amounting to 25-30% of  total sales of enzymes. 

The enzymes used be detergents must be cost effective, safe to use and be able to perform the task in the presence of anionic and non-ionic detergents, soaps, oxidants, etc at pH between 8-10.5%. The chief enzymes used are proteases, α-amylase and sometimes cellulase.