Biogas, is defined as the mixture of gas produced by the anaerobic breakdown of biomass with the help of methanogenic bacteria. The biogas is made up of methane (50-70%), carbon dioxide (30-40%) with traces of nitrogen, hydrogen sulphide, and hydrogen. It is also called gobar gas. This gas can be produced by waste material coming from agriculture fields, and manure, municipal waste.

Name two bacteria which are used as biofertilizer.

Biofertilizers are microorganisms that bring about nutrient enrichment of soil by enhancing the availability of nutrients to crops. The major sources of biofertilizers are bacteria, fungi, and blue-green algae (cyanobacteria). Bacteria have the ability to fix atmospheric nitrogen into organic compounds and help to increase the fertility of the soil and therefore act as a fertilizer. It is called biological nitrogen fixation. Examples: Clostridium, Azotobacter , etc., are free-living nitrogen fixers and Rhizobium is a symbiotic nitrogen fixer.

Which microbes is used for commercial production of lactic acid.

For commercial production of lactic acid, Lactobacillus or Lactic acid bacteria (LAB) is used. It is produced commercially by bacterial fermentation of carbohydrates mainly sugar or starch or by chemical synthesis from acetaldehyde. These bacteria convert milk into curd.

Fermentors are metallic containers used for growing organisms (yeast, bacteria or animal cells) under controlled conditions. It is also called bioreactors. It is the system that supports the growth of cells, tissues or organisms and is used in industrial processes to produce vaccines, alcohol or antibodies.

Name the two disease which are treated by antibiotics.

Antibiotics are the types of antimicrobial drugs used in the treatment and prevention of bacterial infections such as cholera, leprosy, etc. They either kill or inhibit the growth of bacteria by damaging mainly their cell wall. Antibiotics are not effective against the diseases such as AIDS, mumps, the common cold or influenza, etc., that are caused by viruses.

Name the fungus which produce Penicillin.

Penicillin was the first antibiotic to be discovered by Alexander Fleming (1928) from Penicillium notatum . Antibiotics are chemical substances produced by some microorganisms which can kill or retard the growth of harmful bacteria. For commercial production of penicillin, Penicillium chrysogenum and Penicillium notatum are used.