Write short notes on the following.
(i) Brewer's yeast (ii) Ideonella sakaiensis (iii) Microbial fuel cells

Explanation

(i) Brewer.s yeast: Saccharomyces cerevisiae is commonly called as brewer.s yeast. It is used for fermenting malted cereals and fruit juices to produce various alcoholic beverages. Beer and wine are produced without distillation. But the rum, whiskey and brandy are produced by fermentation and distillation.
(ii) Ideonella sakaiensis: It is the microbes currently used in bioremediation process of recycling PET plastic. These bacteria produce enzymes PET ase and MHET ase, which break down PET plastic into terephthalic acid and ethylene glycol.
(iii) Microbial fuel cells: Microbial fuel cell is a bio-electrochemical system. This derives an electric current by redox reaction of bacteria found in nature. Bacteria are capable of oxidizing or reducing organic molecule. The electrons are produced by redox reactions during respiration of bacteria. A microbial fuel cell consists of an anode and a cathode separated by a proton exchange membrane. The organic fuel at the anode is oxidized by the microbes, generating protons. These protons pass through the membrane to the cathode and electrons pass through the anode to the external circuit to generate current.