State two economically important uses of (a) heterotrophic bacteria (b) archaebacteria
(a) Heterotropic bacteria : These bacteria are natural scavengers. The souring of milk into lactic acid and alcohol to vinegar is brought about by some saprophytic bacteria, e.g., Lactic acid bacteria and acetic acid bacteria respectively. A number of antibiotic are extracted from actinomycetes especially from the genus Streptomyces e.g. Streptomycin, Chloramphenicol, Oilorotetracycline, Erythromycin, Terramycin etc. (b) Archaebacteria live as symbionts in the rumen of herbivorous animals. Methanogens are present in the guts of several ruminant animals such as cows and buffaloes and they are responsible for the production of methane (biogas) from the dung of these animals.
