Hi there!

Microbes like bacterium E.coli present in the intestine of man help in synthesis of vitamin B and K.

Several other bacteria like Streptomyces, etc. are used in making antibiotics.

Fungi like Penicillium is a source of first ever discovered antibiotic Penicillin.

Yeast (Saccharomyces cerevisiae) is used in baking and brewing industries to employ in fermentation. Some fermented products are beer and wine.

Thanks