Antioxidant compounds from microbial sources: A review.

Free radicals are one or more unpaired electrons containing reactive molecules, which can damage nucleic acids, proteins, carbohydrates, and lipids, leading to several diseases including early aging, cancer and atherosclerosis. Antioxidants can scavenge these free radicals to prevent cellular damage by ultimately reducing the oxidative stress and thus have a beneficial effect on human health. Epidemiological studies have already revealed that higher intake of antioxidants as food supplements results in reduced risk of many diseases. Exploring natural antioxidants and its role in human health & nutrition is an emerging field. Several biological sources like medicinal plants, vegetables, spices and fruits have been evaluated as sources of potentially safe natural antioxidants. Beside plants, microorganisms are the potential source of novel bioactive compounds to be used in medical, agricultural, and industrial sectors. As compared to plants, microbes can be grown under controlled conditions at a faster rate, which make them a potential source of natural bioactive molecules for food and nutraceutical applications. This review summarizes the potential of different microorganisms including actinomycetes, bacteria, blue green algae, fungi, lichens and mushrooms to be explored as the source of such bioactive compounds.