Exploring plant and agro-industrial wastes for antimicrobial biochemicals

Abstract

Antimicrobial agents are substances of chemical or biological origin, which help in either inhibiting the growth or killing of the microorganisms, such as bacteria, viruses, fungi, algae, or other parasites. The demand for antimicrobial compounds (products) throughout the world has been continuously increasing as the population is more and more concerned about the health and hygiene. Global change in the lifestyle pattern and livelihood has resulted in generation of increasing quantities of solid wastes, which include agro-industrial residues. These residues are usually organic in nature which makes them potential candidates as feedstock for developing the bioprocesses through biotechnological interventions. The usage of these residues as substrates not only opens a new avenue in their utilization but also reduces the pollution concerns, which their disposal in the environment would have caused otherwise. Numerous scientific investigations have reported the production of antimicrobial products from a variety of agro-industrial residues, such as vegetable peels, seeds, cereal, and fruits waste, and essential oils from the peel of various fruits, which have shown effective properties to be used as preservatives or food additives and in pharmaceuticals because of their antimicrobial, anti-inflammatory, and antioxidant characteristics. Antimicrobial products are also isolated from the plants as these are present in all parts of the plant, viz., bark, stalks, leaves, fruits, roots, flowers, pods, seeds, stems, latex, hull, and fruit rind, and are usually derivatives of phenolic acids and flavonoids. The hydroxyl groups of polyphenols are very reactive in neutralizing the free radicals by donating a hydrogen atom or an electron, chelating metal ions, inactivating lipid-free radical chains, and preventing hydroperoxide conversions into reactive oxyradicals. These are thus effective against various deadly diseases and for processed food preservation, pharmaceuticals, alternative medicine, and natural therapies. A newer application on the usage of the antimicrobial has emerged in recent times with the aid of nanotechnology to fight against the disease-causing organisms, replacing heavy metals and toxins and may attain effective application in future.