Bioutilisation of agro‐industrial waste for lactic acid production

Abstract

Summary With the advancement in science and technology, the importance of bioconversion of industrial waste into value‐added products through biotechnological route has been realised. Moreover, to make the process economic and environment responsive, agro‐industrial waste/by‐products can be used as substrates in fermentation processes as an inexpensive raw material. In the field of food biotechnology, organic acids represent the third largest category among the biological products, which can be produced chemically or by fermentation process. Among organic acids, lactic acid holds an important position because of its multivariate applications in food, pharmaceutical, cosmetics, textiles and other industries. Traditionally, lactic acid was produced from pure substrates, but agricultural feedstocks and industrial by‐products have evoked the interest of researchers to use them as raw materials for the biotechnological production of lactic acid. The utilisation of biomass has gained major attention due to environmental hazards, scarcity of fossil fuels and meet the increasing world food and feed demand. Integrated biorefinery approaches have also been adopted for the production of lactic acid along with primary product to minimise the cost. This review provides comprehensive information on the recent advances in biotechnological production of lactic acid utilising agro‐industrial waste/by‐products.

Food waste as a source of value‐added chemicals and materials: a biorefinery perspective

“…It has a large potential as monomer, as combinations of D-and L-enantiomers give rise to several biodegradable PLA polymers with different mechanical and thermal properties (Panesar & Kaur, 2015). It is used mainly in foods as an acidulant and preservative and as a monomer in polymers.…”

“…It is also a main reagent to obtain lactate esters, regarded as green solvents. It has a large potential as monomer, as combinations of D-and L-enantiomers give rise to several biodegradable PLA polymers with different mechanical and thermal properties (Panesar & Kaur, 2015). Currently, LA demand is in excess of 1.2 million tons (2016 data), with an expected compound annual growth rate of 16.2% till 2025.…”

Review on a novel biosilica source for production of advanced silica‐based materials: Wheat husk

“…Agricultural activities together with industrial processing create many agro‐industrial wastes . It was predicted that annually, 3.7 × 10 9 tons of agricultural wastes is generated by agricultural industries around the world .…”

“…Agricultural activities together with industrial processing create many agro-industrial wastes. 1 It was predicted that annually, 3.7 × 10 9 tons of agricultural wastes is generated by agricultural industries around the world. 2 The agro-industrial wastes are generally either burnt or left to landfill areas 3 that result in environmental problems such as air, soil, and water pollution.…”

Microbial biotechnology addressing the plastic waste disaster

“…While PLA sales are growing year on year, the production cost can be reduced further. The microbial conversion of cheap substrates (Zhang and Vadlani, 2013;Muller et al, 2017) and waste (Panesar and Kaur, 2015;Pleissner et al, 2017) into lactic acid has been investigated. In parallel with efforts to improve the chemical synthesis of PLA (Dusselier et al, 2015), enzymatic polymerization of lactide is underway (Lassalle and Ferreira, 2008;Jeon et al, 2013).…”