Bioprocesses for Enzyme Production Using Agro-Industrial Wastes: Technical Challenges and Commercialization Potential

TLDR: In this paper, the authors provide a holistic view of perspectives, unprecedented progress made, and state-of-the-art scenario envisaging environmentally benign and industrially viable agro-waste-based bioprocesses for enzyme production.

Abstract: The realm of industrial enzymes from microorganisms in energy, food, brewery, feed, textile, paper, and agriculture sectors is experiencing an upthrust ($4.4 billion market by 2015) due to strict government policies, environmental legislations, and market pressures. Enormous quantities of agro-industrial wastes, such as cassava bagasse, sugar cane bagasse, sugar beet pulp, coffee pulp/husk, apple pomace, among others are generated throughout the year by either industrial or agricultural activities. A major part of this precious biomass is disposed by burning and unplanned land filling leading to air and land pollution, respectively. These residues represent a commercially attractive, renewable, and abundant resource rich in carbon, nitrogen, and minerals that can boost bioprocess economics for enzyme production by serving as low-value alternatives to costly medium components utilized under submerged fermentation (SmF) or solid-state fermentation (SSF). However, the techno-commercial success of enzymes from agro-waste-based bioprocesses is hampered by two-pronged obstacles: (1) recalcitrance due to the molecular organization (consisting of an interwoven network of lignin, cellulose, and hemicellulose) of agro-residues and (2) fermentation bottlenecks, such as lack of process controls and automation, heterogeneous fermentation conditions, difficulty in scale-up operations, complicated product purification in SSF and high energy requirement, and poor enzyme productivities along with high production cost in SmF. At present, a collaborative pancontinental interdisciplinary research encompassing molecular biology, microbiology, process engineering, and computational biology is trying to accelerate effective utilization of agro-industrial lignocellulosic biomass in bioprocesses to produce industrial enzymes. The present chapter provides a holistic view of perspectives, unprecedented progress made, and state-of-the-art scenario envisaging environmentally benign and industrially viable agro-waste-based bioprocesses for enzyme production.