Recent Developments in Heterologous Expression of Cellulases Using the Pichia pastoris Expression System: A Comprehensive Literature Review
N. Muzaffar, Abdur Raziq, Muhammad Waseem Khan, Niaz Muhammad Khan, Bushra Shahid, Anbareen Gul, Hayat Ullah
Abstract
Cellulosic biomass is considered an important and sustainable source of renewable energy, which needs a complex mixture of different enzymes for its degradation. After amylase, cellulases are the second most important enzymes, gain more importance due to their broad range of applications at the industrial level, and are considered more economical and environmentally friendly; researchers have focused more on the production of cellulase with its higher expression rate and low cost. Pichia pastoris, a methylotrophic yeast strain, has a more effective and well-established system for the production of heterologous proteins, particularly for industrial enzymes. Moreover, its readily achievable high-density fermentation, high capacity for protein secretion, tractable genetic modifications, typical post-transcriptional modifications, and strong regulated promoters makes it superior to other expression systems. In this review, we address the P. pastoris expression system including protein expression platforms, plasmids, and cellular metabolism quantification as a potential candidate for heterologous protein production, particularly for cellulase enzymes.