Title : Unraveling the effect of pH-responsive gene elements on cellulase production in the filamentous fungus Penicillium funiculosum
Abstract:
A rapid increase in energy demand alongwith continuous price and depletion of fossil fuels has necessitated the need to explore alternative channels of energy generation for every growing economy. Lignocellulosic biomass, from agricultural landwaste, is an abundant feedstock for second-generation bioethanol production. This complex biomass requires an array of carbohydrate-active enzymes (CAZymes), for its deconstruction to monomeric sugars for the production of value-added fuels and chemicals. Microorganisms such as bacteria and fungi secrete cellulolytic enzymes to degrade biomass to produce monomeric sugars. In search of efficient cellulose degraders, we identified a strain of Penicillium funiculosum, NCIM1228, whose secretome was discovered to be a good source of biomass-degrading enzymes (CAZymes). pH, being one of the most critical environmental parameters affecting enzyme activity, has an impact on a variety of biological processes. Fluctuations in ambient pH lead to many physiological disturbances thus every organism has evolved a mechanism by which they maintain its pH to sustain varying environmental conditions. Fungi have evolved a sophisticated mechanism known as the Pal/PacC-pH pathway to control the expression of genes that respond to external pH. Seven members of this pathway have been discovered in filamentous fungi. Amongst them, pacC is the dominant transcription factor. However, their role in cellulase regulations is still not clear. Our study aims to decipher the role of pacC and other pH-responsive genes in P. funiculosum in regulation of CAZymes.
