Technical Abstract: Carbon storage in terrestrial ecosystems is contingent upon the natural resistance of plant cell wall polymers to rapid biological degradation. Nevertheless, certain microorganisms have evolved remarkable means to overcome this natural resistance. Lignocellulose decomposition by microorganisms comprises an essential step in closing the loop of the global carbon cycle as it facilitates the recycling of carbon reposited in the form of structural polymers in plant cell walls. The significance of microbial decomposition of lignocellulose has recently risen to greater heights with the revisitation of the potential of lignocellulosic biomass as a valuable and abundant feedstock for the renewable energy and bioproducts industry. The scope of this chapter is to succinctly touch upon the composition of lignocellulosic biomass, the major enzymes involved in decomposing lignocellulosic biomass, and the fungi and bacteria that secrete these enzymes.