CBP of lignocellulose to bio ethanol refers to the combining of the four biologically mediated transformations required for this conversion process (production of saccharolytic enzymes, hydrolysis of the polysaccharides present in pretreated biomass, fermentation of hexose sugars, and fermentation of pentose sugars) in one reactor mediated by a microbial consortium [466]. CBP offers the potential for lower biofuel production costs due to simpler feedstock processing, lower energy inputs, and higher conversion efficiencies than SHF processes .Although no natural microorganism exhibits all the features desired for CBP, a number of microorganisms, both bacteria and fungi, possess some of the desirable traits . Cellulolytic fungi, such as T. reesei, naturally produce a large repertoire of saccharolytic enzymes to digest lignocellulose efficiently, assimilate all LC sugars, and convert these sugars to ethanol, showing that they naturally possess all pathways for conversion of lignocelluloses to bioethanol. For the development of fungi as CBP organisms, the remaining challenges to be met are their low yields and ethanol tolerance, as well as slow rates of fermentation .Biomass-to-ethanol processing mainly focuses on the pure-culture technology that employs recombinant strains to convert the LC biomass into ethanol [. One of the challenges in this method is the elevated cost of the external hydrolytic enzymes, which were estimated to account for over 7% of the total production cost , thus adding significant operating costs. Furthermore, to prevent contamination, strict aseptic conditions are required ; therefore, expensive stainless steel vessels are required, which add significantly to the capital costs.As an attractive alternative to the traditional pure-culture biotechnology, mixed microbial cultures have evolved to convert biomass into fuels and chemicals. This allows for adaptive microbial diversity, no sterilization requirements, the capacity to use mixed substrates, and the possibility of a continuous process . Mixed-culture fermentation was used successfully with sugarcane bagasse, corn stover , chicken manure, and MSWs .The biomass is chemically pretreated to enhance digestibility and then is fermented anaerobically using a mixed culture of natural acid-forming microorganisms. Enzyme production, substrate hydrolysis, and mixed-acid fermentation are integrated in a single CBP . Traditionally, lime (Ca(OH)2) treatment is employed as a pretreatment option, because it is robust, effective, inexpensive, and highly recoverable . Furthermore, the calcium cation is common to both the pre-treatment agent (Ca(OH)2) and the fermentation buffer (CaCO3)