**4.7 Biotreatment**

Biotreatment is basically biological pretreatment method applying either bacteria, fungi or yeast cells in sinngle culture of mix microbial communities composition. Additionally, specific enzymes in as a single entity or mixed enzymes solution has also been used in biotreatment system. The nature and function of enzymes and microbial culture could be different but the overall target is to fractionate the biomass into separate polysaccahrides molecules. A number of enzymes such as lignin peroxidases, laccases, xylanases, endoglucanases, peptidases, esterase and hydrolases has been applied in biomass saccharification process. Beside enzymes, a number of fungal strains *Phanerochaete chrysosporium, Trametes versicolor, Pleurotus ostreatus, Ceriporiopsis subvermispora,* and bacterial speies particularly *Clostridum sp. Pseudomonas sp.* LD002 [41], actinomycetes [42], *Streptomyces viridosporus* T7A [43], *Rhodococcus jostii* RHA 1 and *Pseudomonas putida* [44, 45], *B*acillus sp. strains [20–23]*,* and thermophile *anaerocellum thermophilum* are reported for oxidative hydrolysis of lignin from biomass [46, 47]. Fungi like white and brown-rot fungi has the ability to hydrolyze both lignin and cellulose [48]. Such strains has the enzymes machinery of lignin peroxidase, manganese peroxidase, versatile peroxidase, laccase and cellulases [49]. The eficiency and percentage of lignin degradation depends on the enzymes and growth of the microorgansims like *Stereum hirsutum (*white-rot fungi) has 14.5%, degradation of the lignin from the wood biomass [49]. Wherase, *Coniochaet ligniaria* fungus reported upto 75% of lignin degradation from pepper plant, likwise, *Pleurotus Florida* with 45–50% degradation of lignin from corn straw [50]. The importance of biological treatment method is consumption of low energy, safe for environment and has no involvement of toxic chemcials. However, the problems that needs to be adjusted is sluggish growth, optimum conditions of enzymes, products inhibition, pretreatment time, enzymes purification, economical approach, feasible for the degradation of diverse agriculture biomasses [51]. However, all of these studies proposed that biological treatment is economical pre-treatment method among the all for inexpensive biofuels productions.
