Microbial Identification and Population Successions in the Novel Carabao Hydrolysis Pretreatment of Agriculture Crops Lignocelluloses Intended for Cellulose Ethanol Production

Abstract

This study was conducted with the objective to elucidate physical, chemical and microbial changes in carabao rumen fluid hydrolysis of bagasse of sweet sorghum and sugarcane, corn stover and rice straw. Identification of microbial species, composition of populations and succession behavior at durations of 3, 6, and 9days of the carabao novel process were determined using API20A kit for anaerobes, spectrophotometry and compound microscopy. Efficiency of microbial conversion of carbohydrates into soluble sugars, pH changes in hydrolysates were determined at various durations. Morphology and physiochemical characterizations showed the occurrences of bacterial groups Clostridium, Bacteroidetes, Streptococcus, Actinomyces, Bifidobacterium, Lactobacillus and Staphylococcus, rumen fungi species Ruminomyces, Orpinomyces and Neocallimastix and various protozoa of the family Ophryoscolocedae and Isotrichia. Population of microbes was highest in the hydrolysate crop residues sweet sorghum, corn stover, sugarcane and rice straw with corresponding significant difference in average carbohydrates conversion efficiency of 66.49%, 52.43% 52.12%, and 39.28% respectively(p<0.05). Novel process with duration of 6 days had the highest carbohydrates conversion efficiency average of 55.02%. Hydrolysis initial average pH 6.98 had turned acidic at durations of 3 days, 6 days and 9 days while pH variations were significantly different among feedstock, lowest in sugarcane(pH 4.91) sweet sorghum(pH 5.46), corn stover (pH 5.72) and near neutral in rice straw(pH 6.56). Succession behavior of bacteria, fungi and protozoan had influenced microbial population, growth pattern and diversity of species in the novel carabao. In conclusion, the isolation, morphological and physiochemical characterizations of rumen bacteria, fungi and protozoa shows the diversity in the microbial community in the novel carabao, has provided elucidation of the novel carabao microbes efficient conversion of carbohydrates into soluble sugars. Information generated in this study will be of great help in understanding the novel carabao and the improvements when the process proceeds to upscaling as pretreatment of lignocellulosic feedstocks intended for cellulose ethanol production.