A comparative study of the hydrolysis of gamma irradiated lignocelluloses

Abstract

-The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis) and softwood (Triplochiton scleroxylon) were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p ≤ 0.05), hardwood was hydrolysed significantly better compared to the softwood.

Irradiation Pretreatment of Tropical Biomass and Biofiber for Biofuel Production

“…A comparison on gamma ray irradiation pretreatment on soft and hardwood has also been carried out using different level of dosage ranges between 10-100 kGy [37]. The study found that the most suitable condition for softwood was at 40 kGy, while higher dosage is required to pretreat hardwood (90 kGy).…”

Prospects for Irradiation in Cellulosic Ethanol Production

“…Starch and cellulosic and pectic polysaccharides are degraded by cleavage of glycosidic bonds [ 13 ]. High doses of gamma rays depolymerize or delignify the cell wall constituents [ 15 , 16 ]. Loss in the fiber content has been observed in plant matter [ 17 ].…”

“…A reduction in the rumen dry matter has been found in spruce sawdust, barks of spruce, pine, and larch when irradiated with high doses of gamma rays due to the solubilization and partial breakdown of the dry matter [ 18 ]. The degradation of cell wall has been reported to show increase in digestibility of the organic matter [ 16 ] as evidenced in rice straw [ 19 ], barley straw, pea straw, sugarcane bagasse, sunflower hulls, and pine sawdust [ 20 ]. Combined NaOH and gamma radiation treatment of wheat straw, cotton shells, peanut and soybean shells, and extracted olive oil cake and extracted unpeeled sunflower seeds showed improved digestibility compared to the individual methods [ 21 ].…”

“…Growth enhancement in cellulolytic microbes, such as Myrothecium verrucaria fungus, has been noticed in irradiated rice straw [ 26 ]. A marked increase has been witnessed in hydrolysis yield of gamma irradiated Khaya senegalensis and Triplochiton scleroxylon [ 16 ]. Efficiency of gamma irradiation is manifested in its capability of increasing enzymatic hydrolysis of rice straw even at high substrate loadings [ 27 ] and improved pretreatment results in comparison to steam explosion method [ 28 ].…”

Lignocellulosics as a Renewable Feedstock for Chemical Industry: Chemical Hydrolysis and Pretreatment Processes

“…Gamma radiation and electron beam irradiation pretreatment have been used to improve enzymatic digestibility solely or in combination with alkali agent [31,[320][321][322][323]. However, the enzymatic efficiency of irradiation-pretreated biomass is typically still low, presumably due to the introduction of insoluble crosslinkages.…”