Enhancement of Biological Pretreatment on Rice Straw by an Ionic Liquid or Surfactant

Abstract

Fungal delignification can be a feasible process to pretreat biomass for bioethanol production if its performance is improved in terms of efficiency through a few modifications. The aim of this study was to enhance the biodelignification pretreatment of rice straw using laccase in the presence of ionic liquid (1-Allyl-3-methylimidazolium chloride, [AMIM]Cl) or surfactant (TritonX-100). Addition of 750 mg/L [AMIM]Cl and 500 mg/L TritonX-100 increases the lignin removal to 18.49% and 31.79%, which is higher than that of laccase only (11.97%). The enzymatic saccharification process was carried out based on different strategies. The highest cellulose conversion, 40.96%, 38.24%, and 37.91%, was obtained after 72 h of enzymatic saccharification when the substrate was washed with distilled water after pretreatment of rice straw with laccase + TritonX-100, laccase + [AMIM]Cl, and laccase only, respectively. In addition, the morphology and structure changes of pretreated and untreated rice straw were studied. Both surface area and cellulose crystallinity are substantially altered after laccase + [AMIM]Cl and laccase + TritonX-100 pretreatment. Enhanced saccharification efficiency of rice straw was achieved by laccase pretreatment with ionic liquid or surfactant in a single system.

Enhancing Bioethanol Production from Rice Straw through Environmentally Friendly Delignification Using Versatile Peroxidase

“…The samples were uniformly spread on a conductive adhesive strip with a thickness of less than 1 cm. Subsequently, a gold coating was applied to the samples, which were then subjected to SEM analysis using a VE-9800 SEM instrument from KEYENCE, Japan. , …”

“…Subsequently, a gold coating was applied to the samples, which were then subjected to SEM analysis using a VE-9800 SEM instrument from KEYENCE, Japan. 15,35 Fourier Transform Infrared Spectroscopy Analysis of Treated Rice Straw. Fourier transform infrared spectroscopy (FTIR) was employed to evaluate changes in functional groups resulting from VP treatment.…”

“…14 Over the years, physical, chemical, and biological approaches have been investigated for lignin degradation in biomass. 15 In industrial applications, physical and chemical pretreatment methods, such as steam explosion, or organosolv, acid, or alkali treatment, have been employed successfully for the efficient degradation and removal of lignin from biomass. 15 This results in the production of high-yield cellulose compound, which can be further processed into valuable products like paper or bioethanol, ultimately leading to economically viable processes.…”

“…To overcome this limitation, pretreatment of RS becomes necessary to break down lignin and to enhance cellulase’s accessibility to cellulose . Over the years, physical, chemical, and biological approaches have been investigated for lignin degradation in biomass …”

“…15 In industrial applications, physical and chemical pretreatment methods, such as steam explosion, or organosolv, acid, or alkali treatment, have been employed successfully for the efficient degradation and removal of lignin from biomass. 15 This results in the production of high-yield cellulose compound, which can be further processed into valuable products like paper or bioethanol, ultimately leading to economically viable processes. 16 However, it is crucial to acknowledge that these methods often necessitate high reaction temperatures and the use of harsh chemicals.…”