Combined pretreatment of sugarcane bagasse using alkali and ionic liquid to increase hemicellulose content and xylanase
- PDF / 2,185,561 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 32 Downloads / 223 Views
RESEARCH ARTICLE
Open Access
Combined pretreatment of sugarcane bagasse using alkali and ionic liquid to increase hemicellulose content and xylanase production Rozina Rashid1,2, Uroosa Ejaz1, Firdous Imran Ali3, Imran Ali Hashmi3, Ahmed Bari4, Jing Liu5, Li Wang5, Pengcheng Fu5* and Muhammad Sohail1*
Abstract Background: Lignin in sugarcane bagasse (SB) hinders its utilization by microorganism, therefore, pretreatment methods are employed to make fermentable components accessible to the microbes. Multivariate analysis of different chemical pretreatment methods can aid to select the most appropriate strategy to valorize a particular biomass. Results: Amongst methods tested, the pretreatment by using sodium hydroxide in combination with methyltrioctylammonium chloride, an ionic liquid, (NaOH+IL) was the most significant for xylanase production by Bacillus aestuarii UE25. Investigation of optimal levels of five significant variables by adopting Box-Behnken design (BBD) predicted 20 IU mL− 1 of xylanase and experimentally, a titer of 17.77 IU mL− 1 was obtained which indicated the validity of the model. The production kinetics showed that volumetric productivity of xylanase was much higher after 24 h (833.33 IU L− 1 h− 1) than after 48 h (567.08 IU L− 1 h− 1). The extracted xylan from SB induced more xylanase in the fermentation medium than pretreated SB or commercially purified xylan. Nuclear Magnetic Resonance, Fourier transform infrared spectroscopy and scanning electron microscopy of SB indicated removal of lignin and changes in the structure of SB after NaOH+IL pretreatment and fermentation. Conclusion: Combined pretreatment of SB with alkali and methyltrioctylammonium chloride appeared better than other chemical methods for bacterial xylanase production and for the extraction of xylan form SB. Keywords: Bacillus aestuarii, Ionic liquid, FTIR, NMR, Pretreatment,Xylan
Background Sugarcane bagasse (SB) is one of the abundant, low-cost agricultural deposits in the world which is mainly composed of lignin, hemicellulose, cellulose, wax and ash [1]. Owing to its site availability at sugar industries, SB can be used to generate additional revenues by utilizing it for the synthesis of chemicals, fuels and enzymes [2]. Pakistan, * Correspondence: [email protected]; [email protected] 1 Department of Microbiology, University of Karachi, 75270, Karachi, Pakistan 5 State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China Full list of author information is available at the end of the article
China, Mexico, India, Philippines, Thailand and Brazil are the major sugarcane producing countries [3] and therefore, can be befitted by adopting SB-based technologies. SB is a polysaccharides rich waste and hence a promising raw material in context of biorefineries [4] which can be utilized in various transformation processes. Therefore, the advances in biorefineries from SB have been investigated in numerous studies, with an immense range of configurations [5]. Sugar monomers l
Data Loading...
