title: Effect of physicochemical pre-treatment of rice straw on its digestibility by Clostridium cellulolyticum.
abstract: Rice straw (RS) may serve as a low-cost biomass for the production of biofuels and biochemicals, but its native structure is resistant to enzymatic and microbial deconstruction. Therefore, an efficient pre-treatment method is required to modify crystalline cellulose to a more reactive amorphous form. This work investigated pre-treatments of rice straw involving size reduction (S) followed by either sodium hydroxide (NaOH) or diluted sulfuric acid (H2SO4) and liquid hot water (LHW). The shrinkage of the vascular bundles in the rice straw structure pre-treated with NaOH-LHW-S was higher than that with LHW-S and H2SO4-LHW-S pre-treatments. The highest levels of total fermentative products and residual sugars were obtained at the concentrations of 7.8 ± 0.2 and 2.1 ± 0.3 g/L, respectively, after fermentation by Clostridium cellulolyticum for NaOH-LHW-S pre-treated rice straw at 121 °C for 120 min. Overall, the combined physicochemical pre-treatment of RS led to improved microbial hydrolysis during cellulose degradation at the percentage of 85.5 ± 0.5.
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree, Muang, Nakhon Ratchasima, 30000, Thailand.|Faculty of Science, Udon Thani Rhajabat University, 64 Taharn Road, Muang, 41000, Thailand.
authors.forename: Metinee
authors.initials: M
authors.lastname: Wasoontharawat
authors.affiliation: Division of Biopharmacy, Faculty of Pharmaceutical Sciences, Ubon Ratchathani University, Warinchamrap, Ubon Ratchathani, 34190, Thailand.
authors.forename: Sirima Suvarnakuta
authors.initials: SS
authors.lastname: Jantama
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree, Muang, Nakhon Ratchasima, 30000, Thailand. ksunthorn@yahoo.com.
authors.forename: Sunthorn
authors.initials: S
authors.lastname: Kanchanatawee
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree, Muang, Nakhon Ratchasima, 30000, Thailand. kaemwich@sut.ac.th.
authors.forename: Kaemwich
authors.initials: K
authors.lastname: Jantama
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D046973:Ruminiclostridium cellulolyticum / Q000254:growth & development*; D006358:Hot Temperature; D006868:Hydrolysis; D012275:Oryza / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*
chemical_list: D013464:Sulfuric Acids; D012972:Sodium Hydroxide; D002482:Cellulose; C033158:sulfuric acid
keywords: Clostridium cellulolyticum; Fermentation; Pre-treatment; Rice straw