title: Butyric acid fermentation of sodium hydroxide pretreated rice straw with undefined mixed culture.
abstract: This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at 50°C for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China.
authors.forename: Binling
authors.initials: B
authors.lastname: Ai
authors.forename: Jianzheng
authors.initials: J
authors.lastname: Li
authors.forename: Xue
authors.initials: X
authors.lastname: Chi
authors.forename: Jia
authors.initials: J
authors.lastname: Meng
authors.forename: Chong
authors.initials: C
authors.lastname: Liu
authors.forename: En
authors.initials: E
authors.lastname: Shi
mesh_terms: D001673:Biodegradation, Environmental; D001711:Biotransformation; D020148:Butyric Acid / Q000378:metabolism*; D005285:Fermentation; D054892:Metagenome; D064307:Microbiota; D008969:Molecular Sequence Data; D012275:Oryza / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology; D010802:Phylogeny; D012972:Sodium Hydroxide / Q000737:chemistry; D013696:Temperature
chemical_list: D020148:Butyric Acid; D012972:Sodium Hydroxide