Isolation of Bacillus sp. strains capable of decomposing alkali lignin and their application in combination with lactic acid bacteria for enhancing cellulase performance

• Published in: Bioresource technology 2014-01, Vol.152, p.429-436
• Main Authors: Chang, Young-Cheol, Choi, DuBok, Takamizawa, Kazuhiro, Kikuchi, Shintaro
• Format: Article
• Language: English
• Subjects: Alkalies - metabolism; Anthraquinones - isolation & purification; Bacillus; Bacillus - isolation & purification; Bacillus - metabolism; Bacillus sp; Bacteria; Bacteria - metabolism; Biodegradation, Environmental; Biological and medical sciences; Cellulase; Cellulase - metabolism; Cellulase performance; Degradation; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Laccase; Laccase - metabolism; Lactic Acid - metabolism; Lactic acid bacteria; Lignin - metabolism; Lignin-degradation; Molecular Sequence Data; Oryza - chemistry; Performance enhancement; Pretreatment; Soil Microbiology; Solubility; Strain; Time Factors; Waste Products
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.11.032

•Two alkali lignin-degrading bacteria (CS-1 and CS-2) were isolated from forest soils in Japan.•CS-1 and CS-2 displayed alkali lignin degradation capability.•High laccase activities were observed in crude enzyme extracts.•Improving surface area accessible to cellulose is an important.•A two-step procedure is effective at accelerating cellulase performance. Effective biological pretreatment method for enhancing cellulase performance was investigated. Two alkali lignin-degrading bacteria were isolated from forest soils in Japan and named CS-1 and CS-2. 16S rDNA sequence analysis indicated that CS-1 and CS-2 were Bacillus sp. Strains CS-1 and CS-2 displayed alkali lignin degradation capability. With initial concentrations of 0.05–2.0gL−1, at least 61% alkali lignin could be degraded within 48h. High laccase activities were observed in crude enzyme extracts from the isolated strains. This result indicated that alkali lignin degradation was correlated with laccase activities. Judging from the net yields of sugars after enzymatic hydrolysis, the most effective pretreatment method for enhancing cellulase performance was a two-step processing procedure (pretreatment using Bacillus sp. CS-1 followed by lactic acid bacteria) at 68.6%. These results suggest that the two-step pretreatment procedure is effective at accelerating cellulase performance.