A New Biological Pretreatment Method for Enhancing Cellulase Performance
|Young-Cheol Chang* and Shintaro Kikuchi|
|Division of Applied Sciences, College of Environmental Technology, Muroran Institute of Technology, Muroran, Japan|
|Corresponding Author :||Young-Cheol Chang
Division of Applied Sciences
College of Environmental Technology
Muroran Institute of Technology, Muroran, Japan
E-mail: [email protected]
|Received February 21, 2014; Accepted February 22, 2014; Published February 27, 2014|
|Citation: Chang YC, Kikuchi S (2014) A New Biological Pretreatment Method for Enhancing Cellulase Performance. J Bioremed Biodeg 5:e142. doi:10.4172/2155-6199.1000e142|
|Copyright: © 2014 Chang YC, et al. This is an open-a ccess article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
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Introduction: Only a few bacteria capable of degrading lignin have been reported. Of these bacteria, Bacillus sp. is very useful because this soil bacterium can divide asymmetrically, producing an endospore that is resistant to environmental factors such as heat, acid, and salt for long periods of time. This manuscript suggests an effective biological pretreatment method for enhancing cellulase performance.
Materials and methods: An alkali lignin-degrading bacterium was isolated from forest soils and named CS-1. 16S rDNA sequence analysis indicated that CS-1 from Hokkaido from Okinawa was Bacillus sp. (100% identity with HQ727971.1).
Results: Strains CS-1 displayed alkali lignin degradation capability. With initial concentrations of 0.05–2.0 g l-1, at least 61% alkali lignin could be degraded within 48 h. The maximum lignin-degrading rate of CS-1 was estimated to be 99.5% at a concentration of 0.05 g l-1. High laccase activities were observed in crude enzyme extracts from the isolated strain. Very low (negligible) lignin peroxidase and low manganese peroxidase activities were observed. This result indicated that alkali lignin degradation was correlated with laccase activities.
Discussion: 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 (Lactobacillus bulgaricus(NBRC13953) and Streptococcus thermophiles (NBRC13957)] at 68.6%. These results suggest that the two-step pretreatment procedure is effective at accelerating cellulase performance.