Biodegradation of lignin and nicotine with white rot fungi for the delignification and detoxification of tobacco stalk. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Su, Yulong; Xian, He; Shi, Sujuan; Zhang, Chengsheng; Manik, S.; Mao, Jingjing; Zhang, Ge; Liao, Weihong; Wang, Qian; Liu, Haobao
• Is Part Of: BMC biotechnology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2016-12
• Subjects: Tobacco stalk -- Nicotine degradation -- Delignification -- Phanerochaete chrysosporium -- Lignocellulolytic enzymes; Biotechnology -- Periodicals; 660.605
• DOI: 10.1186/s12896-016-0311-8
• Languages: English
• ISSNs: 1472-6750

Abstract

Abstract Background Tobacco stalk is one kind of abundant crop residues in China. The high lignification of tobacco stalk increases its reusing cost and the existing of nicotine will cause serious pollution. The biodegradation of lignocellulosic biomass has been demonstrated to be an environmental and economical approach for the utilization of plant stalk. Meanwhile, many nicotine-degrading microorganisms were found in nature. However, microorganisms which could degraded both nicotine and lignin haven't been reported. Therefore, it's imperative to find some suitable microorganisms to break down lignin and simultaneously remove nicotine in tobacco stalk. Results The nicotine in tobacco stalk could be degraded effectively byTrametes versicolor, Trametes hirsute andPhanerochaete chrysosporium . The nicotine content in tobacco stalk was lowered to below 500 mg/kg (a safe concentration to environment) after 10 days of fermentation withPhanerochaete chrysosporium andTrametes versicolor, and 15 days withTrametes hirsute . The degradation rate of lignin in the fermented tobacco stalk was 37.70, 51.56 and 53.75% withTrametes versicolor, Trametes hirsute andPhanerochaete chrysosporium, respectively. Meanwhile, 24.28% hemicellulose was degraded byPhanerochaete chrysosporium and 28.19% cellulose was removed byTrametes hirsute . Through the enzyme activity analysis, the main and highest ligninolytic enzymes produced byPhanerochaete chrysosporium, Trametes hirsute andTrametes versicolor were lignin peroxidase (88.62 U · L−1 ), manganese peroxidase (100.95 U · L−1 ) and laccase (745.65 U · L−1 ). Meanwhile, relatively high and stable cellulase activity was also detected during the fermentation withPhanerochaete chrysosporium, and the highest endoglucanase, exoglucanase and filter paper enzyme activities were 0.38 U · mL−1, 0.45 U · mL−1 and 0.35U · mL−1, respectively. Moreover, the products in the fermentation of tobacco stalk withP. chrysosporium were identified with GC-MS, besides the chemicals produced in the degradation of lignin and nicotine, some small molecular valuable chemicals and fatty acid were also detected. Conclusions Our study developed a new method for the degradation and detoxification of tobacco stalk by fermentation with white rot fungiPhanerochaete chrysosporium andTrametes hirsute . The different oxidative enzymes and chemical products detected during the degradation indicated a possible pathway for the utilization of tobacco stalk.