Research Article: Biodegradation of ramie stalk by Flammulina velutipes: mushroom production and substrate utilization

Date Published: September 12, 2017

Publisher: Springer Berlin Heidelberg

Author(s): Chunliang Xie, Wenbing Gong, Li Yan, Zuohua Zhu, Zhenxiu Hu, Yuande Peng.

http://doi.org/10.1186/s13568-017-0480-4

Abstract

In the textile industry, ramie stalk is byproducts with a low economic value. The potential use of this leftover as a substrate ingredient for Flammulina velutipes (F. velutipe) cultivation was evaluated. The degradation and utilization of ramie stalk by F. velutipes was evaluated through mushroom production, lignocelluloses degradation and lignocellulolytic enzymes activity. The best substrate mixture for F. velutipes cultivation comprised 50% ramie stalk, 20% cottonseed hulls, 25% wheat bran, 4% cornstarch and 2% CaCO3. The highest biological efficiency of fruiting bodies was reached 119.7%. F. velutipes appears to degrade 12.7–32.0% lignin, 14.4–30.2% cellulose and 9.3–25.7% hemicellulose during cultivation on the different substrates. The results of enzymes activities showed that laccase and peroxidase were higher before fruiting; while cellulase and hemicellulase showed higher activities after fruiting. The biological efficiency of fruiting bodies was positively correlated with the activities of cellulase, hemicellulase and ligninolytic enzyme. The results of this study demonstrate that ramie stalk can be used as an effective supplement for increasing mushroom yield in F. velutipes.

Partial Text

Ramie, known as China grass (Boehmeria nivea L. Gaudich., Urticaceae), is an industrially important crop which is cultivated in China, Brazil, South Korea, Lao PDR, Philippines, India, and Thailand (Zhu et al. 2014). China is the world’s largest producer of ramie. In China, more than 1,000,000 ton of ramie residue such as ramie stalk is produced as textile industry byproduct in 2013 year which have very little or no economic value (Zhou et al. 2015). The ramie stalk is predominately composed of cellulose, hemicellulose and lignin. Many edible white rot fungi can utilize a variety of lignocellulosic residues by producing several extracellular secreted enzymes including cellulases, hemicellulases, pectinase and ligninase (Isikhuemhen et al. 2012; Levin et al. 2012; Varnai et al. 2014; Wang et al. 2013). So cultivation of mushrooms on ramie byproducts may be one of the possible solutions to converting these agro-wastes into accepted edible biomass of high and useful market value.

F. velutipes is one of the six most popular cultivated edible mushrooms in the world (Senik et al. 2015; Liu et al. 2017). In recent years, its consumption has increased and over 300,000 tons of F. velutipes are produced per year (Shi et al. 2017). Selecting an economic and efficient substrate material to reduce production costs has been an important consideration in F. velutipes cultivation. Ramie stalk is an agricultural residue and is generally disposed of by burning or burying which represents a major cause for environmental pollution. If it could be re-used wholly or partially as F. velutipes cultivation substrate, as a substitute for cottonseed hull or sawdust, the cost of cultivating mushroom should be reduced. In the present research, the possibility of using ramie stalk as a substrate for F. velutipes cultivation was tested and a deeper understanding on the bioconversion of the substrate was also discussed.

 

Source:

http://doi.org/10.1186/s13568-017-0480-4

 

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