백영고 버섯의 공학적 기법을 이용한 액체배양에 관한 연구

Abstract

A Study on the Liquid Culture of Pleurotus nebrodensis Inzenga Using Engineering Technique

Hyung-Gun Nam Advisor : Prof. Wol-Suk Cha Ph.D. Department of Chemical Engineering, Graduate School of Chosun University

The objective of the present study was to determine the optimal culture conditions and medium composition for production of mycelial and exo- polysacchride in liquid-state fermentation from Pleurotus nebrodensis Inzenga. Optimal culture conditions for mycelial growth and exo-polysaccharide production in flask culture were determined in this research. The optimal temperature and pH were 25℃, and 6.5, respectively. The optimal culture volume was 50 mL in a 300 mL flask and shaking speed was 150 rpm. The optimal inoculum age and volume percent were 7 days and 5%(w/v), respectively. Among the 10 carbon source tested, glucose was the best carbon source. The maximum mycelial growth and exo-polysaccharide production were achieved in a 5%(w/v) glucose. The best nitrogen sources were polypeptone and yeast extract, respectively. The optimal concentrations of polypeptone and yeast extract were 1.0% (w/v) and 0.8% (w/v), respectively. K₂HPO₄ (0.12%(w/v) and MgSO₄ㆍ7H₂O (0.12%(w/v) were the most effective inorganic salts for mycelial growth and exo-polysaccharide production. In summary, the optimal medium composition was glucose 5%, polypeptone 1.0%, yeast extract 0.8%, K₂HPO₄ 0.12% and MgSO₄ㆍ7H₂O 0.12% (w/v). Jar fermentations were carried out to optimize the culture conditions for mycelial growth and exo-polysaccharide production. The optimal agitation speed and aeration rate were 150 rpm and 1.5 v.v.m., respectively. Under optimal culture conditions, the maximum mycelial growth and exo-polysaccharide production after 11 days with a 5 L jar fermenter containing the optimized medium were 12.84 g/L and 4.85 g/L, respectively. However, the fundamental information obtained this study is insufficient in the development of a efficient process for mycelial growth and exo-polysaccharide production from P. nebrodensis Inzenga. To meet the requirements of large-scale mycelial and exo-polysaccharide production, therefore, further studies are needed, including configuration of suitable reactor, optimization of culture conditions and characterization of exo-polysaccharide produced from P. nebrodensis Inzenga.