Short communication
Medium optimization of carbon and nitrogen sources for the
production of eucalyptene A and xyloketal A from Xylaria sp. 2508
using response surface methodology
Zeng Xiaobo a,*, Wang haiying b, He Linyu c, Lin Yongcheng c, Li Zhongtao a
aCollege of Pharmacy, Wuhan University, 430072 Wuhan, PR China
bCollege of Life Science, South-center University for Nationalities, 430074 Wuhan, PR China
c School of Chemistry & Chemical Engineering, Sun Yat-sen University, 510275 Guangzhou, PR China
Received 30 March 2005; received in revised form 6 June 2005; accepted 7 June 2005
Abstract
To optimize the production of novel ketal compounds and allenic ethers from a mangrove fungus Xylaria sp. 2508, optimization of the
culture mediumwas carried out using a two-step approach. A quick identification of a suitable source of carbon and nitrogen was obtained by a
simple screening experiment, which was followed by an application of response surface methodology (RSM) for further optimization design.
A second order model was found to fit the eucalyptene A production. Response surface analysis revealed that the optimum values of the tested
variables for the production of eucalyptene Awere: glucose 2.86% (w/v), peptone 0.78% (w/v) and yeast extract 0.35% (w/v). A production of
4.89 107 g ml1 for eucalyptene A, which was close to the predicted response, was observed in verification experiment. The production of
xyloketal A was 2.20 107 g ml1. In comparison to their production of basal medium, 1.53- and 1.32-fold increase had been obtained,
respectively. The 3-D response surface curves implied that high yeast extract concentration repressed the growth of Xylaria sp.
# 2005 Elsevier Ltd. All rights reserved.
Keywords: Medium optimization; Ketal compounds; Allenic ethers; Xylaria sp.; Response surface methodology
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Process Biochemistry 41 (2006) 293–298
1. Introduction
After almost 40 years of investigation, the number of
compounds isolated from various marine organisms has
virtually s