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Optimization of mycelial
biomass and protease production by Laccocephalum mylittae
in submerged fermentation
Li-Hua Zhou, Yi-Qiong Zhang, Ruo-Jun Wang, Xue-Ling Shen,
Yong-Quan Li* and Wen-Jun Guan*
College of
Life Sciences, Zijingang Campus, Zhejiang University,
Yuhangtang Road No. 388, Hangzhou 310058, P. R. China.
*Corresponding author. E-mail:
biopharmacylab@zju.edu.cn or
lyq@zju.edu.cn,
guanwj@zju.edu.cn. Tel.: +86-571-88206546. Fax:
+86-571-88208569.
Accepted
10 February, 2009 |
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Laccocephalum mylittae
is
a
traditional Chinese medicinal fungus. Its
wild sclerotium has been used in anthelmintic therapy for
many years. Previous studies revealed that the main
pharmaceutical component for the anthelmintic function of
L. mylittae is an intracellular neutral protease,
isolated from the wild sclerotium of this fungus. In this
study, the mycelial biomass and protease production by L.
mylittae in submerged fermentation was optimized using
response surface methodology (RSM) and orthogonal matrix
method. Under the optimum medium and conditions, the maximum
activity of the anthelmintic protease from the mycelia of
L. mylittae reached 4557.22 ± 147.36 U per gram mycelial
dry weight (U/g), with the biomass of 11.65 ± 0.33 g/l after
3 d batch fermentation in a 15 l fermenter. This is a
2.71-fold and a 3.32-fold increase in protease productivity
and biomass yield respectively, compared with that in the
initial un-optimized fermentation process. The production
time was also reduced from 4.5 d to 3 d. In addition,
protease activity from the mycelia in optimized fermentation
is 8.14-fold higher than that from the wild
sclerotium of L. mylittae. These results provided valuable
information for the further industrial production
and applications of this fungus as well as its
main
pharmaceutical component.
Key
words:
Laccocephalum mylittae, protease production,
submerged fermentation, optimization, response surface
methodology, orthogonal matrix method. |
