Extraction optimization and in vivo antioxidant activities of exopolysaccharide by Morchella esculenta SO-01
Fanyun Meng 1,Bo Zhou 1,Rongshan Lin 1,Le Jia *,Xiaonan Liu,Peng Deng,Keming Fan,Guoyi Wang,Li Wang,Jianjun Zhang
College of Life Science,Shandong Agricultural University,Taian,Shandong 271018,PR China
a r t i c l e i n f o Article history:
Received 16November 2009
Received in revised form 16January 2010Accepted 22January 2010
Available online 13February 2010Keywords:
Morchella esculenta SO-01Exopolysaccharide
Response surface methodology Antioxidant activity Mice
a b s t r a c t
Response surface methodology was used to optimize extraction parameters for Morchella esculenta SO-01exopolysaccharide (EPS)produced during submerged culture.The optimum conditions for EPS extraction were predicted to be,concentration at 84.07°C,precipitation for 22.19h and pH 8.44,and EPS production was estimated at 5.45g/L.The actual yield of EPS under these conditions was 5.32g/L.The antioxidant capacity of the EPS was measured in vivo after ﬁlling the stomach with different doses of EPS and results showed that the activities of superoxide dismutase (SOD)and glutathione peroxidase (GSH-Px)of blood,spleen,liver,heart,and kidney were increased by 125%,46.11%,23.33%,12.19%,41.29%,and 63.24%,63.12%,166.54%,98.01%,57.68%,respectively,and that malonaldehyde (MDA)of blood,spleen,liver,heart,and kidney were decreased by 21.80%,67.84%,28.48%,56.15%,41.62%.The results provide a refer-ence for large-scale extraction of EPS by M.esculenta SO-01in industrial fermentation.
Ó2010Elsevier Ltd.All rights reserved.
Interest in medicinal mushrooms has increased in recent years (Wang et al.,2009)and some compounds extracted from mush-rooms are potential immunomodulators (Lee et al.,2009)or bio-logical response modiﬁers (BRM)(Zaidman et al.,2005).Polysaccharides from fruiting bodies,cultured mycelium or culture broths have potential antitumor and immunomodulating proper-ties (Masuda et al.,2009;Ooi and Liu,2000;Wasser,2002).
Morchella esculenta ,an edible and medicinal mushroom,con-tains many biological active materials,such as protein,fat,mineral contents,ash,ﬁber,and carbohydrates (Litchfteld et al.,2006;Nesim Dursun et al.,2006).Polysaccharides from M.esculenta fruit-ing bodies and cultured mycelia have antioxidation,antitumor,and antivirus properties and increase fatigue resistance (Elmastas et al.,2006;Nitha and Janardhanan,2008;Rotaoll et al.,2005;Xu et al.,2008).
Since extraction parameters for exopolysaccharide (EPS)from M.esculenta have apparently not been studied,statistical designs were applied to optimize extraction conditions.Factors affecting the extraction of EPS were analyzed by Plackett–Burman (PB)experiments,and three signiﬁcant variables (concentration tem-perature,precipitation time,and pH)were chosen to optimize the extraction conditions using response surface methodology
(RSM),a collection of statistical techniques for designing experi-ments,building models,evaluating the effects of factors,and searching optimum conditions of factors for desirable responses (Gouda et al.,2001).In addition,animal experiments were per-formed to explore the antioxidant activities of EPS in vivo .2.Methods
2.1.Microorganism and culture conditions
Morchella esculenta SO-01was obtained from the Shandong Agricultural Academy of Sciences,China and maintained on syn-thetic potato dextrose agar (PDA).The cultures were incubated for 14d at 25°C,stored at 4°C,and subcultured every 2months.Cultivation in liquid media was carried out in 250-mL Erlenmeyer ﬂasks containing 100mL of (g/L):bran,40;sucrose,40;yeast ex-tract,5;KH 2PO 4, 1.5;MgSO 4Á7H 2O, 1.5,and NH 4NO 3,3with pH 5.5.Flasks were inoculated with a 0.5-cm 2mycelial block of M.esculenta SO-01from the solid media,incubated at 25°C for 24h without shaking,and then shaken on a rotary shaker (Anting,Shanghai,China)at 180rpm for 3d.2.2.Measurement and preparation of EPS
The M.esculenta SO-01culture was centrifuged at 3000g for 15min,the supernatant liquid was mixed with 3volumes of 95%ethanol (v/v),stirred vigorously,and kept at 4°C for 18h.After
0960-8524/$-see front matter Ó2010Elsevier Ltd.All rights reserved.doi:10.1016/j.biortech.2010.01.113
*Corresponding author.Tel.:+865388249958;fax:+865388248696.E-mail address:jiale9015@http://m.sodocs.net/doc/f2fc01543c1ec5da50e270fd.html (L.Jia).1
Equal contributors.Bioresource Technology 101(2010)
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