LED光提高蛹虫草的活性成分

Scientia Horticulturae 175(2014)139–143

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LED lights increase bioactive substances at low energy costs in culturing fruiting bodies of Cordyceps militaris

Zhi-Li Yi a ,Wen-Fang Huang a ,Yan Ren b ,∗,Eugen Onac c ,Guo-Fu Zhou b ,Sheng Peng b ,Xiao-Jing Wang a ,Hai-Hang Li a ,∗

a

Guangdong Provincial Key Lab of Biotechnology for Plant Development,College of Life Sciences,South China Normal University,Guangzhou 510631,China b

Philips Research China,No.9Lane 888Tian Lin Road,Shanghai 200233,China c

Philips Research Europe,High Tech Campus 34,5656AE Eindhoven,The Netherlands

a r t i c l e

i n f o

Article history:

Received 15December 2013

Received in revised form 30May 2014Accepted 3June 2014

Keywords:

Cordyceps militaris

Light-emitting diode (LED)Primordial formation Fruiting body growth Bioactive substances

a b s t r a c t

Cordyceps militaris is widely cultured to produce fruiting bodies for medicinal and health food use.Illu-mination is an important factor for the growth,quality and production costs.The effects of different light-emitting diode (LED)light combinations on primordia induction,the growth and bioactive sub-stances of fruiting bodies were investigated.The results showed that the monochromatic red or far-red LED failed to induce primordia.Blue light was a must for primordia induction and a red:blue 2:1with 10%far-red induced the greatest frequency of primordia.Dry weights of fruiting bodies were lower under red and far-red LED treatments.Cordycepin contents in fruiting bodies were significantly higher in red and white (red:blue:far-red 6:3:1)LED treatments,with the increases up to 62%over the fluorescent control.Carotenoids content was significant lower in the red or far-red LED treatment than in other treatments.The results demonstrated the functions of different wavelength lights on the growth and biosynthesis of bioactive substances and that using the low heat release and energy consumption LED lights to replace the traditional fluorescent lights can improve the product quality and increase the contents of bioactive substances.A red to blue ratio of 2:1with 10%far-red is the optimal light quality for culturing fruiting bodies of itaris .

©2014Elsevier B.V.All rights reserved.

1.Introduction

Cordyceps militaris is widely cultured in China and some other Asian countries for traditional medicine and health food use regarding its multiple pharmacological functions,such as immunoregulation,anti-aging,antitumor and antimicrobial activi-ties (Ni et al.,2007;Paterson,2008).More than 50t of dried fruiting bodies were produced through solid fermentation in culture houses in Guangdong Province which is located in the south area of China (Ni et al.,2009).The life cycle of itaris mainly consists of two growth stages,the mycelia growth stage with no need of light and the fruiting body development stage requiring light at a temperature around 22◦C.The fruiting body development stage includes a 15-day primordial induction and a 30-to 40-day fruiting body growth under continuous light irradiation.As the tempera-ture is higher than 22◦C in most time of the year in Guangdong,

∗Corresponding authors.Tel.:+862085212630.

E-mail addresses:renyan2006@ (Y.Ren),li haihang@ (H.-H.Li).

the culture room needs a cooling system to maintain the temper-ature for a normal growth of fruiting bodies.Energy costs for both light irradiation and the cooling system are becoming the major expenses for regular production of itaris fruiting bodies.

In additional to the regulatory roles on the growth,develop-ment and reproduction,light can also affect the biosynthesis of secondary metabolites (Idnum and Heitman,2005),i.e.,increase contents of bioactive substances and improve nutritional and/or color quality of medicinal fungi and plants.Cordycepin (Ni et al.,2009;Cai et al.,2013;Yao et al.,2013),canotenoids (Dong et al.,2013)and polysaccharides (Lee et al.,2010)are the main bioac-tive substances in itaris .Carotenoids also contribute to the dark golden color of its itaris fruiting body products.These substances represent the quality of commercial Cordyceps prod-ucts.Shrestha et al.(2006)found that light was the most critical factor in determining the density,texture,and pigmentation of the mycelium culture of itaris ,and there was no pigmen-tation of the mycelium in the dark condition.Dong et al.(2012)indicated that red light benefited mycelium growth and adenosine content,while blue light was favorable for cordycepin biosynthe-sis in itaris mycelium.Dong et al.(2012,2013)reported that

/10.1016/j.scienta.2014.06.0060304-4238/©2014Elsevier B.V.All rights reserved.