嗜热侧孢霉生物学特性及其液体发酵研究

嗜热侧孢霉(Sporotrichum thermophile)是一种嗜热丝状真菌,具有分解纤维素的特性.固体PDA培养条件下进行形态观察表明,所采用的嗜热侧孢霉菌株,菌丝丛枝状、有隔,分生孢子浅褐色,顶生或侧生.利用ITS序列进行分子分类发现嗜热侧孢霉与嗜热革节孢(Scytalidium thermophilium)及特异腐质霉(Humicola insolens)2种嗜热菌相距最近.嗜热侧孢霉的生长pH值范围较宽,在初始pH值4.0-12.0的PDA平板上均可生长,以4.0-8.0时生长较好.以还原糖含量变化和蔗渣减少量为指标,以蔗渣为唯一碳源进行液体发酵,在30 g.L-1蔗渣、11.45 g.L-1NH4NO3、初始pH值4.0和接种量15%(孢子悬液浓度106个.mL-1)条件下,蔗渣降解效果好.

Study on the liquid fermentation and bio-characters of Sporotrichum thermophile

As thermophilic mycelial fungus,Sporotrichum thermophile can decompose cellulose.When it was cultivated on solid PDA culture,the hyphae branched with dissepiments,producing conidiophores from the top and the side.Sporotrichum thermophile was identified closest to Scytalidium thermophilium and Humicola insolens by ITS-PCR analysis.It could grow at the wide pH value range from 4.0 to 12.0,but the pH from 4.0 to 8.0 was better for its growth.The conditions for decomposing bagasse under liquid fermentation was optimized by observing the growth and determining the concentration of reduce sugar and the decrement of bagasse.The optimum conditions were bagasse 30 g·L-1,NH4NO3 11.45 g·L-1,initial pH value 4.0,inoculation 15%(spore concentration 106 spores·mL-1).