耐硒驯化灵芝菌种的液态发酵中硒的富集特征

Characterization of Selenium Accumulation on Domesticated Ganoderma lucidum in Liquid Fermentation

对灵芝(Ganoderma lucidum)菌株在平板上做耐硒驯化,然后对驯化前后灵芝菌种液态发酵过程中富硒性能进行了比较,最后对驯化灵芝液态发酵中硒富集特征进行了研究。实验结果表明,灵芝菌种经耐硒驯化后,其生物量、菌丝体硒含量、总硒含量最高分别达到16.1 g/L,13 264μg/L和91.5 mg/L,明显优于未驯化组。对驯化灵芝液态培养过程中硒富集特征研究表明,富硒灵芝中存在硒代蛋氨酸(SeMet)、硒代胱氨酸(SeCys2)、硒甲基硒代半胱氨酸(SeMeCys)和无机硒(Se(IV))等4种硒形态,其中SeMet、SeCys2占主要部分,分别可达硒代氨基酸总量的60%～90%、10%～40%;在培养过程中单一增加Na2SeO3添加浓度,并不能显著增加灵芝中硒代氨基酸含量,而更多以Se(IV)形式存在。

Ganoderma lucidum strain was domesticated in Na2SeO3 medium to investigate its selenium （Se） ac- cumulation ability. Atomic Fluorescence Spectrometry （AFS） and Liquid Chromatographic-Atomic Fluorescence Spectrometry （LC-UV-AFS） were used to determine the total Se contents and Se speciation in cultured Ganoderma lucidum, respectively. The results showed that the largest harvested biomass could reach 16.1 g/L and the respondent Se content could reach 13264μg/g after the Ganoderma lucidum strain was domesticated by Na2SeO3 medium, which were significantly better than those in non-domesticated ones. SeMet, SeCys2, SeMeCys and inorganic selenium （Se （IV）） could be determined in cultured Ganoderma lucidum, and SeMet and SeCys2 fractions could be 60% -90% and 10% -40% , respectively. It should be pointed out that the Se species was dominated by Se（IV） instead of Se- amino acid if only the contents of Na2SeO3 was increased.