He-Ne激光诱变黑曲霉Sx的原生质体

对生淀粉糖化菌黑曲霉Sx用混和酶制取原生质体进行了探索.在GM培养基中加入一定量的Cu²⁺、Mn²⁺,原生质体产量较高;采用pH4～5的蜗牛酶、纤维素酶、溶菌酶的混合酶,最佳浓度比为:1.5:3.5:1.5(mg/mL).取在GM培养基中培养17～18h的菌丝,在32℃酶解3h,原生质体产量最高,达到2.4×10⁵个/mL;在加入β-巯基乙醇及二硫苏糖醇处理菌丝时,原生质体产量提高近3倍.在再生培养基中,加入终浓度为30mmol/LMgSO₄时,原生质体再生率由16.7%提高到25.6%.用He-Ne激光照射原生质体时,功率9mW照射30min时致死率为50%,随着时间的延长,原生质体存活率降低.采用波长632.5nm、功率9mW、光斑直径5mm的He-Ne激光多次照射诱变,筛选出一株酶活力最高菌株黑曲霉Sy,活力提高51%,经连续传代5次,酶活力稳定.

He-Ne LASER TREATMENT OF THE PROTOPLAST FROM ASPERGILLUS NIGER Sx

This article deals with the formation and regeneration of the protoplast from A.niger Sx.The protoplast production is relatively high when Cu²⁺ or Mn²⁺ was added to the growth media.2.4×10⁵/mL protoplasts can be obtained at 32℃ lasting 3 hours from 17～18 hours cell age mycelia,using the mixture of Snailase(1.5mg/mL),Cellulase(3.5mg/mL)and Lysozyme(1.5mg/mL)with pH 4～5.Treated with β-MercaptoethanoL and DTT,the production of protoplast was nearly three times of the original one.When the concentration of MgSO 4 in RM was 30mmol/L,the regeneration rate increased from 16.7% to 25.6%.With the He-Ne laser(λ have 632.8nm,the power have 9mW,the diameter have Φ5mm)irradiating 30 minutes,the death rate of protoplast is 50%,and the He-Ne is used to mutagenize the protoplast,through a large amount of screening,a high activity raw starch amylomyces,named A. niger-Sy.The enzyme activity is increased by 51%.