激光诱变筛选高产植酸酶黑曲霉菌株的研究

Aspergillus of High Phytase Activity Filtrated by Laser Radiation Mutagenesis

用1.06um,15KHz高重复率声光调QNd:YAG激光以20W和15W的辐照功率分别照射产植酸酶的黑曲霉孢子液和原生质体液不同时间,检定再生菌落数并经透明圈初筛和摇瓶复筛,测定诱变菌株所产植酸酶酶活。结果表明:20W的功率辐照黑曲霉孢子1 以上,致死率近乎100%,15W功率辐照原生质体液20"～4 ,存活率在8.571%～117.14%之间,正变率在27.45%～100%之间,正变辐度60.69%～124.96%,说明原生质体比孢子耐受激光诱变的能力强,并且诱变效果好。筛选到了一株酶活提高达3.75倍的单个变异菌株。

Phytase producing Aspergillus Niger spore and protoplast were treated by 20W or 15W power high repetition rate, 1.06 um, 15KHz soundoptic Qmodulation Nd:YAG laser at different time, regenerated fungus was counted and the phytase activity of mutated fungus were measured after priscreen and rescreen. It showed that laser with power 20W acted on spore more than 1 min, the lethal ratio is almost 100%; laser with power 15W acted on protoplast 20s～60s, the survival ratio among 8.571%～117.14%, the forward mutate ratio among 27.45%～100%, the forward mutate range is 60.69%～124.96%, the result show that protoplast of Aspergillus Niger has more durability against laser and gets better mutable effect than that of the spore. One most high phytase activity mutation fungus was screened, its phytase activity was promoted 3.75.