离子束注入技术选育胶质芽孢杆菌KNP414的解磷突变菌株(英文)

利用离子束注入对胶质芽孢杆菌KNP414进行诱变,获得可降解植酸的突变菌株。离子束注入效应表明,菌株KNP414的存活率显著受离子束剂量及菌体荚膜的影响,但与所研究的离子种类及其能量没有相关性。经离子束N+(20keV,5×1015~5×1016ions cm-2)诱变后,筛选到14个植酸降解突变株,它们对植酸的降解率为15%~35%。其中的3个突变株(KNP414-04,KNP414-05,KNP414-12)分解矿物磷和钾的能力也明显提高,分别增加14.7%~27.5%和16.2%~26.4%。在优化培养基中,突变菌株KNP414-12对植酸的降解率达到57.3%,且在连续培养及保藏过程中保持稳定。植酸降解突变株KNP414-12的成功选育表明离子束为胶质芽孢杆菌的性状改良提供了有效途径。

EFFECT OF ION IMPLANTATION ON B. mucilaginosus KNP414 AND SCREENING FOR MUTANTS WITH HIGHER RELEASE OF PHOSPHATE AND POTASSIUM

Effect of ion implantation on strain KNP414 of Bacillus mucilaginosus was investigated. Survival ratio of isolate KNP414 was independent of the tested ions species and energy, but was highly dependent on their doses and the presence of bacterial capsule. 14 phytate-degTadation mutants were obtained from the spores implanted with N+ (20keV, 5×1015～5×1016 ions cm-2) , and their phytate-degradation capacities were 15%～35%. Amongst, 3 mutants (KNP414-04, KNP414-05, KNP414-12) with higher solubilizing capacities of mineral phosphate and potassium were identified. Their solubilizing capacities of the two minerals increased by 14.7%～27.5% and 16.2%～26.4%, respectively. Mutant KNP414-12 was found to be able to dissolve 57.3% phytate in the optimized medium and the degradation ratio was comparatively stable in seven continuous generations and during the storage process. In conclusion, ion implantation was an effective mutagenic source for isolate KNP414, since it increased the abilities to solubilize phosphate and potassium as well as to degradate phytate.Meanwhile the screening method used in this study has been proved to be successful for rapid selection of phytate-degradation mutants.