【摘要】 目的：分析血链球菌染色体ＤＮＡ片段序列，探讨血链球菌遗传生物学特性。方法：采用ＴＡ克隆技术将此片段转化克隆并进行碱基序列测定，通过ＧｅｎＢａｎｋ进行同源分析。结果：血链球菌ＡＴＣＣ１０５５６ＤＮＡ片段含有与固氮菌高度同源的ｎｉｆＳ、ｎｉｆＵ基因，同源分值为１１４点（ｂｉｔｓ）。结论：国内外首次报道血链球菌ＤＮＡ片段含有ｎｉｆＳ、ｎｉｆＵ部分基因。更多还原

【Abstract】 Objective: To analyze the sequence of Streptococcus sanguis chromosome which contains one DNA fragment of 800 base pairs (bp) and discuss Streptococcus sanguis biological features of heredity. Methods: Streptococcus DNA of 800 bp genetic fragment was cloned and analyzed by using eukaryotic expression vector. Results:By Genebank’s database, it showed that the 800 bp genetic sequence was highly homologous with other bacterial nifS and nifU gene, and the highest homologous score was 114. Conclusion: this nif gene of ATCC 10556 strain may correlate with nutrient metabolism and peroxide hydrogen release of Streptococcus sanguis.更多还原