指某一受体细菌通过直接吸收来自另一供体细菌的含有特定基因的脱氧核糖核酸(DNA)片段,从而获得了供体细菌的相应遗传性状,这种现象称为细菌转化。自然界的转化现象,一般发生在同一物种或近缘物种中。细菌转化方法已被引入其他生物,例如采用原生质体转化法,可将外源DNA注入到不具摄取DNA能力的生物中,使其获得某些新的特性。
甜菜根包含高浓度的硝酸盐,它可被口腔内细菌转化为亚硝酸盐。
Beet roots contain high concentrations of nitrates, which are converted into nitrites by bacteria in the mouth.
结论:所用方法操作简便,重复性好,适用于光合细菌转化槲寄生培养液中多糖的含量测定。
Conclusion: the method is simple, accurate, reproducible and suitable for the determination of polysaccharide in cultivating liquid of photosynthetic bacteria transforming ramulus viscid.
大多酿酒师会把红酒存放一段时间,细菌会把苹果酸转化成更“柔和”、更“圆润”的乳酸。
Most vintners let the wine age a bit so bacteria can turn malic acid into the "softer," "rounder" lactic acid.
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