不同营养因子对土壤细菌可培养物种多样性的影响

通过在改良的VL55培养基中添加6种不同的营养因子,利用大量稀释法对采自河北、青海和云南的3份土壤样品进行细菌分离,并对所分离菌株进行16S r RNA基因序列系统发育分析,比较利用不同营养因子分离的可培养细菌物种多样性。结果表明,添加营养因子分离得到的细菌物种多样性明显高于对照;土样1对照分离得到5个属,添加6种营养因子的处理共分离得到22个属;土样2对照分离得到2个属,添加6种营养因子的处理共分离得到17个属;土样3对照分离得到6个属,添加6种营养因子的处理分离得到15个属。添加不同营养因子的培养基组合分离得到各自独特的细菌类群。其中,从青海土样中分离得到的菌株HBUM200206与运动东菌(Dongia mobilis)LM22T的亲缘关系最近,序列相似性为94.58%,可能是红螺菌科(Rhodospirillaceae)的一个潜在新属。此外,有12株菌与亲缘关系最近的模式菌株的16S r RNA基因序列相似性均小于98.65%,可能为潜在的新种。

Effects of different nutritional factors on culturable species diversity of soil bacteria

By adding six different nutrient factors to the modified VL55 medium, a large number of dilutions were used to isolate bacteria from three soil samples collected from three regions of Hebei, Qinghai, and Yunnan. The phylogenetic analysis of the 16S rRNA gene sequences was performed on the strains isolated using six different nutrient factors to compare the species diversity of culturable bacteria. The results showed that the bacterial species diversity obtained from the addition of nutritional factors was significantly higher than that of the control; 5 genera were isolated from the soil sample 1 control, 22 genera were isolated from the experimental group with the addition of six nutritional factors; soil sample 2 control was isolated two genera, 17 genera were isolated from the experimental group; 6 genera were isolated from the soil sample 3 control, and 15 genera were isolated from the experimental group. The combination of culture media with different nutrient factors was added to isolate their unique bacterial populations. Among them, the strain HBUM200206 isolated from the soil sample of Qinghai Province had the closest genetic relationship with Dongia mobilis LM22T, and the 16S rRNA gene sequence similarity was 94.58%, which may be a potential new genera of Rhodospirillaceae. In addition, the 16S rRNA gene sequence similarity of the 12 strains and the closest relatives of the type strains were all less than 98.65%, which may be potential new species.