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.