重金属抗性解磷细菌的磷溶解特性研究

从湖南省湘西州花垣县的铅锌矿表层土壤中,筛选出两株具有重金属抗性和解磷特性的细菌T PSB1和T PSB2.通过16S rRNA基因序列比对,分别鉴定为嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)和唐菖蒲伯克霍尔德菌(Burkholderia gladioli).T PSB1和T PSB2在含有难溶性无机磷液体培养基中,其上清液的可溶性磷含量最高分别达到了402.9 mg·L-1和589.9 mg·L-1;在难溶性有机磷固体和液体培养基中,固体平板上均出现解磷圈,而液体培养基上清液中,可溶性磷含量也分别达到了2.97 mg·L-1和4.69 mg·L-1.另外,两株细菌对重金属Zn2+的抗性最高,在其浓度为2000 mg·L-1固体和液体培养基条件下均可以生长,磷溶解浓度分别为114.8 mg·L-1和125.1 mg·L-1.而在含铬和铅的浓度为1 000 mg·L-1的液体培养基中,两株细菌同样表现出重金属抗性.在Pb2+浓度为1000 mg·L-1的液体培养基中,磷溶解浓度分别达到了57.9 mg·L-1和71.7 mg·L-1;而在Cr2+浓度为1000 mg·L-1的培养基中磷溶解浓度分别为60.1 mg·L-1和98.4 mg·L-1.

Isolation and Characterization of Two Bacteria with Heavy Metal Resistance and Phosphate Solubilizing Capability

Two phosphate solubilizing bacteria (T PSB1 and T PSB 2) with high heavy metal resistance were isolated from soil of a lead-zinc mine in Huayuan of Hunan Province, China. These two bacteria were identified as Stenotrophomonas maltophilia and Burkholderia gladioli by 16S rRNA sequencing analysis, respectively. In the media containing insoluble inorganic calcium phosphate, the soluble phosphate amounts reached respectively 402.9 mg·L^-1 and 589.9 mg·L^-1 with the bacteria T PSB1 and T PSB2 after two weeks' growth. Moreover, the two bacteria developed solubilizing halos on the plates supplemented with the organic phosphate compounds, and the resulting soluble phosphate amounts in the broth media were respectively 2.97 mg·L^-1 and 4.69 mg·L^-1. In addition, these two bacteria showed the resistance to up to 2000 mg·L^-1 Zn²⁺, and their phosphate solubilizing amounts reached respectively 114.8 mg·L^-1 and 125.1 mg·L^-1. Similarly, their heavy metal resistance and phosphate solubilizing ability were also found in the Cr and Pb broth media with the concentration of 1000 mg·L^-1. In the Pb media, the soluble phosphate amounts reached respectively 57.9 mg·L^-1 and 71.7 mg·L^-1, and the soluble P amounts in the Cr media were 60.1 mg·L^-1and 98.4 mg·L^-1 at the concentration of 1000 mg·L^-1.