接种泡囊假单胞菌对土壤生物性质及A. corsicum吸收Ni的影响

采用室内模拟试验方法,研究了在水稻土、元江土和墨江土中添加泡囊假单胞菌（Pseulormanas vesicularis）后土壤中微生物种群数量、土壤酶活性和镍超积累植物Alyssum corsicum对土壤镍的富集效果.土壤接种泡囊假单胞菌70d后,水稻土中DTPA提取态镍较对照土中的明显减少、元江土和墨江土中的有所减少;土壤中细菌、真菌和放线菌数量增加,5种土壤酶活性提高.试验结果表明,水稻土、元江土、墨江土添加泡囊假单菌后植物地上部生物量较对照分别增加了29%、309%和43%,进而提高了A.corsicum自土壤中富集镍的效率：水稻土中增加54%,元江土中增加306%,墨江土中增加32%.泡囊假单胞菌这一新用途的发现,可为植物修复微生物制剂和基因工程菌的开发提供本土的微生物的菌种资源.

Effect fo soil inoculation with Pseudomonas vesicularis on biological properties of three nickel-contaminated soils and on Ni accumulation by the hyperaccumulator Alyssum corsicum

In recent years, phytoremediation using metal hyperaccumulators has been proposed as a cost-effective and environmentally-friendly solution to the problem of heavy metal contaminated soils. Despite their ability to accumulate high levels of metals in the shoot, however, most hyperaccumulators are of limited usefulness for commercial-scale soil remediation because of their small size and slow growth. Finding ways to improve the phytoremediation performance of hyperaccumulators will contribute to the development of phytoremediation as a commercial technology. We studied phytoremediation by the Ni hyperaccumulator Alyssum corsicum in three soils (a paddy soil, Yuangjing soil, and Mojing soil) with and without inoculation of the soil with the plant growth promoting rhizobacterium (PGPR) Pseudomonas vesicularis. After 70 days of incubation, several plant and soil indices, including soil nickel concentration, soil bacteria, soil fungus, soil actinomyces, soil microbial biomass and soil enzyme activity, were studied. DTPA-extractable Ni concentration in the paddy soil with added P. vesicularis was significantly lower than it was in the control treatment, and there was some reduction of DTPA-Ni in the inoculated Yuanjiang and Mojiang soils. In all three soil types, microorganism population and microbial biomass were elevated in the inoculated treatments, suggesting that P. vesicularis had colonized the tested soils successfully. Amplification of microbial DNA from the tested soils with five primers showed that the Shannon-Weaver index of microbial DNA sequence diversity was higher in control soils than that in treated soils. Activities of soil enzymes, including urease, alkaline phosphatase, acid phosphatase, polyphenol oxidase and catalase, were generally higher in treated soils than in control soils. In the inoculated treatments, the biomass of A. corsicum was increased by 29% in the paddy soil, 309% in Yuanjiang soil and 43% in Mojiang soil compared to the control treatments. Phytoremediation efficiency was also improved, by 54% in the paddy soil, 306% in Yuanjiang soil and 32% in Mojiang soil. The nickel concentration in A. corsicum shoots, however, was not significantly affected by inoculation with P. vesicularis. In conclusion, the PGPR P. vesicularis promoted the growth of the Ni hyperaccumulator A. corsicum and increased its phytoremediation efficiency.