脲酶产生菌(UPB)广泛存在于土壤中,在土壤生态系统中发挥着重要作用。在这项研究中,从云南省某铅锌矿区镉(Cd)污染土壤中分离出65株UPB菌株,中国。耐Cd,从水溶液中去除Cd,研究了吲哚乙酸(IAA)的产生和这些材料的植物生长促进作用。结果表明,在65株UPB菌株中,筛选了4株具有IAA生产能力的菌株,分别为苏云金芽孢杆菌W6-11,蜡样芽孢杆菌C7-4,粘质沙雷氏菌W11-10和粘质沙雷氏菌C5-6。在这四种菌株中,蜡状芽孢杆菌C7-4对Cd的耐受性最高,中位效应浓度(EC50)为59.94mg/L。在Cd5mg/L下,美国粘质纤维C5-6对水溶液中Cd的去除率最高,高达69.83%。在Cd25mg/kg下,接种蜡状芽孢杆菌C7-4通过增加根体积显著促进沙罐中的玉米生长,根表面积,根分支的数量减少了22%,29%,20%,分别,植物高度和生物量分别增加16%和36%,分别,并显着增加了玉米根系对Cd的吸收。因此,UPB是增强Cd污染植物对Cd胁迫适应性的潜在资源。
本研究利用从云南铅锌矿区土壤中筛选的产脲酶菌,以中国为研究对象,丰富了云南的微生物资源。此外,本文验证了脲酶产生菌的IAA生产能力和除镉能力,筛选出具有镉污染控制和促进植物生长潜力的双功能脲酶产生菌。
Urease-producing bacteria (UPB) are widely present in soil and play an important role in soil ecosystems. In this study, 65 UPB strains were isolated from cadmium (Cd)-polluted soil around a lead-zinc mine in Yunnan Province, China. The Cd tolerance, removal of Cd from aqueous solution, production of indoleacetic acid (IAA) and plant growth-promoting effects of these materials were investigated. The results indicate that among the 65 UPB strains, four strains with IAA-producing ability were screened and identified as Bacillus thuringiensis W6-11, B. cereus C7-4, Serratia marcescens W11-10, and S. marcescens C5-6. Among the four strains, B. cereus C7-4 had the highest Cd tolerance, median effect concentration (EC50) of 59.94 mg/L. Under Cd 5 mg/L, S. marcescens C5-6 had the highest Cd removal from aqueous solution, up to 69.83%. Under Cd 25 mg/kg, inoculation with B. cereus C7-4 significantly promoted maize growth in a sand pot by increasing the root volume, root surface area, and number of root branches by 22%, 29%, and 20%, respectively, and plant height and biomass by 16% and 36%, respectively, and significantly increasing Cd uptake in the maize roots. Therefore, UPB is a potential resource for enhancing plant adaptability to Cd stress in plants with Cd-polluted habitats.
This study utilized urease-producing bacteria screened from the soil of lead zinc mining areas in Yunnan, China as the research object, enriching the microbial resources in Yunnan. In addition, this article verified the IAA production ability and cadmium removal ability of urease-producing bacteria, and screened out bifunctional urease-producing bacteria that have potential in cadmium pollution control and plant growth promotion.