一株好氧反硝化细菌的筛选及对土壤脱氮效果研究

为了探究反硝化生物菌剂于盐渍化土壤修复的应用机制和条件，以好氧反硝化能力为主要指标，以宁波慈溪地区的大棚种植土壤为样本，通过筛选比较进行菌株分离，得到一株高效好氧反硝化菌DPT001。通过形态、生理生化特征和16SDNA基因序列分析对菌种进行了菌属鉴定，并研究了该菌株适宜的生长条件。筛分出的好氧反硝化菌为革兰氏阳性短杆菌，属于克伯氏菌属的Castellaniella脱氮杆菌。在好氧环境下，52 h时NO3-降解率达到92%。菌株的适宜生长条件为中性或弱碱性土壤，盆栽试验表明，以此菌剂制备的生物菌肥（培养的菌种和腐熟花生壳混合）对土壤总盐度和硝酸盐浓度都有明显的降低作用。本研究从大棚土中筛选出的好氧反硝化菌，具有较高的反硝化特性，并优于市售的商品脱氮生物菌剂。

Screening of an Aerobic Denitrification Strain and Its Nitrogen Removal Characteristics for Soil

To explore the application mechanism and condition of denitrifying biological agent in saline soil remediation, aerobic denitrification capacity was used as the main index, the planting soil of greenhouse in Ningbo Cixi was used as the material, the bacterial strain was isolated by screening and comparing. An aerobic bacterial strain with the highest activities was obtained and named DPT001. The strain was identified according to its morphological, physiological and biochemical properties and 16S DNA gene sequence analysis. The suitable culture condition of this strain was studied. The results showed that DPT001 was a gram-positive bacillus and was identified as Castellaniella ginsengisoli. In the anaerobic environment, NO3- degradation rate was 92% in 52 h. The suitable growth conditions were neutral or weak alkaline soil. The pot experiment showed that the biological bacterial fertilizer (mixed with the strain and decomposed peanut shell) obviously decreased the total salt concentration and NO3- concentration. An aerobic denitrifying strain was isolated from greenhouse soil and it exhibited high denitrification characteristics and was better than the commercial denitrification biological bacterial agent.