生态环境学报2016，Vol.25Issue(12)：1991-1998,8.DOI:10.16258/j.cnki.1674-5906.2016.12.014
珠江河口湿地沉积物中耐盐硝化细菌的筛选及其河口硝化特性研究
Screening of Salt Tolerant Nitrifying Bacterium in the Sediments of the Pearl River Estuary and the Characteristics of Its Nitrification
摘要
Abstract
In order to alleviate the nitrogen pollution in estuarine waters, nitrifying bacteria were separated from different sediments of the Pearl River estuary, and acclimated at high salinity medium. And obtained strain with high salt tolerance and high nitrification efficiency was classified through colony morphology observation, physiological characteristics and 16S rDNA sequence analysis. The nitrification efficiencies of this strain cultured at different pH values, temperatures, inoculating rates and sediment qualities were analyzed. Its nitrification property under the environmental condition of estuarine water was also revealed by combining its cells with wetland salt-tolerant plants. The results proved a theoretical basis for alleviate the estuary nitrogen pollution especially by the salt tide intrusion as well as the repair after intrusion. The number of nitrifying bacteria contained in sediments from three typical wetlands, including phragmites wetland, spartina alterniflora wetland and mudflat wetland, were 2.1×105 cells·g-1, 1.8×105 cells·g-1 and 0.5×105 cells·g-1, respectively. The net nitrification rates were (0.41±0.02) mg·m-2·d-1, (0.35±0.03) mg·m-2·d-1 and (0.12±0.02) mg·m-2·d-1, and nitrification intensity were phragmites > spartina alterniflora> mudflat areas. A salt tolerant and high efficient nitrifying bacteria (L4), namely Nitrosomonas communi, was isolated from the sediment of phragmites. When the salinity ranged from 5‰ to 20‰, the nitrification efficiency decreased from 80.5% to 7.7%. After salinity domestication, the nitrification efficiency reached 75.6% at 20‰. The optimal pH value, temperature value and optimal inoculum wet biomass was 7.2 , 30 ℃,and 1g·L-1, respectively, whereas, the sediment was not the vital factor. When the estuary environment was simulated with different salinity and hydrodynamic conditions, strain L4 and phragmites combination system exhibited a stable nitrification efficiency within 0-20‰salinity, the nitrification efficiency in 7 days reached 80.9%-88.91%. It showed a certain degree of synergy when in the salinity of 30‰ and 40‰, the nitrification efficiencies were 52.13% and 31.89%, were all greater than the sum of the nitrification efficiencies of phragmites and strain L4 alone. The nitrification efficiency could reach 67.5% in the absence of hydrodynamics, and reached 81.5% at the ventilation volume rate of 1.5 L·h-1. Oxygen enrichment of hydrodynamic effects could promote nitrification. Strain L4 and phragmites showed a synergistic effect in nitrogen pollution remediation of estuary wetland.关键词
河口湿地/沉积物/硝化细菌/盐度/芦苇Key words
estuarine wetland/sediment/nitrifying bacteria/salinity/phragmites分类
资源环境引用本文复制引用
周雪芳,王立立,刘铃,郭世鸿..珠江河口湿地沉积物中耐盐硝化细菌的筛选及其河口硝化特性研究[J].生态环境学报,2016,25(12):1991-1998,8.基金项目
广东省科技计划项目(2016A020221015) （2016A020221015）
