高脱氮活性海洋着色菌YL28生物膜特性  

Biofilm formation characteristics in marine purple sulfur bacterium Marichromatium gracile YL28 with high nitrite removal efficiency

作　　者：周广静 张晓波[1] 朱笔通 赵春贵[1] 杨素萍[1] ZHOU Guang-Jing;ZHANG Xiao-Bo;ZHU Bi-Tong;ZHAO Chun-Gui;YANG Su-Ping(Department of Bioengineering and Biotechnology,Huaqiao University,Xiamen,Fujian 361021,China)

机构地区：[1]华侨大学生物工程与技术系,福建厦门361021

出　　处：《微生物学通报》2018年第9期1980-1988,共9页Microbiology China

基　　金：国家海洋公益性行业科研专项(201505026);福建省自然科学基金(2018J01049;2015J01137);华侨大学研究生科研创新能力培育项目~~

摘　　要：【背景】细菌生物膜在废水处理领域显示出良好的前景,但目前应用于海水养殖水体处理的菌株主要源自淡水菌株,存在难以适应海水高盐环境的问题。源自红树林的海洋着色菌(Marichromatiumgracile)YL28应用于海水养殖水体处理,不仅具有高效除氮能力,而且趋光贴壁能力很强。【目的】阐明海洋着色菌(Marichromatium gracile) YL28的生物膜形成特性和规律,以期为海水养殖水体生物膜反应系统的开发和应用提供参考。【方法】以生物膜和游离菌体生物量、脱氢酶活性、生物膜多糖含量和蛋白含量、无机三态氮去除活性为测定指标,在光照厌氧环境中研究海洋着色菌YL28菌株的生物膜形成规律、生物活性和脱氮效果。【结果】随着时间延长,4 000 lx光照时游离菌体生物量逐渐升高,但在稳定期前快速降低,而成膜生物量经过延滞期后逐渐升高并趋于稳定,表明培养过程中游离菌体能趋光贴壁生长并形成生物膜。在0-5 000 lx光照范围内培养4 d,低光照强度(500 lx)时成膜率(71.21%)最高,1 000-4 000 lx光照强度下成膜率虽然不是最高(54.64%-68.66%),但适宜菌体成膜,膜生物量干重达到0.60-0.80 mg/cm2。除了5 000 lx光照对成膜菌体脱氢酶活性有不利影响外,成膜菌体和游离菌体脱氢酶活性随光照强度升高而升高,而且没有明显差异。生物膜的形成会导致光反应器内部光照受限,但反应器内部游离菌体的脱氢酶活性并没有降低,由此表明,培养液中的菌体主要在生物膜及其界面生长并游离扩散至培养液中。随光照强度(1 000-5 000 lx)和培养时间(4-10 d)的变化,胞外复合物(Extracellularpolymericsubstances,EPS)中蛋白含量变异较大,多糖含量变化较小;随时间延长,蛋白含量升高,其中3 000 lx时蛋白含量最高;4 000 lx时生物膜菌体与游离菌体脱氮活性相比,单位质量菌体的氨氮和亚硝氮去除活性未受到明显影响,而硝�[Background] The bacterial biofilm has gained widespread application in waste water treatment field. However, the bacterial strains used in marine aquaculture are lack of the adapation to the high salt environment. Marichromatium gracile YL28 isolated mangrove is a true salt-requirement marine bacterium. Strain YL28 not only exhibits effective inorganic nitrogen removal ability, moreover, it has better biofilm-forming traits in response to illumination. [Objective] This work aims to investigate the characterizations of biofilm formation in marine purple sulfur bacterium Marichromatium gracile YL28 with the basis for the development and application of biofilm bioreactor in marine aquaculture. [Methods] The characteristics of biofilm formation and nitrogen removal of YL28 were examined by measuring biomass, dehydrogenase activity, polysaccharide content, protein content and inorganic nitrogen removal in simulated seawater system under anaerobically in the light condition. [Results] The planktonic bacterial biomass in culture suspension increased gradually with increasing time at 4 000 lx and followed by a rapid decrease in biomass before stationary period, and the biofilm-forming bacterial biomass reached a stabilization after stationary period, indicating that the planktonic bacteria had phototaxis and formed biofilm on the vessel wall. The biofilm forming rate of YL28 was highest （71.21%） under lower light illumination condition （500 1x） for 4 d. The light illumination in the range from 1 000-4 000 1x benefited for biofilm formation （0.60-0.80 mg/cm2 dry weight） although its biofilm forming rate （54.64%-68.66%） was not higher than low light condition. The light illumination of 5 000 1x had negative effect on the dehydrogenase activity of biofilm-forming bacteria. The activity of dehydrogenase of both the biofilm-forming bacteria and planktonic bacteria increased with the increasing light intensity, no significant difference in dehydrogenase activity between biofilm-forming bacteria and planktonic

关 键 词：紫细菌 海洋着色菌 生物膜 脱氮 

分 类 号：X172[环境科学与工程—环境科学]