Microbiosensors for Measurement of Microbially Available Dissolved Organic Carbon: Sensor Characteristics and Preliminary Environmental Application
Microbiosensors for Measurement of Microbially Available Dissolved Organic Carbon: Sensor Characteristics and Preliminary Environmental Application
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DOI：
10.1128/aem.00641-06
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发表时间：
2006-08
影响因子：
4.4
通讯作者：
M. Köster;C. Gliesche;Rainer Wardenga
中科院分区：
文献类型：
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作者：
M. Köster;C. Gliesche;Rainer Wardenga
摘要描述了基于微生物呼吸的微生物传感器，用于定量微生物瞬时呼吸的可用溶解有机碳 (ADOC)。传感膜含有固定在聚氨酯水凝胶中的需氧海水微生物。分子研究表明，所使用的细菌菌株与华氏葡萄球菌关系最密切。该菌株的特点是底物选择性低，这反映在对各种单糖和二糖、短链脂肪酸和氨基酸的响应上，如使用 Biolog 微孔板测定的。特别强调的是严格评估生物传感器的功能，该功能受所选菌株的预处理、传感膜的化学和几何特性（例如组成、渗透性和厚度）、固定细胞的分布、生物量和生理状态以及暴露条件（例如温度和营养供应）的影响。传感器显示，根据传感器的类型、特性和近期历史，葡萄糖浓度高达 500 μM 时存在线性响应。传感器的检测限相当于约 6 至 10 μM 葡萄糖。 90% 的响应时间为 1 至 5 分钟。一般来说，生物传感器的响应随着时间的推移而变弱。单个传感器的保质期长达两周。基于光学 ADOC 微生物传感器的测量表明，在以光自养为主的沙质沿海沉积物中，ADOC 的池大小和周转率受到底栖微藻的光合活动和微生物有氧呼吸的调节。在微型底栖植物初级生产力在中午达到最大值后不久，ADOC 产量大幅增加，而 ADOC 在夜间被微生物呼吸消耗。
ABSTRACT Microbial respiration-based microbiosensors used for quantification of available dissolved organic carbon (ADOC) instantaneously respired by microorganisms are described. The sensing membranes contained aerobic seawater microorganisms immobilized in a polyurethane hydrogel. Molecular investigations revealed that the bacterial strain used was most closely related to Staphylococcus warneri. This strain was characterized by low substrate selectivity, which was reflected in the response to various mono- and disaccharides, short-chain fatty acids, and amino acids, as determined using Biolog microplates. Specific emphasis was placed on critically assessing biosensor functioning that was affected by preconditioning of the selected bacterial strain, chemical and geometric properties of the sensing membrane (e.g., composition, permeability, and thickness), and the distribution, biomass, and physiological state of immobilized cells, as well as the exposure conditions (e.g., temperature and nutrient supply). The sensors revealed that there was a linear response up to a glucose concentration of 500 μM depending on the type, characteristics, and recent history of the sensors. The detection limit of the sensors was equivalent to about 6 to 10 μM glucose. The 90% response time ranged from 1 to 5 min. Generally, the response of the biosensors became weaker with time. The shelf lives of individual sensors were up to 2 weeks. Measurements based on optical ADOC microbiosensors revealed that in photoautotrophically dominated sandy coastal sediments, the pool sizes and turnover of ADOC were regulated by the photosynthetic activity of benthic microalgae and microbial aerobic respiration. A large increase in ADOC production was observed shortly after the microphytobenthic primary production reached the maximum value at midday, whereas ADOC was consumed by microbial respiration during the night.