De Vittor Cinzia, Larato Chiara, Umani Serena Fonda
Dipartimento di Oceanografia Biologica, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Via A. Piccard 54, 34014 Trieste, Italy.
Bioresour Technol. 2009 Dec;100(23):5721-8. doi: 10.1016/j.biortech.2009.06.056. Epub 2009 Jul 23.
Most of the ambient dissolved organic carbon (DOC) is refractory to microbial degradation; bacteria can consume a minor but variable part of the DOC pool over periods of hours and days. It is important to increase our knowledge of the dynamics of the biodegradable fraction of DOC (BDOC) to understand the global carbon budget. Several methods for determining BDOC have been developed; however, the problem of most of them is the time (days/weeks) required for the colonization and/or determination. In this paper, we describe the application to seawater of a plug-flow bioreactor to measure BDOC within 3-4 h. The bioreactor was built following Søndergaard and Worm [Søndergaard, M., Worm, J., 2001. Measurement of biodegradable dissolved organic carbon (BDOC) in lake water with a bioreactor. Water Res. 35, 2505-2513.] protocols for the measurement of BDOC in lake water. We analyzed BDOC on samples collected in the Gulf of Trieste during autumn-winter and summer 2003-2004. BDOC concentrations varied from 8 to 24 microM and represented from 10.3% to 25.5% of the total DOC. To evaluate the effectiveness of this method, we compared bioreactor BDOC measurement with data obtained from batch cultures. The results indicate that BDOC in coastal seawater can be measured rapidly and reliably with this bioreactor.
大部分环境溶解有机碳（DOC）难以被微生物降解；细菌在数小时至数天的时间内能够消耗一小部分但数量可变的DOC库。增加我们对DOC可生物降解部分（BDOC）动态变化的了解对于理解全球碳收支至关重要。已经开发了几种测定BDOC的方法；然而，它们大多数的问题在于定殖和/或测定所需的时间（数天/数周）。在本文中，我们描述了一种活塞流生物反应器在海水中的应用，以便在3 - 4小时内测定BDOC。该生物反应器是按照Søndergaard和Worm [Søndergaard, M., Worm, J., 2001. Measurement of biodegradable dissolved organic carbon (BDOC) in lake water with a bioreactor. Water Res. 35, 2505 - 2513.]用于测定湖水中BDOC的方案构建的。我们分析了2003 - 2004年秋冬和夏季在的里雅斯特湾采集的样品中的BDOC。BDOC浓度在8至24微摩尔之间变化，占总DOC的10.3%至25.5%。为了评估该方法的有效性，我们将生物反应器测定的BDOC与分批培养获得的数据进行了比较。结果表明，使用这种生物反应器可以快速、可靠地测定沿海水域中的BDOC。
