Viruses, prokaryotes and biochemical composition of organic matter in different types of mucilage aggregates
Viruses, prokaryotes and biochemical composition of organic matter in different types of mucilage aggregates
复制标题
DOI：
10.3354/ame01126
复制
发表时间：
2007-10-16
影响因子：
1.4
通讯作者：
Danovaro, Roberto
中科院分区：
文献类型：
--
作者：
Bongiorni, Lucia;Armeni, Monica;Danovaro, Roberto
据推测，几种微生物过程有助于粘液的形成和转化。然而，迄今为止，这些机制都没有得到一致的测试使用不同类型的粘液。我们调查了2000年，2002年和2003年夏季在亚得里亚海收集的9种不同类型的粘液聚集体（macroflocs，纵梁，蜘蛛网，丝带，纵梁/蜘蛛网云，大奶油状表层，假底和缺氧假底）的生化组成和微生物活动。较大和老年聚集体，其特征在于碳水化合物和低脂质部分的积累，表现出显着的生化差异相比，年轻的聚集体。原核生物的丰度，C生产和胞外酶活性增加，从小到中等大小的聚集体（对应约中期寿命），而他们在较大的（和老年人）聚集体下降。最高的原核C生产和酶活性与最高的病毒丰度相结合。在显示最高病毒丰度的粘液中，观察到酶促降解的C掺入原核生物生物量减少。这一结果表明，在海洋聚集体的微生物循环功能的损害病毒的潜在参与。通过对微生物变量的多变量分析，可以确定粘液生命周期的3个阶段：（1）早期阶段，以聚集体和DOM积累的大量原核生物定殖为特征;（2）成熟阶段，其特征在于将降解的C掺入原核生物生物量的能力降低和高病毒丰度，以及（3）病毒和原核生物的丰度和活性都下降的衰老阶段。这些结果提供了新的见解海洋聚集体的微生物生态学和影响其寿命的过程。
It has been hypothesised that several microbial processes contribute to mucilage formation and transformation. However, to date, none of these mechanisms have been consistently tested using different types of mucilage. We investigated the biochemical composition and the microbial activities occurring in 9 different types of mucilage aggregates (macroflocs, stringers, cobwebs, ribbons, stringers/cobwebs clouds, big creamy surface layer, false bottoms and anoxic false bottoms) collected during summer 2000, 2002 and 2003 in the Adriatic Sea. Larger and aged aggregates, characterized by the accumulation of carbohydrate and a low lipid fraction, displayed significant biochemical differences when compared with younger aggregates. Prokaryote abundance, C production and extracellular enzymatic activities increased from small to medium-sized aggregates (corresponding approximately to mid life span) while they decreased in larger (and aged) aggregates. The highest prokaryotic C production and enzymatic activities were coupled with highest viral abundance. In mucilage displaying the highest viral abundance a reduced incorporation of enzymatically degraded C into prokaryote biomass was observed. This result suggests a potential involvement of viruses in the impairment of the microbial loop functioning in marine aggregates. Applying a multivariate analysis to the microbial variables, 3 stages of mucilage life span can be identified: (1) an early stage characterized by a large prokaryote colonization of the aggregate and DOM accumulation; (2) a mature stage characterized by a decreased capability of incorporating degraded C into prokaryote biomass and high viral abundance and (3) an aged stage characterized by the decrease in both viral and prokaryote abundance and prokaryote activity. These results provide new insights into the microbial ecology of marine aggregates and the processes influencing their life span.