BAROPHILIC BACTERIA ASSOCIATED WITH DIGESTIVE TRACTS OF ABYSSAL HOLOTHURIANS
BAROPHILIC BACTERIA ASSOCIATED WITH DIGESTIVE TRACTS OF ABYSSAL HOLOTHURIANS
复制标题
DOI：
10.1128/aem.44.5.1222-1230.1982
复制
发表时间：
1982-01-01
影响因子：
4.4
通讯作者：
COLWELL, RR
中科院分区：
文献类型：
--
作者：
DEMING, JW;COLWELL, RR
深海海参和沉积物样品是在德梅拉拉深海平原（北大西洋）4 430 - 4 850米深处采集的。用荧光显微镜测定了海参消化道和周围表层沉积物中细菌浓度。最近被动物摄入的沉积物中的细菌总数比最深站周围沉积物中的细菌总数高1.5至3倍。在前肠中始终观察到最低的计数，据信海参的消化过程发生在那里。在大多数动物中，后肠中的计数增加了3至10倍。3 ℃时的微生物活性C和原位和大气压测定肠道和沉积物样品的利用[14 C]谷氨酸，倍增时间的混合人口的可培养的细菌和酵母提取物的存在下，萘啶酸，使用落射荧光显微镜响应的总细菌计数的百分比。一个嗜压微生物种群，深海压力下显示出升高的活动，检测到所有3种方法从后肠的沉积物。透射电镜显示，完整的细菌直接与肠衬里只在后肠。这种细菌被认为是作为一种活跃的代谢性肠道植物群携带的，它能转化海参摄取的深海沉积物中的有机物质。使用本研究中获得的数据，据计算，沉积物中的有机物改变微生物活动清除海参肠每16小时，这表明深海海参及其相关的肠道植物群是深海底栖海洋的营养循环的重要参与者。
Abyssal holothurians and sediment samples were collected at depths of 4430-4850 m in the Demerara abyssal plain (North Atlantic Ocean). Bacterial concentrations in progressive sections of the holothurian digestive tract and in surrounding surface sediments were determined by epifluorescence microscopy. Total bacterial counts in sediments recently ingested by the animals were 1.5- to 3-fold higher than in surrounding sediments at the deepest station. Lowest counts were observed consistently in the foregut, where the digestive processes of the holothurian are believed to occur. In most animals, counts increased 3- to 10-fold in the hindgut. Microbial activity at 3.degree. C and in situ and atmospheric pressure were determined for gut and sediment samples by measuring the utilization of [14C]glutamic acid, the doubling time of the mixed-population of culturable bacteria and the percentage of the total bacterial count responsive to yeast extract in the presence of nalidixic acid, using epifluorescence microscopy. A barophilic microbial population, showing elevated activity under deep-sea pressure, was detected by all 3 methods in sediments removed from the hindgut. Transmission EM revealed intact bacteria directly associated with the intestinal lining only in the hindgut. The bacteria are believed to be carried as an actively metabolizing, commensal gut flora that transforms organic matter present in abyssal sediments ingested by the holothurian. Using data obtained in this study, it was calculated that sediment containing organic matter altered by microbial activity cleared the holothurian gut every 16 h, suggesting that abyssal holothurians and their associated gut flora are important participants in nutrient cycles of the abyssal benthic ocean.