School of Oceanography, University of Washington, WB-10, 98195, Seattle, Washington, USA.
Microb Ecol. 1989 Jul;18(1):29-44. doi: 10.1007/BF02011694.
Antibiotic-insensitive mutants of natural sedimentary bacteria from an intertidal site were selected on gradient plates. Two of these strains, anAeromonas sp. andVibrio alginolyticus, were mixed with natural sediments from the field and fed toAbarenicola vagabunda, an intertidal lugworm characteristic of sandy beaches in the Pacific Northwest. Digestive removal was apparent in the midgut, 97% efficiency being seen forAeromonas sp. Both strains showed rapid growth in the hindgut, increasing between 2 and 3 orders of magnitude in abundance between the midgut and rectum of the polychaete, corresponding with a doubling time of about 50 min for each strain. Direct epifluorescence counts of natural bacteria in guts of animals freshly collected from the field suggest a mean doubling time that is only slightly greater (66 min) for all ingested bacteria that survive midgut digestion. These bacterial growth rates exceed by orders of magnitude the greatest rates reported for ambient marine sediments and suggest that hindgut bacterial growth, though of little immediate importance in the energetics of the animals, may strongly influence both population dynamics of marine bacteria and diagenesis of sedimentary organic matter.
从潮间带沉积物中筛选出对抗生素不敏感的天然细菌突变体，在梯度平板上进行选择。这两种菌株，一种是气单胞菌和弧菌 alginolyticus，与从野外采集的天然沉积物混合，然后喂给北方太平洋沿岸沙滩特有的多毛类环节动物沙蚕。在中肠可以明显观察到消化作用，气单胞菌的效率达到 97%。两种菌株在后肠中均表现出快速生长，在中肠和环节动物的直肠之间的丰度增加了 2 到 3 个数量级，与每种菌株的倍增时间约为 50 分钟相对应。从野外新鲜采集的动物肠道中自然细菌的直接荧光计数表明，所有在中肠消化过程中存活下来的摄入细菌的平均倍增时间仅略长（66 分钟）。这些细菌的生长速度超过了环境海洋沉积物中报道的最大速度，这表明尽管后肠细菌的生长对动物的能量学没有直接的重要性，但它可能强烈影响海洋细菌的种群动态和沉积物有机质的成岩作用。
