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Distribution of microaerophilic bacteria through the oxic-anoxic transition zone of lagoon sediments

✍ Scribed by Maria J. Ferrara-Guerrero; Armand Bianchi


Publisher
Springer
Year
1990
Tongue
English
Weight
536 KB
Volume
207
Category
Article
ISSN
1573-5141

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✦ Synopsis


In marine sediments, where soluble gases diffuse only very slightly, many organisms struggle for molecular oxygen. Microaerophilic bacteria, able to grow at reduced p0, between 0.2 and 12 %, have an advantage. Distribution of aerobes, microaerophiles and anaerobes was compared with the oxygen gradient in seawater and sediment samples collected in a northern Mediterranean lagoon. In the near bottom seawater and in the O-10 mm upperlayer of sediment, the microaerophilic counts were less than 1 y0 of aerobe densities. In the lo-15 mm zone, these two groups were equivalent in density (1 x lo5 cells ml-'). As expected, the microaerophiles took advantage of their low oxygen tension requirements in the subsurface sediments, between the well aerated zone (O-5 mm depth) and the low redox potential zone. Then, beyond a depth of 20 mm, the anaerobes prevailed in this sandy clay.