Distribution and activity of oceanic bacteria

Abstract

A survey was conducted on 381 samples collected to depths of 1200 m at 47 offshore stations in the Pacific, Caribbean and Atlantic. All samples were cultured in Agar roll tubes and incubated within 4·5°C of the temperature of the water from which they were obtained. The heterotrophic population thus obtained was tested directly for a few biochemical activities or isolated, tested more extensively and keyed to genus. A marked bacterial flora in the 150 μ thick surface film overlying 'low count' waters was observed only off the west coast of Central America in an area known for upwelling. The ratio of lipolytic: proteolytic: amylolytic bacteria in thid Flora was 93:92:24 compared to a ratio of 46:53:54 for 'high count' surface and subsurface samples which were obtained sporadically from the Caribbean and Atlantic. Atypical pseudomonads dominated the Pacific samples, while types two and four pseudomonads were twice as high in the Caribbean and Atlantic samples. The bacteria in the more typical 'low count' samples had biochemical activities which differed from the 'high count' samples. The 'low count' flora had similar proteolytic ratios regardless of latitude, depth or oceanic area. © 1971.