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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 1305

Takeuchi Jun-ichi, Taguchi Yukio, Satake Kenichi, and Mori Tadahiro; [Methods for the determination of the number and the activity of sulfate-reducing bacteria]. Suishituodaku kenkyu 11(1):38-49, 1988

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For enumerating the sulfate-reducing bacteria, the most probale number method was recommended because of its reliability. The modified ISA medium (Mara and Williams, 1970) facilitated the early growth and metabolism of the bacteria, and then could shorten their incubation period. The sulfate-reducing bacteria in natural habitats, i.e., mixed culture with other heterotrophic bacteria, were able to enumerate easily by using the semi-liquid agar medium without reducing agents. Because the medium did not precipitate after being autoclaved, it was suitable for forming the distinct black colonies. Anaerobic pouches were available for the isolation as well as the enumeration. The rate of bacterial sulfate reduction was determined with a radiotracer of [35]S. In the case of aquatic sediment, a whole core sample of the sub-sampled mud suspension was used for the incubation. Two types of procedure for recovering acid-soluble sulfides were introduced: a stripping method with an inert gas or an absorbing method with a filter paper. The latter, simple and rapid procedure was more suitable for routine works. These methods for the quantification of the bacterial number and activity, described herein, are considered to be practically used to research in the applied field, such as sewage treatment.