Abstract
The present paper is concerned with the influences of temperature, pH value and salinity upon the sulfate-reducing activity of marine sulfate-reducing bacteria.
It is thought that these environmental factors are primarily affecting the development of sulfides in the bottom mud of coastal regions of the sea receiving a large quantity of industrial drainage from pulp manufactories1).
It was therefore hoped that the infor ?? tion obtained would provide a better understanding of the sulfides production in such regions of the sea, about which very little is known at present.
The development of sulfides in the sea water medium inoculated with the pure culture of marine sulfate-reducing bacteria was observed at various temperatures, at various pH values and at various salinities.
The results obtained are shown in Figs. 1, 2, 3 and 4, and may be summarized as follows:
1) The marine sulfate-reducing bacteria grew well over the range 20-40°C but failed to grow at 15.5°C and 45°C. The op ?? imum temperature for the production of sulfides was at about 35°C. Below 35°C sulfides were more vigorously produced with raising of temperature.
2) The sulfate reduction by this organism occurred within relatively narrow pH range 5.8-7.5. The maximum production of sulfides resulted at pH 6.5.
3) The sulfate reduction by this organism occurred over the relatively wide range of salinity 1.5-6.1%. The maximum development of sulfides was obtained in the medium having a salinity of 3%.
