Study of immobilized and free Thiobacillus thioparus capability for detection of hydrogen sulfide

The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was used for entrapment of Thiobacillus thioparus, a sulfide oxidizer bacterium. The immobilized beads and free cells of Thiobacillus thioparus were applied to a system in which hydrogen sulfide was produced. As H2S was consumed by the bacteria, the content of dissolved oxygen was decreased and this reduction was determined by use of an O2 electrode. Theimmobilized system showed a lag time in detection of hydrogen sulfide because of the resistance which is caused by the matrix of poly vinyl alcohol. The reduction rate of oxygen was also calculated and it was shown that consumption rate of hydrogen sulfide in immobilized system is more uniform than free cell system. H2S was used in 10 ppm and 20 ppm concentration.

Keywords:

immobilization , free cell , Thiobacillus thioparus , poly vinyl alcohol