Environmental Engineering Reference
In-Depth Information
anoxic zone. Phylotypes were related to members of hydrocarbon-degrading
consortia, SAR406 cluster, and to
Desulfobacterium anilini
[58]. Perry et al.
[37] isolated
Shewanella putrefaciens
from the Black Sea water column, a res-
piratory facultative anaerobe that can reduce quantitatively thiosulfate, sulfite,
and elemental sulfur to sulfide.
Shewanella
species were accounted for 20 to
50% of the total bacterial counts in the suboxic zone (10
5
cells ml
−
1
) [30].
Several authors speculated that due to their respiratory versatility,
Shewanella
may play a significant role in both, metal and sulfur cycling.
Figure 4.
Combined depth profiles of sulfate reduction rates (SRR) and dark
14
CO
2
fixation
rates (CO
2
fix) in the open Black Sea at Station 4 in May 1988; 44˚20.23'N, 32˚09.54'E, depth
1998 m.
Bacteria of the Nitrogen Cycling.
A brief overview of different bacter-
ial groups related to the sulfur cycling present in the Black Sea chemocline
shows that autotrophic and chemolithotrophic thiobacilli of
Thiobacillus
and
Thiomicrospira
genera play an important role in the chemosynthesis and sul-
fide oxidation in the chemocline. Some of these strains may use nitrate as an
electron acceptor in oxidizing sulfide [52, 56, 57], but the depth distribution of
