APPLICATION OF ANTISERA RAISED AGAINST SULFATE-REDUCING BACTERIA FOR INDIRECT IMMUNOFLUORESCENT DETECTION OF IMMUNOREACTIVE BACTERIA IN SEDIMENT FROM THE GERMAN BALTIC SEA

Polyclonal rabbit antisera raised against sulfate-reducing bacteria (S RB) could detect several distinct populations of bacteria in sediment from the German Baltic Sea. The depth distribution of immunoreactive b acteria was determined by an indirect immunofluorescence filter method , Anti-Desulfovibrio desulfuricans DSM 1926 serum showed maximum bacte rial numbers at a depth of IS cm, with a concentration of 60 x 10(6) c ells cm(-3). With anti-Desulfovibrio baculatus DSM 2555 serum, counts were highest at the same depth, approaching 0.7 x 10(6) cells cm(-3). Other significantly smaller populations were observed. Anti-SRB(Strain ) (1) (lactate,vibrio) maxima were at 0 to 4 cm and at 17 to 18 cm, An ti-SRB(Strain) (2)(lactate,vibrio) serum showed several local maxima. Anti-SRB(Strain) (3)(lactate,oval) serum detected one single peak at a depth of 10 to 12 cm, Also determined were rates of sulfate reduction , total bacterial counts by acridine orange staining, and the viable c ounts by dilution series on anaerobic lactate medium, The total bacter ial counts were highest (180 x 10(6) cells cm(-3)) at 3 to 4 cm and dr opped to 24 x 10(6) cells cm(-3) at 10 to 11 cm but showed additional local maxima reaching 140 x 10(6) cells cm(-3) at a depth of 17 to 18 cm. Viable counts (most probable number) were above 10(5) CFU cm(-3) a t 0 to 3.6 cm but remained below 10(3) CFU at 7.2 to 18 cm. The sulfat e reduction rate was maximal (107 nmol cm(-3) day(-1)) at a depth of 1 to 2 cm, dropped to 10 mmol cm(-3) day(-1) at 12 to 13 cm, and reache d 38 nmol cm(-3) day(-1) at 17 to 18 cm.