Open AccessSimple organic electron donors support diverse sulfate‐reducing communities in fluidized‐bed reactors treating acidic metal‐ and sulfate‐containing wastewater
Author(s) -
Kaksonen Anna H,
Plumb Jason J,
Franzmann Peter D,
Puhakka Jaakko A
Publication year - 2004
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1016/s0168-6496(03)00284-8
Subject(s) - library , sulfate , temperature gradient gel electrophoresis , biology , bacteria , sulfate reducing bacteria , microbiology and biotechnology , 16s ribosomal rna , microbial population biology , desulfovibrio , wastewater , bioreactor , thermophile , microorganism , environmental chemistry , electron donor , food science , biochemistry , waste management , chemistry , botany , catalysis , organic chemistry , genetics , engineering
Bacterial diversity of lactate‐ and ethanol‐utilizing sulfate‐reducing fluidized‐bed reactor (FBR) communities was investigated with culture‐independent methods. The FBRs were fed for 500 days with synthetic mineral processing wastewater containing sulfate, zinc and iron with hydraulic retention time of 16–24 h. Sodium lactate or ethanol was used as electron donor for microbial sulfate reduction. For microbial characterization, 16S rRNA gene clone libraries and denaturing gradient gel electrophoresis (DGGE) fingerprinting were employed. The FBR communities were diverse and contained many previously undescribed bacteria. The clone library indicated significant differences between bacterial communities of the two reactors. Most notable was the large number of Proteobacterium sequences retrieved from the ethanol‐fed reactor, whereas in the lactate‐fed reactor, sequences clustering with Nitrospira phylum were most abundant. Ethanol‐utilizing FBR culture was more diverse than the lactate‐utilizing one. Some sequences from each reactor were closely related to known sulfate reducers, such as Desulfobacca acetoxidans , Desulforhabdus amnigenus , and species of Desulfovibrio . DGGE profiling showed some changes in the bacterial communities over 393 days of continuous FBR operation. This study showed that it is possible to maintain diverse sulfate‐reducing consortia using simple electron donors, lactate or ethanol in an open engineered ecosystem.