Multiple strains of sulfate-reducing bacteria（SRB）were isolated from sulfate wastewater treatment bioreactor and determined by polymerase chain reaction（PCR） with SRB-specific 16S ribosomal RNA gene primers.One of...Multiple strains of sulfate-reducing bacteria（SRB）were isolated from sulfate wastewater treatment bioreactor and determined by polymerase chain reaction（PCR） with SRB-specific 16S ribosomal RNA gene primers.One of the strains isolated,strain F28-1 was further studied by sequencing the complete 16S ribosomal RNA gene,testing carbon resource utilization,and demonstrating the key enzyme gene structure related to sulfate metabolism,dissimilatory sulfite reductase（Dsr）gene.Blast retrieving results indicated that the SRB belonged to Desulfovibrio,its 16S ribosomal RNA gene sequence was similar to Desulfovibrio desulfuricans subsp.desulfuricans strain Essex 6（AF192153）,with identity 99.9%,and therefore,the strain was named as D.strain F28-1.Strain F28-1 was able to use glucose,propionic acid,lactic acid,acetic acid,ethanol and methanol as sole carbon resource and reduce sulfate to sulfide.It removed 95% sulfate within 72 h in a lab-scale experiment with lactic acid as electron donor.ORF finder program checked out two open reading frames（ORFs）in dsr gene sequence,dsrA and dsrB,which had 14% identity.Corresponding α-and β-subunit amino acid sequences were obtained according to the DNA sequence.α-subunit contained two conserved motifs,i.e.（C-X5-C）-Xn-（C-X3-C）,which was required for binding to siroheme; and CP-Xn-C-X2-C-X2-C required for binding to Fe4S4 clusters.In addition,the β-subunit contained only the Fe4S4 clusters binding site,but the siroheme binding site was missing.The SRB,which had multi-substrates utilization and high sulfate reduction power,supplies the starting bacterium for enhancing the efficiency of sulfate wastewater treatment.The detailed knowledge of the enzyme structure provides the target for the quantitative PCR gene locus and helps to improve its biological sulfate-removal potential.展开更多
A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and...A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and nitrogen source. The sequence analysis of 16S rDNA illustrated that the similarity of F8 and Desulfovibrio desulfuricans (AF192153) was 99%, and the similarity sequence of dissimilatory sulfite reductase gene (DSR) cloned from the strain and Desulfovibrio desulfuricans (AF273034) was 98%. Their phylogenitic analysis was basically anastomosed, and thus temporarily named as Desulfovibrio desulfuricans F8. The DSR cloned from F8 strain was 2740 bp in length consisting of three ORF, DSRA, DSRB and DSRD as a single operon (DSRABD) regulated by the same operator. DSRA contained typical conservative box of sulfate—sulfite reducing enzyme (SiteⅠand SiteⅡ), which could bind siroheme and [Fe4S4]. DSRB retained a [Fe4S4] binding site, with an uncomplimentary structure for siroheme binding. There was no conservative box in DSRD. Sequence analysis of DSR will provide a theoretical basis for quantitative detection, metabolic pathway modification through gene engineering, and sulfate reducing bacteria (SRB) suppression.展开更多
文摘Multiple strains of sulfate-reducing bacteria（SRB）were isolated from sulfate wastewater treatment bioreactor and determined by polymerase chain reaction（PCR） with SRB-specific 16S ribosomal RNA gene primers.One of the strains isolated,strain F28-1 was further studied by sequencing the complete 16S ribosomal RNA gene,testing carbon resource utilization,and demonstrating the key enzyme gene structure related to sulfate metabolism,dissimilatory sulfite reductase（Dsr）gene.Blast retrieving results indicated that the SRB belonged to Desulfovibrio,its 16S ribosomal RNA gene sequence was similar to Desulfovibrio desulfuricans subsp.desulfuricans strain Essex 6（AF192153）,with identity 99.9%,and therefore,the strain was named as D.strain F28-1.Strain F28-1 was able to use glucose,propionic acid,lactic acid,acetic acid,ethanol and methanol as sole carbon resource and reduce sulfate to sulfide.It removed 95% sulfate within 72 h in a lab-scale experiment with lactic acid as electron donor.ORF finder program checked out two open reading frames（ORFs）in dsr gene sequence,dsrA and dsrB,which had 14% identity.Corresponding α-and β-subunit amino acid sequences were obtained according to the DNA sequence.α-subunit contained two conserved motifs,i.e.（C-X5-C）-Xn-（C-X3-C）,which was required for binding to siroheme; and CP-Xn-C-X2-C-X2-C required for binding to Fe4S4 clusters.In addition,the β-subunit contained only the Fe4S4 clusters binding site,but the siroheme binding site was missing.The SRB,which had multi-substrates utilization and high sulfate reduction power,supplies the starting bacterium for enhancing the efficiency of sulfate wastewater treatment.The detailed knowledge of the enzyme structure provides the target for the quantitative PCR gene locus and helps to improve its biological sulfate-removal potential.
基金Sponsored by the National Basic Research and Development (973) Program of China(Grant No.2004CB418505)
文摘A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and nitrogen source. The sequence analysis of 16S rDNA illustrated that the similarity of F8 and Desulfovibrio desulfuricans (AF192153) was 99%, and the similarity sequence of dissimilatory sulfite reductase gene (DSR) cloned from the strain and Desulfovibrio desulfuricans (AF273034) was 98%. Their phylogenitic analysis was basically anastomosed, and thus temporarily named as Desulfovibrio desulfuricans F8. The DSR cloned from F8 strain was 2740 bp in length consisting of three ORF, DSRA, DSRB and DSRD as a single operon (DSRABD) regulated by the same operator. DSRA contained typical conservative box of sulfate—sulfite reducing enzyme (SiteⅠand SiteⅡ), which could bind siroheme and [Fe4S4]. DSRB retained a [Fe4S4] binding site, with an uncomplimentary structure for siroheme binding. There was no conservative box in DSRD. Sequence analysis of DSR will provide a theoretical basis for quantitative detection, metabolic pathway modification through gene engineering, and sulfate reducing bacteria (SRB) suppression.
