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The investigated deeply buried marine sediments of the shallow shelf off New Jersey, USA, are cha... more The investigated deeply buried marine sediments of the shallow shelf off New Jersey, USA, are characterized by low organic carbon content and total cell counts of < 10 7 cells per mL sediment. The qPCR data for Bacteria and Archaea were in the same orders of magnitude as the total cell counts. Archaea and Bacteria occurred in similar 16S rRNA gene copy numbers in the upper part of the sediments, but Bacteria dominated in the lowermost part of the analyzed sediment cores down to a maximum analyzed depth of c. 50 meters below seafloor (mbsf). The bacterial candidate division JS1 and the classes Anaerolineae and Caldinilineae of the Chloroflexi were almost as highly abundant as the total Bacteria. Similarly high dsrA gene copy numbers were found for sulfate reducers. The abundance of the Fe(III) and Mn(IV) reducers comprising Geobacteraceae in the upper c. 15 mbsf correlated with concentrations of manganese and iron in the pore water. The isolated 16S rRNA gene sequences of Archaea in clone libraries could be allocated to the phyla Thaumarchaeota, Euryarchaeota, and Crenarchaeota with 1%, 14%, and 85%, respectively. The typical deep subsurface sediment-associated groups MBG-B, MBG-D, MCG, and SAGMEG were represented in the sediment community. MCG was the dominant group with a high diversity of the isolated 16S rRNA gene sequences.
More than 100 cultures of acidophilic Fe(II)-and/or sulfur-oxidizing microorganisms from mine was... more More than 100 cultures of acidophilic Fe(II)-and/or sulfur-oxidizing microorganisms from mine waste dumps in 10 different countries all over the world have been maintained in liquid media in the BGR-strain collection for many years. Our 16S rDNA analysis showed that most of the cultivated Fe(II)-oxidizers belong to four genera: Acidithiobacillus, Acidimicrobium, " Ferrimicrobium " and Leptospirillum. All analyzed Acidithiobacillus strains were identified as At. ferrooxidans. The Leptospirillum strains were affiliated with L. ferriphilum or L. ferrooxidans. The Gram-positive strains related to Acidimicrobium or " Ferrimicrobium " were phylogenetically more diverse than the strains of the genera Acidithiobacillus and Leptospirillum and fell into three separate clusters. While several strains could be identified as syngeneic (16S rDNA) with " Ferrimicrobium acidiphilum " , two other 16S rDNA clusters were distantly related and might represent new species or even new genera. In addition, one new Sulfobacillus strain and one new Alicyclobacillus strain could be identified. Furthermore several strains related to Acidiphilium acidophilum have been detected and form one 16S rDNA cluster.
The investigated deeply buried marine sediments of the shallow shelf off New Jersey, USA, are cha... more The investigated deeply buried marine sediments of the shallow shelf off New Jersey, USA, are characterized by low organic carbon content and total cell counts of < 10 7 cells per mL sediment. The qPCR data for Bacteria and Archaea were in the same orders of magnitude as the total cell counts. Archaea and Bacteria occurred in similar 16S rRNA gene copy numbers in the upper part of the sediments, but Bacteria dominated in the lowermost part of the analyzed sediment cores down to a maximum analyzed depth of c. 50 meters below seafloor (mbsf). The bacterial candidate division JS1 and the classes Anaerolineae and Caldinilineae of the Chloroflexi were almost as highly abundant as the total Bacteria. Similarly high dsrA gene copy numbers were found for sulfate reducers. The abundance of the Fe(III) and Mn(IV) reducers comprising Geobacteraceae in the upper c. 15 mbsf correlated with concentrations of manganese and iron in the pore water. The isolated 16S rRNA gene sequences of Archaea in clone libraries could be allocated to the phyla Thaumarchaeota, Euryarchaeota, and Crenarchaeota with 1%, 14%, and 85%, respectively. The typical deep subsurface sediment-associated groups MBG-B, MBG-D, MCG, and SAGMEG were represented in the sediment community. MCG was the dominant group with a high diversity of the isolated 16S rRNA gene sequences.
More than 100 cultures of acidophilic Fe(II)-and/or sulfur-oxidizing microorganisms from mine was... more More than 100 cultures of acidophilic Fe(II)-and/or sulfur-oxidizing microorganisms from mine waste dumps in 10 different countries all over the world have been maintained in liquid media in the BGR-strain collection for many years. Our 16S rDNA analysis showed that most of the cultivated Fe(II)-oxidizers belong to four genera: Acidithiobacillus, Acidimicrobium, " Ferrimicrobium " and Leptospirillum. All analyzed Acidithiobacillus strains were identified as At. ferrooxidans. The Leptospirillum strains were affiliated with L. ferriphilum or L. ferrooxidans. The Gram-positive strains related to Acidimicrobium or " Ferrimicrobium " were phylogenetically more diverse than the strains of the genera Acidithiobacillus and Leptospirillum and fell into three separate clusters. While several strains could be identified as syngeneic (16S rDNA) with " Ferrimicrobium acidiphilum " , two other 16S rDNA clusters were distantly related and might represent new species or even new genera. In addition, one new Sulfobacillus strain and one new Alicyclobacillus strain could be identified. Furthermore several strains related to Acidiphilium acidophilum have been detected and form one 16S rDNA cluster.