Henricus T. S. Boschker

Bio: Henricus T. S. Boschker is an academic researcher. The author has contributed to research in topics: Sulfurimonas autotrophica & Sulfate. The author has an hindex of 3, co-authored 3 publications receiving 155 citations.

Sulfurimonas gotlandica sp. nov., a chemoautotrophic and psychrotolerant epsilonproteobacterium isolated from a pelagic redoxcline, and an emended description of the genus Sulfurimonas

Abstract: A psychro- and aerotolerant bacterium was isolated from the sulfidic water of a pelagic redox zone of the central Baltic Sea. The slightly curved rod- or spiral-shaped cells were motile by one polar flagellum or two bipolar flagella. Growth was chemolithoautotrophic, with nitrate or nitrite as electron acceptor and either a variety of sulfur species of different oxidation states or hydrogen as electron donor. Although the bacterium was able to utilize organic substances such as acetate, pyruvate, peptone and yeast extract for growth, these compounds yielded considerably lower cell numbers than obtained with reduced sulfur or hydrogen; in addition, bicarbonate supplementation was necessary. The cells also had an absolute requirement for NaCl. Optimal growth occurred at 15 °C and at pH 6.6–8.0. The predominant fatty acid of this organism was 16 : 1ω7c, with 3-OH 14 : 0, 16 : 0, 16 : 1ω5c+t and 18 : 1ω7c present in smaller amounts. The DNA G+C content was 33.6 mol%. As determined in 16S rRNA gene sequence phylogeny analysis, the isolate belongs to the genus Sulfurimonas , within the class Epsilonproteobacteria , with 93.7 to 94.2 % similarity to the other species of the genus Sulfurimonas , Sulfurimonas autotrophica , Sulfurimonas paralvinellae and Sulfurimonas denitrificans . However, the distinct physiological and genotypic differences from these previously described taxa support the description of a novel species, Sulfurimonas gotlandica sp. nov. The type strain is GD1T ( = DSM 19862T = JCM 16533T). Our results also justify an emended description of the genus Sulfurimonas .

Identification of sulfate reducers and Syntrophobacter sp. in anaerobic granular sludge by fatty-acid biomarkers and 16S rRNA probing

Abstract: The sulfate‐reducing bacterial sludge population in anaerobic bioreactors, treating different types of wastewater in the presence or absence of sulfate, was evaluated by polar‐lipid fatty acid (PLFA) analyses, and by 16S rRNA dot‐blot hybridizations using specific 16S rRNA‐targeted oligonucleotide probes for sulfate reducers and Syntrophobacter sp. The 16S rRNA dot blot hybridizations were useful for estimating the relative amount of sulfate reducers in the sludge. The PLFA profiles of the sludge were usefid to obtain a quick general impression of the total bacterial sludge composition, but were less suitable for an accurate characterization and quantification of the sulfate‐reducing population in the sludge. This was due to the lack of selective biomarkers for these bacteria. The combined results of the PLFA analysis and 16S rRNA dot‐blot hybridizations showed that the presence of sulfate reducers in the sludge was not dependent on the presence of sulfate in the wastewater. This may be explained by the s...

Isolation of thermophilic Desulfotomaculum strains with methanol and sulfite from solfataric mud pools, and characterization of Desulfotomaculum solfataricum sp. nov.

Abstract: Four strains of thermophilic, endospore-forming, sulfate-reducing bacteria were enriched and isolated from hot solfataric fields in the Krafla area of north-east Iceland, using methanol and sulfite as substrates. Morphologically, these strains resembled thermophilic Desulfotomaculum species. The strains grew with alcohols, including methanol, with glucose and fructose as electron donors, and with sulfate, sulfite or thiosulfate as electron acceptors. For all four strains, the optimum temperature and pH for growth were 60 degreesC and pH 7.3, respectively; no added NaCl was required. Phylogenetic analysis based on partial 16S rRNA gene sequence comparisons showed high levels of similarity of the novel strains (> 92 %) with Desulfotomaculum kuznetsovii and Desulfotomaculum luciae. However, DNA-DNA hybridization studies with D. kuznetsovii revealed that the four strains belonged to one novel species. A representative of this group of isolates, strain V21(T), is proposed as the type strain of a novel species of the spore-forming, sulfate-reducing genus Desulfotomaculum, namely Desulfotomaculum solfataricum (type strain V21(T) = DSM 114956(T) = CIP 107984(T)).

Identification and characterization of ecologically significant prokaryotes in the sediment of freshwater lakes: molecular and cultivation studies

Abstract: The aim of this review is to interpret recent studies in which molecular methods were used to identify and characterize prokaryotes in lake sediments and related habitats. In the first part studies based on the phylogenetic diversity of prokaryotes found in lacustrine habitats are summarized. The application of various cultivation-independent methods for the characterization of distinct groups of sediment bacteria is exemplified with morphologically conspicuous, colorless sulfur bacteria in the second part of this review. Finally, traditional and recently developed methods are described which could be used for linking the function of microbial populations with their identification. The potential of these approaches for the study of lake sediments is discussed in order to give a perspective for future studies in this habitat.

Stable-isotope probing of microorganisms thriving at thermodynamic limits: syntrophic propionate oxidation in flooded soil.

Abstract: soil by rRNA-based stable-isotope probing (SIP). After 7 weeks of incubation with [ 13 C]propionate (<10 mM) and the oxidation of 30 mol of 13 C-labeled substrate per g dry weight of soil, we found that archaeal nucleic acids were 13 C labeled to a larger extent than those of the bacterial partners. Nevertheless, both terminal restriction fragment length polymorphism and cloning analyses revealed Syntrophobacter spp., Smithella spp., and the novel Pelotomaculum spp. to predominate in “heavy” 13 C-labeled bacterial rRNA, clearly showing that these were active in situ in syntrophic propionate oxidation. Among the Archaea, mostly Methanobacterium and Methanosarcina spp. and also members of the yet-uncultured “rice cluster I” lineage had incorporated substantial amounts of 13 C label, suggesting that these methanogens were directly involved in syntrophic associations and/or thriving on the [ 13 C]acetate released by the syntrophs. With this first application of SIP in an anoxic soil environment, we were able to clearly demonstrate that even guilds of microorganisms growing under thermodynamic constraints, as well as phylogenetically diverse syntrophic associations, can be identified by using SIP. This approach holds great promise for determining the structure and function relationships of further syntrophic or other nutritional associations in natural environments and for defining metabolic functions of yet-uncultivated microorganisms.

Nested PCR-Denaturing Gradient Gel Electrophoresis Approach To Determine the Diversity of Sulfate-Reducing Bacteria in Complex Microbial Communities

Abstract: Here, we describe a three-step nested-PCR-denaturing gradient gel electrophoresis (DGGE) strategy to detect sulfate-reducing bacteria (SRB) in complex microbial communities from industrial bioreactors. In the first step, the nearly complete 16S rRNA gene was amplified using bacterial primers. Subsequently, this product was used as a template in a second PCR with group-specific SRB primers. A third round of amplification was conducted to obtain fragments suitable for DGGE. The largest number of bands was observed in DGGE patterns of products obtained with primers specific for the Desulfovibrio-Desulfomicrobium group, indicating a large diversity of these SRBs. In addition, members of other phylogenetic SRB groups, i.e., Desulfotomaculum, Desulfobulbus, and Desulfococcus-Desulfonema-Desulfosarcina, were detected. Bands corresponding to Desulfobacterium and Desulfobacter were not detected in the bioreactor samples. Comparative sequence analysis of excised DGGE bands revealed the identity of the community members. The developed three-step PCR-DGGE strategy is a welcome tool for studying the diversity of sulfate-reducing bacteria.

Monoalkylether phospholipids in the sulfate-reducing bacteria Desulfosarcina variabilis and Desulforhabdus amnigenus.

Abstract: In this study, cellular lipid compositions of two mesophilic sulfate-reducing bacteria were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). In Desulfosarcina variabilis and Desulforhabdus amnigenus, alkylether-containing phospholipids were detected which had previously only been found in significant amounts in deeply branching hyperthermophilic bacteria and archaea. Combining information from HPLC-MS analysis and chemical degradation experiments, ether lipids were identified as 1-alkyl-2-acyl-phosphatidyl ethanolamines, glycerols and cholines. In Desulforhabdus amnigenus, n-penta-, n-hexa- and n-heptadecyl ethers were present (in order of decreasing abundance), whereas Desulfosarcina variabilis solely contained n-hexadecyl ether side chains.