Sulfur analysis of Bolu-Mengen lignite before and after microbiological treatment using reductive pyrolysis and gas chromatography/mass spectrometry

Atmospheric pressure-temperature programmed reduction coupled with on-line mass spectrometry (AP-TPR/MS) is used for the first time on microbiologically treated coal samples as a technique to monitor the degree of desulfurization of the various sulfur functionalities. The experimental procedure enables the identification of both organic and inorganic sulfur species present in the coal matrix. A better insight in the degradation of the coal matrix and the accompanying processes during the AP-TPR experiment is obtained by a quantitative differentiation of the sulfur. The determination of the sulfur balance for the reductive pyrolysis gives an overview of the side reactions and their relative contribution in the total process. The volatile sulfur species are unambiguously identified using AP-TPR off-line coupled with gas chromatography/mass spectrometry (GC/MS). In this way, fundamental mechanisms and reactions that occur during the reductive pyrolysis could be quantified, explaining the differences in AP-TPR recoveries. Therefore, this study gives a clearer view on the possibilities and limitations of AP-TPR as a technique to monitor sulfur functionalities in coal

Contrasting Microbial Community Assembly Hypotheses: A Reconciling Tale from the Río Tinto

The Río Tinto (RT) is distinguished from other acid mine drainage systems by its natural and ancient origins. Microbial life from all three domains flourishes in this ecosystem, but bacteria dominate metabolic processes that perpetuate environmental extremes. While the patchy geochemistry of the RT likely influences the dynamics of bacterial populations, demonstrating which environmental variables shape microbial diversity and unveiling the mechanisms underlying observed patterns, remain major challenges in microbial ecology whose answers rely upon detailed assessments of community structures coupled with fine-scale measurements of physico-chemical parameters.By using high-throughput environmental tag sequencing we achieved saturation of richness estimators for the first time in the RT. We found that environmental factors dictate the distribution of the most abundant taxa in this system, but stochastic niche differentiation processes, such as mutation and dispersal, also contribute to observed diversity patterns.We predict that studies providing clues to the evolutionary and ecological processes underlying microbial distributions will reconcile the ongoing debate between the Baas Becking vs. Hubbell community assembly hypotheses

MECHANISM OF OXIDATION OF REDUCED SULPHUR COMPOUNDS BY THIOBACILLI

The mechanism of transport sulphur both outside and inside the cells was studied. Macroroentgen structural analysis and electronicmicroscopic researches showed that the membrane structures of thiobacilli carry out not only the oxidation function, but the transport function as well, which consists in the extraction of the formed sulphur from cell. This mechanism of sulphur deposition develops ac-— cording to the exocytosis type. The transport of elemental sulphur inside the cell involves the surface membrane structures (vesicles), while oxidation of the sulphur to sulphuric acid takes place on the outer surface of the cytoplasmic membrane. The vesicles are supposed also to participate in the primary dissolution of elemental sulphur at the site of contact of the cells with the mineral. The study of bacterial oxidation of sulphide minerals has shown the electrochemical nature of microbiological oxidation of sulphide minerals, which takes place at the level of its electronic structure. Pyrite with hole conductivity (with the cation deficit in composition) is oxidized by means of Thiobacillus ferrooxidans not only much more intensively, but also continuously as compared to pyrite with electron conductivity. Thiobacilli play a leading role in the oxidation of reduced sulphur compounds under natural conditions. The mechanism of this process however have not been studied sufficiently well so far. The main purpose of this work was to study the mechanism of sulphur transport, when sulphur was deposited or oxidized by thiobacilli, by means of cytological and cytochemical techniques. We believed that the mechanism,of sulphur transport either from, or into, the cell must be closely related to the submicroscopic organization of thiobacill

Phylogenetic assessment of culture collection strains of Thiobacillus thioparus, and definitive 16S rRNA gene sequences for T. thioparus, T. denitrificans, and Halothiobacillus neapolitanus

The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by different culture collections have been compared. A definitive sequence for the reference type strain (Starkey; ATCC 8158T) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, confirming their sustained identity after passage through different laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539T) was determined and used to confirm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitrificans indicated that the sequence for the type strain (NCIMB 9548T) should always be used as the reference sequence for new and existing isolates

ABA-binding proteins was detected in cyanobacteria (Synechocystis sp. PCC 6803)

This article dedicates the study concerning evolution of the hormonal system of plants, in particular, detection of components of the regulatory system of abscisic acid (ABA) in cyanobacteria, which are considered as the precursors of the chloroplasts. ABA-binding proteins with molecular masses of 23, 50, 60 and 67 kDa were isolated using affinity chromatography on Sepharose conjugated with ABA from the lysate of cyanobacteria Synechocystis sp. PCC 6803. Interaction of isolated proteins with idiotypic antibodies to the ABA was shown. Total transcription in transcription system of cyanobacteria was activated by this ABA-binding proteins in vitro. This suggests, that some elements of the hormonal system of plants, which are associated with the ABA, was transfered from cyanobacterias to the eukaryotic cell