Ultrastruct of Methylosinus trichosporium as revealed by freeze etching.

The methane-oxidizing bacterium Methylosinus trichosporium forms extensive intracytoplasmic membranes that lie near the cell periphery and paralled to it. These membranes enclose cavities within the cytoplasm and exist as flattened, balloon-like vesicles. The internal membranes are passed along to both cells during budding. The bacteria accumulate poly-beta-hydroxybutyrate granules that lie in the center of the cells, neither within the internal membrane vesicles nor attached to them. Intercellular bridges result in the formation of chains of bacteria two to four cells in length.     

Ester Synthesis by Zoogloea ramigera 115 Grown in the Presence of Ethanol

The ester ethyl butyrate is produced by Zoogloea ramigera 115, a bacterium isolated from an aerobic waste treatment plant, when ethanol is present in culture media. The cells appear to produce butyric acid which is then esterified with residual ethanol in the culture medium.     

Microbial Sulfate Reduction and Its Potential Utility as an Acid Mine Water Pollution Abatement Procedure

The presence of high concentrations of sulfate, iron, and hydrogen (acid) ions in drainage from coal mines and other areas containing waste pyritic materials is a serious water pollution problem. Sulfate can be removed from solution by microbial reduction to sulfide and subsequent precipitation as FeS. A mixed culture of microorganisms degraded wood dust cellulose, and the degradation products served as carbon and energy sources for sulfate-reducing bacteria. Metabolism of carbon compounds resulted in a net pH increase in the system. Oxidation-reduction potential (Eh) and temperature and carbon supplements were studied in an effort to accelerate the sulfate reduction process, with the ultimate objective of utilizing the process as a pollution abatement procedure.     

PRIMARY PULMONARY RESECTION FOR TUBERCULOSIS—Medical and Economic Aspects in a Small Sanatorium

Twenty-eight patients with pulmonary tuberculosis in a small, tax-supported sanatorium were treated by primary pulmonary resection. In a comparison of results with those obtained in the same sanatorium by thoracoplasty and extrapleural pneumothorax, it was noted that in general the patients who had resection had earlier conversion of sputum to “negative” and had a shorter stay in hospital.Complications were not of sufficient frequency to contraindicate use of resection in cases in which there was doubt that thoracoplasty would be effective.The cost of hospitalization for surgical treatment and postoperative care was considerably less when resection was done than it was for either three-stage or two-stage thoracoplasty.     

Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. I. Preliminary experiments in controlled shaken flasks

Changes of pH and sulfate concentration in high-sulfur coal refuse slurries are used as measurements of microbial pyrite oxidation in the laboratory. Sodium lauryl sulfate (SLS), alkylbenzene sulfonate (ABS), benzoic acid (BZ) and combinations of SLS plus BZ and ABS plus BZ effectively inhibited formation of sulfate and acid when added in concentrations greater than 50 mg/L to inoculated 20 or 30% coal refuse slurries. Here 25 mg/L concentrations of SLS, ABS, and ABS + BZ stimulated acid production. Formic, hexanoic, oxalic, propionic, and pyruvic acids at 0.1% concentrations were also effective inhibitors. Four different lignin sulfonates were only slightly effective inhibitors at 0.1% concentrations. It was concluded that acid formation resulting from microbial oxidation in high-sulfur coal refuse can be inhibited.     

Antigenic mosaic of Methanogenium spp.: analysis with poly- and monoclonal antibody probes.

Eight well-characterized Methanogenium strains, including the six described type strains, were analyzed with poly- and monoclonal antibody probes to examine the antigenic mosaic of the genus. The pattern of cross-reactions showed that the mosaic is complex and varies with the strains; thus, these organisms have developed a considerable antigenic diversity, which is expressed in their envelopes. Every strain shared at least one determinant with at least one other strain, demonstrating the antigenic cohesiveness of the group. This finding, together with the fact that most strains displayed a distinctive antigenic fingerprint (notwithstanding the limited number of probes available), emphasizes the potential of antibodies for rapid identification of new isolates and for direct elucidation of Methanogenium strains in microbial mixtures.     

Constrained global optimization for estimating molecular structure from atomic distances.

Finding optimal three-dimensional molecular configurations based on a limited amount of experimental and/or theoretical data requires efficient nonlinear optimization algorithms. Optimization methods must be able to find atomic configurations that are close to the absolute, or global, minimum error and also satisfy known physical constraints such as minimum separation distances between atoms (based on van der Waals interactions). The most difficult obstacles in these types of problems are that 1) using a limited amount of input data leads to many possible local optima and 2) introducing physical constraints, such as minimum separation distances, helps to limit the search space but often makes convergence to a global minimum more difficult. We introduce a constrained global optimization algorithm that is robust and efficient in yielding near-optimal three-dimensional configurations that are guaranteed to satisfy known separation constraints. The algorithm uses an atom-based approach that reduces the dimensionality and allows for tractable enforcement of constraints while maintaining good global convergence properties. We evaluate the new optimization algorithm using synthetic data from the yeast phenylalanine tRNA and several proteins, all with known crystal structure taken from the Protein Data Bank. We compare the results to commonly applied optimization methods, such as distance geometry, simulated annealing, continuation, and smoothing. We show that compared to other optimization approaches, our algorithm is able combine sparse input data with physical constraints in an efficient manner to yield structures with lower root mean squared deviation.