Microbial modification of ground water

When ground water is tapped by wells, microbial and chemical deposits often develop. Sloughing and clogging may occur in the distribution system adding considerable expense to the operation of the water systems as well as imparting taste and odor to the water itself. The purpose of this project has been to define the physical and microbial basis of these deposits using microbial flocs found in Southern Illinois as a "model system." These flocs proliferate at the air-water interface of a domestic flush tank producing copious amounts of flocculent material. Observation of the flocs by phase microscopy revealed a dense population of bacteria with several distinct morphological types. Analysis by scanning and transmission electron microscopy revealed that the floc members reside in a matrix and that the consortium consists of two ultrastructurally distinct types of bacteria. Results of chemical analysis of the well water indicated low levels of organic material, whereas results of gas chromatographic analysis indicated high amounts of methane to be present in the water. The predominant organism, an elipsoidal rod, was isolated from floc enrichments grown under a methane-air atmosphere. Two organisms of a second morphological cell type have also been isolated and their unique nutritional properties investigated. Extracellular matrix produced by the two organisms appear to be responsible for the formation of the floc. A number of heterotrophic organisms have also been isolated from the consortium. Cross-feeding experiments involving mixed cultures of the consortium isolates revealed a microbial food chain to exist with methane as the primary energy source for the development of these aquatic consortia. Dissolved methane in ground waters is a previously unappreciated energy source for the development of microbial communities in water supplies.U.S. Department of the InteriorU.S. Geological Surve

One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production

This reporting period, progress is reported on the following: metabolic pathway of solvent production in B. methylotrophicum; the biochemical mechanism for metabolic regulation of the succinate fermentation; models to understand the physiobiochemical function of formate metabolism in anaerobes and; models for understanding the influence of low pH on one carbon metabolism. (CBS

Energy input is primary controller of methane bubbling in subarctic lakes

Emission of methane (CH4) from surface waters is often dominated by ebullition (bubbling), a transport mode with high‐spatiotemporal variability. Based on new and extensive CH4 ebullition data, we demonstrate striking correlations (r2 between 0.92 and 0.997) when comparing seasonal bubble CH4 flux from three shallow subarctic lakes to four readily measurable proxies of incoming energy flux and daily flux magnitudes to surface sediment temperature (r2 between 0.86 and 0.94). Our results after continuous multiyear sampling suggest that CH4 ebullition is a predictable process, and that heat flux into the lakes is the dominant driver of gas production and release. Future changes in the energy received by lakes and ponds due to shorter ice‐covered seasons will predictably alter the ebullitive CH4 flux from freshwater systems across northern landscapes. This finding is critical for our understanding of the dynamics of radiatively important trace gas sources and associated climate feedback

2-Amino-5-chloro­pyridinium hydrogen succinate

In the title salt, C5H6ClN2 +·C4H5O4 −, the pyridine N atom is protonated. The pyridinium and amino groups associate via a pair of N—H⋯O hydrogen bonds to the carboxyl­ate O atoms of the singly deprotonated succinate anion. The hydrogen succinate anions self-assemble via O—H⋯O hydrogen bonds into chains along the b axis. The crystal structure is further stabilized by additional N—H⋯O hydrogen bonds involving the second amino H atoms, as well as C—H⋯O contacts, forming a three-dimensional network

Bis(2-amino­thia­zolium) succinate succinic acid

In the title compound, 2C3H5N2S+·C4H4O4 2−·C4H6O4, the thia­zolium ring is almost planar, with the maximum deviation from planarity being 0.0056 (8) Å for the C atom carrying the amine substituent. The N atom of the 2-amino­thia­zole mol­ecule is protonated. Both the anion and the acid lie across inversion centres. The crystal packing is consolidated by inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds. Mol­ecules are stacked down the b axis

4-Amino­pyridinium hydrogen succinate

In the title salt, C5H7N2 +·C4H5O4 −, the asymmetric unit comprises an amino­pyridinium cation and a hydrogen succinate anion as protonation of the aromatic N atom of the 4-amino­pyridine mol­ecule has occurred. The crystal packing is stabilized by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds that lead to a two-dimensional array. Short C—H⋯O contacts are also present