[en] Full-text: Microbes have been used as the bio factory for providing various bio-products for mankind. Among their involvements include the productions of antibiotics, soya sauce, yogurt drink, vinegar, enzymes, organic acids, ethanol etc. For centuries, these microbial bioprocesses are continually improved to meet the rising demands for quality life. Despite much effort to improve these microbial bioprocesses via genetic manipulation and related -omics techniques, much are yet to be done. Biotechnology techniques (random or site-directed mutagenesis) and genetic manipulations are the commonly employed strategies for improvement of biological samples. Mutagenesis via radiation is another tool to obtain mutants of interest. The use of ionizing radiation on microbes has been studied for decades. Few studies were reported to successfully develop mutants with significantly higher enzyme activity and improved enzyme properties. In this paper, we will share some activities of harnessing the nuclear technology to generate bacterial mutants with modified enzymatic activities and biomaterial productions. (author)

[en] The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs

[en] MEOR as a potentially additional method to the EOR methods is discussed in this paper. Most of the field trails carried out in the last 35 years with special reference to the kind of bacteria, nutrient support and protocol of well injection as well as the response to such treatments are presented and discussed. (author)

No abstract available

[en] Anaerobic treatment was evaluated to determine its effectiveness in treating a waste stream from the process of Enhanced Oil Recovery (EOR) to remove solubilized CO_2 (98%) and petroleum hydrocarbons (83%) using formate (2 g/L) and sucrose (2.5 g/L) as electron donors in two consecutive reactors. The method of evolutionary operation (EVOP) factorial design was applied to optimize the system and the net energy ratio (NER) of 3.7 was calculated for the system which showed a sustainable biogas production. This method is less complex than other competitive methods, and in addition to its low energy requirements, it can produce CH_4 from CO_2 as a clean source of energy. (author)

[en] This work shows the development of a technique for biological removal of barium from production waters. This technology, called stratified microbial associations (SMA), was evaluated at laboratory and bench scale levels. Removal capacity of this metal was demonstrated by microcosms and bioreactor assay. The role of reduced sulfur availability, residence time, and flow pattern and bioreactor size were also evaluated. Elemental composition of the solid constituents, localization and nature of the metal deposits in the bioreactor were determined by electron microscopy. This process has an efficiency of 95%-98% of barium removal with concentrations between 8 and 50 gm Metal capture is mainly due to bio sorption and the formation of low solubility complexes such as barium sulphate

[en] Microbiological analyses were conducted on core samples collected along a vertical profile (0-66 m below surface) from the tailings management facility (TMF) at the Rabbit Lake uranium mine in northern Saskatchewan, Canada. Bacterial numbers in the core materials were similar to surrounding soils and surface waters, regardless of the seemingly unfavorable pH (mean = 9.9) and temperature (∼0^oC) in the TMF. The greatest number of viable cells (10⁵ CFU/g) was detected at the interface between the tailings and overlying standing water, below which cell counts decreased rapidly with depth. Whole-community metabolic profiles for samples from the different depths grouped into 3 clusters; however, these groups could not be positively correlated with sampling depth, temperature, redox potential, pH, or ore-mill feed. Flow-cell studies demonstrated microbial communities in the tailings surface water could develop biofilms and maintain cell activity at both pH 10 and 7, and altering the pH between these 2 values had little effect on biofilm viability. These results demonstrate the resilience and adaptive nature of naturally occurring microbial communities and signify a potential role of microbial activity in the long-term geochemical evolution of the TMF. (author)

[en] Power plants have experienced tuberculation and microbially influenced corrosion (MIC) in systems that use raw, or minimally treated, water. Piping geometry can have a significant effect on MIC. A geometry that allows the action of thermal convection to provide constant low levels of oxygen, under near static flow conditions, are known to promote tuberculation and MIC. The two geometries studied in this paper are: Piping geometry with horizontal secondary headers between a flowing ring header and a vertical riser (pipestand) which is susceptible to MIC; and, piping geometry with vertical secondary headers between a flowing ring header and a vertical riser (pipestand) which is not susceptible to MIC. A trend of historical failures due to pinhole leaks has been noted in pipes that are routinely stagnant or have low flow, but are connected to pipes that see regular flow. Accurate predictions of problem areas were made from our understanding of the failure mechanism. Initially, inspections were completed to determine the extent of degradation in the PNGS fire protection system. Radiographic inspections and visual inspections indicated that sections of the secondary headers that had an immediate vertical take-off from the flowing ring header (as opposed to the typical horizontal take-off) appeared to exhibit a much lower rate of subsequent tuberculation. This paper will present historical station data to support the concept that piping geometry changes can significantly lower the risk of MIC. An explanation will be presented demonstrating how convective mixing is reduced with the vertical configuration, thus reducing the tuberculation and MIC. Similar geometry changes are expected to significantly lower the incidence of tuberculation and MIC in other systems that use raw water with similar flow patterns. (author)

[en] Microbial activity in clay-based barriers immediately adjacent to metal used-fuel containers in a repository could affect the longevity of such containers. The current emphasis is, therefore, on reducing or minimizing microbial activity in such clay-based barriers through material composition design. Factors affecting microbial activity in clay-based materials were studied in large-scale and smaller-scale experiments. Results suggested that keeping water activity (a_w) values below ∼0.95 may minimize microbial activity in clay-based barrier materials. A considerably higher effective montmorillonite dry density (EMDD), which partially controls a_w, is achievable for 100% bentonite than for previously proposed reference buffer materials, which contain only 50% bentonite. (author)

[en] Research topics include 1) securing new radiation-resistant microorganisms, 2) study on signaling transduction system of radiation-resistant microorganism, and 3) development of useful microbial resources. We isolated almost 50 kinds of new radiation-resistant microorganisms from environment of domestic soil and fresh water. Six genomes from novel radiation resistant microorganisms isolated from freshwater and polar environment were analyzed and compared with D. radiodurans . In addition, the genome of D. radiodurans was reanalyzed. To investigate the radiation-responsible signal transduction systems in D. radiodurans, DrtR/DrtS, DR1558 and DR0743, catalase, and PprM, a radiation responsible protein, were studied. Radiation-induced phospho-proteomic analysis was used to monitor the changes in the expression levels of total protein and phosphorylated protein before and after gamma irradiation to obtain a radiation response protein profile. The use of radiation resistance gene proved the increased environmental stress resistance of DR1558 or PprM introduced E. coli , proving the possibility of improving the microorganism for industrial usage by introducing the genes from radiation resistant microorganism. In particular, the DR1558 gene is also used for the production of high production level of organic acids such as GABA, lysine and succinic acid. To develop useful microbial resources with radiation biotechnology, we developed Salmonella attenuated strains by using rapid radiation molecular evolution technology and proved their efficacy as a vaccine strain. At the same time, technology for production of vaccine strain is secured through repeated irradiation. We confirmed the antioxidant and cell growth promoting effect of water-soluble polymer polysaccharide (EPS) from D. radiodurans