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Omsättningen av kisel (Si) är en av de viktiga biogeokemiska processerna på jorden. Den lösta formen av Si (DSi) är ett nödvändigt näringsämne för såväl markens som havens ekosystem. Löst kisel kommer från den långsamma kemiska vittringen av kiselmineral. Denna process förbrukar koldioxid och bidrar därför till att reglera jordens klimat genom årmiljonerna. Kisel transporteras huvudsakligen via odSilicon (Si) cycle is one of Earth's major biogeochemical cycles. Furthermore, the dissolved form of Si (DSi) is an essential nutrient for both terrestrial and marine ecosystems. DSi ultimately derives from the slow process of chemical weathering of silicate minerals, a mechanism that consumes carbon dioxide, and therefore participates in regulating Earth's climate over geologic timescales. Si is

OBJECTIVES: There are significant geographical differences in the prevalence and incidence of celiac disease that cannot be explained by HLA alone. More than 40 loci outside of the HLA region have been associated with celiac disease. We investigated the roles of these non-HLA genes in the development of tissue transglutaminase autoantibodies (tTGA) and celiac disease in a large international prosp

BACKGROUND: A possible role for prostate cancer in Lynch syndrome has been debated based on observations of mismatch-repair defective tumors and reports of an increased risk of prostate cancer in mutation carriers. Potential inclusion of prostate cancer in the Lynch syndrome tumor spectrum is relevant for family classification, risk estimates and surveillance recommendations in mutation carriers.M

Respiratory proteins such as myoglobin and hemoglobin can, under oxidative conditions, form ferryl heme iron and protein-based free radicals. Ferryl myoglobin can safely be returned to the ferric oxidation state by electron donation from exogenous reductants via a mechanism that involves two distinct pathways. In addition to direct transfer between the electron donor and ferryl heme edge, there is

A chimeric bifunctional enzyme composing of galactose dehydrogenase (galDH; from Pseudomonas fluorescens) and lactate dehydrogenase (LDH; from Bacillus stearothermophilus) was successfully constructed. The chimeric galDH/LDH possessed dual characteristics of both galactose dehydrogenase and lactate dehydrogenase activities while exhibiting hexameric rearrangement with a molecular weight of approxi

The partitioning of Bacillus stearothermophilus lactate dehydrogenase (LDH) in an aqueous two-phase system was studied. Particularly, the influence of tyrosine tags on the partitioning was evaluated. The hydrophobic effect, caused by the addition of tyrosine residues, was determined in a system based on dextran and the thermoseparating ethylene oxide-propylene oxide random copolymer (EO30PO70). Fi

A pCb plasmid encoding a beta-lactamase from Haemophilus ducreyi was transferred to Escherichia coli, purified, and characterized. The beta-lactamase could be isolated from a culture filtrate and further purified by ammonium sulfate and chelating Sepharose fast flow loaded with Zn(2+). The purified enzyme resulted in a major band at approximately 30-kDa on SDS-PAGE and its pI was determined to be

Two beta-lactamases, penicillinase type I from Bacillus cereus and TEM-1 beta-lactamase from Haemophilus ducreyi, were immobilized on a Chelating Sepharose Fast Flow column loaded with Ni2+ in an active form. Flow-injection analysis of beta-lactams was performed by using an enzyme column reactor fitted into the enzyme thermistor. With both enzymes it was possible to monitor both penicillins and ce

The expression of metal-binding proteins or peptides in microorganisms and plants in order to enhance heavy metal accumulation and/or tolerance has great potential. Several different peptides and proteins have been explored. This review focuses on cadmium (Cd) because of the significant importance of this metal and because of its global presence in many food materials.

Expression of the gene encoding bacterial hemoglobin (VHb) from Vitreoscilla has been previously used to improve recombinant cell growth and enhance product formation under microaerobic conditions. It is very likely that the properties of VHb are not optimized for foreign hosts; therefore, we used error-prone PCR to generate a number of randomly mutated vhb genes to be expressed and studied in Esc

L-lactate dehydrogenase (LDH) from Bacillus stearothermophilus is a redox enzyme which has a strong preference for NADH over NADPH as coenzyme. To exclude NADPH from the coenzyme-binding pocket, LDH contains a conserved aspartate residue at position 52. However, this residue is probably not solely responsible for the NADH specificity. In this report we examine the possibilities of altering the coe

Chancroid caused by Haemophilus ducreyi has been described as a significantly predisposing factor of HIV heterosexual transmission in an endemic region of both diseases. The fastidious, H. ducreyi has been reported world wide with various antimicrobial susceptibility patterns. A high tendency of drug resistances has generally been found among isolates derived in Thailand. In this study, the plasmi

Manipulation of starch biosynthesis/degradation and formation of novel molecules in storage organs of plants through genetic engineering is an attractive but technically challenging goal. We report here, for the first time, that starch was degraded and glucose and fructose were produced directly when crushed potato tubers expressing a starch degrading bifunctional gene were heated for 45 minutes a

The strictly aerobic bacterium Vitreoscilla expresses a hemoglobin-like protein, VHb, when subjected to oxygen stress. When expressed in plants, this has several intriguing physiological effects, such as improving the overall growth rate, speeding germination and flowering, and increasing the productivity of certain oxygen-requiring metabolic pathways. Although the mechanisms behind the effects of

In searching for novel peptides with affinity for cadmium, the phage display technique was utilized. In the selection procedure, cadmium ions were immobilized on a metal chelating Sepharose gel. The peptides selected from a hexapeptide library showed no homology to naturally occurring metallothioneins. From the phage clones selected in the biopanning process, phages with affinity for Cd-109 in fre

The gene for Vitreoscilla hemoglobin (VHb) has been introduced and expressed in Nicotiana tabaccum (tobacco). Transgenic tobacco plants expressing VHb exhibited enhanced growth, on average 80-100% more dry weight after 35 days of growth compared to wild-type controls. Furthermore, germination time is reduced from 6-8 days for wild-type tobacco to 3-4 days and the growth phase from germination to f

The Thermus thermophilus xylA gene encoding xylose (glucose) isomerase was cloned and expressed in Saccharomyces cerevisiae under the control of the yeast PGK1 promoter. The recombinant xylose isomerase showed the highest activity at 85 degrees C with a specific activity of 1.0 U mg-1. A new functional metabolic pathway in S. cerevisiae with ethanol formation during oxygen-limited xylose fermentat

Both freezing tolerance and NaCl tolerance are improved when antifreeze proteins are expressed as fusion proteins with two domains of staphylococcal protein A (SPA) in Escherichia coli. To characterize these properties further we created a randomly mutated expression library in E. coli, based on the winter flounder antifreeze protein HPLC-8 component gene. Low-fidelity PCR products of this gene we

Proteins carrying genetically attached polyhistidine tails have been purified using affinity precipitation with metal chelates. DNA fragments encoding four or five histidine residues have been genetically fused to the oligomeric enzymes lactate dehydrogenase (Bacillus stearothermophilus), beta-glucoronidase (Escherichia coli), and galactose dehydrogenase (Pseudomonas fluorescens) as well as to the