Serinol: small molecule - big impact

The amino alcohol serinol (2-amino-1,3-propanediol) has become a common intermediate for several chemical processes. Since the 1940s serinol was used as precursor for synthesis of synthetic antibiotics (chloramphenicol). In the last years, new scopes of applications were discovered. Serinol is used for X-ray contrast agents, pharmaceuticals or for chemical sphingosine/ceramide synthesis. It can either be obtained by chemical processes based on 2-nitro-1,3-propanediol, dihydroxyacetone and ammonia, dihydroxyacetone oxime or 5-amino-1,3-dioxane, or biotechnological application of amino alcohol dehydrogenases (AMDH) or transaminases. This review provides a survey of synthesis, properties and applications for serinol

Implications of various phosphoenolpyruvate-carbohydrate phosphotransferase system mutations on glycerol utilization and poly(3-hydroxybutyrate) accumulation in Ralstonia eutropha H16

The enhanced global biodiesel production is also yielding increased quantities of glycerol as main coproduct. An effective application of glycerol, for example, as low-cost substrate for microbial growth in industrial fermentation processes to specific products will reduce the production costs for biodiesel. Our study focuses on the utilization of glycerol as a cheap carbon source during cultivation of the thermoplastic producing bacterium Ralstonia eutropha H16, and on the investigation of carbohydrate transport proteins involved herein. Seven open reading frames were identified in the genome of strain H16 to encode for putative proteins of the phosphoenolpyruvate-carbohydrate phosphotransferase system (PEP-PTS). Although the core components of PEP-PTS, enzyme I (ptsI) and histidine phosphocarrier protein (ptsH), are available in strain H16, a complete PTS-mediated carbohydrate transport is lacking. Growth experiments employing several PEP-PTS mutants indicate that the putative ptsMHI operon, comprising ptsM (a fructose-specific EIIA component of PTS), ptsH, and ptsI, is responsible for limited cell growth and reduced PHB accumulation (53%, w/w, less PHB than the wild type) of this strain in media containing glycerol as a sole carbon source. Otherwise, the deletion of gene H16_A0384 (ptsN, nitrogen regulatory EIIA component of PTS) seemed to largely compensate the effect of the deleted ptsMHI operon (49%, w/w, PHB). The involvement of the PTS homologous proteins on the utilization of the non-PTS sugar alcohol glycerol and its effect on cell growth as well as PHB and carbon metabolism of R. eutropha will be discussed

Radiotherapy: Impact of quality of life and need for psychological care: Results of a longitudinal study

Background: In the framework of a prospective longitudinal study, the quality of life (QoL) and support requirements of patients from a university hospital department of radiotherapy were evaluated for the first time by means of established psychodiagnostic questionnaires. Patients and Methods: At first, 732 patients were screened, of whom 446 (60.9%) fulfilled the criteria for inclusion; 39.1% did not (refusals 21.0%, low Karnofsky performance status 6.6%, management problems 3.4%, language barriers 3.0%, cognitive restrictions 2.6%, death 2.5%). Disease-specific aspects of QoL (Functional Assessment of Cancer Treatment - General, FACT-G) and moderating variables {[}Social Support Scale (SSS), Disease Coping (FKV), Self-Assessment Depression Scale (SDS), and Self-Defined Care Requirements (BB)] were self-rated by patients with different tumor types before radiotherapy (T1), after radiotherapy (T2), and 6 weeks after the end of radiotherapy (T3). We studied 265 patients (157 male, 108 female; median age 58.6 years) with complete data of three time points. Results: In general, QoL of patients decreased significantly over all time points in all subscales. Social support was rated high and remained constant throughout the treatment. Apparent coping mechanisms were active problem-oriented coping, leisure activities, and self-support. The patients' depression proved to be an important and constant factor without significant changes. The support requirement is characterized by the need for more medical information and dialogue with a physician. Conclusions: Early specific support from personnel with radiotherapeutic skills, during the disease-coping process as well as during rehabilitation, should be a permanent component of an integrated radiooncological treatment schedule

Fatty acid synthesis in Escherichia coli and its applications towards the production of fatty acid based biofuels

The idea of renewable and regenerative resources has inspired research for more than a hundred years. Ideally, the only spent energy will replenish itself, like plant material, sunlight, thermal energy or wind. Biodiesel or ethanol are examples, since their production relies mainly on plant material. However, it has become apparent that crop derived biofuels will not be sufficient to satisfy future energy demands. Thus, especially in the last decade a lot of research has focused on the production of next generation biofuels. A major subject of these investigations has been the microbial fatty acid biosynthesis with the aim to produce fatty acids or derivatives for substitution of diesel. As an industrially important organism and with the best studied microbial fatty acid biosynthesis, Escherichia coli has been chosen as producer in many of these studies and several reviews have been published in the fields of E. coli fatty acid biosynthesis or biofuels. However, most reviews discuss only one of these topics in detail, despite the fact, that a profound understanding of the involved enzymes and their regulation is necessary for efficient genetic engineering of the entire pathway. The first part of this review aims at summarizing the knowledge about fatty acid biosynthesis of E. coli and its regulation, and it provides the connection towards the production of fatty acids and related biofuels. The second part gives an overview about the achievements by genetic engineering of the fatty acid biosynthesis towards the production of next generation biofuels. Finally, the actual importance and potential of fatty acid-based biofuels will be discussed

Production optimization of cyanophycinase ChpEal from Pseudomonas alcaligenes DIP1

Pseudomonas alcaligenes DIP1 produces an extracellular cyanophycinase (CphEal). The corresponding gene (cphEal) was identified from subclones of a genomic DNA gene library by heterologously expressing the functionally active enzyme in Escherichia coli. The nucleotide sequence of the gene (1260 base pairs) was determined indicating a theoretical mass of 43.6 kDa (mature CphEal) plus a leader peptide of 2,6 kDa which corresponds well to the apparent molecular mass of 45 kDa as revealed by SDS-PAGE. The enzyme exhibited a high sequence identity of 91% with the extracellular cyanophycinase from P. anguilliseptica strain BI and carried an N-terminal Sec secretion signal peptide. Analysis of the amino acid sequence of cphE revealed a putative catalytic triad consisting of the serine motif GXSXG plus a histidine and a glutamate residue, suggesting a catalytic mechanism similar to serine-type proteases. The cyanophycinase (CphEal) was heterologously produced in two different E. coli strains (Top10 and BL21(DE3)) from two plasmid vectors (pBBR1MCS-4 and pET-23a(+)). The signal peptide of CphEal was cleaved in E. coli, suggesting active export of the protein at least to the periplasm. Substantial enzyme activity was also present in the culture supernatants. The extracellular cyanophycinase activities in E. coli were higher than activities in the wild type P. alcaligenes DIP1 in complex LB medium. Highest extracellular enzyme production was achieved with E. coli BL21(DE3) expressing CphEal from pBBR1MCS-4. Using M9 minimal medium was less effective, but the relatively low cost of mineral salt media makes these results important for the industrial-scale production of dipeptides from cyanophycin

Chelatococcus thermostellatus sp. nov., a new thermophile for bioplastic synthesis: comparative phylogenetic and physiological study

The poly(3-hydroxybutyrate), PHB, accumulating thermophilic strain MW9(T), isolated from an aerobic organic waste treatment plant, was characterized by detailed physiological and phylogenetic studies. The strain is a Gram-stainnegative, rod shaped, non-spore forming member of Alphaproteobacteria. It shows optimum growth at 50 degrees C. Based on 16S rRNA gene sequence similarity, the strain together with five very similar isolates, was affiliated to the genus Chelatococcus (Ibrahim et al. in J Appl Microbiol 109: 1579-1590, 2010). Rep-PCR genomic fingerprints and partial dnaK gene sequence also revealed that these isolates are very similar, but differ from other Chelatococcus type strains. The major fatty acids were similar to those of other strains of the genus Chelatococcus. DNA-DNA hybridization of strain MW9(T) with Chelatococcus species type strains revealed 11.0-47.7 % relatedness. G+C content of DNA was 67.1 mol%, which is comparable with the other strains of Chelatococcus species. The physiological and phenotypic characteristics of the new strain MW9(T) are sufficient to differentiate it from previously described species in the genus Chelatococcus. Strain MW9(T) is considered to represent a novel species of the genus Chelatococcus, for which the name Chelatococcus thermostellatus is proposed. The type strain is MW9(T) (= LMG 27009(T) = DSM 28244(T)). Compared to known Chelatococcus strains, strain MW9(T) could be a potent candidate for bioplastic production at elevated temperature

Strain and process development for poly(3HB-co-3HP) fermentation by engineered Shimwellia blattae from glycerol

Poly(3-hydroxybytyrate-co-3-hydroxypropionate), poly(3HB-co-3HP), is a possible alternative to synthetic polymers such as polypropylene, polystyrene and polyethylene due to its low crystallinity and fragility. We already reported that recombinant strains of Shimwellia blattae expressing 1,3-propanediol dehydrogenase DhaT as well as aldehyde dehydrogenase AldD of Pseudomonas putida KT2442, propionate-CoA transferase Pct of Clostridium propionicum X2 and PHA synthase PhaC1 of Ralstonia eutropha H16 are able to accumulate up to 14.5% (wtPHA/wtCDW) of poly(3-hydroxypropionate), poly(3HP), homopolymer from glycerol as a sole carbon source (Appl Microbiol Biotechnol 98:7409-7422, 2014a). However, the cell density was rather low. In this study, we optimized the medium aiming at a more efficient PHA synthesis, and we engineered a S. blattae strain accumulating poly(3HB-co-3HP) with varying contents of the constituent 3-hydroxypropionate (3HP) depending on the cultivation conditions. Consequently, 7.12, 0.77 and 0.32 gPHA/L of poly(3HB-co-3HP) containing 2.1, 8.3 and 18.1 mol% 3HP under anaerobic/aerobic (the first 24 hours under anaerobic condition, thereafter, aerobic condition), low aeration/agitation (the minimum stirring rate required in medium mixing and small amount of aeration) and anaerobic conditions (the minimum stirring rate required in medium mixing without aeration), respectively, were synthesized from glycerol by the genetically modified S. blattae ATCC33430 strains in optimized culture medium

Heterologous Expression of Various PHA Synthase Genes in Rhodospirillum rubrum

The phototrophic non-sulfur purple bacterium Rhodospirillum rubrum is known for its metabolic versatility. Particularly, R. rubrum is able to synthesize PHA under heterotrophic or even autotrophic growth with carbon monoxide as carbon and energy source. R. rubrum has therefore become a promising candidate for future cheap PHA production. However, R. rubrum synthesizes lower amounts of PHAs in comparison to well-known PHA producers like Ralstonia eutropha H16 or recombinant Escherichia coli strains. Since the PHA synthase is the key enzyme of PHA biosynthesis, genes encoding for twelve different PHA synthases were heterologously expressed in two generated phaC deletion mutants of R. rubrum in this study. To clearly see the effect of the foreign PHA synthases, PHA-negative mutants were required. The single mutant R. rubrum ΔphaC2 showed a PHA-leaky phenotype (< 1 % PHA, wt/wt, of CDW), while the double mutant R. rubrum ΔphaC1ΔphaC2 accumulated no measurable PHA. Eight different PHA synthase genes of class I, and four of class IV were chosen for heterologous expression. All recombinant R. rubrum strains showed significant PHA synthesis and accumulation, although PHA contents in the recombinant strains of the single mutant R. rubrum ΔphaC2 were generally higher in comparison to those of the double mutant R. rubrum ΔphaC1ΔphaC2. Recombinant strains of the single mutant could be divided into two groups according to the accumulation of PHA in the cells. While recombinant strains dedicated to group one showed an increased PHA synthesis when compared to the wild type carrying an empty vector, strains of group two accumulated less PHA than the wild type. Finally, it was possible to increase the accumulation of PHA by up to 25 % due to heterologous expression of PHA synthase genes compared to the wild type

Assessing quality of life in older people: psychometric properties of the WHOQOL-BREF

The World Health Organization has developed a brief generic questionnaire to assess quality of life, the WHOQOL-BREF. It has been studied in diverse groups, but not specifically in older people. The purpose of this study was to analyze the psychometric properties of the French version of the WHOQOL-BREF questionnaire in healthy older people and to compare the mean profiles of participants with the mean profile obtained in the international validation study of the WHOQOL-BREF. Of the total sample of 262 Swiss French speaking older participants, 122 completed a retest after 2weeks. The WHOQOL-BREF items demonstrated high test-retest reliability and validity. The WHOQOL-BREF items were differentially related to physical and mental health measures (SF-12 components, morbidity, and depression), thereby demonstrating convergent and discriminant validity. Compared to the international validation sample of the WHOQOL-BREF, participants of the present study reported higher QOL on 22 of the 26 items. A comparison of item profiles between male and female participants revealed gender differences for two items only (social support and negative feelings). We conclude that the psychometric properties of the WHOQOL-BREF items in older adults are good. To consider the 24 specific facets that are assessed by the WHOQOL-BREF appropriately, we recommend using item profiles on the individual and the sample leve

Molekulare Mechanismen der Plasmodium-Anopheles Interaktionen

Im Rahmen der Dissertationsarbeit wurden drei Projekte verfolgt, die sich mit den molekularen Mechanismen der Plasmodium-Anopheles Interaktionen beschäftigen. 1. Die melanotische Einkapselung von Plasmodium-Parasiten im Mitteldarm der Anopheles gambiae Mücke stellt eine effiziente Immunantwort dar, die den Lebenszyklus des Malaria-Erregers unterbrechen kann. Die Prophenoloxidasen (PPOs) gelten als Schlüsselenzyme dieser Reaktion. Eine funktionelle Charakterisierung der neun PPOs von An. gambiae erfolgte durch die gezielte Herunterregulierung der Gene mittels RNA-Interferenz in der adulten Mücke, verbunden mit anschließenden Infektionsexperimenten. Für sechs PPO-Gene konnte unter bestimmten Knockdown-Voraussetzungen eine deutliche Reduktion der melanisierten Parasiten nachgewiesen werden. Interessanterweise hatte das gene-silencing in suszeptiblen und refraktären Mücken unterschiedliche Auswirkungen. Während der Rückgang der melanisierten Parasiten beim G3/dsCTL-MA2 gleichzeitig in einer steigenden Anzahl lebender Oozysten resultierte, führte die Reduktion der eingekapselten Plasmodien im refraktären L3-5 Stamm dagegen zu keiner erhöhten Überlebensrate. 2. Die Invasion der Plasmodium-Sporozoiten in die Speicheldrüse der Mücke ist entscheidend für die Übertragung auf den Säugetierwirt. Da Sporozoiten präferentiell die beiden lateralen Lappen der Speicheldrüsen und erst dann den medialen Lappen invadieren, wurde mittels subtraktiver cDNA-Hybridisierung eine lateral-spezifische cDNA-Bibliothek erstellt, um potentielle Speicheldrüsen-Rezeptoren zu identifizieren. Als mögliche Kandidaten wurden die Gene SGS4 und 5 der SGS-Familie von An. gambiae beschrieben. 3. Sporozoiten sind die einzigen Stadien innerhalb des Plasmodium-Lebenszyklus, die in der Lage sind, zwei vollkommen unterschiedliche Organe zu invadieren – die Speicheldrüse der Mücke und die Leber des Säugetiers. Im dritten Teil der Arbeit stand die molekulare und funktionelle Charakterisierung des Sporozoiten-spezifischen UOS3 Gens von Plasmodium berghei im Mittelpunkt. Genetische Deletionsstudien haben gezeigt, dass UOS3 essentiell für die gliding motility und Zellinvasion der Sporozoiten in die Speicheldrüsen der Mücke und Hepatozyten des Säugetiers ist. Damit konnte erstmals neben dem Invasin TRAP ein weiteres Parasiten-Gen beschrieben werden, das zentrale Sporozoiten-Funktionen vermittelt