The Yeast ATF1 Acetyltransferase Efficiently Acetylates Insect Pheromone Alcohols: Implications for the Biological Production of Moth Pheromones

Many moth pheromones are composed of mixtures of acetates of long‐chain (≥10 carbon) fatty alcohols. Moth pheromone precursors such as fatty acids and fatty alcohols can be produced in yeast by the heterologous expression of genes involved in insect pheromone production. Acetyltransferases that subsequently catalyze the formation of acetates by transfer of the acetate unit from acetyl‐CoA to a fatty alcohol have been postulated in pheromone biosynthesis. However, so far no fatty alcohol acetyltransferases responsible for the production of straight chain alkyl acetate pheromone components in insects have been identified. In search for a non‐insect acetyltransferase alternative, we expressed a plant‐derived diacylglycerol acetyltransferase (EaDAcT) (EC 2.3.1.20) cloned from the seed of the burning bush (Euonymus alatus) in a yeast system. EaDAcT transformed various fatty alcohol insect pheromone precursors into acetates but we also found high background acetylation activities. Only one enzyme in yeast was shown to be responsible for the majority of that background activity, the acetyltransferase ATF1 (EC 2.3.1.84). We further investigated the usefulness of ATF1 for the conversion of moth pheromone alcohols into acetates in comparison with EaDAcT. Overexpression of ATF1 revealed that it was capable of acetylating these fatty alcohols with chain lengths from 10 to 18 carbons with up to 27‐ and 10‐fold higher in vivo and in vitro efficiency, respectively, compared to EaDAcT. The ATF1 enzyme thus has the potential to serve as the missing enzyme in the reconstruction of the biosynthetic pathway of insect acetate pheromones from precursor fatty acids in yeast.     

Crossing times: Temporal boundary-spanning practices in interorganizational projects

This paper introduces the notion of “temporal boundary spanning” and highlights the key role of project management in resolving temporal tensions among partners participating in interorganizational projects (IOPs). The present study, which is based on data from 93 IOPs undertaken within a major change program, relies on in-depth, semi-structured interviews, observations, and detailed analyses of written documents and procedures from those IOPs. Based on the data, we inductively develop a practice-based theory that identifies three main practices (framing, synchronizing, hyping) used to resolve the central temporal tensions observed in the studied IOPs. In that respect, the paper offers novel insights into the role and practice of project management in IOPs.     

Continuous generating grinding—Tooth root machining and use of CBN-tools

Profile accuracy, no burning and residual compressive stresses at the tooth root fillet are required for the durability of highly stressed gears. This paper reveals the challenges for continuous generating grinding with corundum and CBN. For this purpose, material removal simulations and experimental investigations were carried out to gain knowledge of the tool–workpiece contact conditions. The potential of CBN tools was analysed due to the fact that the mechanical loads at the grinding worm tip result in high profile wear of the corundum tools. In this context, especially the interrelationship between the dressing strategy and the workpiece quality was investigated in detail.     

Comparison of single and joint effects of Zn and Cu in continuous flow and batch reactors

BACKGROUND: Microbial behavior in batch reactors may be different from that in continuous flow reactors, which is expected to affect microbial response to heavy metal exposure. Four parallel continuous flow reactors and batch growth tests were used to investigate the single and joint toxicity of Zn and Cu to Artrobacter sp. JM018. RESULTS: The results indicated that Cu is more toxic than Zn under all conditions. In the batch reactors, all Zn concentrations showed a stimulatory effect on microbial growth. However in the continuous system, 125 µmol L^?1 Zn exposure produced inhibition. In the case of mixed Zn and Cu exposures in the batch system, the presence of Zn reduced the severity of Cu inhibition, with a net impact of reduced growth in all cases, whereas in the continuous system microbial growth and substrate utilization rates sharply decreased and ceased. CONCLUSION: The results clearly showed that growth in batch reactors underestimated significantly the heavy metal inhibition, compared with the continuous system. Therefore, the results of batch reactor tests should not be used directly when heavy metal inhibition is to be interpreted for continuous flow systems. Copyright © 2011 Society of Chemical Industry     

Detection of UF resin on wood particles and in particleboards: potential of selected methods for practice-oriented offline detection

In the wood-based panel industry, controlling the manufacturing process is crucial for ensuring product quality, using resources efficiently and cutting production costs. One major aspect for the final quality of particleboards is the distribution of resin on particles within a board. This study deals with the comparison of techniques that can be used for a practice-oriented detection of urea formaldehyde resin within an industrial environment. Resin detection was carried out by staining the resin with visible and fluorescent dyes as well as by near infrared spectroscopic (NIR) in combination with CHN elemental analysis. Using the fluorescent dye Brilliant Sulphaflavine, resin as well as single resin droplets could be detected best. NIR measurements did not lead to coherent results and should be further improved, especially because of its potential for online detection.     

Hydroxyl‐functional polyurethanes and polyesters: synthesis,properties and potential biomedical application

This mini review gives an overview of the synthesis of polyurethanes and polyesters with pendant hydroxyl groups performed mainly in our group. Significant for the synthesis of most of these polymers with hydroxyl‐functional side groups is that no protection groups are needed. This is realised either by generating the OH group during polymer synthesis—demonstrated by the preparation of hydroxyl‐functional polyurethanes from dicarbonate monomers and diamines—or by using catalysts which discriminate between primary and secondary OH groups—demonstrated by the synthesis of hydroxyl‐functional polyesters based on malic acid using scandium triflate as catalyst. In addition, the potential of carbonate couplers for the synthesis of multifunctional polyurethane is presented. The application of such multifunctional polyurethanes as antimicrobial polymers and coatings is briefly discussed. Copyright © 2012 Society of Chemical Industry