The effect of nutrient limitation on bacterial wax ester production

Nutrient limitation is widely employed to alter the behaviour of micro-organisms. Here, the impact of nitrogen and, for the first time, phosphate limitation is investigated on the production of bacterial storage lipids; specifically wax esters, a class of storage lipids of industrial interest, by the bacterium Acinetobacter baylyi ADP1 grown on the low-cost substrate acetate. Studies determined the absolute and temporal effects of nutrient limitation and identified a maximum wax titre of 132 mg/L and content of 17 % of biomass. A 4-fold increase in wax production was achievable by manipulating carbon: phosphate ratio. Multivariable analysis identified a novel interaction effect between carbon: nitrogen and carbon: phosphate ratios on wax production. Extreme phosphate starvation shifted the dominant lipid class from wax esters to triacylglycerols, the first report of the potential of phosphate limitation to alter the type of lipid generated. These findings offer valuable insights for future microbial bioproduction studies

CBR Based Risk Management for Virtual Organization

After researching various factors that influence the management and decisions on risk management of virtual organization, CBR based risk management for virtual organization is proposed in this paper. Relevant theories of fuzzy mathematics are utilized in the process of modifying the corresponding similar cases. Correct application of the new method is demonstrated substantially through instance simulation

Risk Sorting for Enterprise under EC Environments

With the rapid development of internet and emerging of global economic, risk management for enterprise under EC (Electronic Commerce) environments has drawn attentions of many researchers. In this paper, the characteristics of risk for EC enterprise are analyzed. Further, focused on the project organization mode and the uncertain factor of the enterprise under EC, which are main different characteristics from the conventional enterprise, enterprise risk sorting, which is one of the key problems of risk management under EC environments, is studied by using fuzzy ISODATA cluster method based on fuzzy describing of risks. Case study suggests the effectiveness of the method

Anaerobic co-digestion of Euphorbia tirucalli with pig blood for volatile fatty acid production

Acidogenic fermentation of biomass to produce volatile fatty acids provides a renewable pathway to industrial chemicals ordinarily derived from petrochemicals. Crassulacean acid metabolism plants such as Euphorbia tirucalli are cultivable on marginal land and offer promising feedstocks for this purpose. This study investigated how the refining of E. tirucalli biomass to fatty acids could be augmented with a high-protein co-substrate, pig blood. Blood mono-digestions provided the highest titres of total fatty acid (up to 38 ± 2 g/L), while at high substrate concentrations, acetic acid was maximal in co-digestions. 75 % blood with 25 % E. tirucalli produced acetic acid titres 40.8 % (p < 0.001) and 30.8 % (p = 0.001) higher than those in mono-digestions of E. tirucalli and blood, respectively. Where acetate is the desired product, inclusion of blood as a co-substrate offers significant benefit for Euphorbia biorefining

Cyclin-dependent Kinase 5 (Cdk5)-dependent Phosphorylation of p70 Ribosomal S6 Kinase 1 (S6K) Is Required for Dendritic Spine Morphogenesis.

The maturation and maintenance of dendritic spines depends on neuronal activity and protein synthesis. One potential mechanism involves mammalian target of rapamycin, which promotes protein synthesis through phosphorylation of eIF4E-binding protein and p70 ribosomal S6 kinase 1 (S6K). Upon extracellular stimulation, mammalian target of rapamycin phosphorylates S6K at Thr-389. S6K also undergoes phosphorylation at other sites, including four serine residues in the autoinhibitory domain. Despite extensive biochemical studies, the importance of phosphorylation in the autoinhibitory domain in S6K function remains unresolved, and its role has not been explored in the cellular context. Here we demonstrated that S6K in neuron was phosphorylated at Ser-411 within the autoinhibitory domain by cyclin-dependent kinase 5. Ser-411 phosphorylation was regulated by neuronal activity and brain-derived neurotrophic factor (BDNF). Knockdown of S6K in hippocampal neurons by RNAi led to loss of dendritic spines, an effect that mimics neuronal activity blockade by tetrodotoxin. Notably, coexpression of wild type S6K, but not the phospho-deficient S411A mutant, could rescue the spine defects. These findings reveal the importance of cyclin-dependent kinase 5-mediated phosphorylation of S6K at Ser-411 in spine morphogenesis driven by BDNF and neuronal activity.published_or_final_versio

Virtual Enterprises Risk Management DSS under Electronic Commerce

Risk management is important to the development of enterprise as well as social-economic prosperity. Virtual enterprise is the potential mode of future enterprise under electronic commerce environment and the risk management for it is a popular research area recently. Due to the complexity of its risk management a decision support system (DSS) with 3-bases-1-cell structure was designed. By coordinating data base, model base, algorithm base and dialogue cell, the functions of project management, risk identification, risk assessment, risk evaluation and risk programming was supported. The user-friendly system has such main characteristics as generality for verity virtual enterprise as well as different projects and the flexibility of model and algorithm, ensuring a standardized, scientific and informational risk management for virtual enterprises

Risk Evaluation for Virtual Enterprise

Virtual Enterprise is the potential mode of enterprise in the future. The risk management for virtual enterprise is the new research area recently. In virtual enterprise, the enterprise operation is always organized by project mode and there is always less historical data and there are many uncertain factors. Hence, in this paper, the fuzzy synthetic evaluation model for the risk evaluation of virtual enterprise is established focus on the project mode and uncertain characteristics of virtual enterprise. In the 5 levels model, the goal and sub-goal of the enterprise, the process of the project, as well as the risk event and risk factors are considered. The case study suggests that the method is useful

A Risk Identification Method of Virtual Enterprise

Virtual enterprise is the potential mode of future enterprise under global economic environment and the risk management for it is a popular research area recently. Risk identification is the key phrase of risk management. Considering the risk identification problem in the virtual enterprise, a new identification method based on the BP network is provided in this paper. Using this method and the data related to the problem, the possible to take place of the risks could be obtained by training the neural network, so that risks can be investigated in time and managed effectively. The simulation results prove its validit