This paper describes the thermo-mechanical design of the Focal Plane Assembly (FPA) of the PLAnetary Transits and Oscillations of stars (PLATO) Instrument, developed by INTA and LIDAX. This is an ESA program with OHB as industry prime. In terms of assembly, alignment, and operational stability very demanding needs are required by a huge focal plane composed of four CCDs to assure the proper performance. This is translated into a complex thermomechanical design which shall be also focused on the correct production approach of the main parts involved, including several processes, and taking into account the number of cameras, and therefore Focal Plane Assemblies, to be produced (26). Part of these challenges, and their associated risks, are mitigated by means of the development of a totally representative prototype, which is currently finishing the integration phase and facing the test campaign.

PLATO (PLAnetary Transits and Oscillations of stars) is an ESA mission, which is dedicated to the detection and characterization of terrestrial exo-planets. In the baseline design, it is planned to mount 26 cameras in the same instrument bench. Each camera consists on a telescope, the focal plane assembly (FPA) and the detector electronics. This amount of cameras that has to be manufactured, integrated and tested at the same time makes this mission an industrialization process. This paper explains the approach of the initial model philosophy used and the tests results of the FPA prototype.

PLATO, PLAnetary Transits and Oscillation of stars, is an ESA mission mainly devoted to survey the Galaxy searching for and characterizing Earth-like exoplanets, and their host stars. This will be achieved using continuous and extremely accurate photometry for both exoplanetary transits and asteroseismology analysis. Current design plans to mount 26 cameras in the same instrument bench in order to cover a large field of view with the highest possible photon statistics. Each PLATO camera consists of the telescope (TOU, Telescope Optical Unit), the focal plane assembly (FPA), and the detector and camera read out electronics (FEE). Four CCDs (Charge Coupled Devices) will be included in each FPA, which implies a really delicate assembly and integration verification (AIV) process due to the stringent scientific requirements breakdown into hard engineering ones (among others, CCDs co-alignment in terms of tip and tilt and roll with respect to the optical axis). In the following lines, the FPA current opto-mechanical design is briefly presented and an integration process conceptual proposal is reported on, discussing the error budgets associated to the main requirements to be verified during FPAs AIV, and the main results obtained during the prototype first AIV round.

Introduction Proteins are chains of amino acids which can be modified by a post-translational modification process. There are many different post-translational modifications (PTMs) such as phosphorylation, methylation, ubiquitination or acetylation. Protein acetylation is a post-translational modification (PTM) consisting in the transference of an acetyl group from an acetyl donor molecule to the ε-amino group of a lysine residue. The importance of protein acetylation has greatly increased in last years, due to its impact on the function, structure, stability and/or location of thousands of proteins involved in diverse cellular processes. Protein acetylation can be carried out by an enzymatic way (catalyzed by an acetyltransferase) or by a non-enzymatic or chemist way [1]. Protein acetylation can be reverted by deacetylases or histone deacetylases (HDACs). There are four classes of HDACs, class I, class II, class II and class IV. The class III proteins are known as sirtuins, which are broadly conserved from bacteria to humans. Sirtuins three-dimensional structure consists of a typical Rossmann-fold and a Zn 2+ binding domain [2]. Sirtuins employ NAD +

Lycopene is an import ant compound with an increasing industrial value. However, there is still no biotechnological process to obtain it. In this study, a semi-continuous system for lycopene extraction from recombinant Escherichia coli BL21 cells is proposed. A two-phase culture mode using organic solvents was found to maximize lycopene production through in situ extraction from cells. Within the reactor, three phases were formed during the process: an aqueous phase containing the recombinant E. coli, an interphase, and an organic phase. Lycopene was extracted from the cells to both the interphase and the organic phase and, consequently, thus enhancing its production. Maximum lycopene production (74.71 ± 3.74 mg L−1) was obtained for an octane-aqueous culture system using the E. coli BL21LF strain, a process that doubled the level obtained in the control aqueous culture. Study of the interphase by transmission electron microscopy (TEM) showed the proteo-lipidic nature and the high storage capacity of lycopene. Moreover, a cell viability test by flow cytometry (CF) after 24 h of culture indicated that 24 % of the population could be re-used. Therefore, a batch series reactor was designed for semi-continuous lycopene extraction. After five cycles of operation (120 h), lycopene production was similar to that obtained in the control aqueous medium. A final specific lycopene yield of up to 49.70 ± 2.48 mg g−1 was reached at 24 h, which represents to the highest titer to date. In conclusion, the aqueous-organic semi-continuous culture system proposed is the first designed for lycopene extraction, representing an important breakthrough in the development of a competitive biotechnological process for lycopene production and extraction.

This chapter focuses on the application of enzyme technology in non-aqueous green solvents as ionic liquids (ILs) to transform biomass, mainly non-edible biomass (e.g. cellulose, lignocellulose, wood, forest residues, etc.), into fermentable monomeric compounds, and low cost vegetable oils or animal fats in biodiesel. This review aims to identify the key parameters that determine the biocompatibility of ionic liquids with enzymes for the rational design of ionic liquid-based formulations in biocatalysis for biofuel production.

Panthenyl esters (panthenyl monoacetate and panthenyl diacetate) were synthesized in high yields (approximate to 100%) by a kinetic reaction control using a commercial immobilized Candida Antarctica lipase B (Novozyme 435) in acetonitrile. The enzyme showed excellent synthetic activity, regioselectivity, and operational stability under the conditions used.

The efficient production of biodiesel in hydrophobic ionic liquids using immobilized lipase was demonstrated. The use of ionic liquids containing long alkyl chains on the cation has the important advantage of producing homogeneous systems at the start of the reaction but, when the reaction is complete, a three-phase system is created that allows selective extraction of the products using straightforward separation techniques, while the ionic liquid and the enzyme can be reused. Fifteen ionic liquids based on different alkyl chain length of the methyl imidazolium cation ([C10MIM], [C12MIM], [C14MIM], [C16MIM] and [C18MIM]) combined with [BF4], [PF6] or [NTf2] anions were assayed as reaction media for two immobilized lipases (Candida antarctica lipase B and Pseudomonas fluorescens lipase AK) for biodiesel production. The highest synthetic activity was obtained in [C16MIM] [NTf2] using Novozym 435 (immobilized Candida antarctica lipase with 245.13 U g(-1) IME), its activity being more than three times higher than in a solvent-free system. Additionally, in this IL the fatty acid methyl esters production was 90.29% after 3 h, while in the solvent-free system it was 27.3%. The influence of several reaction parameters, such as temperature, methanol-to-oil molar ratio, alkyl-chain length of the alcohols, IL : substrate volume ratios, amount of enzyme, and oils feedstock were studied and optimized.

Immobilized Candida antarctica lipase B suspended in ionic liquids containing long alkyl-chain cations showed excellent synthetic activity and operational stability for biodiesel production. The interest of this process lies in the possibility of recycling the biocatalyst and the easy separation of the biodiesel from the reaction mixture. The ionic liquids used, 1-hexadecyl-3-methylimidazolium triflimide ([C(16)MIM][NTf(2)]) and 1-octadecyl-3-methylimidazolium triflimide ([C(18)MIM][NTf(2)]), produced homogeneous systems at the start of the reaction and, at the end of the same, formed a three-phase system, allowing the selective extraction of the products using straightforward separation techniques, and the recycling of both the ionic liquid and the enzyme. These are very important advantages which may be found useful in environmentally friendly production conditions.

Ionic liquids (ILs) have attracted growing interest as alternative reaction media for enzyme-catalyzed transformations because of their unique properties as green solvents, opening up news opportunities in the field of pharmaceutical synthesis. Additionally, enzymatic transformations in ILs/scCO(2) biphasic systems have been described as an interesting way of carrying out clean synthetic processes whereby enzyme molecules are "immobilized" into the IL phase, while substrates/products are transported by the scCO(2) phase. Several ILs based on alkyl-imidazolium cations and associated with different anions, ([PF6], [BF4] and [NTf2]), have been assayed for the Candida antarctica lipase B (CALB)-catalyzed resolution of the analgesic rac-ketoprofen by esterification with different 1-alkanols. A membrane reactor working with both IL and supercritical carbon dioxide (scCO(2)) phases has been applied for separation of R-ketoprofen ester products.

An electrochemical bioreactor with glucose dehydrogenase immobilized on to the electrode surface produced gluconic acid from glucose with concomitant recycling of the NAD+ coenzyme at 0.7 V. Since the enzyme is deactivated during operation at this redox potential, co-immobilization of 3,4-dihydroxybenzaldehyde as mediator allowed the system to operate at 0.2 V and increased both the activity (2.4-times) and the stability of the immobilized enzyme (2.2-times). The different effective electrochemical surfaces resulting from the different mediator immobilization modes are important in determining these three properties.

A flow injection analysis method for determining L-carnitine is reported. The system uses the enzyme L-carnitine dehydrogenase covalently immobilized to Eupergit C. The NADH produced by the action of the enzyme, which is proportional to the L-carnitine concentration, is quantified using fluorescence detection. The system response was rapid and had a wide range of linearity. At a flow rate of 0.2 ml/min, a detection limit of 1 microM (20 pmol) was obtained for L-carnitine, peak areas were linear up to 100 microM, and samples could be injected every 4 min. The method performed well as a routine assay, showing high sensitivity (54,000 AU/microM), a precision of 0.96%, and the ability to carry out 144 consecutive assays with an RSD of 1.47% (good stability). Comparisons were made with other known methods for L-carnitine determination. Presence of D-carnitine had no effect on L-carnitine assay. The analysis was valid for determining L-carnitine concentrations in commercial pharmaceutical preparations.

NAD(H) was retained in a noncharged ultrafiltration membrane reactor for the simultaneous and continuous production of L-lactate and gluconate with coenzyme regeneration. Polyethyleneimine (PEI), a 50-kDa cationic polymer, achieved coenzyme retentions above 0.8 for PEI/NAD(H) molar ratios higher than 5. The ionic strength of the inlet medium caused a decrease of NAD(H) retention that can be counterbalanced by an initial addition of 1% bovine serum albumin (BSA). Continuous reactor performance in the presence of PEI and BSA showed that NAD(H), glucose dehydrogenase, and lactate dehydrogenase were retained by 10-kDa ultrafiltration membranes; L-lactate and gluconate were produced at conversions higher than 95%. PEI enhanced the thermal stability of the enzymes used and increased the catalytic efficiency of glucose dehydrogenase, while no effect was found on the kinetic parameters of lactate dehydrogenase. A model that implements the kinetic equations of the two enzymes describes the reactor behavior satisfactorily. In brief, the use of PEI to retain NAD(H) is a new interesting approach to be widely applied in continuous synthesis with the large number of known dehydrogenases.

The stability of the enzyme glucose dehydrogenase (GDH) has been studied under turnover conditions in an electrochemical reactor with NAD(P) + regeneration on a preparative scale. The enzyme showed first-order deactivation patterns closely related to imposed potential. An increase in the applied potential caused a decrease of the half-life deactivation time of the enzyme ( t 1/2 ) . However, this detrimental effect was compensated with an enhancement of the substrate consumption rate ( r s ) attained as a consequence of the higher cofactor regeneration rates observed at more positive potentials. A 0.7 V potential ( vs Ag|AgCl) was selected as a compromise between the activity and the stability of the enzyme ( t 1/2 = 4.2 h; r s = 32 μmol min −1 ) . The protective effect on the activity of glucose dehydrogenase of well-known stabilizing agents such as NaCl, sorbitol, bovine serum albumin (BSA) or polyethyleneimine (PEI) has been studied. PEI (50 000 MW) at concentrations between 0.3 and 0.5 mM showed the highest protection of the enzyme activity in the electrochemical reactor as well as the highest substrate consumption rates ( t 1/2 = 24.5 h; r s = 59 μmol min −1 ) . This beneficial effect of PEI is explained in terms of an electrode, cofactor, and enzyme modification that induces an increase of the concentrations of NAD(P) H and glucose dehydrogenase in the vicinity of the electrode and minimizes the adsorption of the enzyme on the electrode contact.

The effect of temperature and pH on thermoinactivation kinetics of glucose dehydrogenase from Haloferax mediterranei has been studied in the presence of different monovalent salts (LiCl, LiBr, NaCl, NaBr, KCl, KBr, NH4Cl, and NH4Br) and polyols (glycerol, erythrytol, xylitol, and sorbitol) concentrations. The stabilization degree of salts followed the rank of the Hofmeister series, and the product of the Setchenov constant (Ks) times the concentration of solute (Cs) was useful to predict the enzyme stability in the presence of salt solutions. Polyols stabilized the halophilic enzyme as much as salts. For an equal polyol concentration, the thermostability increased in the range glycerol < erythritol < xylitol < sorbitol. The overall hydroxyl group concentration proved to be a good parameter for correlating the protective effect of polyols with the polyol nature. Thermoinactivation of the halophilic glucose dehydrogenase in the presence of NaCl and sorbitol was compared with that of a nonhalophilic glucose dehydrogenase in terms of the transition state theory. The free activation energy was, in all cases, enthalpy driven, and hydrogen-bond and/or ionic-binding interactions are the main forces involved in protein stabilization. The halophilic enzyme showed, in general, lower free activation energies for the deactivation process. The adaptation of the enzyme to a halophilic environment led to an enzyme with higher activity at high salt concentrations, but such an increase in enzyme activity was not related to an enhancement in enzyme thermostability.

A new concept of membrane reactor for continuous retention of NADP(H) with non-charged ultrafiltration membranes is proposed. The presence of the high molecular weight polymer polyethyleneimine (PEI) in the reaction medium allow to achieve high retainment ratios for the native coenzyme when the molar ratio PEI/NADP(H) in the reactor is > 1. Nad concentrations > 0.3 M decrease significantly the retainment ratio of NADP + in the reactor. Therefore, this system is applicable for enzyme reactions requiring low ionic strength media. This reactor configuration has been applied to obtain simultaneously gluconate and glutamate by coupling two enzymes for coenzyme regeneration, glucose dehydrogenase and glutamate dehydrogenase. Sorbitol stabilization of the halophilic enzymes allows to compensate the reduced NaCl concentration required for coenzyme retention. Experimental performance of the reaction is compared successfully with a theoretical model that considers the kinetic mechanisms of the enzymes involved.

Adenine in unbuffered nanopure water at a concentration of 2 mM is completely deaminated (>99%) to hypoxanthine at room temperature in ca. 10 weeks, with an estimated half-life (t1/2) less than 10 days, about six orders of magnitude faster than previously reported. Cytosine is not deaminated under the same condition, even after 3 years. This is in contrast to previous observations that cytosine deaminates 20–40 times faster than adenine free base, in nucleoside, in nucleotide and in single-stranded DNA in buffered neutral aqueous solutions.

Grapevine (Vitis vinifera L. cv Gamay Fréaux) cells from a suspension culture were immobilized in reticulate polyurethane foam matrices. Growth pattern and anthocyanin accumulation within the immobilized cells were compared with results from freely suspended cultures. An increase in both the length of the initial lag-growth phase (from 5 to 12 days) and the amount of peonidin 3-glucoside stored within the cells was shown as a result of the immobilization process. This fact gave some insight about the effect of retention within the matrix on this plant cell line.

Limonin can be effectively degraded byRhodococcus fascians cells. These bacteria can be entraped in κ-carrageenan, and used in a continuous stirred tank reactor to degrade limonin in a continuous process. The effects of temperature limonin concentration, dilution rate, and aeration on the reactor behaviour have been tested, and the results correlated with changes in limonin conversion, substrate degradation rate, and free and immobilized biomass. Results showed that the immobilized cells were able to debitter limonin-containing media and the immobilized biomass was quite stable throughout the operational conditions tested. A population of free biomass was present in the reactor, the quantity of which was dependent on dilution rate. The immobilized bacteria increased its limonin-degrading capability when the substrate concentration was increased. The aeration was not strictly necessary for limonin degradation. Additionally, the immobilized cells were active and stable for more than 2 months of continuous operation, and were able to recover their limonin-degrading capability when used intermittently. Finally, none of the main components of a juice was noticeably altered during limonin degradation, so the reactor response was good enough to consider its application.