High yield lipase-catalyzed synthesis of Engkabang fat esters for the cosmetic industry

Engkabang fat esters were produced via alcoholysis reaction between Engkabang fat and oleyl alcohol, catalyzed by Lipozyme RM IM. The reaction was carried out in a 500 ml Stirred tank reactor using heptane and hexane as solvents. Response surface methodology (RSM) based on a four-factor-five-level Central composite design (CCD) was applied to evaluate the effects of synthesis parameters, namely temperature, substrate molar ratio (oleyl alcohol: Engkabang fat), enzyme amount and impeller speed. The optimum yields of 96.2% and 91.4% were obtained for heptane and hexane at the optimum temperature of 53.9 °C, impeller speeds of 309.5 and 309.0 rpm, enzyme amounts of 4.82 and 5.65 g and substrate molar ratios of 2.94 and 3.39:1, respectively. The actual yields obtained compared well with the predicted values of 100.0% and 91.5%, respectively. Meanwhile, the properties of the esters show that they are suitable to be used as ingredient for cosmetic applications.     

Twelve Months of Routine HIV Screening in 6 Emergency Departments in the Paris Area: Results from the ANRS URDEP Study

Objective

In October 2009 the French National Authority for Health recommended that HIV testing be proposed at least once to all persons aged 15 to 70 years in all healthcare settings. We examined whether routine HIV screening with a rapid test in emergency departments (EDs) was feasible without dedicated staff, and whether newly diagnosed persons could be linked to care.

Methods

This one-year study started in December 2009 in 6 EDs in the Paris area, using the INSTI™ test. Eligible individuals were persons 18 to 70 years old who did not present for a vital emergency, for blood or sexual HIV exposure, or for HIV screening. Written informed consent was required.

Results

Among 183 957 eligible persons, 11 401 were offered HIV testing (6.2%), of whom 7936 accepted (69.6%) and 7215 (90.9%) were tested (overall screening rate 3.9%); 1857 non eligible persons were also tested. Fifty-five new diagnoses of HIV infection were confirmed by Western blot (0.61% (95% CI 0.46–0.79). There was one false-positive rapid test result. Among the newly diagnosed persons, 48 (87%) were linked to care, of whom 36 were not lost to follow-up at month 6 (75%); median CD4 cell count was 241/mm³ (IQR: 52–423/mm³).

Conclusions

Screening rates were similar to those reported in opt-in studies with no dedicated staff. The rate of new diagnoses was similar to that observed in free anonymous test centres in the Paris area, and well above the prevalence (0.1%) at which testing has been shown to be cost-effective.     

Inventory and abundance of mealybug species in immature and mature cocoa farms in Côte d'Ivoire

From 2013 to 2018, surveys were conducted in counties not previously surveyed in order to determine species of mealybugs present in the cocoa orchard in Côte d'Ivoire as well as their abundance according to the age of cocoa trees. Immature and mature cocoa trees were inspected to hand‐height in 5 and 29 counties infected with Cacao swollen shoot virus (CSSV). In each cocoa farm, mealybugs were searched for on fruits, leaves, flowers, twigs and trunks. Mealybug species were identified, and colonies were counted. Five mealybug species were identified on immature cocoa trees: Ferrisia virgata, Formicococcus njalensis, Planococcus citri, Planococcus kenyae and Pseudococcus longispinus. In addition to these species, four species, Dysmicoccus brevipes, Maconellicoccus hirsutus, Phenacoccus hargreavesi and Pseudococcus jackbeardsleyi were identified on mature cocoa trees. On immature cocoa trees, Fo. Njalensis, Pl. citri and Ps. longispinus comprised were, respectively, 35%, 33% and 19% of colonies, respectively. On mature cocoa trees, Fo. Njalensis and Pl. citri comprised 63.2% and 21.0%, and others species 15.8%. Nevertheless, the abundance of mealybug species varied according to the age of cocoa trees. The preferred organs of mealybugs were pods (74.1%) followed by twigs (13.4%) and flowers (7.4%). Previously, the mealybug Paracoccus burnerae (Brain) was found on Theobroma cacao, which is the first record for this species in Côte d'Ivoire and on this host‐plant.     

Spectaflavoside A, a new potent iron chelating dimeric flavonol glycoside from the rhizomes of Zingiber spectabile Griff

The rhizomes of Zingiber spectabile yielded a new dimeric flavonol glycoside for which the name kaempferol-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside-(I-6,II-8)-kaempferol-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside; spectaflavoside A (1) was proposed, along with kaempferol and its four acetylrhamnosides (2-6), demethoxycurcumin (7) and curcumin (8). The structure of spectaflavoside A was elucidated by spectroscopic methods including, 1D and 2D NMR techniques. This is the first report on the occurrence of a dimeric flavonol glycoside in the Zingiberaceae and the second in nature. Spectaflavoside A was found to be a potent iron chelating agent.     

Inhibition of Klebsiella pneumoniae ATCC 13883 cells by hexane extract of Halimeda discoidea (Decaisne) and the identification of its potential bioactive compounds

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 log10, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GCMS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.     

Cyanofuels: biofuels from cyanobacteria. Reality and perspectives

Photosynthesis Research - Cyanobacteria are represented by a diverse group of microorganisms that, by virtue of being a part of marine and freshwater phytoplankton, significantly contribute to the...     

Water relations,photosynthesis, growth and water-use efficiency in tomato plants subjected to partial rootzone drying and regulated deficit irrigation

Abstract

Partial rootzone drying (PRD) and regulated deficit irrigation (RDI) are water-saving irrigation systems that have been developed to increase water-use efficiency (WUE) without significant yield reduction. In order to investigate whether a high-value horticultural crop such as tomato responded differently to RDI and PRD, we compared the physiological and growth responses of tomato plants using a split-root system. Plants were grown in a greenhouse under controlled conditions with their roots separated equally between two soil compartments. Three irrigation treatments were imposed: (i) Control, receiving an amount of water equivalent to 100% of plant transpiration; (ii) PRD, in which one compartment was watered with 50% of the amount of water supplied to the controls, allowing one-half of the root system to be exposed to dry soil and switching irrigation between sides weekly; and (iii) RDI, in which 50% of the amount of water given to the controls was supplied, half to each side of the root system. Leaf RWC and midday leaf Ψ decreased substantially in RDI-treated plants, while the PRD plants exhibited relatively higher Ψ and RWC values. Both PRD and RDI treatments reduced by about 30% the total plant dry mass compared with the control. However, plant transpiration was reduced by about 50% in both PRD and RDI, allowing a significant improvement in whole-plant WUE. Stomatal conductance (Gs) and leaf growth were also significantly reduced by PRD and RDI. These results may be related to a significant increase in xylem sap pH and leaf apoplastic pH. Generally, the photosynthetic apparatus of tomato leaves had a high resistance to restricted water availability. In fact, the decreased Gs had no major negative impact on carbon assimilation. However, V _cmax, i.e. Rubisco efficiency, was significantly decreased in RDI plants with respect to control ones. This may imply that, although the differences between the PRD and RDI treatments in our study were subtle, they may become more marked with a more prolonged and severe water deficit.