Utilisation of by-products from sunflower-based biodiesel production processes for the production of fermentation feedstock

By-products streams from a sunflower-based biodiesel plant were utilised for the production of fermentation media that can be used for the production of polyhydroxyalkanoates (PHA). Sunflower meal was utilised as substrate for the production of crude enzyme consortia through solid state fermentation (SSF) with the fungal strain Aspergillus oryzae. Fermented solids were subsequently mixed with unprocessed sunflower meal aiming at the production of a nutrient-rich fermentation feedstock. The highest free amino nitrogen (FAN) and inorganic phosphorus concentrations achieved were 1.5 g L-1 and 246 mg L-1, respectively, when an initial proteolytic activity of 6.4 U mL-1 was used. The FANconcentrationwas increased to 2.3 g L-1 when the initial proteolytic activity was increased to 16 U mL-1. Sunflower meal hydrolysates were mixed with crude glycerol to provide fermentationmedia that were evaluated for the production of poly(3-hydroxybutyrateco- 3-hydroxyvalerate) (P(3HB-co-3HV)) using Cupriavidus necator DSM545. The P(3HB-co-3HV) (9.9 g l-1) produced contained 3HB and 3HV units with 97 and 3 mol %, respectively. Integrating PHA production in existing 1st generation biodiesel production plants through valorisation of by-product streams could improve their sustainability.

Sampling uncertainty in gridded sea surface temperature products and Advanced Very High Resolution Radiometer (AVHRR) Global Area Coverage (GAC) data

Sea surface temperature (SST) data are often provided as gridded products, typically at resolutions of order 0.05 degrees from satellite observations to reduce data volume at the request of data users and facilitate comparison against other products or models. Sampling uncertainty is introduced in gridded products where the full surface area of the ocean within a grid cell cannot be fully observed because of cloud cover. In this paper we parameterise uncertainties in SST as a function of the percentage of clear-sky pixels available and the SST variability in that subsample. This parameterisation is developed from Advanced Along Track Scanning Radiometer (AATSR) data, but is applicable to all gridded L3U SST products at resolutions of 0.05-0.1 degrees, irrespective of instrument and retrieval algorithm, provided that instrument noise propagated into the SST is accounted for. We also calculate the sampling uncertainty of ~0.04 K in Global Area Coverage (GAC) Advanced Very High Resolution Radiometer (AVHRR) products, using related methods.

Transcendental Brauer groups of products of CM elliptic curves

Let L be a number field and let E/L be an elliptic curve with complex multiplication by the ring of integers O_K of an imaginary quadratic field K. We use class field theory and results of Skorobogatov and Zarhin to compute the transcendental part of the Brauer group of the abelian surface ExE. The results for the odd order torsion also apply to the Brauer group of the K3 surface Kum(ExE). We describe explicitly the elliptic curves E/Q with complex multiplication by O_K such that the Brauer group of ExE contains a transcendental element of odd order. We show that such an element gives rise to a Brauer-Manin obstruction to weak approximation on Kum(ExE), while there is no obstruction coming from the algebraic part of the Brauer group.