An efficient method to produce 1,4-pentanediol from the biomass of the algae Chlorella ohadi with levulinic acid as intermediate.

Today, the development of innovative methods for production of organic compounds from natural resources is essential topic for many research groups in the worldwide. Levulinic acid is a platform for many important organic processes in the synthesis of natural products, pharmaceuticals, plasticizers, drugs and various other additives. In addition, 1,4-pentanediol which is a product of reduction of levulinic acid, is a valuable raw material in the chemical industry. Here, we report a highly efficient method for the production of levulinic acid from Chlorella ohadi algae using hydrothermal hydrolysis process by using HCl. Our methodology shows that the levulinic acid can be obtained in almost 90% molar yield compared to the glucose in Chlorella ohadi. Finally, we describe a one step reaction for the completely conversion of levulinic acid into 1,4-pentadiol in water using S. cerevisiae yeast as a catalyst.

Effective harvesting of microalgae: Comparison of different polymeric flocculants.

Microalgae harvesting is a major hurdle in the use of microalgae for oil production. Here we describe the use of a standard cationic polymer used for water treatment, Polydiallyldimethylammonium chloride (PDADMAC), for sedimentation of Chlorella vulgaris and comparison of its flocculation properties with two other polymers, chitosan and Superfloc®. We found PDADMAC to be the most effective flocculant with 90% of the algae flocculating at concentrations as low as 5mg/L within 60min, and good activity even at pH=10. Interestingly, with both PDADMAC and chitosan maximum flocculation was achieved much before zeroing of zeta potential. PDADMAC flocculation was also very effective in enhancing harvest by filtration and somewhat at flocculation and sedimentation of marine algae, Nannochloropsis salina.

Drosophila Ten-a is a maternal pair-rule and patterning gene.

The Ten-a gene of Drosophila melanogaster encodes several alternative variants of a full length member of the Odz/Tenm protein family. A number of Ten-a mutants created by inexact excisions of a resident P-element insertion are embryonic lethal, but show no pair-rule phenotype. In contrast, these mutants, and deficiencies removing Ten-a, do enhance the segmentation phenotype of a weak allele of the paralog gene odz (or Ten-m) to the odz amorphic phenotype. Germ line clone derived Ten-a(-) embryos display a pair-rule phenotype which phenocopies that of odz. Post segmentation eye patterning phenotypes of Ten-a mutants establish it as a pleiotropic patterning co-partner of odz.

Drosophila odz gene is required for multiple cell types in the compound retina.

The Drosophila melanogaster pair-rule gene odz (odd Oz, or Ten-m) is expressed in distinct patterns in the larval eye imaginal disc. Its earliest eye expression occurs in ommatidial precursors starting from the posterior edge of the morphogenetic furrow. Loss of function of odz activity leads to visible light photoreceptor loss; R7 photoreceptor loss; ommatidial size, shape, and rotation defects; ommatidial disorder and fusions; interommatidial bristle defects; and ommatidial lens defects. The same effects are seen in odz eye mitotic clones, in odz-Ten-a transheterozygous combinations, and in eyes expressing an Odz-Dominant Negative transgene (Odz-DN). Effects of the same strength are also seen when the Odz-DN transgene is driven only in regions of scabrous expression, which overlaps the four columns of Odz expression clusters behind the furrow. Small odz mitotic clones suggest an odz role in cell proliferation or survival. Senseless is expressed in odz mutant clones, in a fairly ordered manner, indicating that Odz acts downstream of R8 specification. Disorder within each ommatidium in odz clones is accompanied by some loss of R7 precursors and visible photoreceptor precursor order.