In Vivo Characterization and Application of the PHA Synthase from for the Biosynthesis of Polyhydroxyalkanoate Containing 4-Hydroxybutyrate.

Polyhydroxyalkanoate (PHA) is a biodegradable thermoplastic naturally synthesized by many microorganisms, and the PHA synthase (PhaC) is known to be the key enzyme involved in determining the material properties and monomer composition of the produced PHA. The ability to exploit widely distributed, commonly found soil microorganisms such as to synthesize PHA containing the lipase-degradable 4-hydroxybutyrate (4HB) monomer will allow for convenient production of biocompatible and flexible PHA. Comparisons between the wild type and mutant strains, with and without a surface layer (S-layer), respectively, in terms of gene or amino acid sequences, synthase activity, granule morphology, and PHA productivity, revealed that the S-layer is the sole factor affecting PHA biosynthesis by .

Hypothetical protein Avin_16040 as the S-layer protein of Azotobacter vinelandii and its involvement in plant root surface attachment.

A proteomic analysis of a soil-dwelling, plant growth-promoting Azotobacter vinelandii strain showed the presence of a protein encoded by the hypothetical Avin_16040 gene when the bacterial cells were attached to the Oryza sativa root surface. An Avin_16040 deletion mutant demonstrated reduced cellular adherence to the root surface, surface hydrophobicity, and biofilm formation compared to those of the wild type. By atomic force microscopy (AFM) analysis of the cell surface topography, the deletion mutant displayed a cell surface architectural pattern that was different from that of the wild type.

Enrichment, performance, and microbial diversity of a thermophilic mediatorless microbial fuel cell.

A thermophilic mediatorless microbial fuel cell (ML-MFC) was developed for continuous electricity production while treating artificial wastewater concurrently. A maximum power density of 1030 +/- 340 mW/m2 was generated continuously at 55 degrees C with an anode retention time of 27 min (11 mL h(-1)) and continuous pumping of air-saturated phosphate buffer into the cathode compartment at the retention time of 0.7 min (450 mL h(-1)).