Phys.org April 5, 2023 Carboxysomes are proteinaceous bacterial microcompartments that sequester the key enzymes for carbon fixation in cyanobacteria and some proteobacteria. Despite their significance in carbon fixation and great bioengineering potentials, the structural understanding of native carboxysomes is currently limited to low-resolution studies. An international team of researchers (UK, Germany, Austria) has characterized a native α-carboxysome from a marine cyanobacterium by single-particle cryoelectron microscopy. They have determined the structure of its RuBisCO enzyme, and obtained low-resolution maps of its icosahedral shell, and its concentric interior organization. They proposed a complete atomic model of an intact carboxysome, providing insight into […]
Tag Archives: Bioenergy
Producing ‘green’ energy — literally — from living plant ‘bio-solar cells’
Science Daily December 13, 2022 Harvesting an electrical current from biological photosynthetic systems is typically achieved by immersion of the system into an electrolyte solution. Researchers in Israel used the thick water-preserving outer cuticle of the succulent Corpuscularia lehmannii serves as the electrochemical container, the inner water content as the electrolyte into which an iron anode and platinum cathode were introduced. They produced up to 20 μA/cm2 bias-free photocurrent. When 0.5 V bias was added to the iron anode, the current density increased ∼10-fold, and evolved hydrogen gas could be collected with a Faradaic efficiency of 2.1 and 3.5% in […]
Light accelerates conductivity in nature’s ‘electric grid’
Nanowerk September 7, 2022 Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. Without access to oxygen, however, soil bacteria living deep under oceans or buried underground respire by “breathing minerals,” through tiny protein nanowires. Researchers at Yale University found that exposing bacteria-produced nanowires to light yielded up to a 100-fold increase in electrical conductivity showing stable and robust photocurrent that persists for hours. They showed that living biofilms of Geobacter sulfurreducens used nanowires of cytochrome OmcS as intrinsic photoconductors. Photocurrents respond rapidly (<100 ms) to the excitation and persist reversibly for hours. […]
Bacteria for blastoff: Using microbes to make supercharged new rocket fuel
Science Daily June 30, 2022 An international team of researchers (Denmark, USA – Lawrence Berkely National Laboratory, Sandia National Laboratory, Pacific Northwest National Laboratory, UC Berkeley) explored the chemical diversity encoded in thousands of bacterial genomes to identify and repurpose naturally occurring cyclopropanated molecules. They identified a set of candidate iterative polyketide synthases (iPKSs) predicted to produce polycyclopropanated fatty acids (POP-FAs), expressed them in Streptomyces coelicolor, and produced POP-FAs. By determining the structure of the molecules, they were able increase their production 22-fold and produce polycyclopropanated fatty acid methyl esters (POP-FAMEs). Their research showed that the POP-FAMEs and other POPs […]
Towards sustainable, self-powered energy devices with coconuts
Nanowerk April 25, 2022 An international team of researchers (North Korea, Australia, India) has demonstrated both energy harvesting and storage devices such as piezoelectric nanogenerator (PNG) and piezo supercapacitor (PSC) by enforcing coconut husk (CH) as a filler into the polymer separator. The CH powder was immobilized into the polyvinyl difluoride (PVDF) matrix to improve its piezoelectric performance. The poled PNG with a 7 wt% of CH powder/ PVDF composition delivered an output of 14 V, 50 nA current, and a power density of 0.35 μW/cm2 at 100 MΩ. The output is enough to charge commercial capacitors and power electronic […]