Efficient Semi-Artificial Photosynthesis of Ethylene by a Self-Assembled InP-Cyanobacterial Biohybrid System.

Biomanufacturing of ethylene is particularly important for modern society. Cyanobacterial cells are able to photosynthesize various valuable chemicals. A promising platform for next-generation biomanufacturing, the semiconductor-cyanobacterial hybrid systems are capable of enhancing the solar-to-chemical conversion efficiency. Herein, the native ethylene-producing capability of a filamentous cyanobacterium Nostoc sphaeroides is confirmed experimentally. The self-assembly characteristic of N. sphaeroides is exploited to facilitate its interaction with InP nanomaterial, and the resulting biohybrid system gave rise to further elevated photosynthetic ethylene production. Based on chlorophyll fluorescence measurement and metabolic analysis, the InP nanomaterial-augmented photosystem I activity and enhanced ethylene production metabolism of biohybrid cells are confirmed, the mechanism underlying the material-cell energy transduction as well as nanomaterial-modulated photosynthetic light and dark reactions are established. This work not only demonstrates the potential application of semiconductor-N. sphaeroides biohybrid system as a good platform for sustainable ethylene production but also provides an important reference for future studies to construct and optimize nano-cell biohybrid systems for efficient solar-driven valuable chemical production.

Sterilization of Escherichia coli by Photothermal Synergy of WO3-x/C Nanosheet under Infrared Light Irradiation.

The application of photocatalytic sterilization technology for the sterilization of water has been broadly studied in recent years. However, developing photocatalysts with high disinfection efficiency remains an urgent challenge. Tungsten trioxide with coexisting oxygen vacancies and carbon coating (WO3-x/C) has been successfully synthesized toward the photothermal inactivation of Escherichia coli. Oxygen vacancies and carbon coating bring WO3-x/C strong absorption in the infrared region and enhance the carrier separation efficiency. As a result, a higher sterilization rate is obtained compared to WO3. WO3-x/C can completely inactivate E. coli under infrared light within 40 min through photothermal synergy process. During the process of inactivating bacteria over WO3-x/C, E. coli is killed by the destruction of their cell membrane to decrease the activity of enzymes and release the cell contents, which can be ascribed to the efficient generation of reactive oxygen species (O2•- and •OH) and thermal effect. This work demonstrates a novel approach for engineering efficient and energy-saving catalysts for water sterilization.

The data of genomic and phenotypic profiles of the N-acyl homoserine lactone-producing algicidal bacterium Stenotrophomonas rhizophila GA1.

Herein, an algicidal strain, Stenotrophomonas rhizophila GA1, was isolated from a marine dinoflagellate and its genome was sequenced using next-generation sequencing technology. The genome size of S. rhizophila GA1 was determined to be 5.92 Mb with a G+C content of 62.39%, comprising eight scaffolds of 67 contigs. A total of 4579 functional proteins were assigned according to COG categories. In silico genome annotation protocols identified multiple putative LuxI-like genes located in the upstream position at contig 4. The thin-layer chromatography analysis showed that three kinds of acyl homoserine lactone (AHL) signals could be produced by S. rhizophila GA1. This work describes an algicidal bacterium capable of generating AHL molecules for its ecological adaptation. The annotated genome sequence of this strain may represent a valuable tool for studying algae-bacterium interactions and developing microbial methods to control harmful algae. The genome scaffolds generated are available in the National Center Biotechnology Information (NCBI) BioProject with accession number PRJNA485554.

Structural inflexibility of the rhizosphere microbiome in mangrove plant Kandelia obovata under elevated CO2.

Rhizosphere microbial communities play an important role in mediating the decomposition of soil organic matter. Increased CO2 concentration may increase plant growth by stimulating photosynthesis or improving water use efficiency. However, possible eco-physiological influences of this greenhouse gas in mangrove plants are not well understood, especially how rhizosphere microbial communities respond to CO2 increase. We characterized the effect of elevated CO2 (eCO2) on rhizospheric microbial communities associated with the mangrove plant Kandelia candel for 20 weeks, eCO2 increased plant chlorophyll a levels and root microbial biomass. Operational taxonomic unit analysis revealed no significant effects of eCO2 on rhizospheric bacterial communities; however, some influence on archaeal community structure was observed, especially on the ammonia-oxidizing archaea. Principal component analysis showed that microbial biomass C, total nitrogen, C/N ratio, nitrate nitrogen, and salinity were the main factors structuring the microbial community. The relative contribution of environmental parameters to variability among samples was 31.0%. In addition, functional analysis by average well color development showed that carbon source utilization under eCO2 occurred in the order amino acids > carbohydrates > polymers > carboxylic acids > amines > phenolic acids; whereas, sugars, amino acids, and carboxylic acids were the preferred carbon sources in control groups. Differences in utilization ability of carbohydrates and amino acids resulted in changes in carbon metabolism between the two groups. Rhizosphere microbial communities appear to have some buffering ability in response to short-term (20 weeks) CO2 increase, during which the metabolic efficiency of carbon sources is changed. The results will help better understand the structural inflexibility and functional plasticity of the rhizosphere microbiome in mangrove plants facing a changing environment (such as global climate change).