Transcriptomic Insights into Metabolism-Dependent Biosynthesis of Bacterial Nanocellulose.

Bacterial nanocellulose (BNC) is an attractive green-synthesized biomaterial for biomedical applications and various other applications. However, effective engineering of BNC production has been limited by our poor knowledge of the related metabolic processes. In contrast to the traditional perception that genome critically determines biosynthesis behaviors, here we discover that the glucose metabolism could also drastically affect the BNC synthesis in Gluconacetobacter hansenii. The transcriptomic profiles of two model BNC-producing strains, G. hansenii ATCC 53582 and ATCC 23769, which have highly similar genomes but drastically different BNC yields, were compared. The results show that their BNC synthesis capacities were highly related to metabolic activities such as ATP synthesis, ion transport protein assembly, and carbohydrate metabolic processes, confirming an important role of metabolism-related transcriptomes in governing the BNC yield. Our findings provide insights into the microbial biosynthesis behaviors from a transcriptome perspective, potentially guiding cellular engineering for biomaterial synthesis.

Genome Sequence of a Heavy Metal-Detoxifying Actinomycete, Microbacterium proteolyticum ustc.

A complete genome is presented for Microbacterium proteolyticum ustc, a member of the Gram-positive order Micrococcales of the phylum Actinomycetota that is resistant to high concentrations of heavy metals and participates in metal detoxification. The genome consists of one plasmid and one chromosome.

Cobalt(II) Tetraaminophthalocyanine-modified Multiwall Carbon Nanotubes as an Efficient Sulfur Redox Catalyst for Lithium-Sulfur Batteries.

An efficient Li-S redox catalyst consisting of MWCNTs covalently modified by cobalt(II) tetraaminophthalocyanines (TaPcCo-MWCNTs) is developed. Effective lithium polysulfide (LiPS) capturing is enabled by the lithiophilic N-containing phthalocyanine rings and the sulfiphilic Co central atoms. This adsorption geometry utilizes the Co unoccupied d-orbitals as electron super-exchange highways. Elevated kinetics of LiPSs reactions in the liquid phase as well as liquid-solid transitions were revealed by electrochemical measurements and density functional theory calculations. Uniform deposition of Li2 S films was also observed, which preserves cathode integrity and sulfur utilization during cell cycling. The catalyzed sulfur redox is also significantly facilitated by the fast electron and Li-ion transport to and from the reaction sites through the conductive MWCNT skeletons and the lithiophilic substituent amino groups on TaPcCo. With 6 wt % addition of TaPcCo-MWCNT in the cathode coatings, high sulfur utilization is achieved with areal sulfur loadings of up to 7 mg cm-2 . Stable long-term cycling is achieved at 1 C at a sulfur loading of 5 mg cm-2 , with an initial areal capacity of 4.4 mAh cm-2 retention of 3.5 mAh cm-2 after 500 cycles. Considering the high structural diversity of phthalocyanines macromolecules, this study provides opportunities for a new class of Li-S catalysts.