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1. Synthesis of n ‐alkyl methacrylate polymers with pendant carbazole moieties and their derivatives

   https://doi.org/10.1002/pola.29285  

   Bandera, Yuriy; McFarlane, Tucker M.; Burdette, Mary K.; Jurca, Marek; Klep, Oleksandr; Foulger, Stephen H. (December 2018, Journal of Polymer Science Part A: Polymer Chemistry)

   ABSTRACT New methacrylate monomers with carbazole moieties as pendant groups were synthesized by multistep syntheses starting from carbazoles with biphenyl substituents in the aromatic ring. The corresponding polymers were prepared using a free‐radical polymerization. The novel polymers containN‐alkylated carbazoles mono‐ or bi‐substituted with biphenyl groups in the aromatic ring.N‐alkyl chains in polymers vary by length and structure. All new polymers were synthesized to evaluate the structural changes in terms of their effect on the energy profile, thermal, dielectric, and photophysical properties when compared to the parent polymer poly(2‐(9H‐carbazol‐9‐yl)ethyl methacrylate). According to the obtained results, these compounds may be well suited for memory resistor devices. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019, 57, 70–76 

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2. Establishing microbial co‐cultures for 3‐hydroxybenzoic acid biosynthesis on glycerol

   https://doi.org/10.1002/elsc.201800195  

   Zhou, Yiyao; Li, Zhenghong; Wang, Xiaonan; Zhang, Haoran (April 2019, Engineering in Life Sciences)

   Abstract Converting renewable feedstocks to aromatic compounds using engineered microbes offers a robust approach for sustainable, environment‐friendly, and cost‐effective production of these value‐added products without the reliance on petroleum. In this study, rationally designedE. coli–E. colico‐culture systems were established for converting glycerol to 3‐hydroxybenzoic acid (3HB). Specifically, the 3HB pathway was modularized and accommodated by two metabolically engineeredE. colistrains. The co‐culture biosynthesis was optimized by using different cultivation temperatures, varying the inoculum ratio between the co‐culture strains, recruitment of a key pathway intermediate transporter, strengthening the critical pathway enzyme expression, and adjusting the timing for inducing pathway gene expression. Compared with theE. colimono‐culture, the optimized co‐culture showed 5.3‐fold improvement for 3HB biosynthesis. This study demonstrated the applicability of modular co‐culture engineering for addressing the challenges of aromatic compound biosynthesis. 

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3. Xylose and shikimate transporters facilitates microbial consortium as a chassis for benzylisoquinoline alkaloid production

   https://doi.org/10.1038/s41467-023-43049-w  

   Gao, Meirong; Zhao, Yuxin; Yao, Zhanyi; Su, Qianhe; Van Beek, Payton; Shao, Zengyi (November 2023, Nature Communications)

   Abstract Plant-sourced aromatic amino acid (AAA) derivatives are a vast group of compounds with broad applications. Here, we present the development of a yeast consortium for efficient production of (S)-norcoclaurine, the key precursor for benzylisoquinoline alkaloid biosynthesis. A xylose transporter enables the concurrent mixed-sugar utilization inScheffersomyces stipitis, which plays a crucial role in enhancing the flux entering the highly regulated shikimate pathway located upstream of AAA biosynthesis. Two quinate permeases isolated fromAspergillus nigerfacilitates shikimate translocation to the co-culturedSaccharomyces cerevisiaethat converts shikimate to (S)-norcoclaurine, resulting in the maximal titer (11.5 mg/L), nearly 110-fold higher than the titer reported for anS. cerevisiaemonoculture. Our findings magnify the potential of microbial consortium platforms for the economical de novo synthesis of complex compounds, where pathway modularization and compartmentalization in distinct specialty strains enable effective fine-tuning of long biosynthetic pathways and diminish intermediate buildup, thereby leading to increases in production. 

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4. Comparative Genomics Analysis of the Aromatic and Xenobiotic Degradation Capacities and Heavy Metal Resistance in Seven Environmentally Derived Bacterial Isolates

   https://doi.org/10.1007/s11270-023-06495-2  

   Kneubehl, Alexander R.; Iyer, Rupa (July 2023, Water, Air, & Soil Pollution)

   This work is a comparative genomics investigation of the aromatic and xenobiotic compound degradation capabilities and heavy metal resistance of environmental bacterial isolates previously identified by our lab, Achromobacter xylosoxidans ADAF13, Exiguobacterium sp. KKBO11, Ochrobactrum anthropi FRAF13, Pseudomonas putida CBF10-2, Pseudomonas stutzeri ODKF13, Rhizobium radiobacter GHKF11, and Stenotrophomonas maltophilia CBF10-1. This work sought to assess the potential of these isolates as bioremediation tools. We found a variety of aromatic degradation pathways though none directly acts on industrial compounds such as polycyclic aromatic compounds, benzene, phthalate, or xylene. Achromobacter xylosoxidans ADAF13, P. putida CBF10-2, and P. stutzeri ODKF13 showed the most complete pathways for aromatic compound degradation and halobenzoate degradation. All isolates contained heavy metal resistance genes for arsenic, cadmium, copper, chromium, lead, mercury, and zinc. Arsenic resistance genes were the most common among isolates and were organized into structurally diverse ars operons. Collectively, our data indicated that A. xylosoxidans ADAF13, P. putida CBF10-2, and P. stutzeri ODKF13 are strong candidates for further enhancement and development as bioremediation tools. 

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5. Why are the Elemental Nonmetals (F ₂ , Cl ₂ , Br ₂ , I ₂ , S ₈ , P ₄ ) of so Many Hues or of Any Hues and Where is the Chromophore? Insight into Intera ‐X–X Bonds

   https://doi.org/10.1111/php.13270  

   Jabeen, Shakeela; Greer, Alexander; Edwards, Kathleen F.; Liebman, Joel F. (May 2020, Photochemistry and Photobiology)

   Abstract A unique approach is used to relate the HOMO‐LUMO energy difference to the difference between the ionization potential (IP) and electron affinity (EA) to assist in deducing not only the colors, but also chromophores in elemental nonmetals. Our analysis focuses on compounds with lone pair electrons and σ electrons, namely X₂(X = F, Cl, Br, I), S₈and P₄. For the dihalogens, the [IP – EA] energies are found to be: F₂(12.58 eV), Cl₂(8.98 eV), Br₂(7.90 eV), I₂(6.78 eV). We suggest that theinterahalogen X–X bond itself is the chromophore for these dihalogens, in which the light absorbed by the F₂, Cl₂, Br₂, I₂leads to longer wavelengths in the visible by a π → σ* transition. Trace impurities are a likely case of cyclic S₈which contains amounts of selenium leading to a yellow color, where the [IP – EA] energy of S₈is found to be 7.02 eV. Elemental P₄with an [IP – EA] energy of 9.09 eV contains a tetrahedral and σ aromatic structure. In future work, refinement of the analysis will be required for compounds with π electrons and σ electrons, such as polycyclic aromatic hydrocarbons (PAHs). 

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