Abundance, Characterization and Diversity of Culturable Anoxygenic Phototrophic Bacteria in Manitoban Marshlands.

Marshes are an important ecosystem, acting as a biodiversity hotspot, a carbon sink and a bioremediation site, breaking down anthropogenic waste such as antibiotics, metals and fertilizers. Due to their participation in these metabolic activities and their capability to contribute to primary productivity, the microorganisms in such habitats have become of interest to investigate. Since Proteobacteria were previously found to be abundant and the waters are well aerated and organic-rich, this study on the presence of anoxygenic phototrophic bacteria, purple non-sulfur bacteria and aerobic anoxygenic phototrophs in marshes was initiated. One sample was collected at each of the seven Manitoban sites, and anoxygenic phototrophs were cultivated and enumerated. A group of 14 strains, which represented the phylogenetic diversity of the isolates, was physiologically investigated further. Aerobic anoxygenic phototrophs and purple non-sulfur bacteria were present at each location, and they belonged to the α- and ß-Proteobacteria subphyla. Some were closely related to known heavy metal reducers (Brevundimonas) and xenobiotic decomposers (Novosphingobium and Sphingomonas). All were able to synthesize the photosynthetic complexes aerobically. This research highlights the diversity of and the potential contributions that anoxygenic phototrophs make to the essential functions taking place in wetlands.

Diverse aerobic anoxygenic phototrophs synthesize bacteriochlorophyll in oligotrophic rather than copiotrophic conditions, suggesting ecological niche.

While investigating aerobic anoxygenic phototrophs (AAP) from Lake Winnipeg's bacterial community, over 500 isolates were obtained. Relatives of 20 different species were examined simultaneously, identifying conditions for optimal growth or pigment production to determine features that may unify this group of phototrophs. All were distributed among assorted α-Proteobacterial families including Erythrobacteraceae, Sphingomonadaceae, Sphingosinicellaceae, Acetobacteraceae, Methylobacteriaceae, and Rhodobacteraceae. Major phenotypic characteristics matched phylogenetic association, including pigmentation, morphology, metal transformations, tolerances, lipid configurations, and enzyme activities, which distinctly separated each taxonomic family. While varying pH and temperature had a limited independent impact on pigment production, bacteriochlorophyll synthesis was distinctly promoted under low nutrient conditions, whereas copiotrophy repressed its production but enhanced carotenoid yield. New AAP diversity was also reported by revealing strains related to non-phototrophic Rubellimicrobium and Sphingorhabdus, as well as spread throughout Roseomonas, Sphingomonas, and Methylobacterium/Methylorubrum, which previously only had a few known photosynthetic members. This study exemplified the overwhelming diversity of AAP in a single aquatic environment, confirming cultivation continues to be of importance in microbial ecology to discover functionality in both new and previously reported cohorts of bacteria as specific laboratory conditions were required to promote aerobic bacteriochlorophyll production.

The Boron Advantage: The Evolution and Diversification of Boron's Applications in Medicinal Chemistry.

In this review, the history of boron's early use in drugs, and the history of the use of boron functional groups in medicinal chemistry applications are discussed. This includes diazaborines, boronic acids, benzoxaboroles, boron clusters, and carboranes. Furthermore, critical developments from these functional groups are highlighted along with recent developments, which exemplify potential prospects. Lastly, the application of boron in the form of a prodrug, softdrug, and as a nanocarrier are discussed to showcase boron's emergence into new and exciting fields. Overall, we emphasize the evolution of organoboron therapeutic agents as privileged structures in medicinal chemistry and outline the impact that boron has had on drug discovery and development.