The genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

This study was conducted to obtain additional information on exhaust emissions with potential health importance from an indirect injection diesel engine, typical of those in use in underground mines, when operated using a soyderived, fatty-acid mono-ester (or biodiesel) fuel and an oxidation catalytic converter (OCC). Compared to emissions with the diesel fuel without the OCC, use of the diesel (D2) and biodiesel fuel with the OCC had similar reductions (50-80%) in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC. Vapor-phase PAH emissions were reduced (up to 90%) when the OCC was used with either fuel. Use of the OCC resulted in over 50% reductions in both particle and vapor-phase-associated mutagenic activity with both fuels. No vapor-phase-associated mutagenic activity was detected with the biodiesel fuel; only very low levels were detected with the D2 fuel and the OCC. Use of the OCC caused a moderate shift in the particle size/volume distribution of the accumulation mode particles to smaller particles for the diesel fuel and a reduction of particle volume concentrations at some of the tested conditions for both fuels. The nuclei mode did not contribute significantly to total particle volume concentrations within the measured particle size range (∼0.01-1.0 µm). The biodiesel fuel reduced total particle volume concentrations. Overall, use of this OCC for the engine conditions tested with the biodiesel fuel, in particular, resulted in generally similar or greater reductions in emissions than for use of the D2 fuel. Use of the biodiesel fuel should not increase any of the potentially toxic, health-related emissions that were monitored as part of this study.

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Two bromide-bearing, fluorene-based, conjugated polymers with oligo(ethylene glycol)- and poly(ethylene glycol)-tethered spacers have been prepared by the Suzuki coupling polymerization of bromide-bearing, fluorene monomers. beta-Glucose and alpha-mannose residues have been covalently attached to the conjugated polymers by post-polymerization functionalization of the precursor polymers with thiol-functionalized carbohydrates under basic conditions through thioether linkage. A glucose-bearing glycopolymer with oligo(ethylene glycol)-tethered spacers (polymer A) displays poor water solubility. However, glycopolymers with poly(ethylene glycol)-tethered spacers (polymers B and C) are highly water-soluble due to their long, flexible, hydrophilic spacers. Incubation of the ORN178 strain of Escherichia coli (E. coli) with alpha-mannose-bearing glycopolymer (polymer C) results in the formation of fluorescent cell clusters, causing significant red shifts in UV/Vis absorption and fluorescent spectra of the polymer through multivalent cooperative interactions of the polymeric carbohydrates with the bacterial pili. In contrast, polymer C displays no interactions with a mutant ORN208 strain of E. coli.