Transformation of short-chain chlorinated paraffins and olefins with the bacterial dehalogenase LinB from Sphingobium Indicum – Kinetic models for the homologue-specific conversion of reactive and persistent material

Structure, reactivity and physico-chemical properties of polyhalogenated compounds determine their up-take, transport, bio-accumulation, transformation toxicity environmental fate. In technical mixtures chlorinated paraffins (CPs), these are distributed due to the presence thousands homologues. We hypothesized that roles CP dehalogenation reactions, catalyzed by haloalkane dehalogenase LinB, depend on structural substrates, e.g. chlorination degree carbon-chain length. exposed undecanes, dodecanes tridecanes in-vitro LinB from Sphingobium Indicum bacteria. These single-chain CP-materials also contain small amounts olefins (COs), which can be distinct mathematical deconvolution respective mass-spectra. With this procedure, we obtained homologue-specific kinetics substrates differing in saturation degree, carbon chain-length. For all homologues, two-stage first-order kinetic models were established, described faster conversion reactive material slower more persistent material. Half-lifes 0.5–3.2 h 56–162 determined for CP-material. Proportions increased steadily 18 67% lower (Cl6) higher (Cl11) olefins. Conversion efficiencies decreased with increasing 97 70%. Carbon-chain length had only minor effects rates. Hence, was efficient lower-chlorinated material, higher-chlorinated longer-chained CPs COs. Current legislation has banned short-chain (SCCPs) forced a transition longer-chain CPs. This may counterproductive regard enzymatic LinB.