title: Preservation of H₂ production activity in nanoporous latex coatings of Rhodopseudomonas palustris CGA009 during dry storage at ambient temperatures.
abstract: To assess the applicability of latex cell coatings as an 'off-the-shelf' biocatalyst, the effect of osmoprotectants, temperature, humidity and O₂ on preservation of H₂ production in Rhodopseudomonas palustris coatings was evaluated. Immediately following latex coating coalescence (24 h) and for up to 2 weeks of dry storage, rehydrated coatings containing different osmoprotectants displayed similar rates of H₂ production. Beyond 2 weeks of storage, sorbitol-treated coatings lost all H₂ production activity, whereas considerable H₂ production was still detected in sucrose- and trehalose-stabilized coatings. The relative humidity level at which the coatings were stored had a significant impact on the recovery and subsequent rates of H₂ production. After 4 weeks storage under air at 60% humidity, coatings produced only trace amounts of H₂ (0-0.1% headspace accumulation), whereas those stored at < 5% humidity retained 27-53% of their H₂ production activity after 8 weeks of storage. When stored in argon at < 5% humidity and room temperature, R. palustris coatings retained full H₂ production activity for 3 months, implicating oxidative damage as a key factor limiting coating storage. Overall, the results demonstrate that biocatalytic latex coatings are an attractive cell immobilization platform for preservation of bioactivity in the dry state.
authors: University of South Carolina, Aiken, Aiken, SC 29801, USA.
authors: M
authors: M
authors: Piskorska
authors: T
authors: T
authors: Soule
authors: J L
authors: JL
authors: Gosse
authors: C
authors: C
authors: Milliken
authors: M C
authors: MC
authors: Flickinger
authors: G W
authors: GW
authors: Smith
authors: C M
authors: CM
authors: Yeager
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods*; D018914:Cells, Immobilized / Q000378:metabolism*; D003890:Desiccation; D006859:Hydrogen / Q000378:metabolism*; D007840:Latex; D012241:Rhodopseudomonas / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D013696:Temperature
chemical_list: D007840:Latex; D006859:Hydrogen