Bioinduced changes in the colored nitrocellulose-coated cellophane films, induced by the Shewanella J18 143 strain

摘要

Two types of the nitrocellulose (NC)-coated cellophane films, denoted 335 MS films (uncolored) and 335 MSC films (dyed with C.I. Direct Red 81), were incubated with Shewanella J18 143 for a period of 1 month at 50°C. The colored films were decolorized by Shewanella strain throughout this process. Changes in the NC coating of the films were studied by FTIR analysis, by determination of the surface wettability, and by ESEM evaluations. The colored films that were exposed to the Shewanella culture and decolorized, lost a significant amount of nitrate groups and became enriched in the hydroxyl group content. Moreover, the critical surface tension of the colored NC-coated cellophane films increased, from 18.7 mN/m, for the original films, to 33.1 mN/m, for the film that was treated by the Shewanella strain. Unlike the colored film, the uncolored NC-coated films did not give any considerable changes in their NC coating when exposed to the Shewanella culture, for the same time period.