DYNAMICS OF THE IMMOBILIZATION OF ANAEROBIC MESOPHILIC BACTERIA ON A PLASTIC SUPPORT

In this article, a study of the dynamics of the immobilization of meso philic anaerobic bacteria was conducted. Low-density polyethylene (LDP E) ground to fine particles was used as immobilization support in an i nverse fluidized bed. After 135 d of immobilization, the biomass conce ntration attained was 375 mu g protein/g dry plastic support. The spec ific rate for acetate consumption was 0.008 mu mol acetate/mu g protei n/h. The kinetic parameters of the bioparticles (K-c = 1.067 mM and V- max = 0.00754 mu mol acetate/mu g protein/h) were estimated by the ini tial rate method at different acetate concentrations and were compared to the values obtained by a direct parameter estimation method from t he dynamic assays for acetate consumption with an initial substrate co ncentration of 10 mM. The particles were prepared for scanning electro n microscopy (SEM) to evaluate the biofilm qualitatively. The SEM stud ies showed that the surface and cavities of the support were colonized , and the bacterial structures found were bacilli similar to Methanoth rix as the predominant microorganism and a few groups of Methanosarcin a-like cocci. The K-s value found is between those reported for the pr edominant bacterial group immobilized.