3.2 Total Organic Carbon (TOC) In t

3.2 Total Organic Carbon (TOC) In the presence of PLA film, the isolates grew well and utilized the soluble carbon source (yeast extract) present in the medium and resulted in the depletion of TOC values at the initial stages. Later the TOC values increased progressively. Two fold increase in TOC was observed on day 15 indicating the release of organic carbon from the polymer. The TOC value dropped even below the initial value after 25 days of degradation. The decrease in TOC values may be due to microbial assimilation of substrate and reveals the utilization of PLA as carbon source. Similarly, pH of the basal medium was dropped due to the release of lactic acid (Table 2). 3.3 Scanning Eelectron Microscopy (SEM) SEM was used to observe changes in PLA film after incubation with the isolates MS-1, MS-2 and MS-3. ThePLA films were recovered from the culture broth in order to assess the nature of the microbial growth and the surface damage done to PLA film. The film surface was smooth in the control without inoculation of the strain (Fig. 1A), whereas the PLA film, incubated with MS-2 showed large number of pit holes all over the surface of the film and most of the film surface was attacked by the bacilli (Fig. 1B). Similar surface pattern was also observed with isolate MS-1(Fig. 1C) and MS-3 (Fig. 1D) over the PLA films which were flooded with bacilli and budding yeast cells