| dc.description.abstract | Different microorganisms from aged plastics wastes were sampled from various locations in previous studies. 14 strains were isolated and characterized by catalase, oxidase, gram and observational tests. After identification, the capability of these strains was investigated in the biodegradation of low-density polyethylene (LDPE). Three bacterial strains ZZ-12-2, ZZ-7 and ZZ-3 showed better possible biodegradability in comparison with other strains and probably belong to one of Firmicutes or Proteobacteria phyla. Some chemicals such as mineral oil, (NH4)2SO4 and MgSO4 were tested as biodegradation stimulators. Mineral oil inhibited bacterial growth in this study while MgSO4 stimulated ZZ-2 strain biodegradation significantly and (NH4)2SO4 stimulated ZZ-6 sample slightly which resulted in this conclusion that MgSO4 in some strains of bacteria can serve as biodegradation stimulator. On the other hand, to determine the synergistic effect, different mixed cultures were investigated and only ZZ-2 +ZZ-3 and ZZ-11+ ZZ-12-2 suggested a potential synergistic effect after 22 days while it didn’t observe after 112 days. So these mixed cultures cannot decisively be introduced as candidates with synergistic effect on biodegradation and more researches need to be carried out to confirm this statement. | |
