Abundance of polymers degrading microorganisms in a sea-based solid waste disposal site

Abstract

In order to assess the degradability of plastics in solid waste disposal landfill sites, microbial populations capable of degrading five kinds of plastic-constituting polymers, poly epsilon-caprolactone (PCL), polylactic acid (PLA), polyethylene glycol (PEG), poly-beta-hydroxybutyrate (PHB) and cellulose acetate (CA), in a sea-based solid waste disposal site were investigated. Enumeration of aerobic and anaerobic polymers-degrading microorganisms (PDMs) was performed against to total 8 leachate samples, which were seasonally collected from the facultative pretreatment pond and the aerated lagoon. Both aerobic and anaerobic PDMs for natural polymers, PHB and CA, were found in all of the samples, while those for chemically-synthesized polymers, PCL, PLA and PEG, could not be always detected. In most cases, the ratios of the PHB- and CA-degraders to the heterotrophic bacterial population were more than 0.1%. On the other hand, the ratios of PCL-, PLA- and PEG-degraders were often much lower. These data indicate that the plastics degradation potential is commonly present in the studied disposal site, and that the degradation potential for plastics composed of chemically-synthesized polymers is inferior to that of natural polymers. Population sizes of the PDMs correlated to those of heterotrophic bacteria, and the counts of aerobic heterotrophic bacteria and PDMs in the aerated lagoon tended to be higher than those of anaerobic ones, indicating that the aeration of the leachate resulted in the activation of growth of whole aerobic microbial community including the PDMs.

Characterizing Biodegradation of PLA and PLA‐g‐AA/Starch Films Using a Phosphate‐Solubilizing Bacillus Species

“…PG01, as PLA is a polyester compound known to be biodegradable. There are some reports in the literature of bacterial degradation of PLA, [12][13][14] and some of degradation by a variety of enzymes, such as lysozyme. [15][16][17] Our results show that Bacillus sp.…”

Investigation of Garbage Soil for Polyethylene Degrading Microorganisms and Study Their Growth

“…They colonize on the surface of the polyethylene films or plastic cups forming a biofilm. Cell surface hydrophobicity of these organisms was found to be an important factor in the formation of biofilm on the polythene surface, which Kathiresan and Bingham, [11] reported that bacteria caused the biodegradation ranging from 2.19 to 20.54% for polythene and 0.56 to 8.16% for plastics. Among all the species, Aspergillus glaucus was more active than A. niger in degrading 28.8% of polythene and 7.26% of plastics within a month.…”

“…the plastic materials have been colonized commonly by five species of bacteria and two species of fungi. [11] Abundance of polymer degrading microorganisms in a seabed solid waste disposal site has been reported by Ishigaka et al [12] Imam et al observed that significant biodegradation occurred only after colonization of the plastic, a parameter that was dependent on the resident microbial populations. Therefore, it can be reasonably inferred that an increase in the bacterial load has correlation with degradation of the polymer.…”

Synthesis, characterization and evaluation of in vitro toxicity in hepatocytes of linear polyesters with varied aromatic and aliphatic co-monomers

“…In recent years, there has been a renewed interest in polyesters as drug delivery devices due to their favorable biocompatibility and controllable biodegradation profiles [1][2][3][4]. Accordingly, polyester materials are regarded as a material of choice for biomedical applications including drug delivery [5][6][7][8][9], as diagnostic agents [10,11] and for tissue engineering [12][13][14][15][16].…”