Isolation and Characterization of Polyester-Based Plastics-Degrading Bacteria from Compost Soils
- Authors: Sriyapai P.1,2, Chansiri K.3,2, Sriyapai T.4,2
-
Affiliations:
- Department of Microbiology, Faculty of Science
- Center of Excellence in Biosensors
- Department of Biochemistry, Faculty of Medicine
- Faculty of Environmental Culture and Ecotourism
- Issue: Vol 87, No 2 (2018)
- Pages: 290-300
- Section: Experimental Articles
- URL: https://journals.rcsi.science/0026-2617/article/view/163478
- DOI: https://doi.org/10.1134/S0026261718020157
- ID: 163478
Cite item
Abstract
Four potential polyester-degrading bacterial strains were isolated from compost soils in Thailand. These bacteria exhibited strong degradation activity for polyester biodegradable plastics, such as polylactic acid (PLA), polycaprolactone (PCL), poly-(butylene succinate) (PBS) and polybutylene succinate-co-adipate (PBSA) as substrates. The strains, classified according to phenotypic characteristics and 16S rDNA sequence, belonging to the genera Actinomadura, Streptomyces and Laceyella, demonstrated the best polyester- degrading activities. All strains utilized polyesters as a carbon source, and yeast extract with ammonium sulphate was utilized as a nitrogen source for enzyme production. Optimization for polyester-degrading enzyme production by Actinomadura sp. S14, Actinomadura sp. TF1, Streptomyces sp. APL3 and Laceyella sp. TP4 revealed the highest polyester-degrading activity in culture broth when 1% (w/v) PCL (18 U/mL), 0.5% (w/v) PLA (22.3 U/mL), 1% (w/v) PBS (19.4 U/mL) and 0.5% (w/v) PBSA (6.3 U/mL) were used as carbon sources, respectively. All strains exhibited the highest depolymerase activities between pH 6.0–8.0 and temperature 40–60°C. Partial nucleotides of the polyester depolymerase gene from strain S14, TF1 and APL3 were studied. We determined the amino acids making up the depolymerase enzymes had a highly conserved pentapeptide catalytic triad (Gly-His-Ser-Met-Gly), which has been shown to be part of the esterase-lipase superfamily (serine hydrolase).
Keywords
About the authors
P. Sriyapai
Department of Microbiology, Faculty of Science; Center of Excellence in Biosensors
Email: thayat@g.swu.ac.th
Thailand, Bangkok; Bangkok
K. Chansiri
Department of Biochemistry, Faculty of Medicine; Center of Excellence in Biosensors
Email: thayat@g.swu.ac.th
Thailand, Bangkok; Bangkok
T. Sriyapai
Faculty of Environmental Culture and Ecotourism; Center of Excellence in Biosensors
Author for correspondence.
Email: thayat@g.swu.ac.th
Thailand, Bangkok; Bangkok
Supplementary files
