Korean Journal of Environmental Biology (환경생물)

Korean Society of Environmental Biology (한국환경생물학회)
권호 표지

Isolation of a Poly (L-lactide) Degrading Bacterium and Improvement of its Degradation Capacity

Poly(L-lactide)분해 세균의 분리 및 활성 증진

  • Published : 2007.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

A thermophilic bacterium capable of poly (L-lactide)(PLLA) degradation was isolated from cultivating soil in Korea. The isolate was Gram positive rod-shaped bacterium, and was identified as Geobacillus caldoxylosilyticus based on the 16S rDNA sequence analysis. The strain proved to be a new PLLA degrading bacterium which has not been reported in the open literatures yet. The degradation activity of the strain was assessed in a sterilized compost inoculated with the strain under controlled compost condition at $58^{\circ}C$ for 40 days. The strain mineralized 66%, 57%, 41% and 40% of PLLA5000, PLLA11000, PLLA34000 and PLLA256000 whose weight average molecular weights were 5000, 11000, 34000 and 256000, respectively. Incorporation of 0.1% each of gelatin, yeast extract and ammonium sulfate in the compost containing PLLA256000 as a nutritional supplement raised the biodegradation activity by 27%, 13% and 10%, respectively. Increase of the inoculum size from $10^9cfu\;g^{-1}\;to\;10^{10}cfu\;g^{-1}\;and\;10^{11}cfu\;g^{-1}$ also enhanced the biodegradation activity by 14% and 20%, respectively.

PLLA분해활성을 가진 고온성세균을 우리나라 경작토로부터 분리하였다. 분리된 균주는 그람양성 간균으로 16S rDNA 염기서열분석 결과 Geobacillus caldoxylosilyticus로 동정되었으며, 현재까지 보고되지 않은 새로운 PLLA분해세균으로 밝혀졌다. 조절화된 퇴비화조건에서 멸균퇴비에 분리균주를 접종하고 $58^{\circ}C$에서 40일간 분해활성을 측정하였다. 이 균주는 중량평균 분자량이 5000, 11000, 34000 및 256000인 PLLA5000, PLLA11000, PLLA34000 및 PLLA256000를 각각 66%, 57%, 41%및 40%생분해하였다. PLLA256000을 기질로 하여 gelatin, yeast extract 및 ammonium sulfate를 0.1%씩 첨가하여 분해활성 변화를 조사한 결과 대조군에 비하여 분해활성이 각각 27%, 13% 및 10%증진되었으며, 접종량을 $10^9cfu\;g^{-1}$로부터 $10^{10}cfu\;g^{-1}$ 및 $10^{11}cfu\;g^{-1}$로 증가시킴에 따라 PLLA256000의 생분해도는 각각 14% 및 20% 증가하였다.

Keywords

References

  1. Arutchelvan V, V Kanakasabai, R Elangovan, S Nagarajan and V Muralikrishnan. 2006. Kinetics of high strength phenol degradation using Bacillius brevis. J. Hazard. Mater. 129: 216-222
  2. Itavaara M, S Karjomaa and JF Selin. 2002. Biodegradation of polylactide in aerobic and anaerobic thermophilic conditions. Chemosphere 46:879-885 https://doi.org/10.1016/S0045-6535(01)00163-1
  3. Jarerat A, H Pranamuda and Y Tokiwa. 2002. Poly (L-Iactide)-degrading activity in various Actinomycetes. Macromol. Biosci. 2:420-428 https://doi.org/10.1002/mabi.200290001
  4. Karjomaa S, T Suortti, R Lempiainen, JF Selin and M Itavaara, 1998. Microbial degradation of poly-(L-Iactic acid) oligomers. Polym. Degrad. Stabil. 59:333-336 https://doi.org/10.1016/S0141-3910(97)00204-8
  5. Kijchavengkul T, R Auras, M Rubino, M Ngouajio and RT Fernandez. 2006. Development of an automatic laboratory-scale respirometric system to measure polymer biodegradability. Polym. testing 25:1006-1016 https://doi.org/10.1016/j.polymertesting.2006.06.008
  6. KS M3100-1:2002; MOD ISO 14855:1999. Determination of the ultimate aerobic biodegradability and disintegration of plastic materials under controlled composting conditions Part I: Analysis of evolved carbon dioxide by titration method. Seoul, South Korea
  7. Kumar S, K Tamura and M Nei. 2004. MEGA3: Integrated software for molecular evolutionary genetic analysis and sequence alignment. Briefings in Bioinformatics. 5: 150-163 https://doi.org/10.1093/bib/5.2.150
  8. Nakamura K, T Tomita, N Abe and Y Kamio. 2001. Purification and characterization of an extracellular poly (L-lactic acid) depolymerase from a soil isolate, Amycolatopsis sp. Strain K104-1. Appl. Environ. Microbiol. 67:345-353 https://doi.org/10.1128/AEM.67.1.345-353.2001
  9. Pranamuda H, Y Tokiwa and H Tanaka. 1997. Polylactide degradation by an Amycolatopsis sp. Appl. Environ. Microbiol. 63: 1637-1640
  10. Pranamuda Hand Y Tokiwa. 1999. Degradation of poly (L-lactide) by strains belong to genus Amycolatopsis. Biotech. Lett. 21:901-905 https://doi.org/10.1023/A:1005547326434
  11. Sakai K, H Kawano, A Iwami, M Nakamura and M Moriguchi. 2001. Isolation of a thermophilic poly-L-lactide degrading bacterium from compost and its enzymatic characterization. J. Biosci. Bioeng. 92:298-300 https://doi.org/10.1263/jbb.92.298
  12. Teeraphatpomchai T, T Nakajima-Kambe, Y Shigeno-Akutsu, M Nakayama, N Nomura. T Nakahara and H Uchiyama. 2003. Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics. Biotech. Lett. 25:23-28 https://doi.org/10.1023/A:1021713711160
  13. Tokiwa Y and A Jarerat. 2003. Microbial degradation of aliphatic polyesters. Macromol. Symp. 201 :283-289
  14. Tokiwa Y and A Jarerat. 2005. Accelerated microbial degradation of poly (L-lactide). Macromol. Symp. 224:367-376
  15. Tomita K, Y Kuroki and K Nagai. 1999. Isolation of thermophiles degrading poly (L-lactic acid). J. Biosci. Bioeng. 87: 752-755 https://doi.org/10.1016/S1389-1723(99)80148-0
  16. Tomita K, T Nakajima, Y Kikuchi and N Miwa. 2004. Degradation of poly (L-lactic acid) by a newly isolated thermophile. Polym. Degrad. Stabil. 84:433-438 https://doi.org/10.1016/j.polymdegradstab.2003.12.006
  17. Torres A, SM Li, S Roussos and M Vert. 1996. Screening of microorganisms for biodegradation of poly (lactic acid) and lactic acid-containing polymers. Appl. Environ. Microbiol. 62:2393-2397
  18. Uchida H, T Nakajima-Kambe, Y Shigeno-Akutsu, N Nomura, Y Tokiwa and T Nakahara. 2000. Properties of a bacterium which degrades solid poly (tetramethylene succinate)-co-adipate, a biodegradable plastic. FEMS Microbio. Lett. 189:25-29 https://doi.org/10.1111/j.1574-6968.2000.tb09201.x