title: Isolation and screening of biopolymer-degrading microorganisms from northern Thailand.
abstract: Forty agricultural soils were collected from Chiang Mai and Lampang provinces in northern Thailand. Bacteria, actinomycetes and fungi were isolated and screened for their ability to degrade polylactic acid (PLA), polycaprolactone (PCL) and poly(butylene succinate) (PBS) by the agar diffusion method. Sixty-seven actinomycetes, seven bacteria and five fungal isolates were obtained. The majority of actinomycetes were Streptomyces based on morphological characteristic, chemotaxonomy and 16S rRNA gene data. Seventy-nine microorganisms were isolated from 40 soil samples. Twenty-six isolates showed PLA-degradation (32.9 %), 44 isolates showed PBS-degradation (55.7 %) and 58 isolates showed PCL-degradation (73.4 %). Interestingly, 16 isolates (20.2 %) could degrade all three types of bioplastics used in this study. The Amycolatopsis sp. strain SCM_MK2-4 showed the highest enzyme activity for both PLA and PCL, 0.046 and 0.023 U/mL, respectively. Moreover, this strain produced protease, esterase and lipase on agar plates. Approximately, 36.7 % of the PLA film was degraded by Amycolatopsis sp. SCM_MK2-4 after 7 days of cultivation at 30 °C in culture broth.
authors.affiliation: Department of Biology, Faculty of Science, Chiang Mai University, 239 Huay Kaew Road, Muang District, Chiang Mai, 50200, Thailand, watsanapenkhrue@gmail.com.
authors.forename: Watsana
authors.initials: W
authors.lastname: Penkhrue
authors.forename: Chartchai
authors.initials: C
authors.lastname: Khanongnuch
authors.forename: Kazuo
authors.initials: K
authors.lastname: Masaki
authors.forename: Wasu
authors.initials: W
authors.lastname: Pathom-Aree
authors.forename: Winita
authors.initials: W
authors.lastname: Punyodom
authors.forename: Saisamorn
authors.initials: S
authors.lastname: Lumyong
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D001673:Biodegradation, Environmental; D001704:Biopolymers / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D019344:Lactic Acid / Q000378:metabolism; D011091:Polyesters / Q000378:metabolism; D011108:Polymers / Q000378:metabolism; D012988:Soil Microbiology; D013785:Thailand
chemical_list: D001704:Biopolymers; D002072:Butylene Glycols; D011091:Polyesters; D011108:Polymers; C089797:bionole; C016240:polycaprolactone; D019344:Lactic Acid; C033616:poly(lactide)