• 한국미생물·생명공학회지
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• 제22권4호
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• pp.436-442
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• 1994

The characteristics of activated sludge affecting the biodegradation of plastic materials under aerobic condition were studied using cellophane film as a model system. The activated sludges of site 3, which treat a mixture of domestic sewage and supernatant of septic tank, obtained from December 1993 to April 1994 showed similar biodegradation activities. Biodegradations for 28 days reached around 80%. Viable cell number of inoculums maintained at a level of 10$^{6}$~10$^{7}$ /ml. In this range, viable cell number showed no relationship with biodegradation activities. The activa- ted sludges of site 2, which treat a mixture of domestic sewage and anaerobic digest of nightsoil, obtained four times from April 1993 to April 1994 showed very different biodegradation activities ranged from 20% to 80% for 28 days. Inoculum size affects biodegradation significantly. One percent inoculum showed the best biodegradation among the inoculum sizes of 0.1, 1.0 and 10%. Ten percent inoculum revealed inhibitory effects on the biodegradation activity which can be greatly reduced by centrifugation and filtration. Filtration was better than centrifugation in reducing inhibitory effects.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.379-380
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• 2002

기계적 성질이 우수한 PVC와 생분해성이 우수한 고분자로 알려져 있는 폴리카프로락톤 (PCL)과 블렌드하여 새로운 소재의 생분해성 필름을 제조하여 생분해성 효과에 대해 조사하였으며, 그 결과 PCL/PVC 필름의 표면은 8주 후에 다수의 작은 구멍이 형성되었으며, 이러한 결과는 PCL의 함량이 9%로 낮아도 생분해성을 지닌다는 것을 의미한다.

• KSBB Journal
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• 제27권4호
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• pp.215-221
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• 2012

Synthetic plastics are important in many branches of industry. Although synthetic plastics provide numerous benefits, they also cause a significant environmental pollution problem because of their non-readily-biodegradability. Biodegradation may provide solution to the problem, but not enough is known about the biodegradation mechanisms of synthetic plastics. This review has been written to provide an overview of the current state of synthetic plastics (polyethylene, polyurethane, nylon, polyvinyl alcohol) biodegradation. Several biodegradation mechanisms of a few selected synthetic plastics are also presented.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.784-788
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• 1999

The effects of pH, moisture content, and the relative amount of a polymer sample on the biodegradation of degradable polymers in soil were studied using various polymer materials such as cellulose, poly-(butylene succinate-co-adipate) (SG) polycaprolactone (PCL), a blend of PCL and starch (PCL-starch), and a poly-lactic acid (PLA). As with other materials, the polymers degraded faster at a neutral pH than at either acidic or basic conditions. Moisture contents of 60 and 100% water holding capacity exhibited a similar biodegradability for various polymers, although the effects differed depending on the polymer. For synthetic polymers, biodegradation was faster at 60%, while the natural polymer (cellulose) degraded faster at 100%. Fungal hypae was observed at a 60% water holding capacity which may have affected the biodegradation of the polymers. A polymer amount of 0.25% to soil revealed the highest biodegradability among the ratios of 0.25, 0.5, and 1%. With a higher sample amount, the residual polymer could be recovered after the biodegradation test. It was confirmed that a test for general biodegradation condition can be applied to plastic biodegradation in soil.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.34.1-34.7
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• 2020

Purpose: The purpose of this study was to evaluate the influence of biodegradable polycaprolactone membrane on new bone formation and the biodegradation of biphasic alloplastic bone substitutes using animal models. Materials and methods: In this study, bony defect was formed at the canine mandible of 8 mm in diameter, and the defects were filled with Osteon II. The experimental groups were covered with Osteoguide as barrier membrane, and the control groups were closed without membrane coverage. The proportion of new bone and residual bone graft material was measured histologically and histomorphometrically at postoperative 4 and 8 weeks. Results: At 4 weeks, the new bone proportion was similar between the groups. The proportion of remaining graft volume was 27.58 ± 6.26 and 20.01 ± 4.68% on control and experimental groups, respectively (P < 0.05). There was no significant difference between the two groups in new bone formation and the amount of residual bone graft material at 8 weeks. Conclusion: The biopolymer membrane contributes to early biodegradation of biphasic bone substitutes in the jaw defect but it does not affect the bone formation capacity of the bone graft.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2020년도 정기학술대회 발표논문집
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• pp.208-208
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• 2020

The aim of this study was to investigate changes in the weight of Zophobas morio larvae and mass of polystyrene foam when the larvae were fed polystyrene for 27 days. Fourier-transform infrared (FTIR) spectrometry was used to determine whether the polystyrene was broken down by the larvae. Forty Z. morio larvae (four replicates with 10 larvae per replicate) were reared in a chamber under controlled conditions with polystyrene foam blocks as their sole diet. The weight of the Z. morio larvae and mass of the polystyrene foam decreased as a function of time. The average weight of the larvae and mass of the polystyrene foam blocks decreased by 16.3 and 6.5%, respectively, over the 27-day period. The FTIR spectrum of Z. morio larvae fed with polystyrene foam did not reveal the unique peaks associated with polystyrene. In conclusion, this study suggests the possibility of using Z. morio larvae as a management technology for degrading waste plastics without a negative environmental effect. Key words : FTIR spectra, plastic biodegradation, polystyrene foam, Zophobas morio larvae.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.6.1-6.9
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• 2015

Orthognathic surgery requires stable fixation for uneventful healing of osteotomized bony segments and optimal remodeling. Titanium plates and screws have been accepted as the gold standard for rigid fixation in orthognathic surgery. Although titanium osteofixation is the most widely used approach, the use of bioabsorbable devices has been increasing recently. Biodegradation of bioabsorbable devices eliminates the need for a second operation to remove metal plates and screws. However, long-term stability and relapse frequency in bioabsorbable osteofixation are still insufficiently studied, especially in cases of segmental movements of great magnitude or segmental movements to a position where bony resistance exists. This paper reviews the background, techniques, and complications of bioabsorbable osteofixation and compares bioabsorbable and titanium osteofixation in orthognathic surgery in terms of skeletal stability.

• 한국버섯학회지
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• 제22권1호
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• pp.31-36
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• 2024

친환경적인 플라스틱 분해를 위한 연구의 한 종류로 버섯균을 활용한 플라스틱 분해 유도를 위해 본 실험을 진행하였다. 본 실험에서는 주변에서 구하기 쉽고 인체에 유해할 가능성이 낮은 식용 버섯을 활용하여 인체 안정성을 더한 플라스틱 분해 기술을 개발하고자 하였으며 31 종의 버섯균들을 대상으로 플라스틱 PE, PS, PET 필름에 대한 분해 효과를 관찰하였다. 본 연구과정에서 4종의 버섯(종이비늘버섯, 영지버섯, 갈색먹물버섯, 느타리)에 의한 플라스틱 분해 효과를 관찰하였으며, 진균과의 교차 배양을 통해 플라스틱 분해 효과를 촉진시킬 수 있는지를 확인하였다. 해당 확인 과정에서 PS에 대한 분해 효과가 가장 높게 나타났으며 이는 진균 Asp. nidulans의 작용에 의한 것이었다. 그러나 Asp.nidulans가 가진 유해성 (Henriet et al., 2012)으로 인해 인체에 무해한 식용버섯균의 활용이 필요하다고 판단되며 비록 버섯균만을 활용한 분해 결과는 저조하나 진균과 버섯균을 교차 배양한 분해 효과는 Asp. nidulans에 의한 분해 효과에 근접하다고 볼 수 있다. 또한 PET에 대해서는 오히려 PT_2822_nig의 사례와 같이 교차 배양한 샘플이 더 높은 수치의 플라스틱 분해 효과를 보였다. 비록 두 실험 결과값들이 유의성을 보이지 못해 추가적인 보완실험이 요구되고 있으나 해당 실험을 통해 버섯균을 활용한 플라스틱 분해 유도 또한 세균, 진균, 밀웜 등을 활용한 분해 유도 과정과 비교하여 경쟁성을 보이고 있다.

• 한국건설순환자원학회논문집
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• 제4권2호
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• pp.112-117
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• 2016

본 연구에서는 급속히 성장하고 있는 산업분야인 생분해성 플라스틱인 PLA(Poly Lactic Acid)를 사용하여 개발된 식생매트의 생분해기간에 따른 인장성능을 비교하였다. 시험방법은 한국산업표준(KS)에서 정한 방법을 준용하였다. 단일소재로 제작된 PLA 매쉬 및 PLA 플라스틱으로 실험한 두꼐, 인장강도 및 분자량은 5개월 생분해 기간에 반비례하는 결과를 나타내었다. PLA 매쉬의 두께는 11.2%~13.4% 수준까지 두께가 증가하였으며 PLA 매쉬의 인장강도는 32.4%~55.4% 수준까지 감소하였다. PLA 플라스틱의 인장강도 및 분자량도 시간경과에 따라 감소하는 것을 확인할 수 있었다. 다만, PLA 매쉬, 부직포(씨앗포함) 및 황마네트로 혼합 구성된 식생매트의 인장시험결과는 특정한 경향성을 보이지 못하였다.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.342-349
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• 2017

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.