• Journal of the Korean Applied Science and Technology
• /
• v.32 no.4
• /
• pp.685-693
• /
• 2015

In this study, we found that it is necessary to use the relatively new resource from seaweed extracts to extract and process pulp and create a local brand that can contribute to the local fishermen, development of new bio material, establishment of natural infrastructure, and acquisition of foreign investment. This study's seaweed pulp separation process is very overwhelming as seaweed is a compound of glycoside and polysaccharide. Nevertheless, we intend to develop a purification process and introduce applied technology to explore a new applied technology of pulp process. Once this technology is fully developed and mass produced, it would contribute to greater exports and increasing income level for the local fishermen. The ultimate goal of this study is to gather technical data from the first and second years of application, apply seaweed pulp to increase bio effect, and develop new functional bio-plastic packaging material, raw material, and samples with special characteristics of high molecules.

• Journal of Marine Bioscience and Biotechnology
• /
• v.14 no.2
• /
• pp.133-142
• /
• 2022

The increased production and consumption of polyethylene terephthalate (PET)-based products over the past several decades has resulted in the discharge of countless tons of PET waste into the marine environment. PET microparticles resulting from the physical erosion of general PET wastes end up in the ocean and pose a threat to the marine biosphere and human health, necessitating the development of new technologies for recycling and upcycling. Notably, enzyme-mediated PET degradation is an appealing option due to its eco-friendly and energy-saving characteristics. PETase, a PET-hydrolyzing enzyme originating from Ideonella sakaiensis, is one of the most thoroughly researched biological catalysts. However, the industrial application of PETase-mediated PET recycling is limited due to the low stability and poor reusability of the enzyme. Here we developed the whole-cell catalyst (WCC) in which functional PETase is attached to the outer membrane of Escherichia coli. Immunoassays are used to identify the surface-expressed PETase, and we demonstrated that the WCC degraded PET microparticles most efficiently at 30℃ and pH 9 without agitation. Furthermore, the WCC increased the PET-degrading activity in a concentration-dependent manner, surpassing the limited activity of soluble PETase above 100 nM. Finally, we demonstrated that the WCC could be recycled up to three times.

• Microbiology and Biotechnology Letters
• /
• v.22 no.4
• /
• pp.436-442
• /
• 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.