• Journal of Microbiology and Biotechnology
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• 제34권1호
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• pp.132-140
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• 2024

In this study, carrageenase immobilization was evaluated with a concise and efficient strategy. Pomelo peel cellulose (PPC) modified by polyethyleneimine (PEI) using the physical absorption method was used as a carrier to immobilize carrageenase and achieved repeated batch catalysis. In addition, various immobilization and reaction parameters were scrutinized to enhance the immobilization efficiency. Under the optimized conditions, the enzyme activity recovery rate was more than 50% and 4.1 times higher than immobilization with non-modified pomelo peels. The optimum temperature and pH of carrageenase after immobilization by PEI-modified pomelo peel, at 60℃ and 7.5 respectively, were in line with the free enzyme. The temperature resistance was reduced, inconsistent with free enzyme, and pH resistance was increased. A significant loss of activity (46.8%) was observed after reusing it thrice under optimal reaction conditions. In terms of stability, the immobilized enzyme conserved 76.0% of the initial enzyme activity after 98 days of storage. Furthermore, a modest decrease in the kinetic constant (K_m) value was observed, indicating the improved substrate affinity of the immobilized enzyme. Therefore, modified pomelo peel is a verified and promising enzyme immobilization system for the synthesis of inorganic solvents.

• 한국환경농학회지
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• 제27권3호
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• pp.253-259
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• 2008

과수의 생육기간동안 양분흡수는 과원토양의 환경에 영향을 받는다. 수확기에 신고 배에 Ca 결핍장해과로 보이는 과실의 발생 원인을 조사하기 위하여 과실에 생리장해가 발생한 4개 지역(울산,경주,평택,안성)의 과원 토양의 화학성 및 잎과 과실의 무기성분 함량을 조사하였다. 과실에 생리장해가 발생한 과원 토양의 치환성 Ca 함량은 정상관원에 비해 낮은 반면, 치환성K와 Mg 함량 및 T-N 함량은 높았다(P=0.05). 생리장해 과실의 과육과 과피의 Ca 함량은 건전한 과실에 비해 낮았으며, 과육과 과피의 Mg/Ca 비율은 건전 과실보다 높았다(P=0.05). 잎에 N/Ca 및 K/Ca 비율은 생리장해가 발생한 나무가 건전한 나무의 잎 보다 높았다. 따라서 신고 배의 생리장해는 Ca 함량의 부족에 의해 발생하는 유부과로 판단되며, 이는 토양에 치환성 K와 Mg 이온 및 T-N가 Ca 이온의 흡수에 장해요인으로 작용한 것으로 생각된다.