• 한국의류산업학회지
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• 제22권4호
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• pp.523-533
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• 2020

Previous studies are used to examine cellulose content, degumming period, fiber quality, production yield, production cost, development limit of fiber according to physical, chemical, and microbial degumming methods. Three types of degumming methods are used to measure surface condition after degumming, necessity of additional degumming and degree of impurity removal. First, previous studies confirmed that the microbial degumming method is superior in terms of cellulose content, fiber quality, production yield, production cost, and fiber development possibility. Second, surface condition and the necessity of additional degumming were analyzed by SEM. The black skin binding material was removed in the case of the Sangnangyi and chemical degumming; however, it was insufficient and further degumming was required. Skin fiber binding material was removed in the case of microbial degumming and the surface was cleanest after degumming; in addition, most showed the form of yarn decomposition. The FT-IR spectrum determined the degree of removal of impurities and showed that it can utilize inherent physical properties as the best degumming method. The degree of removal of pectin and lignin by microbial degumming was cleanest with hemicellulose also reduced by microbial degumming.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1244-1251
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• 2020

Phospholipase A₂ (PLA₂) from Streptomyces violaceoruber is a lipolytic enzyme used in a wide range of industrial applications including production of lysolecithins and enzymatic degumming of edible oils. We have therefore investigated expression and secretion of PLA₂ in two workhorse microbes, Pichia pastoris and Escherichia coli. The PLA₂ was produced to an activity of 0.517 ± 0.012 U/ml in the culture broth of the recombinant P. pastoris. On the other hand, recombinant E. coli BL21 star (DE3), overexpressing the authentic PLA₂ (P-PLA₂), showed activity of 17.0 ± 1.3 U/ml in the intracellular fraction and 21.7 ± 0.7 U/ml in the culture broth. The extracellular PLA2 activity obtained with the recombinant E. coli system was 3.2-fold higher than the corresponding value reached in a previous study, which employed recombinant E. coli BL21 (DE3) overexpressing codon-optimized PLA₂. Finally, we observed that the extracellular PLA₂ from the recombinant E. coli P-PLA₂ culture was able to hydrolyze 31.1 g/l of crude soybean lecithin, an industrial substrate, to a conversion yield of approximately 95%. The newly developed E. coli-based PLA₂ expression system led to extracellular production of PLA₂ to a productivity of 678 U/l·h, corresponding to 157-fold higher than that obtained with the P. pastoris-based system. This study will contribute to the extracellular production of a catalytically active PLA₂.

• 한국식품과학회지
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• 제47권3호
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• pp.405-408
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• 2015

아라키돈산을 고농도로 함유한 유지를 생산하는 Mortierella sp. M-12로부터 얻은 균체 지방질을 식용에 적합하도록 정제하기 위하여 탈색 공정을 최적화하였다. 동결건조한 균체로부터 Folch's solvent를 사용하여 균체 지방질 조유를 얻은 후 탈검과 탈산을 거쳐 얻은 탈산유를 50-100 mmHg 진공 하에서 탈색을 진행하였다. 활성백토를 1% 수준으로 첨가하여 $90^{\circ}C$에서 20분간 수행하였을 때 식용유지 규격에 적합한 색상을 갖는 탈색유를 얻을 수 있었다. 탈색 공정 중에 부수적으로 일어난 탈검과 탈산 작용으로 인하여 탈색유의 인 함량은 31.7% 감소하였으며, 산값은 0.5로 감소하여 식용유지의 규격에 적합한 수준이 되었다. 모르티에렐라 단세포유지는 일반적인 유지의 탈색공정을 통하여 식용급 동식물 유지와 같은 수준의 탈색유를 얻을 수 있었다.