• Fashion & Textile Research Journal
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• v.22 no.4
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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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• v.30 no.8
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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.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.405-408
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• 2015

The deacidified oil obtained from the oleaginous fungus, Mortierella sp. (M-12) was bleached, after degumming, using activated clay under a 50-100 mmHg vacuum. The bleaching conditions were partially optimized as follows: activated clay, 1%, bleaching temperature $90^{\circ}C$, and treatment time 20 min. After bleaching, the color of bleached oil as determined by the Lovibond Tintometer, satisfied the specification for edible fats and oils. The bleaching process also decreased the contents of free fatty acids and phosphorus in the deacidified oil. The acid value of the bleached oil also satisfied the specification for edible fats and oils. It was early shown that the normal bleaching process can be used for the bleaching of heavily-colored microbial lipids for human consumption.