• Journal of Microbiology and Biotechnology
• /
• 제27권12호
• /
• pp.2180-2189
• /
• 2017

Psychrophilic phytases suitable for aquaculture are rare. In this study, a phytase of the histidine acid phosphatase (HAP) family was identified in Morchella importuna, a psychrophilic mushroom. The phytase showed 38% identity with Aspergillus niger PhyB, which was the closest hit. The M. importuna phytase was overexpressed in Pichia pastoris, purified, and characterized. The phytase had an optimum temperature at $25^{\circ}C$, which is the lowest among all the known phytases to our best knowledge. The optimum pH (6.5) is higher than most of the known HAP phytases, which is fit for the weak acidic condition in fish gut. At the optimum pH and temperature, MiPhyA showed the maximum activity level ($2,384.6{\pm}90.4{\mu}mol{\cdot}min^{-1}{\cdot}mg^{-1}$, suggesting that the enzyme possesses a higher activity level over many known phytases at low temperatures. The phytate-degrading efficacy was tested on three common feed materials (soybean meal/rapeseed meal/corn meal) and was compared with the well-known phytases of Escherichia coli and A. niger. When using the same amount of activity units, MiPhyA could yield at least $3{\times}$ more inorganic phosphate than the two reference phytases. When using the same weight of protein, MiPhyA could yield at least $5{\times}$ more inorganic phosphate than the other two. Since it could degrade phytate in feed materials efficiently under low temperature and weak acidic conditions, which are common for aquacultural application, MiPhyA might be a promising candidate as a feed additive enzyme.

• Applied Biological Chemistry
• /
• 제33권2호
• /
• pp.161-168
• /
• 1990

개량식 고추장의 특징을 검토하기 위하여 재래식과 개량식 고추장의 숙성시 성분 변화, 메주와 고오지의 효소 역가 그리고 소금과 고추가루의 첨가 영향 등을 본 결과 숙성 초기에는 재래식과 개량식 고추장에서 아미노태질소, 환원당 함량의 큰 차이를 보이나 그 이후에는 평행되게 변화되었다. Koji의 protease역가는 악산성에서 메주는 중성에서 최대 활성을 보였다. 기질 소화의 최적 조건은 $60^{\circ}C$에서 3시간이었다. 소금 및 고추가루의 첨가로 protease와 당화 amylase의 역가가 현저하게 떨어지므로 소금과 고추가루는 소화 후에 첨가하는 것이 유리하였다.

• 한국의류산업학회지
• /
• 제19권5호
• /
• pp.620-625
• /
• 2017

In this study, the dyeing conditions(temperature, time, concentration) are changed from various conditions on wool fabrics by using corydalis tuber extract in order to develop new natural dyes. The purpose of this study is to improve the dyeability, color fastness, and functionality and to derive optimal dyeing conditions by comparing and analyzing the changes of K/S values and surface color by dyeing pH changes, mordant method, and mordant type. As a result of the experiment, the optimum dyeing condition of the wool fabrics is shown dyeing temperature:$80^{\circ}C$, dyeing time:90min, dyeing concentration:100%. The dyeability by pH variants of corydalis tuber extract indicates that K/S values is higher alkaline than acidic. The mordant method of corydalis tuber extract showed pre-mordant has high K/S values. In terms of color fastness, marked improvement has not been shown despite of mordant treatment on wool fabrics. In particular, color change of color fastness to washing, color fastness to light indicates the low fastness. In addition, the functionality such as antibacterial activities and deodorization can be given at dyeing with corydalis tuber extract thus it is expected to be applied to underwear or apparel products for the elderly and infirm and children with weak skin that required high functionality.