• Applied Biological Chemistry
• /
• v.24 no.1
• /
• pp.7-14
• /
• 1981

Among the Basidiomycetes, Pleurotus ostreatus 301 and Lentinus edodes 3-1 were chosen because of their good enzyme productivity and rapid mycelial growth in rice straw medium. Their cultural conditions adequate for the enzymes production and effects of various materials and inorganic salts added to thd rice straw media were investigated. L. edodes 3-1 was excellent in productivity of cellulase and xylanase, and P. ostreatus 301 in protease. The optimum conditions for enzyme production were at $30^{\circ}C$ in cellulase production and at $25^{\circ}C$ in xylanase and protease production, with 75% moisture content and 5.0-6.0 initial pH. The appropriate cultural periods, for enzyme production were 30 days and 35 days for P. ostreatus 301 and L. edodes 3-1, respectively. Among the various materials added, defatted soybean, defatted rape seed, or defatted sesame were all effective to enzyme production but reduced mycelial growth. Rice bran was also effective, particularly at 30% concentration. The addition of inorganic salts showed effective to enzyme production. Among inorganic salts, optimum concentration of $CaCO_3$ was 5%, and that of $CaSO_4$ was 2%.

• Journal of Animal Science and Technology
• /
• v.62 no.1
• /
• pp.21-30
• /
• 2020

This study was conducted to evaluate effects of dietary protease (PR) on growth performance, nutrient digestibility, and intestinal morphology of weaned pigs. A total of 75 weaned pigs [7.06 ± 0.18 kg of average body weight (BW); 28 day old] were randomly allotted to 3 dietary treatments in a randomized complete block design (blocks = BW and sex): a diet based on corn and soybean meal to meet the requirement of crude protein (CP) as a positive control (PC; CP = 24.49%), a low protein diet as a negative control (NC; CP = 22.51%), and NC + 0.02% PR. The PR used in this study was a commercial product containing 75,000 protease units/g derived from Nocardiopsis prasina produced in Bacillus licheniformis. Pigs were fed the dietary treatments for 6 weeks and the diets containing 0.2% chromic oxide for the last week of this study. Blood, feces, ileal digesta, and ileum samples were collected from randomly selected two pigs in each pen on respective time points. Measurements were growth performance, apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of dry matter (DM), CP, and energy, frequency of diarrhea, packed cell volume (PCV), and ileal morphology of weaned pigs. Pigs fed PC and PR had higher (p < 0.05) final BW, average daily gain (ADG), and gain to feed ratio (G:F) during overall experimental period than those fed NC. Pigs fed PC and PR had higher (p < 0.05) AID or ATTD of DM, CP, or energy than those fed NC. Moreover, pigs fed PR had higher ratio between villus height and crypt depth (p < 0.05) and number of goblet cells (p < 0.05) than those fed NC. Addition of PR decreased (p < 0.05) frequency of diarrhea for the first two weeks after weaning compared with PC and NC. In addition, pigs fed PR had lower (p < 0.05) PCV on d 14 after weaning than those fed PC and NC. In conclusion, addition of PR in nursery diets with a low protein level significantly improved growth performance, nutrient digestibility, and intestinal morphology of weaned pigs.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.521-527
• /
• 1997

A liquefied seasoning material was manufactured by using the enzymatic hydrolysis for the benefit of highly effective utilization of cockle shell by-product, and their quality was investigated. The weight ratio of by-product to whole cockle shell was 32.7%, and the contents of moisture and crude protein in the raw cockle shell by-product were 83.1% and 10.7%, respectively. The optimal concentrations of protease such as Protease N. P.(Pacific Chemical Co.) and Alcalase(Noo co), used in order to reduced the hydrolysis period, were effective at 4%(w/w), and optimal hydrolyzing time was 8 hours and after 8 hours were little changed. To improve flavor of the liquefied seasoning material, by Maillard reaction used thermal treatment, addition of glucose was very effective. And addition in hydrolysate with 10% glucose, 9% table salt, 2% starch and 0.5% caramel were suitable for promotion of taste. Total nitrogen and amino type nitrogen in the product were 1,607mg% and 1,264mg%, respectively. And the ratio of amino type nitrogen to the total nitrogen was 78.6%. The major free amino acid were glutamic acid, lysine, leucine, valine and aspartic acid, and content of glutamic acid was 1,027.5mg%.

• Journal of Applied Biological Chemistry
• /
• v.59 no.4
• /
• pp.285-288
• /
• 2016

Proteolytic enzymes perform hydrolysis of the peptide bonds in the protein and most commonly use in the industry. Pseudoxanthomonas sp. WD12 and WD32 were previously isolated as protease producers from a rotten wood sample. Here, we report the secreted proteolytic enzymes. The optimum enzyme reaction temperature for the secreted crude enzyme from the strain WD12 and WD32 were $50^{\circ}C$ at pH 9.0 and $45^{\circ}C$ at pH 8.0, respectively. The enzyme activities of both strains were increased by addition of KCl, NaCl, $CaCl_2$ or $MnSO_4$, and decreased by addition of $AgNO_3$, $CuSO_4$, $FeCl_3$ or $AlCl_3$. Secreted enzymes of both strains were most strongly inhibited by addition of $FeCl_3$ or $CuSO_4$. Taken together these results, WD12 could be a candidate strain of industrial alkaline protease production.

• Journal of Life Science
• /
• v.11 no.4
• /
• pp.291-297
• /
• 2001

The marine bacterium isolated from Porphyra dentata showing green spot rot disease was identified as Pseudomonas sp. the strain have CNCase activity, xylanase activity and protease activity as well as agarase activity. But the strain has no pectate lyase activity. Porphyra dentata tissue inoculated this isolate was macerated after 1 week incubation. The characteristics of extracellular crude agarase of this isolate were examined, the optimal pH and temperature were pH7 and 3$0^{\circ}C$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.6 no.1
• /
• pp.27-33
• /
• 1977

The alkaline protease was isolated from the culture of Penicillium species (P-46) grown in the wheat bran media. The crude purification of this enzyme was carried out by extraction with distilled water and precipitated with 0.7-saturated ammonium sulfate, then dialysis for 3days. The activity of this enzyme was determined by Folin's colorimetric method. The results were as follows; 1. The optimum pH and temperature of this enzyme were pH 8.4 and $45^{\circ}C$. 2. This enzyme was stable at pH $7.0{\sim}9.0$. 3. This enzyme was not inactivated by treatment in lower temperature than $30^{\circ}C$. 4. The activity of this enzyme was strongly inhibited by $Hg^{++}$ and $Cu^{++}$, but slightly by $Ag^+$ 5. This enzyme was not inhibited by cystein, thiourea, ${\varepsilon}-aminocaproic$ acid, 2, 4-DNP, EDTA but strongly inhibited by PCMB.

• Food Science of Animal Resources
• /
• v.41 no.1
• /
• pp.164-171
• /
• 2021

Listeria monocytogenes is a representative foodborne pathogen and causes listeriosis. Enterococcus faecium CJNU 2524 was confirmed to produce a bacteriocin with anti-listerial activity. To establish optimal culture conditions for the production of the bacteriocin from E. faecium CJNU 2524, different media (MRS and BHI broth) and temperatures (25℃, 30℃, and 37℃) were investigated. The results showed that the optimal culture conditions were MRS broth and 25℃ or 30℃ temperatures. The crude bacteriocin was stable in a broad range of pH conditions (2.0-10.0), temperatures (60℃-100℃), and organic solvents (methanol, ethanol, acetone, acetonitrile, and chloroform). The bacteriocin activity was abolished when treated with protease but not α-amylase or lipase, indicating the proteinaceous nature of the bacteriocin. Finally, the bacteriocin showed a bactericidal mode of action against L. monocytogenes. Therefore, it can be a biopreservative candidate for controlling L. monocytogenes in dairy and meat products.

• Korean Journal of Food Science and Technology
• /
• v.37 no.3
• /
• pp.377-388
• /
• 2005

Effects of silkworm powder addition on rheological properties of dough and quality characteristics of bread were investigated. Protein content of silkworm powder was 53,98%, much higher than 12.46% of wheat powder, Crude fiber, fat, and pretense contents of silkworm powder were higher than those of wheat flour, Acid analysis revealed glutamic acid content was highest 4,046.16 mg thus, significant depreciation of breadmaking was expected due to weakened gluten structure or dough. Addition of silkworm powder(optimum at 2%) with pretense inactivated by heat treatment resulted in significant improvement of volume and bread quality, with external and internal scores close to those of the control.

• Microbiology and Biotechnology Letters
• /
• v.40 no.4
• /
• pp.303-309
• /
• 2012

Keratinases are of particular interest because of their action on insoluble keratins and generally on a broad range of protein substrates. Alkalophilic and neutrophilic actinomycete strains isolated from different soil samples, rich in keratinaceous substances were screened for keratinolytic activity. An alkalophilic isolate, TBG-S13A5, was found to possess good keratinolytic activity and was able to utilize feather as the sole carbon and nitrogen source. TBG-S13A5 exhibited an off-white aerial mass color with a rectus-flexibilis type of spore chain. The morphological, microscopical and biochemical characters were comparable with that of Streptomyces albidoflavus. Fatty acid methyl ester profiling (FAME) and 16S rDNA sequence analysis confirmed its identity as a strain of S. albidoflavus. Under submerged fermentation conditions, maximum protease production was recorded on the $5^{th}$ day of incubation at $30^{\circ}C$, using basal broth of pH 9.0 with 0.25% (w/v) white chicken feather. This strain could affect feather degradation when the initial pH was 8 and above and maximum protease production was recorded when the initial pH was around 10.5. The effectiveness of the crude enzyme in destaining and leather dehairing were also demonstrated.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.12
• /
• pp.1755-1762
• /
• 2014

The objective of this study was to investigate the effect of maize source and complex enzymes containing amylase, xylanase and protease on performance and nutrient utilization of broilers. The experiment was a $4{\times}3$ factorial design with diets containing four source maize samples (M1, M2, M3, and M4) and without or with two kinds of complex enzyme A (Axtra XAP) and B (Avizyme 1502). Nine hundred and sixty day old Arbor Acres broiler chicks were used in the trial (12 treatments with 8 replicate pens of 10 chicks). Birds fed M1 diet had better body weight gain (BWG) and lower feed/gain ratio compared with those fed M3 diet and M4 diet (p<0.05). Apparent ileal crude protein digestibility coefficient of M2 was higher than that of M3 (p<0.05). Apparent metabolisable energy (AME) and nitrogen corrected AME (AMEn) of M1 were significant higher than those of M4 (p<0.05). Supplementation of the basal diets with enzyme A or B improved the BWG by 8.6% (p<0.05) and 4.1% (p>0.05), respectively. The fresh feces output was significantly decreased by the addition of enzyme B (p<0.05). Maize source affects the nutrients digestibility and performance of broilers, and a combination of amylase, xylanase and protease is effective in improving the growth profiles of broilers fed maize-soybean-rapeseed-cotton mixed diets.