• Parasites, Hosts and Diseases
• /
• v.30 no.3
• /
• pp.227-230
• /
• 1992

Spirometra mansoni plerocercoid (sparganum) was incubated in saline at $4^{\circ}C{\;}or{\;}37^{\circ}C$ up to 100 hours. Protein contests in the excretory$.$secretory product (ESP) were rather constant (mean 7.7 mg of protein/gram of sparganum) in the preparations. Reducing SDS-PAGE of ESP showed similar protein subunit compositions with those in crude extract. Antigenic 36 and 31 kDa Proteins were major bands in ESP. ESP exhibited specific activities of protease(2.9~5.3 units/mg) at pH 6.0 and pH 7.5. Presence of protease activity in ESP may be a supporting evidence that hitherto known cysteiRe protease of sparganum is possibly secreted.

• KSBB Journal
• /
• v.16 no.2
• /
• pp.158-162
• /
• 2001

A halotolerant and extracellular protease-producing yeast was isolated from traditional Meju and identified as a strain of Hansenular polymorpha by investigating its microbiological characteristics. The optimum pH, temperature and NaCl concentration reauired for the growth of Hansenular polymorpha S-9 were found to be pH 6.0, 30$^{\circ}C$ and 0.5 M, respectively. Extracellular protease was produced maximally at 10 U ml(sup)-1 when Hansenular polymorpha S-9 was grown on the medium containing 1.0% beef extract and 0.1 M NaCl for 12 hr at 30$^{\circ}C$. About 13% of the angiotensin-converting enzyme (ACE) inhibitory activity was shown in the hydrolysates which were obtained from the digestion of soybean protein (6 mg) for 6 hr at 30$^{\circ}C$ by the crude enzyme (1 U).

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.10
• /
• pp.1447-1451
• /
• 2004

An experiment was conducted to determine the effects of different dietary crude protein (CP) levels on growth performance, nutrient utilization, small intestine protease activity and immunity index of weaner to 2 month-old New Zealand rabbits. Eighty weaner rabbits were allocated in individual cages to five treatments in which they were fed diets with CP at 14%, 16%, 18%, 20% and 22%, respectively. The growth performance and nutrient digestibility of rabbits increased firstly when dietary CP increased, then decreased. The average daily gain was the highest and feed conversion rate was the lowest when dietary CP reached 20%, namely 34.9 g/d and 2.74:1, respectively. Maximum CP digestibility was 72.1% in the 18% CP group, maximum crude fiber digestibility of 28.4% occurred in the 16% CP group and was significantly different from other treatments (p<0.01), apparent digestibility of Lys and Val followed the same trend as CP digestibility, and reached their maximum when dietary CP was 18%. Apparent digestibility of Cys, Tyr, Leu and Thr also had a similar trend to CP digestibility. Nitrogen retention (RN) increased with CP level (p>0.05), and was highest for 20% CP treatment (1.5 g/d). The effect of CP level on the rate of digestible nitrogen (DN) converted RN was small. The spleen index, thymus index, chymotrypsin and trypsin activities in small intestine were highest when dietary CP was 16%, which were 1.0, 2.8, 15.7 U/g and 125.7 U/g, respectively. There was no significant difference among treatments (p>0.05). According to the above results, the appropriate dietary CP level from weaner to 2 month-old meat rabbits was 18-20%.

• Parasites, Hosts and Diseases
• /
• v.46 no.3
• /
• pp.183-186
• /
• 2008

Helminthic cysteine proteases are well known to play critical roles in tissue invasion, nutrient uptake, and immune evasion of the parasites. In the same manner, the sparganum, the plerocercoid of Spirometra mansoni, is also known to secrete a large amount of cysteine proteases. However, cysteine protease inhibitors regulating the proteolytic activities of the cysteine protease are poorly illustrated. In this regard, we partially purified an endogenous cysteine protease inhibitor from spargana and characterized its biochemical properties. The cysteine protease inhibitor was purified by sequential chromatographies using Resource Q anion exchanger and Superdex 200 HR gel filtration from crude extracts of spargana. The molecular weight of the purified protein was estimated to be about 11 kD on SDS-PAGE. It was able to inhibit papain and 27 kDa cysteine protease of spargana with the ratio of 25.7% and 49.1%, respectively, while did not inhibit chymotrypsin. This finding suggests that the cysteine protease inhibitor of spargana may be involved in regulation of endogenous cysteine proteases of the parasite, rather than interact with cysteine proteases from their hosts.

• Journal of Animal Science and Technology
• /
• v.62 no.5
• /
• pp.659-667
• /
• 2020

This study was conducted to evaluate the effects of different levels of crude protein (CP) and protease on nitrogen (N) utilization, nutrient digestibility, and growth performance in growing pigs. A total of six crossbred ([Landrace × Yorkshire] × Duroc) barrows were individually accepted in 1.2 m × 0.7 m × 0.96 m stainless steel metabolism cages. The pigs (average initial body weight of 27.91 ± 1.84 kg) randomly assigned to six diets with six weeks (6 × 6 Latin square design). The experiment was carried out in an environment with a temperature of 23 ± 1.5℃, a relative humidity of 83 ± 2.3% and a wind speed of 0.25 ± 0.03 m/s. The dietary treatments were arranged in a 2 × 3 factorial design with two levels of CP (15.3% or 17.1%) and three levels of protease (0 ppm, 150 ppm, or 300 ppm). The average daily gain and gain to feed ratio (G:F) tended to increase (p = 0.074) with increasing amounts of protease. The low CP level diet reduced (p < 0.050) urinary and fecal N concentrations, the total N excretion in feces, and increased (p < 0.050) N retention. Different protease levels in the diet did not affect (p > 0.05) at N intake, but supplementation of the diets with 300 ppm protease decreased (p < 0.050) the N concentration in urine and feces and tended to increase (p = 0.061) the percentage of N retention retained of the total N intake. The dietary CP level did not affect (p > 0.050) the apparent total tract digestibility (ATTD) of dry matter, digestible energy (DE), and metabolic energy (ME), but diet supplementation with 300 ppm protease showed higher (p < 0.050) ATTD of DE and ME than in the protease-free diet. Therefore, a low protein diet with protease could improve the utilization of nitrogen, thereby reducing the negative effect of N excretion into the environment while maintaining or increasing growth performance compared to a high protein diet.

• Korean Journal of Microbiology
• /
• v.51 no.1
• /
• pp.75-80
• /
• 2015

Pseudoalteromonas donghaensis HJ51, isolated from the East Sea, has been reported as a novel strain to produce extracellular protease. Crude supernatant was used to determine optimal activity and optimal production conditions for the enzyme. It was found that the optimal temperature and pH of the protease were $40^{\circ}C$ and pH 7.5-10.5, respectively. The enzyme activity was kept to 88% at the pH 11. In metal requirement analysis, the enzyme exhibited the highest activity when 10 mM $Fe^{3+}$ was supplied. While supplementation of additional carbon sources used in study showed no positive effect on cell growth and enzyme activity, the addition of beef extract, tryptone, or casamino acids instead of peptone of PY-ASW containing 1% glucose increased enzyme production to 21, 7, 4%, respectively. Taken together these properties, the enzyme produced from P. donghaensis HJ51 can be applied to the industries that require protease activity under alkaline pH and low temperature.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.2
• /
• pp.147-153
• /
• 1983

To check the differences of the digestive enzymes by the bait habits and the proteolytic activities of the fissile extracts from the fish, omnivorous filefish (Navodon modestus), carnivorous cat shark (Scilliorhinus tarazame) and bloodsucking hag fish (Eptatretus burgeri) were sampled for this experiment. The activity of crude alkaline protease extracted from the muscle and the internal organs of the samples was determined with casein as substrate. The activity of the proteolytic enzymes showed remarkable differences by the organs of the fish. The optimum condition of the pretenses from the muscle revealed in range of pH 7.8-8.3, at $60-65^{\circ}C$, while those of the enzymes from the internal organs were at about pH 8.2, $45-55^{\circ}C$, but those of hag fish were at about pH 6.7, $45-55^{\circ}C$. The proteolytic activity of the enzyme of alimentary canal in filefish and in hag fish was 57 and 11 times stronger than that of muscle, respectively. The crude enzyme from the alimentary canal of file fish showed the strongest proteolytic activity in samples submitted and that of cat shark was the lowest. The activity of pancreatic alkaline protease in cat shark was 50 fold higher than that of muscle alkaline protease in the fish.

• Korean Journal of Agricultural Science
• /
• v.25 no.1
• /
• pp.107-117
• /
• 1998

Ths studies was carried out to investigate the processing possibility of pheasant meat extracts treated with proteases. The crude protein, aminonitrogen, degree of hydrolysis, yield and amino acid composition of pheasant meat extracts when it was treated with proteases at various temperature and reaction time were analyzed. The crude protein contents of pheasant meat extracts processed in $130^{\circ}C$ were more than when it was done in $100^{\circ}C$, but the contents of aminonitrogen were not quite different between two processing temperature. The content of crude protein and aminonitrogen when pheasant meat was hydrolyzed with protease NP and prozyme A. The yields of pheasant meat extracts, when pheasant meat were treated at $100^{\circ}C$ and $130^{\circ}C$, were from 2.24 to 7.10% and from 5.51 to 10.45%, respectively. And the yield of extraction depended on extraction temperature, kinds of enzyme, amount of enzyme, extraction time. The content of aminonitrogen in pheasant meat extracts treated with enzyme was much higher than any other treatments. And it depended on amount of enzyme, extraction time and temperature. The amount of the amino acids in pheasant meat extracts treated by protease NP were eminently higher than by heat at $100^{\circ}C$ or $130^{\circ}C$.

• Preventive Nutrition and Food Science
• /
• v.18 no.4
• /
• pp.273-279
• /
• 2013

Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was $40^{\circ}C$. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at $60^{\circ}C$ and 60 min at $50^{\circ}C$. F1-1 protease was inhibited by $Mn^{2+}$, $Hg^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases.

• Korean Journal of Microbiology
• /
• v.20 no.3
• /
• pp.105-112
• /
• 1982

The strain of Aspergillus, 6368A, producing acid protease showing high activity was isolated from soil, as a result of wide research about mold group. This strain was identified as a species of Aspergillus tubingensis by the investigation of morphological characteristics. The change of the enzyme production under the various media and culture condition was also studied. The optimum pH and stability of crude acid protease are 2.5, 2.0~4.5 and the optimum temeprature and thermal inactivation waas shown $50^{\circ}C,\;55^{\circ}C$, respectively. From the result of the study on the effects of metal ions, it was found that $MnCl_2,\;CoCl_2,\;CuCl_2,\;SrCl_2,\;and\;NiCl_2$ slightly increased the enzyme activity, on the other hand $ZnCl_2,\;CaCl_2,\;MgCl_2,\;SLS,\;and\;KMnO_4$ decreased it.