• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.4
• /
• pp.430-436
• /
• 2010

The objective of the present studies was to develop and validate a system for isolation, purification and extended culture of pigment-producing cells in alpaca skin (melanocytes) responsible for coat color and to determine the effect of alpha melanocyte stimulating hormone treatment on mRNA expression for the melanocortin 1 receptor, a key gene involved in coat color regulation in other species. Skin punch biopsies were harvested from the dorsal region of 1-3 yr old alpacas and three different enzyme digestion methods were evaluated for effects on yield of viable cells and attachment in vitro. Greatest cell yields and attachment were obtained following dispersion with dispase II relative to trypsin and trypsin-EDTA treatment. Culture of cells in medium supplemented with basic fibroblast growth factor, bovine pituitary extract, hydrocortisone, insulin, 12-O-tetradecanolphorbol-13-acetate and cholera toxin yielded highly pure populations of melanocytes by passage 3 as confirmed by detection of tyrosinase activity and immunocytochemical localization of melanocyte markers including tyrosinase, S-100 and micropthalmia-associated transcription factor. Abundance of mRNA for tyrosinase, a key enzyme in melanocyte pigment production, was maintained through 10 passages showing preservation of melanocyte phenotypic characteristics with extended culture. To determine hormonal responsiveness of cultured melanocytes and investigate regulation of melanocortin 1 receptor expression, cultured melanocytes were treated with increasing concentrations of ${\alpha}$-melanocyte stimulating hormone. Treatment with ${\alpha}$-melanocyte stimulating hormone increased melanocortin receptor 1 mRNA in a dose dependent fashion. The results demonstrated culture of pure populations of alpaca melanocytes to 10 passages and illustrate the potential utility of such cells for studies of intrinsic and extrinsic regulation of genes controlling pigmentation and coat color in fiber-producing species.

• Preventive Nutrition and Food Science
• /
• v.20 no.1
• /
• pp.43-51
• /
• 2015

${\varepsilon}$-Polylysine (EPL) is used as a natural preservative in food. However, few studies have been conducted to assess the beneficial functions of dietary EPL. The purpose of this study was to elucidate the mechanism underlying the inhibition of neutral and acidic sterol absorption and hepatic enzyme activity-related fatty acid biosynthesis following EPL intake. EPL digest prepared using an in vitro digestion model had lower lipase activity and micellar lipid solubility and higher bile acid binding capacity than casein digest. Male Wistar rats were fed an AIN-93G diet containing 1% (wt/wt) EPL or L-lysine. After 4 weeks of feeding these diets, the marked decrease in serum and liver triacylglycerol contents by the EPL diet was partly attributed to increased fecal fatty acid excretion. The activities of hepatic acetyl-coenzyme A carboxylase and glucose-6-phosphate dehydrogenase, which are key enzymes of fatty acid biosynthesis, were enhanced in rats fed EPL diet. The increased fatty acid biosynthesis activity due to dietary EPL may be prevented by the enhancement of fecal fatty acid excretion. The hypocholesterolemic effect of EPL was mediated by increased fecal neutral and acidic sterol excretions due to the EPL digest suppressing micellar lipid solubility and high bile acid binding capacity. These results show that dietary EPL has beneficial effects that could help prevent lifestyle-related diseases such as hyperlipidemia and atherosclerosis.

• Food Science of Animal Resources
• /
• v.44 no.3
• /
• pp.533-550
• /
• 2024

Peptides with bioactive effects are being researched for various purposes. However, there is a lack of overall research on pork-derived peptides. In this study, we reviewed the process of obtaining bioactive peptides, available analytical methods, and the study of bioactive peptides derived from pork. Pepsin and trypsin, two representative protein digestive enzymes in the body, are hydrolyzed by other cofactors to produce peptides. Bicinchoninic acid assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, chromatography, and in vitro digestion simulation systems are utilized to analyze bioactive peptides for protein digestibility and molecular weight distribution. Pork-derived peptides mainly exhibit antioxidant and antihypertensive activities. The antioxidant activity of bioactive peptides increases the accessibility of amino acid residues by disrupting the three-dimensional structure of proteins, affecting free radical scavenging, reactive oxygen species inactivation, and metal ion chelating. In addition, the antihypertensive activity decreases angiotensin II production by inhibiting angiotensin converting enzyme and suppresses blood pressure by blocking the AT1 receptor. Pork-derived bioactive peptides, primarily obtained using papain and pepsin, exhibit significant antioxidant and antihypertensive activities, with most having low molecular weights below 1 kDa. This study may aid in the future development of bioactive peptides and serve as a valuable reference for pork-derived peptides.

• Journal of Animal Science and Technology
• /
• v.45 no.1
• /
• pp.87-100
• /
• 2003

This study was conducted in order to determine a proper level of molasses addition through the analysis of changes in appearance, nutritive and silage parameters before and after ensiling or deepstacking of broiler litter, to evaluate the effect of pelleting processed broiler litter and to develop methods to enhance palatability of broiler litter and reduce the adjustment period by ‘Hanwoo’ steers. Molasses addition was effective in ensiling and deepstacking of broiler litter and the proper addition level was about 5%. Changes in nutritive values of broiler litter by ensiling and deepstacking with or without molasses treatment were not great. Adding 5% molasses at deepstacking of broiler litter did not affect(P<0.05) in vitro digestion of dry matter and organic matter. Pelleting of broiler litter resulted in significant(P<0.05) moisture evaporation, organic matter reduction and nearly threefold increase of bulk density. Pelleting or molasses addition of broiler litter improved palatability by ‘Hanwoo’ steers and reduced the adjustment period by half(8-9 d).

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.12
• /
• pp.1746-1751
• /
• 2005

The objective of this study was to evaluate the effects of sarsaponin on methane production, ruminal fermentation, nutrient digestion and blood metabolites using three Holstein steers in a 3${\times}$3 Latin Square design. The steers were fed Sudangrass hay plus concentrate mixture at a ratio 1.5:1 twice daily, and sarsaponin (0, 0.5 and 1% of DM), which was given at 09:00 and 17:00 h daily by mixing with concentrate. Rumen samples were collected 0, 2, and 5 h after morning dosing. Ruminal pH was numerically decreased and numbers of protozoa were decreased linearly (p<0.01) by treatment. Ruminal ammonia-N was reduced (linear; p<0.05) and total VFA was increased (quadratic; p<0.05) at 2 and 5 h after sarsaponin dosing. The molar proportion of acetate was decreased (quadratic; p<0.05) and propionate was increased (linear; p<0.01) at all sampling times. Blood plasma glucose was increased and urea-N was decreased (linear; p<0.05) at 2 and 5 h after dosing. Methane was decreased by approximately 12.7% (linear; p<0.05). The apparent digestibility of DM and NDF were decreased (quadratic; p<0.05) and that of CP remained unchanged due to the sarsaponin. The numbers of cellulolytic bacteria were decreased (quadratic; p<0.05), while numbers of total viable bacteria remained unchanged due to the sarsaponin. These results show that sarsaponin can partially inhibit rumen methanogenesis in vivo and improve ruminal fermentation, which supports our previous in vitro results.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.12
• /
• pp.2100-2105
• /
• 2015

Probiotic bacteria must have not only tolerance against bile salt but also no genes for antibiotic resistance. Leuconostoc citreum is a dominant lactic acid bacterium in various fermented foods, but it is not regarded as a probiotic because it lacks bile salt resistance. Therefore, we aimed to construct a bile salt-resistant L. citreum strain by transforming it with a bile salt hydrolase gene (bsh). We obtained the 1,001 bp bsh gene from the chromosomal DNA of Lactobacillus plantarum and subcloned it into the pCB4170 vector under a constitutive P710 promoter. The resulting vector, pCB4170BSH was transformed into L. citreum CB2567 by electroporation, and bile salt-resistant transformants were selected. Upon incubation with glycodeoxycholic acid sodium salt (GDCA), the L. citreum transformants grew and formed colonies, successfully transcribed the bsh gene, and expressed the BSH enzyme. The recombinant strain grew in up to 0.3% (w/v) GDCA, conditions unsuitable for the host strain. In in vitro digestion conditions of 10 mM bile salt, the transformant was over 67.6% viable, whereas only 0.8% of the host strain survived.

• Korean Journal of Veterinary Service
• /
• v.40 no.4
• /
• pp.265-275
• /
• 2017

The production of enzymes that help digestion, assimilation of essential nutrients, and prevent pathogenic bacteria are important for probiotics used in aquaculture. The objective of this study was to investigate enzyme activities for macromolecular organic matters and antimicrobial properties of the selected potential probiotics isolated from gut of surf clam (Tresus keenae) against well-known shellfish-pathogenic bacteria. Among 65 isolates from guts of 60 surf clams, seven Bacillus strains with outstanding degradation capability of macromolecule organic matter were selected as potential probiotics as follows: TKI01 (B. vietnamensis), TKI02, TKI26 (B. thuringiensis), TKI14, TKI32, TKI42 (B. amyloliquefaciens), and TKI18 (B. stratosphericus). After in vitro antimicrobial activity test was performed against five shellfish-pathogenic bacteria including Listonella anguillarum, Vibrio parahaemolyticus, V. splendidus, V. harveyi, V. tubiashii, PCR assay was performed to detect bacteriocin-producing strain. PCR results revealed that the five Bacillus strains possessed diverse bacteriocin genes including ericinA, coagulin, surfactin, iturin, bacyllomicin, fengycin, bacylisin, subtilin, and lantibiotics. In the present study, the selected seven Bacillus strains showed different enzyme activities according to types of macromolecule organic matters. And their antimicrobial activities varied based on the species of pathogenic bacteria. In addition, at least five Bacillus strains had genetic potential to produce several natural lipopeptide antibiotics that may help biological control of surf clam aquaculture. Therefore, mixed use of probiotics might show co-operative effect and increase the efficiency of probiotics rather than separate use. To the best of our knowledge, it is the first report on antimicrobial properties of Bacillus species isolated from surf clam.

• Food Science and Preservation
• /
• v.23 no.3
• /
• pp.355-360
• /
• 2016

In this study, the quality characteristics of spray dried powders from unripe fig extract were investigated. The protease activities of unripe fig and peeled unripe fig extract were 0.11 unit/mL and 0.28 unit/mL, respectively. The spray dried powder of unripe fig extracts was analzed using different maltodextrin ratios (F-MD 5, 5% maltodextrin; F-MD 10, 10% maltodextrin; and F-MD 20, 20% maltodextrin). The spray-dried powder showed the highest protease activity with F-MD 10 (0.84 unit/g). The moisture content and L value of the spray-dried powder were higher than those of the freeze-dried powder. The particle diameter of the freeze-dried powder ($209.67{\mu}m$) was higher than that of the spray-dried powders ($22.18{\sim}37.33{\mu}m$). The water absorption index ranged from 0.18 to 0.40, while the water solubility index ranged from 94.40% to 98.80%. In the in vitro digestion study, spray-dried powders of the unripe fig showed a protease survival range of 16.47%~24.80%. In conclusion, it is considered appropriate to use the spray-dried powder (F-MD 10) of unripe fig as a meat tenderizer for processing food.

• Food Science and Industry
• /
• v.51 no.4
• /
• pp.302-312
• /
• 2018

Bioactive peptides generated from milk proteins play an important role in the prevention and alleviation of diabetes. Whey proteins possess direct insulinotropic effect by amino acids (especially branch chain amino acids) produced through its gastrointestinal digestion. Additionally, blood glucose level can be lowered by gut hormone which called incretin [glucose dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)]. However, physiological effects of incretin readily disappeared by dipeptidyl peptidase-4 (DPP-4) causing degradation of GLP-1. Several DPP-4 inhibitors are currently used as therapeutic medicines for the treatment of type II diabetes. More than 60 natural peptide (2-14 amino acids) DPP-4 inhibitors were identified in milk proteins. Peptide DPP-4 inhibitors act as substrate inhibitor and delay breakdown of GLP-1 both in vitro and in vivo. This review summarizes nutritional quality of milk proteins, absorption and mode of action of bioactive peptides, and finally up-to-dated knowledge on DPP-4 inhibitory peptides derived from milk proteins.

• Journal of Dairy Science and Biotechnology
• /
• v.36 no.4
• /
• pp.220-225
• /
• 2018

The purpose of this study was to investigate the effect of ultrasonic treatment during probiotics production process on the shelf life and the survival rate. Once Lactobacillus plantarum and Bifidobacterium longum were cultured in edible culture medium, ultrasonic treatment was performed at 100 Hz for 1, 2, 5, 7, and 10 minutes. Ultrasonic-treated L. plantarum HY7715 and B. longum HY8001 were centrifuged, mixed with a cryoprotectant, and lyophilized. The prepared lactic acid bacteria powder was individually packaged. After 6 months, viable cell counts were measured separately under cold storage and room temperature. In vitro digestion experiments were performed to determine the survival rate at digestive tract. As a result, it was observed that shelf life and survival rate were increased compared to untreated control group.