• Journal of Nutrition and Health
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• v.40 no.2
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• pp.118-129
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• 2007

This study was performed to investigate the effect of lysine-limited diets containing different levels of L-carnitine on body weight and lipid metabolism in obesity-induced adult rats. Eight-month-old male Sprague-Dawley rats (n = 90) were raised for one month with high fat diet (40% fat as calorie) to induce obesity. After induction of obesity, rats weighing 739.5 g were randomly blocked into three groups according to the body weight and raised for eight weeks with control diet (Co), 50% lysine-limited diet (-L), 50% lysine limitation with 0.3% pivalate diet (-L + P). Each of three groups was allotted to 0.0% L-carnitine (0.0% CT), 0.5% L-carnitine (0.5% CT) and 2.5% L-carnitine (2.5% CT) groups, respectively. The levels of AST, ALT, total protein and albumin in plasma were within the normal range. Daily food intake and calorie intake tended to be lower in 2.5% CT groups than those of other groups regardless lysine limitation or pivalate intake. And body weight gain and calorie efficiency ratio (weight gain (g) /calorie intake (100 kcal)) were significantly the lowest in 2.5% CT groups among all experimental groups regardless of lysine limitation or pivalate intake. The weights of perirenal, epididymal fat pads and brown adipose tissue in 2.5% CT groups were significantly lower than 0.0% CT groups. Plasma total lipid, triglyceride, total cholesterol concentrations in all groups were not significant by experimental compound. HDL-cholesterol concentrations in -L + P +2.5% CT group were highest in -L + P groups. Levels of hepatic total lipid, triglyceride and total cholesterol in 2.5% CT groups were tend to be lower those than in 0.0% CT groups regardless of dietary lysine limitation and pivalate intake. Fecal total lipid excretions of 2.5% CT groups were significantly lower than in 0.0% CT groups in all experimental groups. But fecal triglyceride excretions of 2.5% CT groups were significantly higher than 0.0% CT groups regardless of lysine limitation and pivalate. In conclusion, there was no difference on body weight and lipid metabolism by dietary lysine limitation and pivalate intake. And feeding of 2.5% L-carnitine was more effective than feeding of 0.5% L-carnitine and 0.0% L-carnitine in reduction of body weight, body fat and lipid metabolism.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.271-282
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• 1982

The browning development, mainly through the Maillard reaction, occurring in the dried fish meat products during storage causes reduction of the nutritional value due to the loss of the essential amino acid such as available lysine as well as off -flavor resulting in the deterioration of the food quality thus shortening the shelflife. In the work, the changes in the amount of available lysine, extractable nitrogenous compounds (nonprotein-N, amino-N, trimethylamine oxide, trimethylamine, and free lysine) and development of browning were measured to assess the relationship between the shelflife and the quality loss in dried filefish under the steady state conditions (35,45, and $55^{\circ}C;a_{w}'s$ of 0.44 0.52, 0.65 and 0.75 at each temperature) and fluctuating temperature condition of $35/55^{\circ}C$ will. alternating 7 day periods at each water activity. The results indicated that the amount of available lysine and extractable nitrogenous compounds except TMA decreased rapidly with increasing temperatures and water activities while the rate of available lysine and extractable nitrogenous compounds must be involved in the initial stage of brown pigment formation. The available lysine loss of the dried filefish products stored under the fluctuating temperature conditions was greater than that stored under its fixed mean temperature, $45^{\circ}C$. The activation energies for lysine loss obtained from the Arrhenius plot ranged 6.9 to 4.4 Kcal/mol and $Q_{10}$ values at $40^{\circ}C$ were 1.4 to 1.2. The values for browning were 15.7 to 14.4 Kcal/mol and 2.2 to 2.0 respectively. Shelf-life, defined as the time to reach 0.15 O. D./g solid or the limit of off-color deterioration by browning reaction, was extented longer than the halflife of Iysine loss, actually corresponding $75\%$ loss of available lysine. This suggested that the halflife of lysine loss might not be adequate to assess the shelf-life of the food system with high potential of protein, nonproteinous nitrogen compounds, and lipids.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.271-275
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• 2017

The expression of Deinococcus radiodurans dr1558 and pprM genes was examined for enhanced lysine production in recombinant Corynebacterium glutamicum. These genes are known to confer high tolerance to pH and osmotic shock in Escherichia coli. D. radiodurans dr1558 and pprM genes were expressed in C. glutamicum by using 6 synthetic promoters of different strengths, to evaluate the effect of expression efficiency on lysine production. Recombinant C. glutamicum expressing DR1558 under the L26 and I64 promoters showed higher lysine production than that expressing DR1558 under other promoters. Similarly, recombinant C. glutamicum expressing PprM under same promoters (L26 and I64) showed a higher increase in lysine production compared to that expressing PprM under other promoters. In the absence of $CaCO_3$ in the medium, the expression of DR1558 or PprM also increased lysine concentration in C. glutamicum depending on the promoter used. Together, these results suggest that genes involved in radiation tolerance in D. radiodurans can be used to enhance production of amino acids and their derivatives.

• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.101-104
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• 1971

The dye-binding method based on the reaction of acidic orange-G dye with basic groups of protein molecule was investigated to observe its applicability to the determination of protein, basic amino acid and lysine contents in brown rice of several high-protein rice lines. The protein content of rice samples ranged from 7.91 to 10.53% and from 8.93 to 11.96% in terms of wet and dry bases, respectively. The correlation between dye-binding absorbance and protein content in terms of both dry and wet bases was highly significant; their correlation coefficients being $-0.955^{**}\;and\;-0.975^{**}$, respectively. The correlation of dye-binding absorbance lysine and basic amino acids were highly significant and their correlation coefficients were similar. Dye-binding absorbance-lysine showed a lower correlation than dye-binding absorbance-protein but a higher correlation than protein-lysine.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1242-1253
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• 2023

The present study aimed to investigate the feasibility of using a diet low in lysine content as a means for increasing the intramuscular fat (IMF) content and pork muscle quality of finishing pigs. Thirty-two crossbred gilts and barrows weighing approximately 80 kg were fed either a low-lysine diet (0.60%; Low-lys) or a control diet (0.80% lysine; Med-lys) under a 2 × 2 factorial arrangement of treatments. The animals were slaughtered at a 132-kg body weight (BW) on average, followed by physicochemical analyses and sensory evaluation on Longissimus lumborum (LL) and Semitendinosus (ST) muscles. The average daily gain (ADG) did not differ between the Med-lys and Low-lys groups. However, ADG exhibited a tendency of sex × diet interaction (p = 0.09), being greater for barrows vs. gilts on the Low-lys diet (p < 0.05), but not on the Med-lys diet. Backfat thickness adjusted for 132-kg BW also exhibited the interaction; it was greater for the Low-lys vs. Med-lys group within gilts but tended to be less for the former in barrows (p = 0.08). The IMF content was not influenced by the diet or sex in either LL or ST. The a^*, b^*, and Warner-Bratzler Shear Force values and fatty acid composition were influenced by the sex or diet in either or both of the muscles, but the treatment effects did not apparently influence the meat quality. Sensory scores for the flavor, juiciness, tenderness, umami, and palatability of cooked muscle were not influenced by the diet in either LL or ST. When the LL and ST data were pooled, scores for those sensory attributes were positively correlated with the IMF content, which was associated with overall greater IMF contents and greater sensory scores for ST vs. LL. Collectively, the Low-lysine diet seemingly elicited the intended lysine deficiency in gilts as indicated by the increased BFT due to the diet. However, the Low-lys diet was not effective for increasing the IMF deposition or eating quality of the pork muscle of finishing pigs slaughtered at high BW probably because its lysine content was not low enough to elicit either outcome.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.22-29
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• 1975

Conditions for submerged culture of Agaricus campestris var. bisporus and the chemical composition of its mycelium were investigated. In shaking culture with TGY basal medium at $27{\sim}30^{\circ}C$, pH tended to increase upon culture period, mycelial growth was the highest on 12th day, with relatively high nitrogen content of 7% and sugar in the medium disappeared almost at the end of culture period. As a nitrogen source, ammonium phosphate (dibasic) gave relatively high mycelial yield and the addition of yeast extract gave rise to better results. As a carbon source, glucose was the best, fructose, maltose, lactose and sucrose gave the same results, and soluble starch was utilized slightly. Mushroom mycelium contained 48% of protein, 8 free amino acids including arginine, histidine, lysine, isoleucine, leucine, phenylalanine, proline, tyrosine and its protein consisted of most essential amino acids, with relatively high contents of lysine and threonine. Therefore, mushroom mycelium deserves to be a high quality protein food.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1199-1202
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• 2011

Infection of surgical wounds is a severe problem. Conventional tissue reattachment methods have limits of incomplete sealing and high susceptibility to infection. Medical adhesives have several advantages over traditional tissue reattachment techniques, but still have drawbacks, such as the probability of infection, low adhesive strength, and high cytotoxicity. Recently, a new medical adhesive (new-adhesive) with high adhesive strength and low cytotoxicity, composed of aldehyded dextran and ${\varepsilon}$-poly(L-lysine), was developed. The antimicrobial activity of the new-adhesive was assayed using agar media and porcine skin. In the agar diffusion method, inoculated microorganisms that contacted the new-adhesive were inactivated, but this was not dependent on the amount of new-adhesive. Similar to the agar media results, the topical antimicrobial effect of new-adhesive was confirmed using a porcine skin antimicrobial assay, and the effect was not due to physical blocking based on comparison with the group whose wounds were wrapped.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1326-1335
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• 2005

The main purpose of this study is to investigate the effects of dietary lysine deficiency on protein turnover of porcine muscles. There were 18 LYD three-breed-crossing postweanling barrows from six litters cannulated with gastric tubes through the esophagus at approximate 10 kg of body weight and allocated into three treatment groups. When their body weights reached over 12 kg, one group was sacrificed for determining the initial protein masses of m. masseter, m. longissimus dorsi, m. adductor and m. biceps femoris from the right body side. The others received a diet containing 100% or 61.4% (calculated values) of the lysine requirement (NRC, 1998) multiplied by 1.103 for a period of 17 days. Daily feed provision was computed for each pig according to body weight at the same day. All pigs were infused a flooding dose of $^2$H$_5$-phenylalanine to determine the fractional protein synthesis rates (FSR) of the aforementioned muscles in the end. Their four muscles from the right body side were also dissected for measuring the fractional rates of protein accretion (FAR). As for protein degradation, fractional rates (FDR) were calculated by differences between synthesis and accretion. Results showed that the lysine deficiency resulted in, significantly (p<0.05), lighter body weights, smaller muscles and a slower growth rate. The protein mass, accreted by the muscles, of the deficient group was only 54% averaged of the pigs fed adequately (p<0.05). The FAR of these muscles in the deficient group was significantly lower (p<0.05) and only achieved 61.1% averaged of the control; there was no significant difference (p>0.05), nevertheless, in the amino-acid composition of muscles between two groups. The lysine deficiency reduced significantly (p<0.05) the FSR of m. longissimus dorsi but did not influence its FDR. The m. biceps femoris also presented an inhibited FSR while its FDR reduced only exhibited a very high tendency (p = 0.055) compared to the adequately-fed pigs. As for the m. masseter and m. adductor, both of the FSR and FDR were depressed significantly (p<0.05) by the lysine deficiency, and changes in the FSR were severer than those in the FDR, so that their FAR were significantly slower (p<0.05) in comparison with the control group. The lysine deficiency also inhibited the RNA translation activity of the muscles while the effects on RNA capacity were not significant (p>0.05). In conclusion, the FAR of muscle protein was changed by the current lysine deficiency through the alterations in the FSR and/or FDR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.481-486
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• 2017

The content of $N^{\varepsilon}$-(carboxymethyl)lysine (CML), an advanced glycation endproduct, in stir-fried anchovy prepared under different cooking conditions was determined, along with their sensory properties. The aim of the study was to optimize cooking conditions of stir-fried anchovy for minimal CML production by using different sugars, sugar concentrations, pH levels, and cooking times. The results showed that CML content increased with increasing sugar concentration. Cooking time did not affect CML content but lowering the pH with lemon juice decreased it significantly. The CML content of samples with a high sugar concentration, and without lemon juice was $4.67{\mu}g/mL$, and that of samples with both a low sugar concentration and lemon juice was $2.49{\mu}g/mL$, indicating a 47% reduction in the CML content of sir-fried anchovy. We conclude that stir-fried anchovy cooked with less sugar and the addition of lemon juice can reduce CML content while maintaining sensory characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.5
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• pp.413-423
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• 1990

Corn proteins have been known as nutritionally poor, being deficient in the essential amino acids. lysine and tryptophan. Improving the quality of protein in the corn grain would be a great benefit to the farmer. This study was conducted to evaluate the variation of the protein content and the protein constitution of the maize germplasms in the Crop Experiment Station in 1989. The average protein content of 101 germplasms was 11.5% with range from 8.0% to 17.3%. Elite hybrid field corns and table corns possessed 9.1-13.9% protein for the dried whole kernel. Major amino acids were glutamic acid and leucine. Lysine and methionine were limited. Varietal differences were observed in the amino acid composition. Qpm, a modified opaque-2 mutant had 1.4-1.7 times higher lysine content than Suwon 19, a dent corn and Suwon SS-21, a sweet corn. Suwon SS-21 had high threonine content. Maize seed protein gave three fractions. an alchol-soluble fraction (zein), an alkali-soluble fraction (glutelin), and a salt-soluble fraction (globulin) by the Osborne method. The zein fraction accounted respectively for 50.7% and 41.7% of the total protein is Suwon 19 and Suwon SS-21. The nonzein fractions increased in percentage of total protein in Qpm kernels. The amino acid composition of zein fraction from three types maize endoperms of dent, sweet and opaque-2 was essentially identical. Zein contained the high contents of glutamic acid and leucine but low content of lysine. The glutelin fractions of three types maize endosperms were mainly similar in overall amino acid composition. The lysine content of glutelin was higher than that of zein. The amino acid composition of globulin fraction was some different from those of zein and glutelin In Qpm it had higher levels of histidine and lysine than both of zein and glutelin. The increased lysine content in Qpm was resulted from changing the proportions of proteins which contained different levels of lysine.