• Journal of Animal Environmental Science
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• v.17 no.3
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• pp.171-180
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• 2011

The researchers have tried to reduce ruminal methane gas ($CH_4$) and to convert it into beneficial nutrient for several decades. This study was conducted to screen the methane-reducing vegetables among lettuce, hot pepper, spring onion, onion, turmeric, sesame leaf, garlic, radish sprout, leek and ginger nutritiously on the in vitro ruminal fermentation. The heat-treated vegetables at the 10% of substrate (timothy) were used to reduce methane production on the in vitro anaerobic experiment of 0, 6, 12, 24 and 48 h incubation time. Total gas production, pH, ammonia, $H_2$, $CO_2$, $CH_4$, and volatile fatty acid (VFA) were measured as indicators of in vitro fermentation product containing methane gas. All treatments except garlic showed a tendency to increase in total gas production. The result of ammonia showed that garlic and hot pepper affected rumen bacteria concerned protein metabolism and that lettuce and spring onion increased ammonia production. Garlic decreased $CH_4$ production in inverse proportion to $H_2$. Lettuce, spring onion, onion, garlic, radish sprout, leek and ginger increased propionate of VFA. Garlic balanced the ruminal fermentation in the pH, $H_2$, $CH_4$, acetate and propionate. This results showed that methane production at in vitro study was inhibited by heat-treated garlic supplementation. In conclusion, this study suggests that ruminal fermentation covering methane production might be controled by proper vegetables.

• Journal of Life Science
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• v.26 no.10
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• pp.1105-1112
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• 2016

The aim of this study was to examine the metabolic adjustment of lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes to the environmental temperature in bluegill (Lepomis macrochirus). This study included three groups of bluegill collected in April (group Ⅰ), May (group Ⅱ), and September (group Ⅲ). The LDH activities of skeletal muscle, heart, and brain tissues were higher in group Ⅲ than in groups Ⅰ and Ⅱ. The citrate synthase (EC 4.1.3.7, CS) activity was higher in skeletal muscle but lower in heart and brain tissues of group Ⅱ as compared to group Ⅰ. In contrast, the CS activity was lower in skeletal muscle and higher in heart and brain tissues in group Ⅲ than in group Ⅱ. Furthermore, the LDH/CS activity ratio was higher in the skeletal muscle and brain in group Ⅲ than in groups Ⅰ and Ⅱ. Accordingly, anaerobic metabolism was increased in group Ⅲ. LDH A₄, A₂B₂, and B₄ isozymes were expressed in skeletal muscle, heart, liver, and brain tissues. The LDH C hybrid was detected in brain tissue. The LDH A₄ isozyme was successfully purified by affinity chromatography. The molecular weight of the purified LDH A₄ isozyme was 136 kDa and its optimal pH for enzymatic activity was 8.0. The K_m^PYR values of LDH in skeletal muscle were 0.161-0.227 mM using pyruvate as a substrate. These kinetic properties of LDH in skeletal muscle are consistent with the fact that bluegill is a cold-adapted species. These results may be useful for predicting the habitat use of this fish.

• Journal of Life Science
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• v.20 no.2
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• pp.260-268
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• 2010

The lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes in tissues from Channa argus were purified and characterized by biochemical, immunochemical and kinetic methods. The activity of LDH in skeletal muscle was the highest at 380.4 units and those in heart, eye and brain tissues were 13.4, 3,5 and 5.4 units, respectively. Citrate synthase (EC 4.1.3.7, CS) activity in heart tissue was the highest at 20.7 units. LDH/CS in skeletal muscle, heart, eye and brain tissues were 172.9, 0.6, 0.32 and 0.47. Protein concentration in skeletal muscle tissue was 14.7 mg/g and specific activities of LDH in skeletal muscle, heart, eye and brain tissues were 25.88, 0.79, 0.31 and 1.38 units/mg, respectively. Therefore, skeletal muscle tissue was anaerobic and heart tissue was aerobic. The LDH isozymes in tissues were identified by polyacrylamide gel electrophoresis, immunoprecipitation and Western blot with antiserum against $A_4$, $B_4$, and eye-specific $C_4$. LDH $A_4$, $A_3B$, $A_2B_2$. $AB_3$ and $B_4$ isozymes were detected in every tissue, $C_4$, $AC_3$, $A_2C_2$ and $A_3C$ were detected in eye tissue, and $A_3C$ was found in brain tissue. LDH $A_4$, $A_3B$, $A_2B_2$, $AB_3$, $B_4$, eye-specific $C_4$ isozymes were purified by affinity chromatography and Preparative PAGE Cells. The LDH $A_4$ isozyme was purified in the fraction from elution with $NAD^+$ containing buffer of affinity chromatography. Eye-specific $C_4$ isozyme was eluted right after $A_4$, after which $B_4$ isozyme was eluted with plain buffer. As a result, one part of molecular structures in $A_4$, $B_4$ and eye-specific $C_4$ were similar, but were different from each other in $B_4$ and $C_4$. Therefore the subunit A may be conservative in evolution, and the evolution of subunit B seems to be faster than that of subunit A. The activity of LDH $A_4$, $A_2B_2$, $B_4$, and eye-specific $C_4$ isozymes remained at 39.98, 21.28, 19.67 and 16.87% as a result of the inhibition by 10 mM of pyruvate, so the degree of inhibition was very high. The $Km^{PYR}$ values were 0.17, 0.27 and 0.133 mM in $A_4$, $B_4$ and eye-specific $C_4$ isozymes, respectively. The optimum pH of LDH $A_4$, $B_4$, eye-specific $C_4$, $A_2B_2$, $A_3B$, and $AB_3$ were pH 6.5, pH 8.5, pH 5.5, pH 6.0-6.5, pH 5.0 and pH 7.5. The $A_4$ and heterotetramer isozymes stabilized a broad range of pH. Especially, LDH activities in skeletal muscle tissue were high, resulting in a high degree of muscle activity.LDH metabolism in eye tissue seems to be converted faster from pyruvate to lactate by eye-specific $C_4$ isozyme as eye-specific $C_4$ have the highest affinity for pyruvate, and right after the conversion, oxidation of lactate was induced by $A_4$ isozyme. It was found that expression of Ldh-C, affinity to substrate and reaction time of $C_4$ isozyme were different according to the ecological environmental and feeding capturing patterns.