• Journal of agriculture & life science
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• v.45 no.3
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• pp.69-79
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• 2011

This study was conducted to estimate effects of by-products of medical herbs replacing rice straw on in vitro fermentation characteristics. Each trial was composed of five treatments including medical herbs : rice straw (%) = 20 : 80 (T1), 40 : 60 (T2), 50 : 50 (T3), 100 : 0 (T4) and the control. Each treatment had eight fermentation times (3, 6, 9, 12, 24, 36, 48 and 72 hours) with three replications. The gas production and DM degradation were significantly (P<0.05) increased by supplementation, especially T4, during the whole fermentation periods. Methane production increased along with addition of by-products similar to the gas production and DM degradation. The pH values ranged from 5.39 to 6.80 and were significantly (P<0.05) decreased by supplementation of by-products of medical herbs. Microbial growth rates reached the peak at between 36 and 48h, thereafter tended to decrease. Although there were no significant differences in the enzyme activities, there was a tendency of increase in T4 treatment. From above results, the replacement levels, particularly 100% replacement of rice straw by by-products of medical herbs, resulted in improving the in vitro fermentation characteristics such as increasing gas production, microbial growth and DM degradation. Also it may help digestion by increasing enzyme activities.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.625-634
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• 2004

The objective of this experiment is to study the possibility of lactate dehydrogenase(LDH) enzyme to prevent lactate accumulation in the rumen, For understanding capacity of bacterial LDH in rumen environments, this study was conducted to explore the effects of temperature, pH, VFAs and metal ions on Lactobacillus sp. FFy111-1's LDH activity, and the LDH activation in rumen fluid accumulated lactate. The optimum pH and temperature of LDH were pH 7.5 and 40$^{\circ}C$, respectively. The LDH activity had a good thennostability at range from 30 to 50$^{\circ}C$. The highest pH stability of the enzyme was at ranges from pH 7.0 to 8.0 and the enzyme activities showed above 64% level of non-treated one at pH 6.0 and 6.5. The LDH was inactivated by VFAs treatments but was enhanced by metal ion treatments without NaCl and $CuSO_4$ Especially, the LDH activity was increased to 127% and 124% of its original activity by 2 mM of $BaCl_2$ and $MnSO_4$, addition, respectively. When the acidic rumen fluid was treated by LDH enzyme of Lactobacillus sp. FFy111-1, the lactate concentration in the rumen fluid was lower compared with non-treated rumen fluid(P<0.05). This lactate reduction was resulted from an action of LDH. It was proved by result of purified D,L-LDH addition that showed the lowest lactate concentration among the treatments(P<0.05). Although further investigation of microbial LDH and ruminal lactate is needed, these findings suggest that the bacterial LDH has the potential capability to decrease the lactate accumulated in an acidic rumen fluid. Also, screening of super LDH producing bacteria and technical development for improving enzyme activity in rumen environment are essential keys for practical application.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.169-180
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• 2020

This study examined the effects of a probiotic complex (PC) containing Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae on growth performance, organ weight, immune parameters, fecal microbial count, and noxious odor in broiler chicks. A total of 216 birds (4-day-old) were fed a basal diet (CON) and a diet supplemented with 0.25% (PC1) and 0.5% (PC2) of PC until 35 days of age. No difference in body weight, feed intake, and FCR was observed among the groups. The intestinal mucosal weight of the PC1 group was greater than that of the CON group without affecting weights of the other organs. Intestinal secretory immunoglobulin A (sIgA) levels in the PC2 group increased significantly (P<0.05) compared with that in the CON group. The PC2 group also had a strong tendency for elevated blood sIgA levels. Dietary PC did not affect the level of interleukin-1β in the blood and mucosal tissues or alter maltase, sucrase, and leucine aminopeptidase activities in the intestinal mucosa. The PC2 group had higher colony-forming units (cfu) for L. plantarum and S. cerevisiae, but lower cfu for E. coli than those in the CON group. Compared to the CON diet, the PC2 diet resulted in a decreased H₂S concentration and a tendency toward decreased CH₃SH concentration. In conclusion, a 0.5% PC diet showed increased sIgA and desirable microbial population, and decreased noxious odor in the feces, suggesting that PC could be applied as an environmentally friendly feed additive in broiler chicks.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.164-168
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• 2014

The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.154-159
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• 2004

Bacillus species were isolated from swine manure to develope the microbial additive suitable for the rapid com-posting. The 3 of 4 isolated strains were identified as Bacillus cereus KD-2, B. pumilus KD-3, and B. licheni-formis KD-4. Bacillus sp. KD-1 was, however, not highly identical with any Bacillus sp. The isolated strains were analyzed their growth rates, enzyme activities, and antibacterial activities. The maximum growth tem-peratures of KD-1, KD-2, KD-3 and KD-4 were $45^{\circ}C$, $50^{\circ}C$, $53^{\circ}C$, and $55^{\circ}C$, respectively. The activities of pro-tease or amylase in mixed culture of 4 strains were similar in the range of $37^{\circ}C$ to $53^{\circ}C$ and activities of lipase in the range of $37^{\circ}C$ to $42^{\circ}C$ were twice higher than those of lipase in the range of $47^{\circ}C$ to $53^{\circ}C$. The antibacterial activity of KD-l, KD-2, or KD-3 against each other was not detected. That of KD-4 against KD-1, KD-2, or KD-3 was, however, detected. The organic compound and C/N ratio of compost fermented by the mixed culture were determined as 61.9% and 22.4%, respectively. The concentration of the ammonia gas was 12.35 mg/l in the liquid compost.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.66-74
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• 2012

The effects of exogenous fibrolytic enzymes (EFE; a mixture of two preparations from Trichoderma spp., with predominant xylanase and ${\beta}$-glucanase activities, respectively) on colonization and digestion of ground barley straw and alfalfa hay by Fibrobacter succinogenes S85 and Ruminococcus flavefaciens FD1 were studied in vitro. The two levels (28 and 280 ${\mu}g$/ml) of EFE tested and both bacteria were effective at digesting NDF of hay and straw. With both substrates, more NDF hydrolysis (p<0.01) was achieved with EFE alone at 280 than at 28 ${\mu}g$/ml. A synergistic effect (p<0.01) of F. succinogenes S85 and EFE on straw digestion was observed at 28 but not 280 ${\mu}g$/ml of EFE. Strain R. flavefaciens FD1 digested more (p<0.01) hay and straw with higher EFE than with lower or no EFE, but the effect was additive rather than synergistic. Included in the incubation medium, EFE showed potential to improve fibre digestion by cellulolytic ruminal bacteria. In a second batch culture experiment using mixed rumen microbes, DM disappearance (DMD), gas production and incorporation of $^{15}N$ into particle-associated microbial N ($^{15}N$-PAMN) were higher (p<0.001) with ammoniated (5% w/w; AS) than with native (S) ground barley straw. Application of EFE to the straws increased (p<0.001) DMD and gas production at 4 and 12 h, but not at 48 h of the incubation. EFE applied onto S increased (p<0.01) $^{15}N$-PAMN at 4 h only, but EFE on AS increased (p<0.001) $^{15}N$-PAMN at all time points. Prehydrolysis increased (p<0.01) DMD from both S and AS at 4 and 12 h, but reduced (p<0.01) $^{15}N$-PAMN in the early stage (4 h) of the incubation, as compared to non-prehydrolyzed samples. Application of EFE to barley straw increased rumen bacterial colonization of the substrate, but excessive hydrolytic action of EFE prior to incubation decreased it.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.293-297
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• 2012

Of the 169 strains of microorganisms stored in Polar and Alpine Microbial Collection of Korea Polar Research Institute, 27 strains were selected for their chitinase activity on ZoBell plates supplemented with 0.4% colloidal chitin. Among them, PAMC 21693 strain have shown the highest chitinolytic enzyme activity toward pNP-$(GlcNAc)_1$ at low temperature and the highest growth rate at $4^{\circ}C$. We cloned a full-length chitinase gene of 2,857 bp which contains an open reading frame of 2,169 bp encoding 872-amino acid polypeptide. Recombinant chitinase protein was expressed in E. coli and its molecular weight was confirmed 96 kDa. In this paper, we suggest the potential use of cold-active chitinase from polar microorganisms in the field of biotechnology.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.109-115
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• 1989

This study was aimed to find out the influence of long-term fertilization for 21 years on soil enzyme activities in the silty clay loam textured normal paddy soil. Total urease activity (TUA) and the microbial urease activity (MUA) were shown to be changed significantly, but the accumulated urease activity (AUA) was similar within trial plots. Especially the MUA of the plots annually applied N.P.K. fertilizers with compost and N.P.K. fertilizers with silicate fertilizer were the highest among plots. The total L-glutaminase activity (TGA) and the accumulated L-glutaminase activity(AGA) were changed significantly among trial plots, but the microbial L-glutaminase activity (MGA) was not. By the simple correlation analysis, it was shown that the TGA and the AGA correlated highly significant to available phosphorus available $SiO_2$ content and pH. Addition of the toluene to the incubation mixture did not markedly affect the activity of phosphatase, but the difference of phosphatase activity among plots was significant. By the simple correlation analysis, it was shown that the phosphatase activity ; correlated highly significant to pH, available $SiO_2$, available phosphorus and exchangeable calcium in soils.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.141-147
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• 2015

Four halophilic bacteria were isolated from a salt water tank of more than 25% above salinity used for production of salt. HJS1 and HJS6 strains were identified as having ${\beta}$-glucosidase producing capabilities at high salinity. ${\beta}$-Glucosidase produced from these bacterial strains showed the best activity at 56-79 U/ml in NaCl (0-5%), showing the highest ${\beta}$-glucosidase activity at NaCl 3%. A salt tolerant ${\beta}$-glucosidase can maintain at least 75% activity of the enzyme in 0-20% NaCl concentration. The 16S rRNA gene sequences of strains HJS1 and HJS6 shows 99.8% similarity with Roseivivax roseus $BH87090^T$. Those sequences were registered as AB971835 and AB971836 in the NCBI GenBank. DNA-DNA hybridization test revealed that both strains showed 90.1 to 90.3% hybridization values with R. roseus $BH87090^T$, which was the closest phylogenetic neighbor. Major Cellular fatty acids of strains HJS1 and HJS6 were $C_{16:0}$, $C_{18:1}$ ${\omega}7c$, $C_{19:0}$ cyclo ${\omega}8c$ and 11-methyl $C_{18:1}$ and the major quinone was Q-10. Their fatty acid composition and quinone were very similar to Roseivivax roseus $BH87090^T$. Meanwhile, Roseivivax roseus $BH87090^T$ did not produce any ${\beta}$-glucosidase. Based on the molecular and chemotaxonomic properties, strains HJS1 and HJS6 were identified as members of Roseivivax roseus.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.272-279
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• 1999

This study was conducted to evaluate possibility for composting by microorganisms in food waste itself. In the result of counting of microorgansm in food waste, the number of bacteria growing at $30^{\circ}C$ and $50^{\circ}C$ were counted $10^5-10^7CFU/g$ and $10^5-10^6\;CFU/g$ in the almost food waste, respectively. Amylase and protease producing microorgansim were counted $10^3-10^7\;CFU/g$ at $30^{\circ}C$ and $50^{\circ}C$. In the result of composting for 30 days, FW1 was reveal that $CO_2$gas production rate and degradation of organic matter were similar to FW2 but higher than that of FW3, FM1 and FM2. Also, In the cases of change of enzyme producing microorgansim during the composting, FW1 were counted $10^5-10^9\;CFU/g$ at $30^{\circ}C$, $50^{\circ}C$ and $60^{\circ}C$ of incubation temperature, while FM1, added to commercial microbial inoculator, were less than that of FM1. Consequently, It was suggested that FW1 was most suitable condition for composting by microorganisms in food waste and there was no need to use microbial inoculator for composting.