• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.201-209
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• 2016

Theoretical maximum methane yield of glucose at STP (1 atm, $0^{\circ}C$) is 0.35 L $CH_4/g$ COD. However, most researched actual methane yields of anaerobic digester (AD) on lab scale is lower than theoretical ones. A wide range of them have been reported according to experiments methods and types of organic matters. Recent year, a MET (Microbial electrochemical technology) is a promising technology for producing sustainable bio energies from AD via rapid degradation of high concentration organic wastes, VFAs (Volatile Fatty Acids), toxic materials and non-degradable organic matters with electrochemical reactions. In this study, methane yields of food waste leachate and sewage waste sludge were evaluated by using BMP (Biochemical Methane Potential) and continuous AD tests. As the results, methane production volume from the anaerobic digester equipped with MET (AD + MET) was higher than conventional AD in the ratio of 2 to 3 times. The actual methane yields from all experiments were lower than those of theoretical value of glucose. The methane yield, however, from the AD + MET occurred similar to the theoretical one. Moreover, biogas compositions of AD and AD + MET were similar. Consequently, methane production from anaerobic digester with MET increased from the result of higher organic removal efficiency, while, further researches should be required for investigating methane production mechanisms in the anaerobic digester with MET.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.55-64
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• 1995

A wastewater purifying system using phototrophic bacterium, Rhodopseudomonas capsulata, is currently in operation in several countries, One of them, is a continuously aerated bioreactor(CABR) system, which treats concentrated swin wasterwater using small amounts of phototrophic bacteria as additive bacterial seeding. Using this plant, total biochemical oxygen demand was decreased to 13%, and most of volatile fatty acids were removed. About 40% of the wastewater(Influx) was evaporated during aerobic digestion for 24h, and 60% of that erupted in a decodorized foam(Efflux). The efflux had enough nutrients, N, P and K kor growing plant, as well as organic matters. When the efflux was applied to Italian ryegrass with high dose, fresh shoot and root weights were significantly greater, and $NO_3-N$ contents of the dried shoot were lower than those of control plant (CDU). These results indicate that the CABR plant is useful for reduction and deodorization of swine wastewater and the efflux from CABR can be used for crop production as an organic fertilizer.

• Animal Bioscience
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• v.35 no.1
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• pp.29-38
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• 2022

Objective: The objective of this study was to compare the feeding value, meat nutrients and associative effects of a diet comprised of various corn silages inclusion with peanut vine or wheat straw in finishing beef cattle. Methods: One hundred and eighty Simmental crossbred beef steers were blocked and assigned to the follow treatments: i) whole plant corn silage-based diet (control, WPCS), ii) mixed forages-based diet (replacing a portion of corn silage with wheat straw, WPCSW), iii) corn stalklage-based diet (CS), and iv) sweet corn stalklage-based diet (SCS). Each group consisted of 5 repeated pens with 9 steers/pen. The diets were formulated to be isonitrogenous and isoenergetic with same forage to concentrate ratio. Experimental diets were fed for 90 d. Results: The effective ruminal degradability of dry matter and crude protein were highest for WPCS diet (p<0.05), for neutral detergent fiber was highest in SCS diet (p<0.05). The average daily gain was greater for cattle offered the WPCS diet, intermediate with WPCSW and SCS and lowest with CS (p<0.001). The concentration of non-esterified fatty acid in serum was higher for steers fed with CS and SCS diets than those offered WPCS and WPCSW steers (p<0.001). The treatments did not affect the general nutritional contents and amino acids composition of Longissimus dorsi of steers (p>0.05). Conclusion: The corn silage-based diet exhibited the highest feeding value. The sweet corn stalklage and wheat straw as an alternative to corn silage offered to beef cattle had limited influence on feeding value and meat nutrients. However, the value of a corn stalklage-based diet was relatively poor. To sum up, when the high quality forage resources, such as corn silage, are in short supply, or the growth rate of beef cattle decreases in the later finishing period, the sweet stalklage and wheat straw could be used as a cheaper alternative in feedlot cattle diet without sharp reducing economic benefits.

• Animal Bioscience
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• v.34 no.9
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• pp.1466-1478
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• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.759-768
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• 2005

The study was designed to estimate the in vitro rumen by-pass rate of both chromium methionine chelate as an organic supplement and $ClCl_3$ as an inorganic supplement. Rumen by-pass rates of the supplements were evaluted by comparing ruminal metabolites in rumen fluid and Cr and methionine contents in the body of ruminal microorganism. For in vitro digestion examination, basic nutrients for ruminal microbes were supplied with 7g(DM) of feed, 2g of rice straw, and 2g of corn silage per each incubation jar. Three treatments including Control(no supplementation of Cr), T1(1000ppb supplementation of $ClCl_3$) and T2(chromium methionine chelate supplementation equivalent to 1000ppb of Cr content) were prepared with five replications per each treatment. pH of T2 was lower than that of Control and T1 regardless of incubation time. Ammonia content was higher in T2 than in Control and T1 during first 6 hours of incubation. However, the ammonia content in Control was remained low after 6 hours. Total volatile fatty acids(VFA) content in control was increased constantly as incubation time was extended. Therefore, VFA content in T1 and T2 were significantly lower (P<0.05) than those of Control. Dry matter recovery rate by ruminal microorganism was the lowest in T1, however ruminal microbial population was increased most efficiently in T2 during 12 hours of in vitro incubation. Cr concentrations in the body of ruminal microbes were not different(P>0.05) between Control and T2, but it was significantly high in T1(P<0.05). Contents of methionine and cystine in ruminal microbes also were not different between Control and T2(P>0.05), but it was relatively low in T1. Based on the above results, the chromium methionine chelate was believed to by-pass rumen and could remain intact until it reaches small intestine compared to inorganic chromium. This results implies that chromium methionine chelate could be more effective to function in the small intestine of ruminant animals.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.947-956
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• 2004

The primary role of lipoprotein lipase(LPL) is the hydrolysis of triglycerides(TG) from the core of triglyceride-rich lipoproteins such as chylomicrons and very low density lipoproteins in plasma. Fatty acids liberated by LPL on capillary endothelial surfaces are available for tissues as energy sources especially in muscles or for storage in the form of TG in adipose tissues. Therefore, as the candidate gene related to the carcass traits of the beef cattle, we have directly sequenced the exon 5${\sim}$exon 6 region in the bovine LPL gene for discovery of single nucleotide polymorphism(SNP) with 24 unrelated Hanwoo(Korean cattle). Novel eight sequence variants were detected: three loci on exon 5, three on intron 5 and two on exon 6. All SNPs identified were strongly linked each other, and one hundred twenty eight Hanwoo samples were genotyped one SNP on intron 5 using PCR-restriction fragment length polymorphism method by digestion with Hae III restriction enzyme. The allele frequency of the polymorphism was 0.76 and 0.24. The effects of this polymorphism on the breeding values of the carcass weight, loin muscle area, back fat thickness and marbling score were analyzed using least square methods of SAS GLM. The marbling score of BB genotype was significantly higher than those of AA and AB genotypes(P<0.05). This result indicates that this polymorphism may be associated with the variation of marbling score. Further study is warranted to investigate the phenotypic association in Hanwoo.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.362-368
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• 2018

Grasshoppers play vital role in the digestion of photosynthetically fixed carbons. With the aid of intestinal microflora, the grasshopper can degrade leaves constituents such as cellulose and hemicellulose. The purpose of this study was to examine cellulolytic yeast isolates from the gut of grasshoppers collected in Gyeonggi Province, South Korea. Among the yeast isolates, ON2, ON17 (two strains), and ON6 (one strain) showed positive cellulolytic activity in the CMC-plate assay. The sequence analyses of D1/D2 domains of the large subunit rDNA gene and the internal transcribed spacer (ITS) regions revealed that the strains ON2 and ON17 were most closely related to Papiliotrema aspenensis CBS $13867^T$ (100%, sequence similarity in D1/D2 domains; 99.4% sequence similarity in ITS) and strain ON6 related to Saitozyma flava (100% in D1/D2 domains; 99.0% in ITS). All these three yeast strains are capable of degrading cellulose; therefore, the members of endosymbiotic yeasts may produce their own enzymes for carbohydrate degradation and convert mobilized sugar monomers to volatile fatty acids. Thus, the endosymbiotic yeast strains ON2, ON17 (represents the genus Papilioterma) and ON6 (Saitozyma) belonging to the family Tremellomycetes, are unreported strains in Korea.