• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1427-1437
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• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1444-1452
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• 2007

An in vitro experiment was conducted to evaluate the differences in microbial activity of five faecal inocula from weaned pigs and one faecal inoculum from unweaned pigs in combination with 6 substrates. The substrates tested were negative control diet, corn, soybean meal, oligofructose (OF), ground chicory roots and a mixture (60% chicory pulp and 40% OF). The inocula used were derived from pigs fed either a corn-soy based diet without antibiotics (NCON), the NCON diet supplemented with oligofructose (OF), a mixture of chicory pulp (40%) and OF (60%) (MIX), ground chicory roots (CHR) or the NCON diet supplemented with antibiotics (PCON). The cumulative gas production measured fermentation kinetics and end products, such as total gas production, ammonia and volatile fatty acids, were also determined. Both the substrate and the inoculum significantly affected the fermentation characteristics. The cumulative gas production curve showed that different substrates caused more differences in traits of fermentation kinetics than the different inocula. Inocula of weaned pigs gave a significantly higher VFA production compared to the inoculum from unweaned animals, whilst the rate of fermentation and the total gas produced did not differ. OF showed the highest fermentation kinetics and the lowest $NH_3$, pH and OM loss compared to other substrates. It was concluded that the microbial activity was significantly affected by substrate and inoculum. Inoculum from weaned pigs had more potential for microbial fermentation of the carbohydrate ingredients and oligofructose than that of unweaned pigs. A combination of high and low polymer inulin may be more beneficial to the gut ecosystem than using high- or low-polymer inulin alone.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.327-333
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• 1988

For optimal production of recombinant human interleukin-2 (IL-2) in E. coli the effect of fermentation conditions on cell growth, IL-2 production, and stability of recombinant cells were investigated. Among the complex nutrients tested in this work, yeast extract, peptone and corn steep liquor were found to be effective for recombinant cell growth. The recombinant cells were maintained stably under repression condition (3$0^{\circ}C$), but the stability of recombinant cells were drastically reduced upon induction of IL-2 expression (42$^{\circ}C$) even under the selection pressure. Addition of antibiotics to the culture medium resulted in the cell growth inhibition without significant improvement in recombinant stability. When the expression of IL-2 gene was induced at different growth phases, highest IL-2 production was achieved by the induction of IL-2 at the middle-exponential growth phase. It was found that the production of IL-2 significantly inhibited the cell growth and the ex-pression of other genes in the plasmid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.779-784
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• 1995

The effective production of 5'-GMP(5'-Guanylic acid) by immobilized 5'-GMP producing fusant RC102(intergeneric protoplast fusion between Brevibacterium ammoniagenes ATCC21263 and Corynebacterium glutamicum ATCC21171) was investigated. The Fusant RC102 was immobilized by entrapping in -carrageenan, agar, polyacrylamide or Ca-alginate. 3% k-carrageenan was selected as the most suitable matrix. In the production of 5'-GMP using the immobilized whole cells of fusant RC102, the optimum conditions were $32^{\circ}C$, pH 8.0, $30\mu\textrm{g}/L\;of\;Mn^{2+},\;1{\times}10^{-6}%\;of\;Zn^{2+}$. In order to use fermentation medium containing CSL(Corn Steep Liquor) plentiful in $Mn^{2+}$, the optimum conditions of penicillin G, D-cycloserine and POESA(polyoxyethylene stearylamine) for production of 5'-GMP were 0.8unit/ml, 0.8unit/ml, 0.8unit/ml and 5mg/ml, respectively. Cationic surfactant, POESA was effective and superior to the antibiotics, penicillin G or D-cyloserine in 5'-GMP productivity. The condinuous fermentation using immobilized fusant RC102 showed that 5'-GMP productivity was stable for more than 15 days.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.402-405
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• 2001

The production of fumaric acid in shaken flask cultures by Rhizopus oryzae KCTC 6946 was studied. The effects of various carbon and nitrogen sources on fumaric acid production were investigated. The strain fermented starch (or glucose) and corn steep liquor (or polypepton) better than other carbon and nitrogen sources to fumaric acid. When C/N ratio of carbon and nitrogen source was 41.7, the concentration of fumaric acid produced with 2N NaGH as a neutralizing agent was more than 10 g/L after 3 days.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.570-576
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• 1993

For the production of glucose-1-phosphate from sucrose, bacteria having sucrose phosphorylase were isolated from Kimchi. Among them, JS-05, newly isolated strain having high activity of sucrose phosphorylase was selected and identified as Leuconostoc sp. The specific activity of sucrose phosphorylase of Leuconostoc sp. JS-05 was the highest when the strain was cultured at 25C for 20 hrs in the medium (pH 7.5) containing 10 g sucrose, 5g corn steep liquor, and 2.5g yeast extract per liter.

• Korean System Dynamics Review
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• v.6 no.1
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• pp.17-32
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• 2005

An agricultural commodity production cycle model consisting of corn, beef, and dairy sectors was constructed for the purpose of exploring the propagating effects of large-scale disruptive events. In an initial proof-of-concept exercise, we considered an agricultural disruption scenario in which foot-and-mouth disease (FMD) is introduced into the U.S., causing a large-scale outbreak of the disease in both beef and dairy cattle. The magnitude of disruption to the beef and dairy sectors are presented under the existing W response policy and then improvements under two alternative policies are shown.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.259-264
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• 1999

A field experiment was carried out to determine the optimum application level of dicamba herbicide for efficient control of Calystegia japonica in silage corn field. Six treatments of application levels (0 ; control, $0.75{\ell},\;1.0{\ell},\;1.25{\ell},\;1.5{\ell},\;and\;2.0{\ell}/ha$) were arranged at National Livestock Research Institute, RDA, Suwon in 1995. The hybrid silage corn was DK 729, and dicamba herbicide was applied at 5~6 leaf stage of corn. The growth of corn was poor in control plot, and the days for tasseling and silking were delayed 1~4 days when compared with the plots of herbicide application. The control efficiency of Calystegia japonica was excellent as 74.3~94.6% in the plots of dicamba application. A slight injury of herbicide was observed at early stage of corn when applied at $1.25{\ell}$ and $1.5{\ell}$ of dicamba per ha, and severe injury was found at $2.0{\ell}$ of dicamba. Forage dry matter(DM) yield, and length of ear in the plots of dicamba treatments were significantly higher than those of control. The DM yield of control(4,866kg/ha) was only about 30% of dicamba treatment plot (14,960~16,340kg/ha). However, there was no yield difference among dicamba application level. The percentage of ear to total DM yield was ranged from 33.6 to 39.4%. With application of herbicide, the contents of crude protein and nitrogen free extract were increased, and that of crude fiber was decreased in stover. However, nutritive value of corn ear was very similar among all treatments, regardless of herbicide treatment. From the above results, it is recommended that optimum application level of dicamba herbicide was $0.75{\sim}1.0{\ell}/ha$ for efficient control of Calystegia japonica and for silage corn production without herbicide injury.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.215-228
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• 1977

In order to provide good germplasm for developing good corn hybrids, a total of 948 Korean indigenous corn lines were collected from various parts of country and major morphological characterstics of ears were investigated. The results obtained were as follows; 1) Ear Type; From the east-north mountaionus region where more than 80% of total corn production is practiced, cylinder (type I) or similar types to cylinder corn were collected, and from the southern plain region, where rather small scales of corn is grown, cone type (type IV) or similar types to cone were prevalent. 2) Kernel color; In the ear colors of all the indigenous corn lines collected from ten regions, ears with mono color were 54.4%, ears with two color mixed were 39.0% and ears with three or more color mixed were 6.6%. In northern mountainous region, region A and region I, ear color was mostly white or white plus other colors, while in other regions ear color was yellow or yellow plus other colors. 3) Denting; Dent type was only 4.3% of Korean indigenous corn lines collected, and others were flint type. Dent type was collected from northern regions, where foreign corn varieties were introduced and grown. 4) Ear row number; Ear row numbers of indigenous corn lines collected were 12 to 16. There was no significant differences among the ear row numbers in a ear ciassified by regions. However, it was observed that ear row number was closely related to kernel size. For instance, the ears with 24 ear-rows were the smallest in kernel size. 5) Quality of starch; 70.9% of the indigenous corn lines collected were kernels with hard starch. Corn with soft starch was 26.0% and medium type was 3.1%. In region A and region I, where lot of corn is grown, corn with hard starch was more frequently collected. 6) Pop corn and waxy corn; In all the indigenous corn lines collected, popcorn was distributed uniformly through the regions except region I, and waxy corn was found more in the northern mountainous region. 7) Ear length; The mean ear length of indigenous corn lines collected was 13cm. In region A and region I ear length was larger than that in other regions. 8) Ear diameter; The mean ear diameter of indigenous corn lines collected was 3.3cm. In region A and region I ear diameter was larger than that in other regions. 9) Kernel length, kernel width and kernel thickness; The mean kernel length, kernel width and kernel thickness of indigenous corn lines collected were 0.82cm, 0.42cm, and 0.78cm, respectively. The kernel size in the region A and region I was larger than that in other regions. 10) Ear weight; The mean ear weight of indigenous corn lines collected was 58.04gr. Ear weight was remarkably heavier in region A and region I. The heaviest ear weighed 330gr, and the lightest ear weighed 5 gr. 11) Kernel weight of a ear and 100 kernel weight; Kernel weight of a ear and 100 kernel of indigenous corn lines collected were 47.07gr and 15.07gr, respectively. Kernel weights and 100 kernel weights were much heavier in region A and region I than other regions.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1152-1159
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• 2013

Four male lambs (Katahdin; average live weight $25.9{\pm}2.9$ kg) with "T" type cannulas in the rumen and proximal duodenum were used in a $4{\times}4$ Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p<0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p<0.01). Replacing corn with DDGS increased (linear, $p{\leq}0.02$) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs.