• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.402-406
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• 2014

The present study was carried out to evaluate the potential of lignocellulosic byproducts for the production of citric acid through solid-state fermentation by Aspergillus niger NRRL 567. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation conditions and media constituents. The results obtained from the optimization indicated that $30^{\circ}C$, 70% moisture content, 0.5~1.0 mm particle size, pH 5.5 and 4% methanol were found to be the optimum condition at 72 hr fermentation. The application the optimization resulted in an improvement of maximum citric acid production from 74.5 to 206.0 g/kg dry material (DM) from wheat straw. The optimal condition was used to produce citric acid from A. niger grown on different lignocellulosic byproducts, including wheat straw, corn stover and peat moss. A. niger produced the highest citric acid levels of 231.8, 213.8 and 240.2 g/kg DM at 120 hr fermentation, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.2
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• pp.159-164
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• 1996

Food intake of birds can be affected by particle size as well as diet composition, In order to investigate whether food intake of diets including excessive amount of phenyalanine(Phe) was influenced by diet types. a series of experiments were conducted in growing chicks and laying hens. Growing chicks significantly decreased food intake in a semipurified excessive Phe diet compared with a semipurified control diet, while laying hens fed a practical diet including excess Phe did not significantly reduce their food intake over a corn starch-substituted control diet. In an attempt to find out whether diet type affects food intake in layers, the semipurified type diet with excess Phe greatly reduced food ingestion, but the effect was delayed in the practical type diet. Moreover, under choice feeding regimes between the Phe and either starch, tyrosine(Tyr) or fiber diets in order to investigate whether the decreased food intake in the presence of an excess of dieary Phe in laying hens is involved in the palatability for the diet, there was no significant difference between Phe and starch diet while a preference for the Phe diet tended to be increased when birds were offered Tyr. Laying hens ingested significantly more the Phe diet than the fiber diet within 1 h after feeding. For supporting the idea that preference for the Phe diet may be affected by manipulating taste sense, an anaesthetic or saline was intramuscularly administered under the tongue just before a choice feeding. Preference for the Phe diet was not significantly different from that for the fiber reference diet within 1 h in the anaesthetized birds while the birds preferred the Phe diet in the saline treated group. It is suggested that because birds are able to select a diet, the decreased food intake induced by dietary excess Phe may be due to the repulsive effect of Phe after ingestion but not the taste of Phe.

• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.147-153
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• 2008

This experiment was conducted to investigate the feed value of Phellinus linteus meal. The chemical composition and particle size of Phellinus linteus meal was determined, and investigated the effect of partial substitution(0, 5, 10 and 20%) of dried Phellinus linteus meal on metabolizability and serum IgG concentration of layers. Crude fiber content of Phellinus linteus meal was higher, and crude protein and crude fat contents were similar level compare to corn, barley, and wheat. Dry matter metabolizability of Phellinus linteus meal was lower in 10 and 20% treatment than those of 0 and 5% treatment significantly(p<0.05). But, Phellinus linteus meal did not affect concentration of serum IgG.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.23-30
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• 2022

This study investigated the characteristics for rice husk pulverization and surface modification of biomass byproducts composed of rice husk, corn extract gourd, wheat bran, and soybean curd. The size of particles of rice husk was at 6.44 ㎛ and represented the most affordable material for preparing the bio-degradable film among the tested byproducts. The silane treatment and adding 2% of ESO (Epoxidized soybean oil) and 3-aminopropyl triethoxysilane solution mixed in a 1:1 ratio were best to the surface modification and SEM-based particle shape. Above the results, adding 2% of mixed solution after silane treatment of rice husks processed through an air classifying mill (ACM) allows for its use as a raw material of bio-degradable plastic film.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.411-415
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• 2009

Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.428-438
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• 2014

Functional effects of cauliflower mushroom (Sparassis latifolia) have been magnified by various media and internal and external research papers, recently. So, optimum condition of wood chip particle size and cultivation method of high ${\beta}$-glucan content for bulk cultivation generalization of cauliflower mushroom farms researched. As a result, T7 (1~2 mm 25%, 2~4 mm 50%, over 4 mm 25%) media as mixed media of certain ratio of particle size, showed excellent growth at $11.5{\pm}1.0$ cm / 44 days. Also, production of fruit body found higher than control and marketable pileus part took 85% ratio. The ${\beta}$-glucan content at media composition condition showed 1.4~2.4 times higher content in stipe part than pileus part. Also, PCF300 medium found 59.5% highest ${\beta}$-glucan content in stipe part. While ${\beta}$-glucan content showed 33.0% low content in pileus part. Therefore it needed additional study that ${\beta}$-glucan content improved in pileus part. In conclusion, production of high ${\beta}$-glucan content cauliflower mushroom was possible by T7 condition (wood chip particle size: 1~2 mm 25%, 2~4 mm 50% and over 4 mm 25%, composition: corn powder, flour and 300 ppm yeast).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.586-594
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• 1996

This study was designed to determine the level of soybean meal (SM) that could be substituted for fish meal in the diet for Korean rockfish (Sebastes schlegeli). A control diet with white fish meal as only protein source was included, SM was substituted at levels of $5\%,\;10\%,\;15\%,\;and\;20\%$ for portions of the fish meal in the diet. Amino acids (met+lys) supplementation and two different SM particle sizes (0.5 mm and 0.25 mm) in the $20\%$ SM diet were compared. In addition, combination of $10\%$ SM, $10\%$ corn gluten meal (CGM) and $10\%$ meat and bone meal (MBM) was substituted for the fish meal in the diet. Duplicate groups of the 30 fish averaging 22.9 g were fed one of 8 isoproteic $(48\%)$and isolipidic $(7.5\%)$ experimental diets to satiation twice a day for 9 weeks. No significant differences were found among fish fed the control, substituting up to $20\%\;SM,\;20\%$ SM containing amino acids, and $10\%\;SM+10\%\;CGM+10\%$ MBM diets in weight gain, feed efficiency, daily feed intake, and protein retention (P>0.05). Feed efficiency, daily feed intake and protein retention in fish fed the diet containing $20\%$ SM with 0.5 mm particle size were not significantly different to those in fish fed the diets containing less than $20\%\;SM\;(P>0.05)$, however, weight gain was significantly lower than that of the control and $5\%\;SM\;diets\;(P<0.05)$. It is concluded that SM ran be used as a partial substitute for fish meal up to $20\%$ in the diet, and that the inclusion of SM with an adequate combination of several protein sources can replace larger amounts of fish meal in the diet.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.9-16
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• 2022

Rice is one of the most important staple foods in Wnju, Jeonbuk, South Korea. However, rice consumption has dramatically decreased as eating habits have diversified owing to rapid economic growth. Recently, floury endosperm rice varieties have been developed to invigorate the rice processing industry, because dry-milled rice flour is economically and environmentally suitable for massive rice flour distribution. The National Institute of Crop Science has developed 'AromaT', an early-maturing black rice with floury-endosperm, suitable for tea and dry milling. 'AromaT' was derived from a cross between 'Suweon542' as the floury endosperm source and 'Heugjinju' as the black and aromatic source. In this study, 'AromaT' and its parents, 'Suweon542' and 'Heugjinju', were analyzed for agronomic traits, anthocyanin content, and their major physicochemical properties by different planting date. The field experiment was conducted in Wanju, Jeollabuk-do Province, South Korea, in 2019. The transplanting dates were May 30 (ordinary season), June 25 (double-cropping season), and July 10 (late season). The yield performance of brown rice 'AromaT' was 330 kg/10 a in the double-cropping cultivation method and was the highest among the transplanting dates. The floury endosperm of 'AromaT' was derived from 'Suweon542' containing 'flo7', located on chromosome 5 and known to control floury endosperm. With the late planting date, the anthocyanin content of 'AromaT' was 570.5 mg/100 g, much higher than that of 'Heugjinju' (376.3 mg/100 mg). The brown rice of 'AromaT' also exhibited the pop-corn-flavoring 2-acetyl-1-pyrroline, exclusively detected in aroma rice varieties. The average particle sizes of 'AromaT' and 'Suweon542' were 67.12 ㎛ and 70.9 ㎛, respectively, lower than that of 'Heugjinju' (95.5 ㎛) with a black transparent endosperm. The average damaged starch content of 'AromaT' was 8.1%, lower than that of 'Heugjinju' (10.05%) and Suweon542 (9.5%). As a result, 'AromaT' with high anthocyanin content, fine particle size, and low damaged starch content is expected to provide a new rice material in various processing fields.