• Korean Journal of Microbiology
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• v.42 no.2
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• pp.160-163
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• 2006

Brown rice contains rice bran and germ with higher nutritional value and dietary fiber content compared with the polished rice. However, brown rice has a limitation of poor digestion. fermented brown rice could be better nutritional source and improve digestibility. Therefore, we tried to select good fermentative microorganisms which have nutritional values with high amylase and protease activities, and probiotic effects. Nineteen micro-organisms, including eight Bacillus strains isolated from Chongkukjang and 11 lactic acid bacteria, were screened for the fermentation ability and enzyme production. The liquid broths containing 2.5%(w/v) of raw brown rice powder as a sole nutritional source were used for culture media. Among the strains tested, all of the Bacillus strains and two lactic acid bacteria (Leuconostoc gelidum and Pediococcus pentosaceus) showed increase in cell population and enzyme activities. The viable cell counts of all the Bacillus strains and two lactic acid bacteria exceeded $10^7 CFU/mL$. The maximal enzyme activities produced by Bacillus sp. Bl, Bacillus sp. B2, Bacillus sp. B11, L. gelidum and P. pentosaceus were 17.85, 17.50, 17.10, 17.10 and 3.24 U/mL for amylase and 22.48, 22.04, 23.76, 12.13, and 3.4 U/mL for pretense, respectively. Therefore, the results of this study demonstrated that the above strains could be potential starters for the fermentation of raw brown rice.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.271-276
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• 2013

A study was conducted to investigate the effect of dietary supplementation of feedstuff of Chlorella (Chlorella vulgaris) to replace of antibiotic in the diets of broiler chickens. A total of 720 1-d-old straight run broiler chicks (Ross ${\times}$ Ross) was randomly assigned into six treatments with four replicate pens (30 birds/replicate pen) for 5-wk. A corn-soy bean meal basal diet was formulated, the treatment groups were negative group (NC, antibiotic-free diet) and 0.1% virginiamycin in as antibiotic growth promoters (PC), 1.0% fresh liquid Chlorella (T1), 1.0% dried Chlorella powder (T2), 1.0% commercial Chlorella product and 1.0% (T3) and commercial Chlorella product 0.5% (T4) were added to the basal diet to form six dietary treatments. No significant differences were found among the treatments for feed intake and feed conversion of broiler chickens during the whole experimental period, but the BW gain was significantly higher (P<0.05) in commercial Chlorella product supplemental groups than the control group (NC and PC groups). Dietary supplementation of Chlorella significantly (P<0.05) increased the plasma IgA, IgM and IgG concentration of chicks compared to NC and PC groups. Supplemental AGPs and commercial chlorella product did not affect the E. coli and Salmonella concentration in the intestinal microflora of broiler chicks; however, the population of Lactobacillus was significantly increased (P<0.05) when birds were fed commercial Chlorella product groups. It is concluded that commercial Chlorella product supplementation could be used as an alternative of antibiotics to promote growth and immune response by increasing the production of lactic acid bacteria in the intestinal microflora of broiler chickens.

• Clean Technology
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• v.21 no.1
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• pp.68-75
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• 2015

In this study, we investigated the structure and properties of a highly heat conductive metal-ceramic core-shell CoAl₂O₄@Al micro-composite for heterogeneous catalysts support. The CoAl₂O₄@Al was prepared by hydrothermal surface oxidation of Al metal powder, which resulted in the structure with a high heat conductive Al metal core encapsulated by a high surface area CoAl₂O₄ shell. For comparison, CoAl₂O₄ was also prepared by co-precipitation method and also utilized for a catalyst support. Rh catalysts supported on CoAl₂O₄@Al and CoAl₂O₄ were prepared by incipient wetness impregnation and characterized by N₂ adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), CO chemisorption, and temperature-programmed reduction (TPR). The properties of catalysts were investigated for glycerol steam reforming reaction for hydrogen production at 550 ℃. Rh/CoAl₂O₄@Al exhibited about 2.8 times higher glycerol conversion turnover frequency (TOF) than Rh/CoAl₂O₄ due to facilitated heat transport through the core-shell structure. The CoAl₂O₄@Al and CoAl₂O₄ also showed some catalytic activities due to a partial reduction of Co on the support, and a higher catalytic activity was also found on the CoAl₂O₄@Al core-shell than CoAl₂O₄. These catalysts, however, displayed deactivation on the reaction stream due to carbon deposition on the catalysts surface.