• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.132-140
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• 1986

Eighty one products from 36 kinds of vitamin and mineral feed supplement collected during August, 1984 to February, 1985 were examined for microbiological contamination. In addition, 83 strains of coliform isolated from the samples were tested for the resistance to 8 kinds of antimicrobial drugs and distribution of R plasmid. General bacteria were detected in all of samples tested. Bacterial population was varied from less than 10 per gram of the sample to 1,400,000 per gram and 34 (42%) of 81 samples were contaminated with 100 to 1,000 cells per gram. Coliform isolation, which was more frequent in samples with larger number of general bacteria, was possible in 14 (17.3%) out of 81 samples tested and 6 (33.3%) out of 18 companies were coliform positive in their products. Forty one (49.4%) out of 83 coliform isolates were fecal coliform. The frequency of resistant strains was the highest to sulfadimethoxine (Sa) with 92.8% and followed by streptomycin (Sm, 67.5%), tetracycline (Tc, 50.6%), kanamycin (Km, 26.5%), chloramphenicol (Cm, 18.1%) and ampicillin (Am, 15.7%). No strain was resistant to nalidixic acid (Na) and gentamicin (Gm). The resistance frequency of fecal coliform strains were higher compare to non-fecal coliform strains. There were minimum inhibitory concentration (MIC) of $3,200{\mu}g/m{\ell}$ or higher in 7 strains to Am, 3 to Sm and 3 to Km, and 70 strains had MIC of $1,600{\mu}g/m{\ell}$ of higher to Sa while Tc had MICs from $1.6{\mu}g/m{\ell}$ to $400{\mu}g/m{\ell}$. All strains had MICs of $6.3{\mu}g/m{\ell}$ of lower to Na and $3.1{\mu}g/m{\ell}$ of lower to Gm. Seventy nine (95.2%) of 83 strains were resistant to one or more drugs tested. The most frequent resistance patterns were SaSm (14.5%) and followed by SaSmTc(12%), SaSmTcKm(8.4%) SaTc (8.4%) and SaSmKm (7.2%) ; total 19 different patterns were noted. Thirty two (40.5%) of 79 resistant strains were transferred all of a part of their resistance to Escherichia coli ML 1410. The frequency of transferable resistance was high in Am (100%) and Cm (80%) while low in Tc (38.1%), Sa (18.2%), Sm (17.9%) and Km (4.5%).

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.67-91
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• 1983

In order to examine the alcohol production from softwoods (Pinus densiflora Sieb. et Zucc., Pinus rigida Miller, Larix leptolepis Gordon) and hardwoods (Alnus japonica Steud., Castanea crenata Sieb. et Zucc. Populus euramericana CV 214), chemical compositions were analyzed and conditions of acid hydrolysis with wood meals were established. Also strains which could remarkably decompose the cellulose were identified, and conditions of cellulase production of strains, characteristics of cellulase, and alcohol fermentation were examined. The results were summarized as follows. 1) In acid hydrolysis of wood, the high yield of reducing sugars was shown from 1.0% to 2.0% of hydrochloric acid and 2.0% of sulfuric acid. The highest yield was produced 23.4% at wood meals of Alnus japonica treated with 1.0% of hydrochloric acid. 2) The effect of raising the hydrolysis was good at $1.5kg/cm^2$, 30 times (acid/wood meal), and 45 min in treating hydrochloric acid and 30 min in treating sulfuric acid. 3) The pretreatments with concentrated sulfuric acid were more effective concentration ranged from 50% to 60% than that with hydrochloric acid and its concentration ranged from 50% to 60%. 4) The quantative analysis of sugar composition of acid hydrolysates revealed that glucose and arabinose were assayed 137.78mg and 68.24mg with Pinus densiflora, and 102.22mg and 65.89mg with Alnus janonica, respectively. Also xylose and galactose were derived. 5) The two strains of yeast which showed remarkably high alcohol productivity were Saccharomyces cerevisiae JAFM 101 and Sacch. cerevisiae var. ellipsoldeus JAFM 125. 6) The production of alcohol and the growth of yeasts were effective with the neutralization of acid hydrolysates by $CaCO_3$ and NaOH. Production of alcohol was excellent in being fermented between pH 4.5-5.5 at $30^{\circ}C$ and growth of yeasts between pH 5.0-6.0 at $24^{\circ}C$. 7) The production of alcohol was effective with the addition of 0.02% $(NH_2)_2CO$ and $(NH_4)_2SO_4$, 0.1% $KH_2PO_4$, 0.05% $MgSO_4$, 0.025% $CaCl_2$, 0.02% $MnCl_2$. Growth of yeasts was effective with 0.04-0.06% $(NH_2)_2CO$ and $(NH_4)_2SO_4$, 0.2% $K_2HPO_4$ and $K_3PO_4$, 0.05% $MgSO_4$, 0.025% $CaCl_2$, and 0.002% NaCl. 8) Among various vitamins, the production of alcohol was effective with the addition to pyridoxine and riboflavin, and the growth of yeasts with the addition to thiamin, Ca-pantothenate, and biotin. The production of aocohol was increased in 0.1% concentration of tannin and furfural, but mas decreased in above concentration. 9) In 100ml of fermented solution, alcohol and yeast were produced 2.201-2.275ml and 84-114mg for wood meals of Pinus densiflora, and 2.075-2.125ml and 104-128mg for that of Alnus japonica. Residual sugars were 0.55-0.60g and 0.60-0.65g for wood meals of Pinus densiflora and Alnus japonica, respectively, and pH varied from 3.3 to 3.6. 10) A strain of Trichoderma viride JJK. 107 was selected and identified as its having the highest activity of decomposing cellulose. 11) The highest cellulase production was good when CMCase incubated for 5 days at pH 6.0, $30^{\circ}C$ and xylanase at pH 5.0, $35^{\circ}C$. The optimum conditions of cellulase activity were proper in case of CMCase at pH 4.5, $50^{\circ}C$ and xylanase at pH 4.5, $40^{\circ}C$. 12) In fermentation with enzymatic hydrolysates, the peracetic acid treatment for delignification showed the best yields of alcohol and its ratio was effective with the addition of about 10 times. 13) The production of alcohol was excellent when wood meals and Koji of wheat bran was mixed with 10 to 8 and the 10g of wood meals of Pinus densiflora produced 2.01-2.14ml of alcohol and Alnus japonica 2.11-2.20ml.

• Korean journal of applied entomology
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• v.12 no.3
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• pp.93-107
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• 1973

Garlic (Allium sativum L.) is an important vegetable crop for the Korean people and has long been cultivated extensively in Korea. More recently it has gained importance as a source of certain pharmaceuticals. This additional use has also contributed to the increasing demand for Korean garlic. Garlic has been propagated vegetatively for a long time without control measures against virus diseases. As a result it is presumed that most of the garlic varieties in Korea may have degenerated. The production of virus-free plants offers the most feasible way to control the virus diseases of garlic. However, little is known about garlic viruses both domestically and in foreign countries. More basic information regarding garlic viruses is needed before a sound approach to the control of these diseases can be developed. Currently garlic mosaic disease is most prevalent in plantings throughout Korea and is considered to be the most important disease of garlic in Korea. Because of this importance, studies were initiated to isolate and characterize the garlic mosaic virus. Symptom expression in test plants, physical properties, purification, serological reaction and morphological characteristics of the garlic mosaic virus were determined. Results of these studies are summarized as follows. 1. Surveys made throughout the important garlic growing areas in Korea during 1970-1972 revealed that most of the garlic plants were heavily infected with mosaic disease. 2. A strain of garlic mosaic virus was obtained from infected garlic leaves and transmitted mechanically to Chenopodium amaranticolor by single lesion isolation technique. 3. The symptom expression of this garlic mosaic virus isolate was examined on 26 species of test plants. Among these, Chenopodium amaranticolor, C. quince, C. album and C. koreanse expressed chlorotic local lesions on inoculated leaves 11-12 days after mechanical inoculation with infective sap. The remaining 22 species showed no symptoms and no virus was recovered from them whet back-inoculated to C. amaranticolor. 4. Among the four species of Chtnopodium mentioned above, C. amaranticolor and C. quinoa appear to be the most suitable local lesion test plants for garlic mosaic virus. 5. Cloves and top·sets originating from mosaic infected garlic plants were $100\%$ infected with the same virus. Consequently the garlic mosaic virus is successively transmitted through infected cloves and top-sets. 6. Garlic mosaic virus was mechanically transmitted to C, amaranticolor when inoculations were made with infective sap of cloves and top-sets. 7. Physical properties of the garlic mosaic virus as determined by inoculation onto C. amaranticolor were as follows. Thermal inactivation point: $65-70^{\circ}C$, Dilution end poiut: $10^-2-10^-3$, Aging in vitro: 2 days. 8. Electron microscopic examination of the garlic mosaic virus revealed long rod shaped particles measuring 1200-1250mu. 9. Garlic mosaic virus was purified from leaf materials of C. amaranticolor by using two cycles of differential centrifugation followed by Sephadex gel filtration. 10. Garlic mosaic virus was successfully detected from infected garlic cloves and top-sets by a serological microprecipitin test. 11 Serological tests of 150 garlic cloves and 30 top-sets collected randomly from seperated plants throughout five different garlic growing regions in Korea revealed $100\%$ infection with garlic mosaic virus. Accordingly it is concluded that most of the garlic cloves and top-sets now being used for propagation in Korea are carriers of the garlic mosaic virus. 12. Serological studies revealed that the garlic mosaic virus is not related with potato viruses X, Y, S and M. 13. Because of the difficulty in securing mosaic virus-free garlic plants, direct inoculation with isolated virus to the garlic plants was not accomplished. Results of the present study, however, indicate that the virus isolate used here is the causal virus of the garlic mosaic disease in Korea.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.15-15
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• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic?iency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet?ween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr?ease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$$$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea?ses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin?ear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num?ber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco?very rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.221-234
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• 1983

A study was conducted to devise a method to estimate the edible meat weight in live broilers. White Cornish broiler chicks CC, Single Comb White Leghorn egg strain chicks LL, and two reciprocal cross breeds of these two parent stocks (CL and LC) were employed A total of 240 birds, 60 birds from each breed, were reared and sacrificed at 0, 2, 4, 6, 8 and 10 weeks of ages in order to measure various body parameters. Results obtained from this study were summarized as follows. 1) The average body weight of CC and LL were 1,820g and 668g, respectively, at 8 weeks of age. The feed to gain ratios for CC and LL were 2.24 and 3.28, respectively. 2) The weight percentages of edible meat to body weight were 34.7, 36.8 and 37.5% at 6, 8 and 10 weeks of ages, respectively, for CC. The values for LL were 30.7, 30.5 and 32.3%, respectively, The CL and LC were intermediate in this respect. No significant differences were found among four breeds employed. 3) The CC showed significantly smaller weight percentages than did the other breeds in neck, feather, and inedible viscera. In comparison, the LL showed the smaller weight percentages of leg and abdominal fat to body weight than did the others. No significant difference was found among breeds in terms of the weight percentages of blood to body weight. With regard to edible meat, the CC showed significantly heavier breast and drumstick, and the edible viscera was significantly heavier in LL. There was no consistent trend in neck, wing and back weights. 4) The CC showed significantly larger measurements body shape components than did the other breeds at all time. Moreover, significant difference was found in body shape measurements between CL and LC at 10 weeks of age. 5) All of the measurements of body shape components except breast angle were highly correlated with edible meat weight. Therefore, it appeared to be possible to estimate the edible meat wight of live chickens by the use of these values. 6) The optimum regression equations for the estimation of edible meat weight by body shape measurements at 10 weeks of age were as follows. $$Y_{cc}=-1,475.581 +5.054X_{26}+3.080X_{24}+3.772X_{25}+14.321X_{35}+1.922X_{27}(R^2=0.88)$$ $$Y_{LL}=-347.407+4.549X_{33}+3.003X_{31}(R^2=0.89)$$ $$Y_{CL}=-1,616.793+4.430X_{24}+8.566X_{32}(R^2=0.73)$$ $$Y_{LC}=-603.938+2.142X_{24}+3.039X_{27}+3.289X_{33}(R^2=0.96)$$ Where $X_{24}$=chest girth, $X_{25}$=breast width, $X_{26}$=breast length, $X_{27}$=keel length, $X_{31}$=drumstick girth, $X_{32}$=tibotarsus length, $X_{33}$=shank length, and $X_{35}$=shank diameter. 7) The breed and age factors caused considerable variations in assessing the edible meat weight in live chicken. It seems however that the edible meat weight in live chicken can be estimated fairly accurately with optimum regression equations derived from various body shape measurements.