• Journal of Microbiology
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• v.43 no.3
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• pp.301-307
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• 2005

The feasibility of laccase production by immobilization of Pleurotus ostreatus 1804 on polyurethane foam (PUF) cubes with respect to media composition was studied in both batch and reactor systems. Enhanced laccase yield was evidenced due to immobilization. A relatively high maximum laccase activity of 312.6 U was observed with immobilized mycelia in shake flasks compared to the maximum laccase activity of free mycelia (272.2 U). It is evident from this study that the culture conditions studied, i.e. biomass level, pH, substrate concentration, yeast extract concentration, $Cu^{2+}$ concentration, and alcohol nature, showed significant influence on the laccase yield. Gel electrophoretic analysis showed the molecular weight of the laccase produced by immobilized P. ostreatus to be 66 kDa. The laccase yield was significantly higher and more rapid in the packed bed reactor than in the shake flask experiments. A maximum laccase yield of 392.9 U was observed within 144 h of the fermentation period with complete glucose depletion.

• Journal of Mushroom
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• v.8 no.1
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• pp.33-36
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• 2010

The effect of wheat straw mix was tested to develop rice straw replacement media. The chemical contents were analysed after late fermentation. Nitrogen content and C/N ratio of the 20% wheat straw mixing medium were 2.2% and 16.7 and the only rice straw using medium were 2.0% and 17.9, respectively. When the 20% wheat straw mixing treatment was compared to the only rice straw medium, pinhead initiation period was shortened and the yield was increased as much as 30%. Therefore the 20% wheat straw mixing medium is expected to replace the rice straw medium.

• Journal of Life Science
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• v.6 no.1
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• pp.6-13
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• 1996

The possible use of milk-wastewater as a fermentation media for the production of citric acid by Aspergillus niger has been investigated. The addition of Mn$^{2+}$ , Fe$^{2+}$ and Cu$^{2+}$ to the medium promoted citric acid production while only Mg$^{2+}$ decreased citric acid production. The concentrations of citric acid produced were marked up to 7.2g/l and 16.5g/l in a batch bioreactor by Aspergillus niger ATCC 9142 with 50g/l and 100g/l of reducing sugar concentration in milk-wastewater, respectively. A mathematical model was developed and simulating the predictability of cell growth, citric acid production and substrate consumption rate, and gave good agreement results with experimental data.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.461-468
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• 2016

One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.726-731
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• 1999

It was discovered that ammonium phosphate in the medium played an important role in both growing mycelium and producing exopolysaccharides (EPS) from G. lucidum. In lower concentration levels of ammonium phosphate (0-3 g/l), an improved mycelial growth was observed by maintaining more filamentous morphology than in high concentrations (5-11 g/l). In addition, it was confirmed by comparing the factual dimension and frequency of the area regarding the mycelial pellets. This must be attributed to limitations of nutrient transfer by maintaining filamentous mycelium during the cultivation in a low ammonium phosphate containing medium. On the other hand, the best EPS production was observed in medium with the absence or low concentration of ammonium phosphate. The shear stress of the culture broth was greatly affected by the shear rate, as compared with that of the culture broth with high ammonium phosphate concentration. The rheological characteristics of the fermentation broth and filtrate worked well according to the Herschel-Bulkley model. It was also found that the morphological changes of the mycelium resulting from the ammonium phosphate concentration directly affected the rheological characteristics of the system and resulted in reversely affecting the EPS production levels. Based on these results, it can be concluded that delicate regulation of the ammonium phosphate concentration in the culture media should be provided in order to obtain optimal mycelial growth and/or EPS production.

• Korean Journal of Veterinary Service
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• v.16 no.2
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• pp.157-165
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• 1993

The present study was conducted to investigate biochemical properties, antimicrobial drug susceptibilities and epidemiology of 71 stranins of Salmonella pullorum isolated from about 110 diseased chickens of 23 poultry farms located in Cheongjoo, Cheongweon and Koesan county, Chungbuk province, from August 1991 to March 1993. The isolates were identified as S. pullorum by serological and biochemical means. S. pullorum were mostly isolated in chicken under 3weeks of age, and also isolated in 58, 72 days and 23 weeks of age. According to breeds, most of the cultures were isolated in colored broiler chicken (14 to 23 cases), and also variously isolated in native chicken, white broiler chicken, black bone chicken and laying hen. According to organs of diseased chickens, most of the cultures were isolated in liver (37 to 71 strains), and also variously isolated in spleen, lungs, blood, heart, oviduct and brain. According to media used for primary culture from organs, most of the cultures were isolated purely with SS and BHI medium. The majority of biochemical properties of S. pullorum isolated from diseased chickens were identical to those of the standard strains, but in the properties of rhamnose, and arabinose fermentation, some isolates were negative in spite of positive in those of standard S. pullorum. All the isolates were highly susceptible to colistin, amikacin, kanamycin, gentamicin, carbenicillin, ampicillin, sulfamethxazole, cephalothin, tetracycline and piperacillin regardless of isolated years, but no susceptible to penicillin, erythromycin, vancomycin, tylosin and novobiocin.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.256-267
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• 2019

The use of low-cost substrates represents one key issue to make single cell oil production sustainable. Among low-input crops, Arundo donax L. is a perennial herbaceous rhizomatous grass containing both C5 and C6 carbohydrates. The scope of the present work was to investigate and optimize the production of lipids by the oleaginous yeast Cutaneotrichosporon curvatus from undetoxified lignocellulosic hydrolysates of steam-pretreated A. donax. The growth of C. curvatus was first optimized in synthetic media, similar in terms of sugar concentration to hydrolysates, by applying the response surface methodology (RSM) analysis. Then the bioconversion of undetoxified hydrolysates was investigated. A fed-batch process for the fermentation of A. donax hydrolysates was finally implemented in a 2-L bioreactor. Under optimized conditions, the total lipid content was 64% of the dry cell weight and the lipid yield was 63% of the theoretical. The fatty acid profile of C. curvatus triglycerides contained 27% palmitic acid, 33% oleic acid and 32% linoleic acid. These results proved the potential of lipid production from A. donax, which is particularly important for their consideration as substitutes for vegetable oils in many applications such as biodiesel or bioplastics.

• The Korean Journal of Mycology
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• v.7 no.1
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• pp.13-73
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• 1979

These studies were conducted to investigate nutrient sources and supplementary materials of synthetic compost media for Agaricus bisporus culture. Investigation were carried out to establish the optimum composition for compost of Agaricus bisporus methods of out-door fermentation and peakheating with rice straw as the main substrate of the media. The incidence and flora of harmful organisms in rice straw compost and their control were also studied. 1. When rice straw was used as the main substrate in synthetic compost as a carbon source. yields were remarkably high. Fermentation was more rapid than that of barley straw or wheat straw, and the total nitrogen content was high in rice straw compost. 2. Since the morphological and physico-chemical nature of Japonica and Indica types of rice straw are greatly dissimilar. there were apparent differences in the process of compost fermentation. Fermentation of Indica type straw proceeded more rapidly with a shortening the compost period, reducing the water supply, and required adding of supplementary materials for producing stable physical conditions. 3. Use of barley straw compost resulted in a smaller crop compared with rice straw. but when a 50%, barley straw and 50% rice straw mixture was used, the yield was almost the same as that using only rice straw. 4. There were extremely high positive correlations between yield of Agaricus bisporus and the total nitrogen, organic nitrogen, amino acids, amides and amino sugar nitrogen content of compost. The mycerial growth and fruit body formation were severely inhibited by ammonium nitrogen. 5. When rice straw was used as the main substrate for compost media, urea was the most suitable source of nitrogen. Poor results were obtained with calcium cyanamide and ammonium sulfate. When urea was applied three separate times, nitrogen loss during composting was decreased and the total nitrogen content of compost was increased. 6. The supplementation of organic nutrient activated compost fermentation and increased yield of Agaricus bisporus. The best sources of organic nutrients were: perilla meal, sesame meal, wheat bran and poultry manure, etc. 7. Soybean meal, tobacco powder and glutamic acid fermentation by-products which were industrial wastes, could be substituted for perilla meal, sesame meal and wheat bran as organic nutrient sources for compost media. B. When gypsum and zeolite were added to rice straw. physical deterioration of compost due to excess moisture and caramelization was observed. The Indica type of straw was more remarkable in increase of yield of Agricus bisporus by addition of supplementing materials than Japonica straw. 9. For preparing rice straw compost, the best mixture was prepared by 10% poultry manure, 5% perilla meal, 1. 2 to 1. 5% urea and 1% gypsum. At spring cropping, it was good to add rice bran to accelerate heat generation of the compost heap. 10. There was significantly high positive correlation (r=0.97) between accumulated temperature and the decomposition degree of compost during outdoor composting. The yield was highest at accumulated temperatures between 900 and $1,000^{\circ}C$. 11. Prolonging the composting period brought about an increase in decomposition degree and total nitrogen content, but a decrease in ammonium nitrogen. In the spring the suitable period of composting was 20 to 25 days. and about 15 days in autumn. For those periods, the degree of decomposition was 19 to 24%. 12. Compactness of wet compost at filling caused an increase in the residual ammonium nitrogen. methane and organic acid during peak heating. There was negative correlation between methane content and yield (r=0.76)and the same was true between volatile organic acid and yield (r=0.73). 13. In compost with a moisture content range between 69 to 80% at filling. the higher the moisture content, the lower the yield (r=0.78). This result was attributed to a reduction in the porosity of compost at filling the beds. The optimum porosity for good fermentation was between 41 and 53%. 14. Peak heating of the compost was essential for the prevention of harmful microorganisms and insect pests. and for the removal of excess ammonia. It was necessary to continue fer mentatiion for four days after peak heating. 15. Ten species of fungi which are harmful or competitive to Agaricus bisporus were identified from the rice compost, including Diehliomyces microsporus, Trichoderma sp. and Stysanus stemoites. The frequency of occurrance was notably high with serious damage to Agaricus bisporus. 16. Diehliomyces microsporus could be controlled by temperature adjustment of the growing room and by fumigating the compost and the house with Basamid and Vapam. Trichoderma was prevented by the use of Bavistin and Benomyl. 17. Four species of nematodes and five species of mites occured in compost during out-door composting. These orgnanisms could be controlled through peakheating compost for 6 hours at $60^{\circ}C$.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.175-180
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• 2003

To develop the health/functional food materials, we investigated the cultural condition of mycelial growth on the solid state fermentation using the brown rise, Acanthopanax sp. and Artemisia sp., and also evaluated inhibitory activity of angiotensin converting enzyme (ACE) of hot water extracts from cultured media of Pleurotus eryngii. As the amount of Acanthopanax nnd Artemisia In the cultural media increased, the mycelial growth rate decreased. Especially, addition of Aeantopanax showed marked effect than Artemisia. Moisture contents in three kinds of cultured media were in the range of $10.9{\sim}12.0%$. Crude protein fat and crude fiber content were the highest value in cultured brown rice medium, whereas the mineral contents (Ca, K and P) were higher in the Acanthopanax supplemented (5%) medium than the other media, The extraction yield of the Artemisia supplemented (5%) medium was the highest value of 4.80%, and the pH of hot water extract from cultured brown rice medium showed the lowest value of 6.1. Lightness (L) values in three kinds of extracts from cultured media were in the range of $85.8{\sim}87.1$. Redness (a) value was the highest In the brown rice and Acanthopanax supplemented media, however cultured Artemisia supplemented medium showed the highest value in yellowness (b). In comparison of sugar components analyzed by the thin layer chromatography with three kinds of samples, two spots were detected to be glucose and maltose, respectively. The ACE inhibitory activity of hot water extract from the cultured Acanthopanax supplemented medium showed the highest value at the concentration of $0.2{\sim}1.0\;mg/ml$. These results suggest that the Pleurotus eryngii grew in natural media using brown rice and Acanthopanax can be supplemented to the brown rice medium to enhance its ACE inhibitory activity as health/functional food materials.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.126-131
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• 2010

In order to maximize the growth of Bifidobacterium lactis BL 740 and soy isoflavone agycones production, we investigated the optimization of a culture medium containing soy hypocotyls, which are the byproducts of the soy manufacturing process, and soy proteins. The ingredients of the medium containing soy materials (S-medium) were selected by fractional factorial design (FFD) and central composite design (CCD) within a desirable range. The FFD was applied by six factors: glucose, cellobiose, fructooligosaccharide, soy peptone, soy protein, and soy hypocotyl. Soy protein, soy peptone, and soy hypocotyl were found to be significant factors from the result of FFD for both the growth of B. lactis BL 740 and aglycone production. The CCD was then applied with three variables found from FFD at five levels each and the optimum values were determined for the three variables: soy peptone, soy protein, and soy hypocotyl. In the case of the growth of B. lactics BL740, the proposed optimal media contained 12.73 g/L of soy protein, 29.55 g/L of soy peptone, and 130.67 g/L of soy hypocotyl. To produce isoflavone aglycones, optimized media was composed of 2.06 g/L, soy protein, 1.25 g/L of soy peptone, and 60.02 g/L of soy hypocotyl.