• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.130-135
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• 1991

The effects of media composition on citric acid fermentation using surface immobilized Saccharomycopsis lipolytica were studied. The use of the standard medium for these organisms resulted in rapid decrease of citric acid production and a transformation of immobilized cell morphologies from a yeast-type to a mycelium-type. When the standard medium was enriched with vitamins, trace minerals, a growth factor and ammonium to form a Vigorous Stationary Phase (VSP) fermentation type medium, relatively stable citric acid production (10 mg/lㆍh) was obtained. Using the VSP type medium, the surface immobilized cells also retained their yeast-type form.

• KSBB Journal
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• v.10 no.3
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• pp.231-236
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• 1995

For continuous ethanol production In an immobilized cell reactor consisting of Saccharomyces sake, feedings of one tenth to three tenths times diluted fermentation media were effective for maintaining the high ethanol productivity and physical stability of immobilized beads. In case two tenths times dilltued one of the fermentation medium supplemented with egg albumin hydrolysate(0.5%) and phosphatidylcholine(0.5%) was fed, a maximum ethanol productivity of $69 g/\ell$-hr was attained at a dilution rate of$1.1lhr^{-1}$, and it was 50% higher than that of the two tenths times diluted one of the fermentation medium without any supplement, $46 g/\ell$-hr.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.98-103
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• 2012

For screening of useful enzymes producing microorganisms from Meju, we isolated high lipase producing strains and their lipolytic enzyme activities were then tested. The lipolytic enzyme activities of isolated microorganisms were therefore tested on the Y124 strain. The gene sequence analysis of ITS from Y124 strain revealed Yarrowia lipolytica. Lipase production by the Y124 strain was studied in media containing various carbon sources. The Y124 strain drastically increased lipolytic enzyme activity in YPO media containing olive oil, as well as in YPDO media containing both olive oil and glucose. Maximal lipase production was achieved in YPD (yeast extract-peptone-D-glucose) media containing 0.7% olive oil when cultured at $30^{\circ}C$ for 8 hrs. The lipase produced from the Y124 strain showed the highest activity in p-NPO (p-nitrophenyl octanoate ($C_8$)), amongst the various p-nitrophenyl esters.

• KSBB Journal
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• v.5 no.1
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• pp.25-35
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• 1990

In the Xanthan gum fermentation by Xanthomonas campestris there are problems of the large energy consumption by long fermentation time, the mass transfer of oxygen and nutrients by high viscous fermentation broth. In this study, the media optimization and the fed batch fermentation were carried out to decrease fermentation time and increase Xanthan gum yield. The $O_2$ uptake rate (OUR) and $CO_2$ evolution rate(CER) which were obtained from the analysis of fermentation exit gas using a gas chromatograph were investigated. As a result, the fermentation time decreased at optimal assimilable nitrogen concentration but increased at poor or rich assimilable nitrogen concentration, the Xanthan gum biosynthesis was stimulated under the limited condition of assimilable nitrogen source and the optimum fermentation medium was obtained as follow; Glucose=30g / l, Peptone=8.0g / l, $K_2HPO_4=2.0g/l$, $MgS0_47H_2O=10g/l$, Sodium acetate=20g/l, Sodium pyruvate=0.5g/1. As the agitation speed and nitrogen concentration increased, the $O_2$ uptake rate and $CO_2$ evolution rate increased. The OUR and CER were 37.3mmol $O_2/\;l$ hr and 20.2 mmol $CO_2/\;L$ hr at peptone 11g / l and agitation speed 990RPM, respectively. In fed batch fermentation, the final concentration of Xanthan gum was enhanced up to 29g / l.

• KSBB Journal
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• v.28 no.6
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.465-469
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• 2006

Two mesophilic trickling bed bioreactors filled with two different types of media, hydrophilic- and hydrophobic-cubes, were designed and tested for hydrogen production via anaerobic fermentation of sucrose. Each reactor consisted of a column packed with polymeric cubes and inoculated with heat-treated sludge obtained from anaerobic digestion tank. A defined medium containing sucrose was fed with changing flow rate into the capped reactor, hydraulic retention time and recycle rate. Hydrogen concentrations in gas-phase were constant, averaging 40% for all conditions tested. Hydrogen production rates increased up to $10.5 L{\cdot};h^{-1}{\cdot}L^{-1}$ of reactor when influent sucrose concentrations and recycle rates were varied. Hydrophobic media provided higher value of hydrogen production rate than hydrophilic media at the same operation conditions. No methane was detected when the reactor was under a normal operation. The major fermentation by-products in the liquid effluent of the both trickling biofilters were acetate and butyrate. The reactor filled with hydrophilic media became clogged with biomass and bio gas, requiring manual cleaning of the system, while no clogging occurred in the reactor with hydrophobic media. In order to make long-term operation of the reactor filled with hydrophilic media feasible, biofilm accumulation inside the media in the reactor with hydrophilic media and biogas produced from the reactor will need to be controlled through some process such as periodical backwashing or gas-purging. These tests using trickling bed biofilter with hydrophobic media demonstrate the feasibility of the process to produce hydrogen gas in a trickle-bed type of reactor. A likely application of this reactor technology could be hydrogen gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.787-791
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• 2005

Mutation and its pilot-scale fermentation were conducted for the production of teicoplanin from Actinoplanes teichomyceticus. The fermentation medium was optimized by replacement and Plackett-Burman experimental design. A maximum production of 1,500 mg/l teicoplanin was obtained by pilot-scale fermentation in an optimized medium containing (g/l): 30 g maltodextrin, 5 g glucose, 5 g yeast extract, 5 g soybean meal, 0.5 g $MgSO_4{\cdot}7H_2O$, 0.1 g NaCl, 0.1 g $CaCl_2{\cdot}2H_2O$, and 50 g Diaion HP-20. The production of teicoplanin was improved 3-fold from the parental strain by mutation, media optimization, and fermentation, and laboratory-scale fermentation was successfully demonstrated in a pilot-scale fermenter for the industrial production of teicoplanin.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.172-176
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• 2006

In order to increase the productivity of lipstatin by Steptomyces toxytricini, the effect of medium components on the lipstatin production was investigated. Using TSB medium as a basal medium, a variety of carbon sources, nitrogen sources, lipid and fatty acids was supplemented into a fermentation medium. The seed culture of S. toxytricini grown in 25 ml TSB medium at $28^{\circ}C$ for 3 days with agitation at 200 rpm was inoculated in the size of 2% in fermentation media containing different components and fermented at $28^{\circ}C$ for 60 more hrs. In the examination of the effect of carbon sources, the best cell growth was observed in fermentation media supplemented with glucose or glycerol, but the lipstatin productivity was the highest in media containing lactose or sucrose. Among complex nitrogen sources, yeast extract was the best one for cell growth, but the highest lipstatin production was found in TSB media composed of 1.7% casitone and 0.3% soytone. The increased concentration of triolein as a lipid caused the promotion of cell growth but the significant suppression of lipstatin production. When 0.5% fatty acids were supplemented to fermentation medium, unsaturated fatty acids like linoleic or oleic acid suppressed cell growth as well as lipstatin production, but 2 times higher lipstatin production was achieved by stearic acid, a saturated fatty acid, differently from expectation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.991-995
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• 2013

This study was conducted to develop an edible culture media with various types of cereals and soybeans for the pre-cultivation of lactic acid bacteria (LAB). To manufacture the edible culture media, LAB enrichment media were prepared using cereals such as brown rice (including germinated brown rice, glutinous brown rice, and germinated glutinous brown rice), yellow soybeans (including yellow soybeans, hulled yellow soybeans, germinated yellow soybeans, hulled and germinated yellow soybeans), and black soybeans (black soybeans, hulled black soybeans, germinated black soybeans, hulled and germinated black soybeans). Seven species of LAB were used in the experiment: Lactobacillus (Lb.) farciminis, Lb. homohiochii, Lb. pentosus, Lb. plantarum, Leuconostoc (Leu.) paramesenteroides, Leu. citreum, and Leu. lactis. For edible culture media from cereals, the average viable cell count of the seven starter cultures was 7.6~8.0 log CFU/mL, while that of the MRS culture medium, a synthetic medium, was 9.2 log CFU/mL; thus proliferation was lower by about 1~2 log CFU/mL in starter cultures from cereals compared to the synthetic medium. In the case of the edible culture media from soybeans, most bacteria showed higher proliferation in the hulled and germinated soybean media. In particular, Lb. plantarum showed the highest cell count at 10.08 log CFU/mL. In the case of edible culture media from black soybeans, the proliferation rate was higher in the hulled and germinated black soybean medium. Lb. homohiochii showed the highest proliferation in the hulled and germinated black soybean medium at 9.90 log CFU/mL. All results show that edible culture media using cereals and soybeans are generally good for LAB. Especially, hulled and germinated black soybeans are optimal for the pre-cultivation of LAB medium.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.202-211
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• 2004

Xylitol is a 5-carbons carbohydrate, which can be replaced with sucrose for preventing dental caries. To study the effect of xylitol on the fermentation of lactose in bacteria, the important oral bacteria such as Streptococcus(S.) mutans, S. oralis and S. salivarius were studied. The optical density using spectophotometer and the cell concentration were assessed to evaluate the combined effect of lactose and xylitol against the bacteria. Thin layer chromatography and lactose-PTS activity test were performed to evaluate the effect of xylitol on the fermentation of lactose in S. mutans and by ${\beta}-galactosidase$ with the following results. 1. The optical density of Streptococcus mutans culture was not increased for 8 hours-incubation in the media added with lactose and xylitol, but was increased at 24 hours-incubation. The number of viable cells at 8 hours-incubation was smaller in the media containing lactose and xylitol in comparison with lactose only. 2. The optical densities of Streptococcus oralis culture and Streptococcus salivarius culture were not increased for 8 hours-incubation in the media added with lactose and xylitol but were increased at 24 hours-incubation. 3. When Streptococcus mutars was incubated for 8 hours in the media added with lactose and xylitol, the amount of remained lactose was larger compared with the media added with lactose only But all lactose was fermented in both media after 24 hours-incubation. 4. When Streptococcus mutans was incubated in the media added with lactose and xylitol, the activity of lactose-PTS was higher compared with the media added with lactose only. 5. When ${\beta}-galactosidase$ was incubated in the media added with lactose and xylitol, the amount of remained lactose was larger compared with the media added with lactose only. These results indicated that xylitol inhibited the fermentation of lactose by Streptococcus.