• KSBB Journal
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• 제28권6호
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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.

• KSBB Journal
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• 제30권1호
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• pp.27-32
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• 2015

The current investigation was carried out to explore the possibility of submerged fermentation of Saccharina japonica as sole substrate using Aspergillus oryzae. In this study we used 2% S. japonica powder as fermentation media for A. oryzae. Fermentation period was optimized by monitoring the fermented sample at regular intervals for a period of 7 days. Results found that a fermentation period of 5 days was effective with maximum desirable characteristics such as total sugar, total phenolic and flavonoid contents. Under optimum fermentation period, fermented extracts showed enhanced antioxidant activity as determined by different assays such DPPH radical scavenging, ABTS scavenging and phosphomolydenum assay. This study provides the information for the enhancement of bioactive molecules in an eco-friendly manner and also paves way towards the development of wide range of seaweed-based functional foods.

• 한국미생물·생명공학회지
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• 제51권1호
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• pp.59-68
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• 2023

Xylanase is an industrially relevant enzyme used for the production of xylobiose and xylose. Various methods are used to enhance the microbial yield of xylanase. In the present study, co-culturing of Bacillus subtilis and Bacillus pumilus were investigated using submerged fermentation for xylanase production, which was markedly increased when sal, sagwan, newspaper, wheat bran, and xylan were used as single carbon sources. Maximum xylanase production was reported after 5 days of incubation in optimized media at pH 7.0 and 37℃, resulting in 2.69 ± 0.25 µmol/min by coculture. The 1:1 ratio of sal and sagwan in optimized production media was shown to be suitable for xylanase synthesis in submerged fermentation (SMF). In comparison to mono-culture using B. pumilus and B. subtilis, co-culturing resulted in an overall 3.8-fold and 2.15-fold increase in xylanase production, respectively.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.1-8
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• 2017

The production of high-value chemicals from natural resources as an alternative for petroleum-based products is currently expanding in parallel with biorefinery. The use of lignocellulosic biomass as raw material is promising to achieve economic and environmental sustainability. Filamentous fungi, particularly Aspergillus species, are already used industrially to produce organic acid as well as many enzymes. The production of lignocellulose-degrading enzymes opens the possibility for direct fungal fermentation towards organic acids such as itaconic acid (IA) and fumaric acid (FA). These acids have wide-range applications and potentially addressable markets as platform chemicals. However, current technologies for the production of these compounds are mostly based on submerged fermentation. This work showed the capacity of two Aspergillus species (A. terreus and A. oryzae) to yield both acids by solid-state fermentation and simultaneous saccharification and fermentation. FA was optimally produced at by A. oryzae in simultaneous saccharification and fermentation (0.54 mg/g wheat bran). The yield of 0.11 mg IA/g biomass by A. oryzae is the highest reported in the literature for simultaneous solid-state fermentation without sugar supplements.

• Journal of Microbiology and Biotechnology
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• 제21권5호
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• pp.470-476
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• 2011

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at $30^{\circ}C$ and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at $30^{\circ}C$ for 20 min, and no inhibitory effect of $Ca^{+2}$ ions on amylase production was observed.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.770-775
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• 2000

Several process parameters were studied to ascertain the effect on degradation of sugar cane bagasse in relation to the production of cellulase enzyme and reducing sugars by Solid Substrate Fermentation (SSF) and Submerged Culture Fermentation (SCF) of Aspergillus terreus SUK-1. The effect of air-flow rate (0-1.3 v/v/m), of different ratios of substrate weight to liquid volume (1:6, 1:10, 1:20, and 1:30 w/v, g/ml), scale-up effect (10, 20, and 100 times of 1:10 ration, w/v) and the effect of temperature (30, 40, 50, and $60^{\circ}C$) in SSF were studied. Air-flow rate of 1.0 v/v/m gave the highest enzyme activity (FPase 0.25 IU/ml, CMCase 1.24 IU/ml) and reducing sugars concentration (0.72 mg/ml). Experiment using 1:10 ratio (w/v) was found to support maximum cellulase activity (FPase 0.58 IU/ml, CMCase 1.97 IU/ml) and reducing sugar concentration (1.23 mg/ml). Scaling-up the ratio of 1:10(w/v) by a factor of 20 gave the highest cellulase activity (FPase 0.71 IU/ml, CMCase 2.25 IU/ml) and reducing sugar concentration (3.67 mg/ml). The optimum temperature for cellulase activity and reducing sugar production was $50^{\circ}C$(FPase 0.792 IU/ml, CMCase 2.25 IU/ml and 3.85 mg/ml for reducing sugar concentration). For SCF, the activity of cellulase enzyme and reducing sugar concentration was found to be lower than that obtained for SSF. The highest cellulase activity obtained in SCF was 50% lower than the highest cellulase activity in SSF, while for reducing sugar concentration, the highest concentration obtained in SCF was 90% lower than that obtained in SSF.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1653-1659
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• 2015

Epothilone, which is produced by the myxobacterium Sorangium cellulosum, contributes significant value in medicinal development. However, under submerged culture conditions, S. cellulosum will accumulate to form bacterial clumps, which hinder nutrient and metabolite transportation. Therefore, the production of epothilone by liquid fermentation is limited. In this study, diatomite-based porous ceramics were made from diatomite, paraffin, and poremaking agent (saw dust). Appropriate methods to modify the porous ceramics were also identified. After optimizing the preparation and modification conditions, we determined the optimal prescription to prepare high-performance porous ceramics. The structure of porous ceramics can provide a solid surface area where S. cellulosum can grow and metabolize to prevent the formation of bacterial clumps. S. cellulosum cells that do not form clumps will change their erratic metabolic behavior under submerged culture conditions. As a result, the unstable production of epothilone by this strain can be changed in the fermentation process, and the purpose of increasing epothilone production can be achieved. After 8 days of fermentation under optimized conditions, the epothilone yield reached 90.2 mg/l, which was increased four times compared with the fermentation without porous ceramics.

• Journal of Microbiology
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• 제44권3호
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• pp.276-283
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• 2006

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (${\alpha}$-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II ${\alpha}$-glucosidase. The optimum temperature of the enzyme was $70^{\circ}C$. In addition, the enzyme was highly thermostable (100% stability for 10 h at $60^{\circ}C$ and a half-life of 15 min at $80^{\circ}C$), and stable within a wide pH range.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권3호
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• pp.184-190
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• 2004

The influences of impeller types on morphology and protein expression were investigated in a submerged culture of Aspergillus oryzae. The impeller types strongly affected mycelial morphology and protein production in batch and fed-batch fermentations. Cells that were cultured by propeller agitation grew in the form of a pellet, whereas cells that were cultured by turbine agitation grew in a freely dispersed-hyphal manner and in a clumped form. Pellet-grown cells showed high levels of protein production for both the intracellularly heterologous protein (${\beta}$-glucuronidase) and the extracellularly homologous protein (${\alpha}$-amylase). The feeding mode of the carbon source also influenced the morphological distribution and protein expression in fed-batch fermentation of A. oryzae. Pulsed-feeding mainly showed high protein expression and homogeneous distribution of pellet whereas continuous feeding resulted in less protein expression and heterogeneous distribution with pellet and dispersed-hyphae. The pellet growth with propeller agitation paralleling with the pulsed-feeding of carbon source showed a high level of protein production in the submerged fed-batch fermentation of recombinant A. oryzae.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.272-276
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• 2005

Candida tropicalis, an osmophilic strain isolated from honeycomb, produced xylitol at a maximal volumetric production rate of 3.5 g $l^{-1}$ $h^{-1}$ from an initial xylose concentration of 200 g $l^{-1}$. Even with a very high xylose concentration, e.g., 350 g $l^{-1}$, this strain produced xylitol at a moderate rate of 2.07 g $l^{-1}$ $h^{-1}$. In a fed-batch fermentation of xylose and glucose, 260 g $l^{-1}$ of xylose was added, and xylitol production was 234 g $l^{-1}$ for 48 h, corresponding to a rate of 4.88 g $l^{-1}$ $h^{-1}$. To increase the xylitol production rate, cells were recycled in a submerged membrane bioreactor with suction pressure and air sparging. In cell-recycle fermentation, the average concentration of xylitol produced per recycle round, total fermentation time, volumetric production rate, and product yield for ten rounds were 180 g $l^{-1}$, 195 h, 8.5 g $l^{-1}$ $h^{-1}$, and 85%, respectively. When cell-recycle fermentation was started with the cell mass contratrated two-fold after batch fermentation and was performed for ten recycle rounds, we achieved a very high production rate of 12 g $l^{-1}$ $h^{-1}$. The production rate and total amount of xylitol produced in cell-recycle fermentation were 3.4 and 11 times higher than in batch fermentation, respectively.