• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.700-709
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• 2016

The mitogen-activated protein kinase HOG1 (high-osmolarity glycerol response pathway) plays a crucial role in the response of yeast to hyperosmotic shock. Trichosporonoides oedocephalis produces large amounts of polyols (e.g., erythritol and glycerol) in a culture medium. However, the effects of HOG1 gene knockout and environmental stress on the production of these polyols have not yet been studied. In this study, a To-HOG1 null mutation was constructed in T. oedocephalis using the loxP-Kan-loxP/Cre system as replacement of the targeted genes, and the resultant mutants showed much smaller colonies than the wild-type controls. Interestingly, compared with the wild-type strains, the results of shake-flask culture showed that To-HOG1 null mutation increased erythritol production by 1.44-fold while decreasing glycerol production by 71.23%. In addition, this study investigated the effects of citric acid stress on the T. oedocephalis HOG1 null mutants and the wild-type strain. When the supplementation of citric acid in the fermentation medium was controlled at 0.3% (w/v), the concentration of erythritol produced from the wild-type and To-HOG1 knockout mutant strains improved by 18.21% and 21.65%, respectively.

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.193-202
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• 1982

The changes of total carbohydrates and trehalose levels during differentiation of A. niger were studied. Aspergillus niger was cultivated in Czapeck-Dox medium by the method of surface culture and shake culture. Total carbohydrates and trehalose were fractionated and determined by the method of Trevelyan and Harrison (1956). Total carbohydrates and trehalose accumulated in A. niger during sporulation. The influences of nutritional starvation on the levels of cellular carbohydrates in A. niger, which was cultivated in each nitrogen, phosphate and glucose limited Czapeck-Dox medium, were studied. The levels of total carbohydrates and trehalose in A. niger cultivated in nitrogen limited medium increased much than those cultured in full medium. The total carborates and trehalose levels in A. niger cultivated in phosphate limited medium increased, but the increases were less than those cultured in nitrogen limitted medium. In glucose limited medium, any changes of total carbohydrates and trehalose levels were not found. It is considered that the biochemical mechanisms responsible for the changes of total carbohydrates and trehalose levels may be related with differentiation of Aspergillus niger.

• Journal of Life Science
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• v.19 no.11
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• pp.1617-1622
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• 2009

Optium conditions for the production of mycelia and extracellular polysaccharide (EXPS) from submerged mycelial culture of Inonotus obliquus and their immunomodulating activities were investigated. The optmium production of mycelia and EXPS from I. obliquus was observed in mushroom complete medium (MCM). The optimum pH, temperature, and agitation speed for the production of mycelia and EXPS were 5.5, $25^{\circ}C$, and 150 rpm, respectively. The culture period for maximum production of mycelia (10.89 g/l) and EXPS (1.25 g/l) in shake flask cultivation was 11 days. The anticomplementary activity of intracellular polysaccharide (INPS) and EXPS form I. obliquus increased in a dose-dependent manner. Lysosomal enzyme activity of EXPS and INPS increased by 2.0- and 2.2-fold at $100{\mu}g/ml$ concentration, respectively, compared to the control group.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1670-1679
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• 2020

The substantial use of fungal enzymes to degrade lignocellulosic plant biomass has widely been attributed to the extensive requirement of powerful enzyme-producing fungal strains. In this study, a two-step screening procedure for finding cellulolytic fungi, involving a miniaturized culture method with shake-flask fermentation, was proposed and demonstrated. We isolated 297 fungal strains from several cellulose-containing samples found in two different locations in Thailand. By using this screening strategy, we then selected 9 fungal strains based on their potential for cellulase production. Through sequence-based identification of these fungal isolates, 4 species in 4 genera were identified: Aspergillus terreus (3 strains: AG466, AG438 and AG499), Penicillium oxalicum (4 strains: AG452, AG496, AG498 and AG559), Talaromyces siamensis (1 strain: AG548) and Trichoderma afroharzianum (1 strain: AG500). After examining their lignocellulose degradation capacity, our data showed that P. oxalicum AG452 exhibited the highest glucose yield after saccharification of pretreated sugarcane trash, cassava pulp and coffee silverskin. In addition, Ta. siamensis AG548 produced the highest glucose yield after hydrolysis of pretreated sugarcane bagasse. Our study demonstrated that the proposed two-step screening strategy can be further applied for discovering potential cellulolytic fungi isolated from various environmental samples. Meanwhile, the fungal strains isolated in this study will prove useful in the bioconversion of agricultural lignocellulosic residues into valuable biotechnological products.

• KSBB Journal
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• v.11 no.6
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• pp.636-641
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• 1996

The production of extracellular mannitol by a new mannitol-producing bacterium, Leuconostoc sp. KY-002 was studied in shake flask cultures. The new isolate has a capability of utilizing fructose and sucrose for mannitol formation. Maximum mannitol production was obtained with fructose as the sole carbon source. Under the optimal culture conditions, within 70 hours of incubation, a final concentration of 26 g/L of mannitol from 50 g/L fructose was obtained with an indicated yield of 52% based on fructose consumed. However, higher concentrations of fructose ranging from 100 to 250 g/L could not effectively be transformed to mannitol due to a lack of osmotolerance. The strain produced no other polyols such as glycerol and sorbitol as by-products. Yeast extract was the best nitrogen source and high levels of inorganic phosphate up to 10 g/L promoted mannitol formation. Any mineral ions and salts did not play important role in both cell growth and mannitol production. Nicotinic acid enhanced mannitol production by 16%. The optimum culture temperature and initial pH were $35^{\circ}C$ and 6, respectively.

• The Korean Journal of Mycology
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• v.10 no.1
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• pp.33-39
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• 1982

Carpophores of ten Korean strains of Lentinus edodes (Berk.) Singer, an antitumor polysaccharide producing fungus, were extracted with 0.1N NaOH solution. The extracts were dialized for seven days in distilled water and lyophilized to produce crude polysaccharide powders. Thus obtained crude polysaccharide samples were assayed for sugar contents by colorimetric method with anthrone reagent. Among ten strains examined Lentinus edododes-DMC7 was found to be the richest strain in polysaccharide content of carpophores. By shake culture experiment for biomass production, L. edodes-DMC7 was found to be the second most productive strain among seven strains examined. Cultural characteristics of L. edodes-DMC7 were investigated by shake culture method. The best result was obtained when L. edodes-DMC7 was cultured in the medium containing glucose 8g, starch 80g, yeast extract 12g, $KH_2PO_4\;0.87g,\;MgSO_4{\cdot}7H_2O\;O.5g,\;CaCl_2\;0.3g,\;FeSO_4{\cdot}7H_2O\;10mg\;ZnSO_4{\cdot}7H_2O\;4mg,\;CuSO_4{\cdot}5H_2O\;lmg,\;MnCl_2{\cdot}4H_2O\;7mg\;per\;11\;at\;28^{\circ}C$, 180 rpm, for 12 days. Thus thirty-three grams of dry mycelia was obtained per one liter of medium.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.425-430
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• 2005

[${\beta}-sitosterol$] is a plant sterol that reduces cholesterol levels and inhibits the growth of human prostate and colon cancer cells. Optimal conditions for ${\beta}-sitosterol$ production were examined from cell suspension cultures of Chrysanthemum coronarium L. The callus induction was optimal in MS medium containing 1 mg/l NAA and 1 mg/l BAP. Cell suspension culture was also established from the callus. Optimal ${\beta}-sitosterol$ production was obtained when the cells were cultured at an initial density of 2 mg DCW/l in MS medium containing 1 X sucrose (30 mg/l), 1 X nitrogen (1900 mg/l $KNO_3$, 1650 mg/l $NH_4NO_3$), and 1 X phosphate source (170 mg/l). In cell suspension cultures of C. coronarium L. using shake flasks, the peak content of ${\beta}-sitosterol$ was $150{\mu}g/g$ DCW. In cell suspension cultures of C. coronarium L. using an air-lift bioreactor, the maximum ${\beta}-sitosterol$ content of $143.8{\mu}g/g$ DCW was obtained at an air-flow rate of 100 cc/min.

• Journal of Life Science
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• v.12 no.3
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• pp.242-249
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• 2002

The optimal culture conditions in 500$m\ell$ flask suture, 5$\ell$ jar fermenter and 2,000 $\ell$ large stale culture were investigated to maximize the production of antibiotic on Rhizoctonia solani AC4, the causal agent of vegetables damping-off, by the strain Bacillus ehimensis YJ-37. Starch (1.5%) as a carbon source, peptone (0.6%) as a nitrogen source and MgC1$_2$(0.15%) as a metal ion in the medium containing N $a_2$HP $O_4$(0.3%) showed the highest production of the antibiotic(s) in a rotary shake (200 rpm). Optimal initial pH of the culture medium, culture temperature and culture time for the antibiotic(s) production were pH 8.0, 32$^{\circ}C$ and 54hrs, respertively. Under the optimal renditions in flask culture, cell growth and antifungal activity (clear zone size) were 1.42 $\times$ 10$^{8}$ cfu/$m\ell$ (21g-DCW/ $\ell$) and 13.9 mm, respectively. In 5 $\ell$ jar fermenter (medium 3 $\ell$), optimal air flow, agitation speed and culture time for the antibiotic(s) production were 2 vvm, 200 rpm and 48hrs, respectively. Under the optimal conditions in 5 $\ell$ jar fermenter, tell growth and antifungal activity were 2.06 $\times$ 10$^{8}$ cfu/$m\ell$ (30g-DCW/ $\ell$) and 13.4 mm, respectively. Under the culture conditions of air flow (30 vvm) and agitation speed (200 rpm) at 32$^{\circ}C$ for 10 days in 2,000 $\ell$ large scale culture (medium 1,800 $\ell$, pH 8.0), cell growth and antifungal activity were 0.81$\times$10$^{8}$ cfu/$m\ell$ (12g-DCW/ $\ell$) and 8.6 mm, respectively.

• Korean Journal of Microbiology
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• v.1 no.1
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• pp.38-44
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• 1963

According to the experiment on pure-isolation and the related contaminants of Chlorella, the phenomena of the ecological distributions of Chlorella in Korea have been manifested in several areas and also the aim that in going to do culture, biological and physiological study of Chlorella is carried out. Contaminants very oftenly occupied on the colony of the strains taken in order to fulfil pure-isolation of Chlorella, but in accordance with being piled up the minute research on this subject, I can obtain the desirable results as follows: 1. For the pure-isolation, the duration chose the time from May to September 1957 so that may easily isolate from contaminant water with utilizing the antibiotic substances. 2. To take long time, 36-48 hours until growth of nascent through the non-sporulated, it originates from the difference of the cultured media. In addition to the above mention, the mechanism of growth until nascent through the sporulated must not always require the ligh. However the supply of metabolic energy depend upon its nutritional conditions per phase. 3. The culture of Chlorella should be based on the lower culturing except adding especial conditions such as reagent concentration of media, artifical shake of media and other facts due to the natural conditions. And also these strains grew not only in distilled water but 2% NaCl solution without any abnormality in cell it self. I, therefore, guess it is possible to culture in sea-water under phasic environment. 4. In the experiment of ammonia detection, it is caused by the sampling surroundings to contain the minute quantity of ammonia in strain No. M 918; that is the place to be plenty of Carbohydrate on behalf of protein. 5. To compare the absorption curve of chlorophyll of higher plant with that of Chlorella, the absorption zone made mostly the Same ones each other but a little absorption grade dose not clearly appear. The colony which formed giant type grows with intensive colour and green band on surrounding of the colony and after that it was changed into all the green colour and developed up to end. 6. At first phase for a week, the development of Chlorella suspends the normal condition as in vivo but after a few days, the colour of chlorophyll gradually changed into blue-yellow which secrete the mucous substances on the agar media. The cell was flew out the contained substances itself on leaving the cell wall only, or the various micro-organism diffused on the outer-region of the cell.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.689-698
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• 2013

The production and characterization of an active recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21(DE3) has been previously reported. In this study, the effect of the signal peptide (SP), inducer concentration, process scale, and operational mode (batch and semi-continuous) on GALNS production were evaluated. When native SP was presented, higher enzyme activity levels were observed in both soluble and inclusion bodies fractions, and its removal had a significant impact on enzyme activation. At shake scale, the optimal IPTG concentrations were 0.5 and 1.5 mM for the strains with and without SP, respectively, whereas at bench scale, the highest enzyme activities were observed with 1.5 mM IPTG for both strains. Noteworthy, enzyme activity in the culture media was only detected when SP was presented and the culture was carried out under semi-continuous mode. We showed for the first time that the mechanism that in prokaryotes recognizes the SP to mediate sulfatase activation can also recognize a eukaryotic SP, favoring the activation of the enzyme, and could also favor the secretion of the recombinant protein. These results offer significant information for scaling-up the production of human sulfatases in E. coli.