• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.122-126
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• 1996

Growth patterns of Saccharomyces cerevisiae NS 2031 and its total RNA contents were observed by a fed-batch fermentation with different media-feeding methods. With an exponential feeding pattern, both final cell concentrations and intracellular RNA contents decreased with increasing feeding rates. Intracellular RNA contents also decreased with the growth time. At the same feeding rate of the exponential pattern, final cell concentrations decreased with the increase of total sugar concentration whereas intracellular RNA contents increased. The highest cellular yield was 0.47 at the total sugar concentration of 10%. With increasing feeding rates of the parabolic feeding pattern, final cell concentrations decreased whereas intracellular RNA contents increased, showing a different tendency from the exponential feeding pattern. In comparison of two feeding methods, the exponential feeding pattern was better than the parabolic feeding pattern in terms of cell growth, cellular yields and intracellular RNA contents of Saccharomyces cerevisiae NS 2031. Also, the intracellular RNA contents of the exponential feeding pattern was found to be about 2% higher than that of the parabolic feeding pattern at the same instantaneous growth rate $({\mu}_{inst})$.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.515-520
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• 2010

The response of broiler chicks to intubation of nutrients (starch, casein, soybean oil or their combinations) into the crop immediately after hatch was evaluated for performance, intestinal development, meat yield and immune competence up to 35 d of age. A control group with no access to feed and two test groups fed either inert material (sawdust) or starter diet for the initial 24 h after hatch were compared with nutrient intubated groups (n = 7). A total of 300 broiler chicks were equally distributed to 10 dietary groups with 6 replicates of 5 chicks each. After 24 h of hatch, all groups were fed ad libitum the starter (0-21 d) and finisher diets (22-35 d). Results indicated that post-hatch intubation of starch into the crop significantly (p${\leq}$0.05) improved body weight (at 14 and 35 d of age), readyto-cook meat yields, weights of breast muscle and small intestine segments, cell-mediated immune response, ND titers and weight of bursa compared to chicks starved or fed sawdust during the initial 24 h after hatch. However, chicks with access to feed immediately after hatch or intubation of starch, soybean oil, starch+casein, starch+soybean oil or starch+casein+soybean oil exhibited similar positive effects. Intubation of casein either alone or in combination with soybean oil was superior to the starved or sawdust fed groups, but inferior to other groups for all the parameters studied. It was concluded from the study that intubation of starch individually or in combination with casein and/or soybean oil effectively circumvented the negative effects of post-hatch starvation for 24 h. Among the nutrients intubated, carbohydrate (starch) was better utilized by the chicks than protein (casein) or fat during the initial post-hatch period.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.348-353
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• 1993

The optimal conditions for operating a moving-aeration bioreactor were determined as 30rpm and 150 (ml/min) of air flow rate, which can yield ca. 7.3 (l/h)of maximum mass transfer coefficient. It was also found that the agitation speed played much much important role than air input rate in oxgen transfer into the medium. $2.6{\times}10^6$ (cells/ml) and 0.6 (ml/l) of maximum cell denisty and IL-2 production were observed in batch cultivation of IL-2 producing BHK cell line. 0.53 (mM/l/h) of oxygen uptake rate was also estimated. The performance of a moving-aeration bioreactor (specific growth rate and oxygen uptake rate, etc.) was superior to other culture systems, such as cell-life and static membrane aeration bioreactors. Ii must be useful to apply this reactor to many culture processes by improving structural limitations in scaling-up the system.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.588-592
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• 1995

Fed-batch fermentation was used to produce the high concentrations of poly-$\beta $-hydroxybutyrate (PHB) and poly-$\beta $-(hydroxybutyrate-co-hydroxyvalerate) (PHB/V). Specific growth rate ($\mu $), yield of cell from glucose (Y$_{x/s}$) were calculated from the two samples in 3 to 5 hours of interval and they were reflected on the determination of glucose feeding rate to maintain the glucose concentration at around 10 g/l in the culture broth. PHB was accumulated after the nitrogen became limited at 60 g/l of dry cell weight by changing ammonia water to 4N-NaOH solution. As results, the final dry cell weight (DCW) of 170 g/l, PHB of 115 g/l were obtained in 50 hours and the overall productivity was 2.4 g/l$\cdot $h. After PHB accumulation, cosubstrate of glucose and propionic acid (PA) was fed to accumulate PHB/V. But, PA feeding rate was decreased from 3 g/l$\cdot $h to 1 g/l$\cdot $h to prevent PA from accumulating to high level in the broth, which is very inhibitory to the cells. As results, DCW, PHB and PHV were 147.5 g/l, 90 g/l and 8 mole % of hydroxyvalerate, respectively.

• 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.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.265-272
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• 2022

Many studies on poultry have been conducted in the poultry industry to improve their important economic traits, such as egg production, meat quality, and carcass yield. Environmental changes affect the poultry's economic traits, including muscle growth. The purpose of this study is to investigate the mechanisms by which simvastatin causes muscle injury in quail muscle cells. Following treatment with various doses of simvastatin, LD50 in the quail myoblast cells was determined using a cell viability test; cell death was caused by apoptosis and/or necrosis. Thereafter, the expression patterns of the atrophy marker genes were examined via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The results showed that the transcriptional levels of the muscle atrophy marker genes (Atrogin-1, TRIM63) and the upstream genes in their signaling cascade were increased by simvastatin treatment. This indicated that simvastatin induced myogenic cell death and muscle injury via protein degradation through muscle atrophy signaling. Further studies should focus on identifying the mechanism by which simvastatin induces the protein degradation signaling pathway in quail muscle..

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.84-90
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• 1999

The growth of Bifidobacterium breve strain HP2 was completely inhibited by the addition of lactate higher than 4.0％ but not by the addition of acetate. Two kinds of lactate-tolerant mutants were isolated by the nitrosoguanidine treatment, enrichment on a liquid medium with 5％ lactate, and selection on agar plates with 5％ lactate. The mutants were not only able to grow in the presence of 5％ lactate but also improved in viable cell stability in the acidic pH range. In a pH-controlled fermentor, mutant N-1-5 grew at a rate slower than that of the wild type but its growth yield was higher. Notably, mutants were more halotolerant and more osmotolerant than the wild type and they were able to grow in the presence of 3％ NaCl or 25％ lactose at which the wild type entirely stopped the growth. The enzyme activities involved in the lactose metabolism in B. breve were measured to elucidate the biochemical basis for lactate tolerance. In the mutants, activities of several enzymes including phosphoglucomutase decreased compared to the wild-type, which may explain their lower growth rate. However, the activity of lactate dehydrogenase or its nature of inhibition by lactate was not altered.

• The Korean Journal of Mycology
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• v.9 no.2
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• pp.49-66
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• 1981

The objectives of this investigation were to produce artificially an antitumor constituent by submerged culture of the mycelium of Coriolus versicolor (Fr.) Quel., to characterize the influence of various modifications of the nutrient and culture conditions with respect to the pro­duction, to determine chemical composition of the antitumor constituent, and to examine effects of the constituent on the immune response of mice. Submerged agitation of the mycelium in flasks containing a nutrient solution showed its adequate growth. Especially the mycelial growth in the medium containing glucose and yeast extract was abundant. The addition of cotton seed flour or ginseng waste to the medium increased the yield of mycelial growth and the production of the antitumor constituent. The replacement of glucose with starch also yielded the adequate growth. The antitumor constituent extracted from the mycelium and isolated from the culture filtrate was a protein-bound polysaccharide. The analyses of this constituent by GLC and amino acid autoanalysis showed that it contained four monosaccharides and fifteen amino acids. The protein-free polysaccharide of the constituent was also found to exert greater antitumor activity against sarcoma-180 in mice than the entire constituent. The antitumor constituent was found to potentiate the immune response of mice against sheep red blood cell. The protein-bound polysaccharide exerted more favorable influence on the immunity than the protein-free moiety.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.292-295
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• 2012

Trametes versicolor, a common inhabitant of dead hardwoods in temperate climates, belongs to one of the important medicinal mushrooms. In this study, spent coffee ground(SCG), instant coffee powder(ICP) and instant decaffeinated coffee powder(IDCP) were examined for their effect on the mycelial growth of T. versicolor. Adding SCG was proven to be significantly beneficial at the concentration as high as 10%. ICP and IDCP, both containing concentrated polyphenols, were also beneficial at low concentration less than 1%. 1% SCG culture resulted in ten-fold increased yield of dry cell mass compared to the control culture. Adding coffee substances was recommended as a useful tool for accelerating the growth and strengthening the physiological activity of the mycelium.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.197-202
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• 1994

Microalga, Spirulina platensis has been cultivated in a pilot scale photo-bioreactor to treat wastewater and to produce high protein feedstocks from swine waste containing medium. 0.31(1/day) of specific growth rate and 0.170 of bioenergeric yield were obtanined from batch cultivation in 30% waster containing medium, compared to 0.71(1/day) and 0.545 from clean culture. An optimal dilution concentration was decided as 20% of working volume, based upon the cell growth and biomass productivity. The removal rate of nitrates in the wastewater was decreased as the adding concentration of wastewater was increased while the decrease of total phosphates was reversed, showing 0.33(1/day) and 0.30(1/day) of rate constants for nitrate removal in 10% addition and for phosphate removal in 30% addition, respectively. The chemical composition and amino acid profile of the biomass were superior to those of commerically available health food product, Spirulina sp.