• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.115.1-115.1
• /
• 2007

See Full Text

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.237-242
• /
• 2004

Cell growth and the production of pullulan by Aureobasidium pullulan HP-2001, the UV-induced mutant of A pullulans ATCC 42023, increased with increased concentration of glucose up to 15.0% (w/v). Maximal production of pullulan in the flask scale was 27.65 g/l, when concentrations of glucose and yeast extract were 15.0 and 0.25% (w/v), respectively. Maximal conversion rate of pullulan from glucose as the carbon source was 0.37, when those of glucose and yeast extract were 5.0 and 0.15% (w/v), respectively. On the basis of total amount of pullulan, the conversion rate of pullulan from glucose, and utilization rate of glucose to cell mass and pullulan by A. pullulans HP-2001, the optimal concentrations of glucose and yeast extract for the mass production of pullulan were determined to be 10.0 and 0.25% (w/v), respectively, at which concentrations the production of pullulan and its conversion rate were 27.14 g/l and 0.27, respectively. Maximal production of pullulan with optimized concentrations of carbon and nitrogen sources by A. pullulans HP-200l in a 7-1 bioreactor was 32.12 g/l for 72 h culture, and that in a 100-1 bioreactor with the inner pressure of $0.4 kgf/cm^2$ was 36.87 g/l. Increased inner pressure of a 100-1 bioreactor resulted in a higher concentration of dissolved oxygen in the medium, which might enhance the production of pullulan by A. pullulans HP-2001.

• Food Science and Preservation
• /
• v.23 no.6
• /
• pp.906-912
• /
• 2016

${\beta}$-Glucan is a natural compound contained in cell walls of yeast or fungi, and cereal's fiber. It is also known to boost the immune system in human. Aureobasidium is a producer of water-soluble ${\beta}$-1,3/1,6-glucan. In this study, natural killer (NK) cell and macrophage activity were tested to investigate the effects of ${\beta}$-1,3/1,6-glucan isolated from A. pullulans on immune activity. Activation of NK cell was increased about 63-39% by the treatment of $10-200{\mu}g/mL$ ${\beta}$-1,3/1,6-glucan than control. Besides, only $10{\mu}g/mL$ of ${\beta}$-1,3/1,6-glucan was enough to boost activation of NK cell. Phagocytosis of macrophage was increased to 15~21% by the treatment of $10{\sim}200{\mu}g/mL$ of ${\beta}$-1,3/1,6-glucan than zymosan-treatment. In LP-BM5 proliferating inhibition test, relative mRNA level of LP-BM5 virus was decreased in ${\beta}$-1,3/1,6-glucan-treated cell about 36~74% than control. The decline of LP-BM5 mRNA level appeared to depend on the concentration of ${\beta}$-1,3/1,6-glucan. These results suggest that pure ${\beta}$-1,3/1,6-glucan from A. pullulans might be contributing to enhancement of immune activity through the activation of NK cell and phagocytosis of macrophage. Moreover, treatment of the ${\beta}$-1,3/1,6-glucan could increase the resistance to virus infection such as LP-BM5 through the restraining of the multiplication.

• KSBB Journal
• /
• v.14 no.1
• /
• pp.66-70
• /
• 1999

Comparison of lead removal characteristics between two strains, Aureobasidium pullulans and Saccharomyces cerevisiae, and effects of extracellular polymeric substances(EPS) excreted by microorganisms on the removal of lead were investigated. The capacity of lead biosorption to A. pullulans which had EPS was increased as the storage time of the cells increased, due to the increased amounts of excreted EPS. When the EPS were removed from A. pullulans cells, the amounts of adsorbed lead were very small(10% of the cell with EPS). In the case of s. cerevisiae which had no EPS, the lead removal capacity was nearly constant with storage time except early stage, but the spending time to reach an equilibrium state decreased with increasing storage time because of lowering the function of cell membrane. Therefore, it seems that the phenomena of lead biosorption were remarkably affected by the presence of extracellular polymeric substances.

• Journal of Microbiology and Biotechnology
• /
• v.3 no.4
• /
• pp.298-302
• /
• 1993

Pullulan was produced from starch hydrolysate with Aureobasidium pullulans SH8646. We could measure the correct amount of pullulan produced without the interference of starch from the culture supernatant by using a bacterial $\alpha$-amylase treatment and ethanol: acetone (1:1) precipitation. When 5% acid-hydrolyzed starch was used as a carbon source, the dry cell weights obtained were similar irrespective of DE values of starch hydrolysates. The dry cell weights of those on the starch hydrolysate media prepared with 0.1 N HC1 treatment, were slightly higher (9.5~10.5 g/l) than those on the starch hydrolysate media prepared with 1.0 N HCl (8.5~9.5 g/l). And among the starch hydrolysates showing DE values lower than 50, maximum pullulan production of 15 g/l was obtained at DE 30~40 starch hydrolysate but those showing DE values higher than 50, the pullulan production was increased with the increase of the DE value of starch hydrolysates. From the media containing 5%, 10%, and 15% starch hydrolysate (DE 25, 45, and 75), about 20~34% pullulan yield was obtained and the maximum pullulan yield of 34% (17g/l) was obtained from 5% DE 75 starch hydrolysate. The pullulan yields from starch hydrolysate media were much lower than those from glucose, maltose, maltotriose, and sucrose media.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.5
• /
• pp.697-706
• /
• 2018

Lactobacillus pentosus K1-23 was selected from among 25 lactic acid bacterial strains owing to its high inhibitory activity against several pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, S. gallinarum, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridium perfringens, and Listeria monocytogenes. Additionally, among 13 strains of Aureobasidium spp., A. pullulans NRRL 58012 was shown to produce the highest amount of ${\beta}$-glucan ($15.45{\pm}0.07%$) and was selected. Next, the optimal conditions for a solid-phase mixed culture with these two different microorganisms (one bacterium and one yeast) were determined. The optimal inoculum sizes for L. pentosus and A. pullulans were 1% and 5%, respectively. The appropriate inoculation time for L. pentosus K1-23 was 3 days after the inoculation of A. pullulans to initiate fermentation. The addition of 0.5% corn steep powder and 0.1% $FeSO_4$ to the basal medium resulted in the increased production of lactic acid bacterial cells and ${\beta}$-glucan. The following optimal conditions for solid-phase mixed culture were also statistically determined by using the response surface method: $37.84^{\circ}C$, pH 5.25, moisture content of 60.82%, and culture time of 6.08 days for L. pentosus; and $24.11^{\circ}C$, pH 5.65, moisture content of 60.08%, and culture time of 5.71 days for A. pullulans. Using the predicted optimal conditions, the experimental production values of L. pentosus cells and ${\beta}$-glucan were $3.15{\pm}0.10{\times}10^8CFU/g$ and $13.41{\pm}0.04%$, respectively. This mixed culture may function as a highly efficient antibiotic substitute based on the combined action of its anti-pathogenic bacterial and immune-enhancing activities.

• KSBB Journal
• /
• v.17 no.6
• /
• pp.555-559
• /
• 2002

Three different strains of Aureobasidium pullulans were grown in batch cultures to compare their abilities of enzyme production. It was found that specific enzyme activity was the highest with strain ATCC 9348 and the enzyme production was closely coupled to growth. Studies on morphology during the growth of A. pullulans revealed that mycelia cells were dominant at the initial stages of growth. However, yeast-like cells and chlamydospores were dominant in the latter stages of batch culture. The pattern of morphological changes during the growth period was not affected by pH. However, it appears that the ratio of intra- to extracellular enzyme activity tended to increase with fermentation time irrespective of the pH employed, suggesting that the secretion efficiency of intracellular enzyme to broth likely depends on cell morphology Using molasses as a cheap source of sucrose, enzymatic production of fructo-oligosaccharides as a feed additive with A. pullulans cells could be achieved successfully at 55$\^{C}$ and pH 5.5.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.3
• /
• pp.265-271
• /
• 2017

In this study, anti-oxidant, whitening and anti-aging effects were investigated the possibility of fermented black tea yeast as a functional cosmetic material. The results of Aureobasidium pullulans (A. pullulans) ferment of black tea (AFBT) were compared with black tea (BT) and A. pullulans ferment (AF). The antioxidant activity of the AFBT product showed DPPH radical scavenging ability higher than that of AF. In the intracellular ROS experiments induced by hydrogen peroxide, the AFBT showed significant decreased activity. In addition, AFBT showed tyrosinase inhibitory activity and inhibited the formation of melanin using Melan-a and B16F10 cells. Through suppression of MMP-1 expression, the AFBT showed higher anti-wrinkle activity than BT and AF. From the results of this study, it was confirmed that AFBT showed antioxidant activity and was developed as a functional cosmetic material based on whitening and anti-wrinkle efficacies.

• KSBB Journal
• /
• v.11 no.4
• /
• pp.497-503
• /
• 1996

In this study, the effects of nitrogen sources and pH on pullulan production were investigated. As a result, the best nitrogen source in pullulan production by Aureobasidium pullulans was shown to be peptone and its product yield was 62%. Optimum concentration of carbon/nitrogen source ratio was 50/0.15 and the production of pullulan was inhibited at ratios higher than 50/0.15. Aureobasidium pullulans had produced 29.1, 27.4 and 26.5 g/L pullulan, respectively in media I, II, and III containing mixed nitrogen sources. This result showed that pullulan could be produced efficiently from mixed nitrogen source. It was found that pullulan yield with pH control was higher than that with no pH control. In fedbatch fermentation, pullulan yield obtained with a feeding rate of 0.05 N-g/L for nitrogen source was higher than that without nitrogen source feeding.

• Korean Journal of Food Science and Technology
• /
• v.53 no.2
• /
• pp.195-203
• /
• 2021

Aureobasidium pullulans, a black yeast, produces pullulan, a linear α-glucan composed of maltotriose repeating units linked by α(1→6)-glycosidic linkages. Pullulan can be widely used in food, cosmetic, and biotechnology industries. In this study, we isolated eight strains of A. pullulans from Forsythia koreana, Magnolia kobus DC., Spiraea prunifolia var. simpliciflora, Cornus officinalis, Cerasus, and Hippophae rhamnoides. Among them, A. pullulans MR was selected as the best pullulan producer. The effects of a carbon source, a nitrogen source, and pH on pullulan production were examined. The optimal cultivation conditions for pullulan production by A. pullulans MR were determined by response surface methodology as 15% sucrose, 0.4% soy peptone, and an initial pH of 7 at 26℃. Under these conditions, the predicted pullulan production was 47.6 g/L, which was very close to the experimental data (48.9 g/L).