• Journal of Life Science
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• v.11 no.2
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• pp.116-119
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• 2001

Xinlei studies on the production of pullulan by Aureobasidium pullulans using batch culture in a 15L bioreactor were carried out. The mathematical models were obtained in this study, which provided a reasonable description for the biomass, the product, and the substrate variation with time. The values frets the mathematical models were satisfactorily coincided with the experimental data for the biomass of A. pullulans, the production of pullulan and the utilization of sucrose as the sole carbon source.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.193-199
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• 1991

The effects of pH on the cell growth, the elaboration of pullulan, and the morphology of Aureobasidium pullulans IFO 4464 were examined. A. pulluans grew in yeast-like form at constant pH7.5 and in mycelial form at constant pH2.5. At the both pH conditions, the elaboration of pullulan was very low, about 6.0~6.5g/l. The mixture of yeast-like form and mycelial form of cells was found at the constant pH4.5, at which condition, the elaboration of pullulan was high, about 24.5g/l. The pH shift experimemts showed that the specific production rates of pullulan were 0.048($hr^{-1}$)for the mycelial form and 0.058($hr^{-1}$)for the yeast like form, which indicated that the yeast-like form has the similar, only slightly higher, biosynthetic activity of pullulan to the mycelial form at pH4.5 and the pH of culture broth is more important factor for the elaboration of pullulan than the morphology of A. pullulans.

• KSBB Journal
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• v.5 no.2
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• pp.101-106
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• 1990

The aspects of pullulan production by Aureobasidium pullulans were investigated under various initial pH, carbon source and nitrogen source conditions. The resulting pullulan fermentation broths were analyzed by using GC, LC and GPC techniques. The maximum pullulan production was obtained in the culture medium containing 5% sucrose at pH 6, 28$^{\circ}C$ after 7 days of cultivation. Under the pH 3, pullulan was almost not produced although the total cell mass of A. pullulans was increased, and the case on using (NH4)SO4 as a nitrogen source, which usually cause the fermentation medium under pH 3, also gave the similar phenomena. Sucrose was believed to converted to trisaccharide and glucose extracellulary and polymerization of glucose was proceeded intracellulary.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.79.2-79.2
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• 2008

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

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• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.409-416
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• 1992

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus were $15^{\circ}C$ and 72 hrs, respectively. The addition of casein, nutrient broth and egg albumin to the basal medium, respectively, increased greatly the enzyme production. The enzyme was purified by ammonium sulfate fractionation, CM-cellulose and DEAE-cellulose column chromatographies. The specific activity of the purified enzyme was 29.09 U/mg protein and the yield of enzyme activity was 17.1% The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 61,000 by SDSpolyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pH 7.0. The optimum temperature and pH were $40^{\circ}C$ and 6.5. The purified enzyme was stable below $35^{\circ}C$ and in the pH range of 6.5-11.0. It was greatly inhibited by $Ag^{+}$, $Hg^{2+}$ and $Zn^{2+}$, and its thermal stability was increased by the addition of $Ca^{2+}$ Among various substrates, pullulan was favorably hydrolyzed by the purified enzyme and the hydrolysis product 011 pulluIan was maltotriose.

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

• Journal of Life Science
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• v.6 no.2
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• pp.79-86
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• 1996

A bacterium producing pullulanase was from soil, and was identified Bacillus cereus and named as Bacillus cereus JK36. The optimal culture conditions for the efficident production of pullulanase from B. cereus JK36 was obtained by cultivating with the medium composed of 1% pullulan, 1% teast extract, 1% bactopeptone, 0.1% NaH$_{2}$PO$_{4}$, 2H$_{2}$O, 0.02% MgSO$_{4}$\ulcorner7H$_{2}$O at 40$\circ$C, initial pH 6.5 for 70 hours. Using the culture supernatant as crude enzyme, the optimal pH and temperature of the pullulanase of this strain were 6.5 and 50$\circ$C. In effect of pH and temperature on the stability of the enzyme, the enzyme was stable in the range of pH6.0$\sim$9.5 and up to 40$\circ$C, respectively. The hydrolysis product on pullulan was mainly maltotriose.

• KSBB Journal
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• v.9 no.2
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• pp.140-146
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• 1994

Aureobasidium pullulans produced high concentration of polyols extracellularly in the media of sucrose, glucose and mannose as sole carbon source. Mannitol was the main polyol produced during the late exponential and stationary phases of growth together with small quantities of glycerol. Sucrose and glucose were rather rapidly metabolized to mannitol among carbon sources examined where the initial glucose concentration showed no difference in the amount of mannitol. In contrast 20%(w/v) of sucrose was the most appropriate concentration tested. However, the yield of mannitol based on substrate used($Y_{p/s}$) was independent on the initial concentration, and the mean value of mannitol yield in 10% glucose and sucrose media was 0.144 and 0.188, respectively. Mannitol production was reduced in response to an elevated water stress imposed by salts within the range from 0.25 to IM of NaCl or KCl as stress solutes. However, glycerol contents and its ratio to mannitol were increased at the conditions of high salinity. Based on the results, extracellular mannitol produced by A. pullulans probably resulted partly from osmoregulation(in case of glycerol) and mainly from, as known to occur in most of fungi, enzymatic reduction of the corresponding hexoses through phosphate pathway.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.315-318
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• 1991

- A bacterial strain No. S-76 which produced pullulanase powerfully was isolated frorn soil. The isolated bacterium was 0.4~$0.6\times 0.8$~1.4 $\mu\textrm{m}$ in size, gram negative, rods, motile and was identified as Aerornonas caviae by Bergey's manual of determinative bacteriology with various characteristics investigated. The highest yield of pullulanase of the strain was obtained by using the following medium: 1% pullulan, soluble starch or corn starch as a carbon sources and 0.5% yeast extract, peptone as nitrogen sources with an initial pH of 9.0. The optimal cutture conditions for production of pullulanase were at $32^{\circ}C$ for 2 days.