• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.459-463
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• 1994

To improve the quality of rice-cake(Cholpyon), raw starch saccharifying (${\beta}-amylase$ from Bacillus polymyxa No. 26 was used in process of raw rice-cake production. 30g of raw rice flour was incubated with $0{\sim}1,200$ RS units of the enzyme for 5 hr at $45^{\circ}C$, and then steamed and stored for 40 hr at $4^{\circ}C$. In instrumental analysis, control group, which was incubated without addition of (${\beta}-amylase$, was completely hardened after incubation for $12{\sim}24$ hr at $4^{\circ}C$. In contrast, enzyme-treated group was not retrograded, and showed a great differences in hardness, cohesiveness and chewiness. On the other hand, in sensory analysis, the effect of the enzyme treatment was higher values of hardness, moistness, and sweetness than these of control group. Therefore, these results clearly suggested that ${\beta}-amylase$ was fully active to degrade raw rice starch in process of rice-cake production, resulting in improvement of starch retrogradation, good digestibility, and taste.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.183-188
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• 1992

A soil bacterium which produces raw starch-digesting $\beta$-amylase in culture medium, has been screened from soils. One strain, isolated and identified as Bacillus polymyxa No. 26, was selected as a $\beta$-amylase producing bacterium. Morphological and biological characteristics of the strain were found to be similar to those of a strain belonging to B. polymyxa. The electron microscopic observations of the bacterial vegetative cells and sporulated cells were extensively done to know the corelation between the enzyme synthesis and sporulation. When the bacterium was cultured on the appropriate media (3% dextrin, 0.3% beef extract, 0.5% polypeptone, 1% yeast extract and 0.3% NaCl at pH 7.0 for 4 days) raw starch-digestible $\beta$-amylase was produced extracellularly. This strain produced 130 units of $\beta$-amylase per ml in a culture medium containing 3% dextrin at $30^\circ{C}$. This value is compared to those of other $\beta$-amylase-producing strains. The optimum pH and temperature for crude enzymes were pH 6.5 to 7.0 and $50^\circ{C}$, respectively. The enzymes were stable between pH 5.5 and 9.0 for 30 min at $45^\circ{C}$.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.215.1-215
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• 2003

Bacillus polymyxa No. 26이 생산하는 생전분 당화형 $\beta$-amylase를 쌀가루 반죽시 첨가하여 45$^{\circ}C$에 5시간 둔 후 증자하여 제조한 절편을 4$^{\circ}C$ 저온실에 40시간 동안 저장하면서 기계적 검사와 관능검사에 의하여 물성과 맛을 측정하고 효소 무 첨가의 경우와 비교하여 노화억제 효과를 조사하였다. 기계적 검사시 효소 무 첨가구의 경우는 40시간까지도 굳지 않아 노화되지 않았으며, 경도, 점착성, 씹힘성에서도 큰 차이를 보였다. 관능검사시에도 경도, 촉촉함성, 단맛에 있어서 효소 첨가효과가 크게 나타났으며 떡의 제조 시 효소의 이용으로 설탕첨가를 생략할 수 있고 소화성과 맛을 좋게하므로서 품질을 향상시킬 수 있었다.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.189-196
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• 1992

A $\alpha$-l, 4-D-glucan maltohydrolase $(\beta$-amylase), secreted by the mesophilic aerobic bacterium Bacillus polymyxa No.26, was purified and characterized. The enzyme production was increased after a logarithmic phase of bacterial growth and paralleled with the onset of bacterial sporulation. By applying anion exchange chromatography and gel filtration the enzyme was purified 16.7-fold and had a specific activity of 285.7 units/mg. Two enzyme activities were eluted on a column of DEAE-Sephadex chromatography, and they were designated as E-I for a major enzyme peak and E-II for a minor peak. Of them, E-I enzyme peak was further purified by using gel chromatography. The molecular mass of this enzyme was determined to be 64, 000 daltons and consisted of a single subunit, showing an isoelectric point of 8.9. The enzyme was able to attack specifically the $\alpha$-l, 4-glycosidic linkages in soluble starch and caused its complete hydrolysis to maltose and $\beta$-limited dextrin. This amylolytic enzyme displayed a temperature optimum at $45^\circ{C}$ and a pH optimum at 7.0. The amino acid composition of the purified enzyme was quite similar to the other bacterial $\beta$-amylases reported. Surprisingly, the purified enzyme from this aerobe only exhibited hydrolytic activity on soluble starch, not on starch granules. The degradation of from starch by $\beta$-amylase was greatly stimulated by pullulanase addition. These results differentiated from other $\beta$-amylases reported. Based on a previous result that showed the enzyme system involves in effective degradation of raw starch granules, this result strongly suggested that the purified enzyme (E-I) can be a synergistic part of starch granule-digestion and E-II plays a crucial role in digestion of starch granules.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.340-345
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• 2010

Two similar microbial fungicides (termed as MA and MB) developed in a Korean biopesticide company were analyzed and compared each other in their biocontrol activities against the phytophthora blight of chili pepper caused by Phytophthora capsici. MA and MB contained the microbe Paenibacillus polymyxa and Bacillus subtilis, respectively, with concentrations over those posted on the microbial products. In comparison of the isolated microbes (termed as MAP from MA and MBB from MB) in the antagonistic activities against P. capsici was effective, prominently against zoospore germination, while MBB only significantly inhibited the mycelia growth of the pathogen. Some effectiveness of MAP and MBB was noted in the inhibition of zoosporangium formation and zoospore release from zoosporangia; however, no such large difference between MAP and MBB was noted. In a pot experiment, MA reduced the severity of the phytophthora blight more than MB, suggesting that the disease control efficacy would be more attributable to the inhibition of zoospore germination than mycelia growth of P. capsici. These results also suggest that the similar microbes MA and MB targeting different points in the life cycle of the pathogen differ in the disease control efficacies. Therefore, to develop microbial fungicides it is required to examine the targeting points in the pathogen's life cycle as well as the action mode of antagonistic microorganisms.