• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.695-703
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• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• 한국식품과학회지
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• 제40권1호
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• pp.70-75
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• 2008

두 개의 amylase를 호알칼리성 Pseudomonas sp. KFCC 10818의 배양액으로부터 정제하여 그 특성을 조사하였다. 정제된 효소의 분자량은 각각 50 kDa과 75 kDa이었다. 이 효소들의 최적반응온도는 각각 $35^{\circ}C$와 $40^{\circ}C$였으며 50 kDa의 효소는 칼슘이온에 의하여 효소활성이 두 배로 촉진되었다. 이 두 효소는 최적 pH가 6-8 부근이었으며 pH 12의 조건에서도 효소활성을 유지하는 알칼리내성을 나타냈다. Maltooligosaccharide이나 soluble starch로부터 maltose와 maltotriose를 최종 효소반응산물로 생산하였다. 두 amylase는 N-말단 아미노산 서열이 각각 QTVPKTTFV와 DTVPGNAFQ로 분석되었다.

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.573-579
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• 1995

A Bacillus strain capable of producing an extracellular malto-oligosaccharides forming $\alpha $-amylase was isolated from soil and designated as Bacillus sp. SUH4-2. The enzyme was purified by ammonium sulfate fractionation, DEAE-Toyopearl and Mono-Q HR 5/5 column chromatographies using a FPLC system. The specific activity of the enzyme was increased by 16.1-fold and the yield was 13.5%. The optimum temperature for the activity of $\alpha $-amylase was 60-65$\circ$C and more than 50% of initial activity was retained after the enzyme was incubated at 60$\circ$C for 40 min. The enzyme was stable over a broad pH range of 5.0-8.0 and the optimum pH was 5.0-6.0. The molecular weight of the enzyme was determined to be about 63.6 kD and isoelectric point was around 5.8. The enzyme activity was strongly inhibited by Mn$^{2+}$, Ni$^{2+}$, and Cu$^{2+}$ ; slightly by Ca$^{2+}$. The purified enzyme produced starch hydrolyzates containing mainly maltose and maltotriose from soluble starch. The starch hydrolyzates were composed of 11% glucose, 59% maltose, 25% maltotriose and 5% maltotetraose.

• Applied Biological Chemistry
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• 제28권3호
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• pp.209-217
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• 1985

토양으로부터 균체외(菌體外) 단백질 생산균주 17주(株)를 분리하여 이 중 단백질생산이 강한 T219를 선정하여 동정(同定)하였으며 단백질 생산에 영향을 미치는 인자(因子)들을 검토하였다. T219균주(菌株)는 Bacillus속으로 동정(同定)되였으며 균체외(菌體外) 단백질생산 최적온도는 $25^{\circ}C$, pH는 7.5이었다. 단백질생산균주들이 분비하는 단백질에서는 protease와 amylase활성은 보이지 않았으며, 배양시간에 따른 단백질생산은 배양 2일에서 최대로 되었다. yeast extract와 meat extract를 함유한 배지에서 균체증식은 컸지만, 단백질 축적은 거의 없었고, polypeptone은 균체(菌體) 증식과 단백질생산에 큰 효과를 보였다. 또한 배지에 glycine과 L-isoleucine을 혼합하여 첨가하였을때 단백질생산의 효과가 커서 4mg/ml의 단백질축적이 있었다. T219균주(菌株)는 streptemycin의 $30{\mu}g/ml$이상의 농도에서 생육이 저해되었고, EDTA의 5mM농도에서는 생육에 영향을 받지 않았다. 또한, 이들 물질은 단백질생산에 영향을 미치지 않았다.

• Mycobiology
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• 제36권1호
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• pp.74-76
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• 2008

To obtain basic information on the biochemical property of basidiospores of shiitake mushroom (Lentinula edodes), the ability of producing extracellular enzyme was assessed using a chromogenic plate-based assay. For the aim, amylase, avicelase, $\beta$-glucosidase, CM-cellulase, pectinase, proteinase, and xylanase were tested against monokaryotic strains generated from forty basidiospores of two different parental dikaryotic strains of shiitake mushroom, Sanjo-101Ho and Sanjo-108Ho. These two parental strains showed different degree of extracellular enzyme activity. No identical patterns of the degree of enzyme activity were observed between monokaryotic strains and parental strains of the two shiitake cultivars. The degree of extracellular enzyme activity also varied among monokaryotic strains of the two shiitake cultivars. Our results showed that dikaryotic parental strains of shiitake mushroom produce monokaryotic basidiospores having very diverse biochemical properties.

• Mycobiology
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• 제35권3호
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• pp.162-165
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• 2007

Thirty seven species of Fusarium were evaluated for their ability of producing extracellular enzymes using chromogenic medium containing substrates such as starch, cellobiose, CM-cellulose, xylan, and pectin. Among the tested species Fusarium mesoamericanum, F. graminearum, F. asiaticum, and F. acuminatum showed high ${\beta}$-glucosidase acitivity. Xylanase activity was strongly detected in F. proliferatum and F. oxysporum. Strong pectinase activity was also found in F. oxysporum and F. proliferatum. Amylase activity was apparent in F. oxysporum. No clear activity in cellulase was found from all the Fusarium species tested.

• 한국식품영양과학회지
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• 제39권1호
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• pp.47-53
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• 2010

제주 전통된장으로부터 세포외효소(protease, fibrinolytic enzyme, amylase, cellulase, lipase) 분비능이 우수한 세균을 분리한 후 16S rRNA 유전자 분석과 생리적 특성을 분석하여 균주를 확인하고자 하였다. Protease 분비능은 JR14, JR19, JR25, JR32, JR38, JR47과 JR64가 표준균주인 Bacillus subtilis KCCM12027보다 활성이 높았다. Amylase 분비능은 JR6, JR25, JR38, JR56, JR81에서 나타난 반면 표준균주인 KCCM12027에서는 나타나지 않았다. Cellulase 분비능은 JR6, JR14, JR48과 JR65가 다른 분리균주 또는 표준균주보다 높았으며, lipase 분비능은 JR14와 JR48이 높았다. 혈전용해 활성은 positive control인 plasmin의 용해 영역에 비하여 JR19가 192%로 가장 높았고, hemolysis 활성도 높았다. 혈전용해능이 있는 균주인 JR19, JR32, JR47, JR64의 배양액을 zymography한 결과, 25～75 kDa 사이에서 4～5개의 밴드가 확인되었다. 된장으로부터 분리한 균주들의 16s rRNA 유전자 염기서열을 분석한 결과 모두 Bacillus species와 99%의 상동성을 나타내었으며, 혈전용해능이 가장 우수한 JR19는 B. stratosphericus $41KF2a^T$와 거의 일치하였다.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.582-587
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• 1993

The extracellular alpha-amylase was purified to homogenity from the culture filtrate of starch grown Sch. castellii CBS 2863. The purified enzyme was glycoprotein with a molecular weight of about 56 kDa. The pH and temperature optimum were 5.5 and 40C, respectively. The enzyme was fairly stable up to 40C and at acid pH range (pH 4.0-7.0). The apparent Km and Vmax of the enzyme toward starch was 1.0mg/ml and 100U/mg protein, respectively. The analysis of amino acid composition was found to be acidic protein. The amino acid sequence of N-terminal peptide consisted of Asp-Val-Ser-Ser-Ala-X-X-Thr-Arg-Ser-Glu-Ser-Ile-Tyr.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.109-114
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• 1997

The Oomycete Saprolegnia ferax produces an extracellular $\beta$-amylase, Maximum enzyme yield was attained after 7 days of growth in YNB starch medium (pH 6.5) at 25$\circ$C. The amylase was pu- rified 24-fold by ultrafitration, HPLC DEAE column and HPLC gel filtration. The purfied enzyme was a monomeric glycoprotein with a molecular weight of about 44,000 dalton. The pH and temperature optima were 6.5 and 50$\circ$C, respectively. The enzyme was fairly stable up to 50$\circ$C and at acidic pH region (pH 4.0-7.0). The apparent Km and Vmax values of the enzyme against soluble starch were 0.77 mg/ml and 2,174 $\mu$moles/mg protein, respectively. Amino acid analysis indicated that the enzyme was enriched in alanine, glycine, leucine and acidic amino acid. Starch hydrolysis with the enzyme released maltose but not glucose, whereas maltotriose, Schardinger dextrin ($\alpha$-cyclodextrin) and pullulan were not hydrolysed by the enzyme. The enzyme was inhibited by Schardinger dextrin, p-chloromercuribenzoate(PCMB), CU$^{2+}$' and Hg$^{2+}$. Inhibition of the enzyme by PCMB could be reversed by the addition of cysteine and mercaptoethanol.

• Journal of Microbiology and Biotechnology
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• 제20권9호
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• pp.1307-1313
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• 2010

An extracellular ${\alpha}$-amylase from Lactococcus lactis IBB500 was purified and characterized. The optimum conditions for the enzyme activity were a pH of 4.5, temperature of $35^{\circ}C$, and enzyme molecular mass of 121 kDa. The genome analysis and a plasmid curing experiment indicated that $amy^+$ genes were located in a plasmid of 30 kb. An analysis of the phylogenetic relationships strongly supported a hypothesis of horizontal gene transfer. A strong homology was found for the peptides with the sequence of ${\alpha}$-amylases from Ralstonia pikettii and Ralstonia solanacearum. The protein with ${\alpha}$-amylase activity purified in this study is the first one described for the Lactococcus lactis species, and this paper is the first report on a Lactococcus lactis strain belonging to the amylolytic lactic acid bacteria (ALAB).