• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.297-302
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• 2004

A chitinase-producing bacterium was isolated from seashore mud around Beobseongpo in Chunmam province through the use of a selective enrichment culture. The best chitinase producing strain was isolated and identified as Serratia marcescens KY from its characteristics. For effective production of chitinase, optimum pH, temperature, and agitation speed were investigated in flask cultures. The optimum pH using Serratia marcescens KY was between pH 6 and 7 and the chitinase produced was 37.9 unit/mL. On the other hand, the optimal pH of the Serratia marcescens ATCC 27117 was 7.5, and the produced amount of chitinase was 35.2 unit/mL. The optimal temperature for chitinase production for Serratia marcescens KY and Serratia marcescens ATCC 27117 was $30^{\circ}$. The cell growth pattern at different temperature was almost identical to the chitinase production. To investigate the optimal shaking speed under optimal culture, speeds were varied in the range of 0∼300 rpm. The maximum production of chitinase was carried at 200 rpm although the cell growth was the highest at 150 rpm. It indicates that oxygen adjustment is required for the maximum chitinase production. Using optimal conditions, batch cultures for comparing Serratia marcescens KY and Serratia marcescens ATCC 27117 were carried out in a 5 L fermentor. The oxygen consumption was increased with the increase of culture. Especially, at 120 h of culture Serratia marcescens KY and Serratia marcescens ATCC 27117 produced 38.3 unit/mL, and 33.5 unit/mL, respectively.

• KSBB Journal
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• 제16권4호
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• pp.365-369
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• 2001

Serratia marcescens KY와 Serratia marcescens ATCC 27117 두 균주 모두 기본 배지에 $K_2$HPO$_4$ 농도를 0.2 g/L 농도 첨가할 경우 최대 chitinase 생성을 나타냈다. 그러나 세포 성장에 따른 균체량은 기본 배지에 $K_2$PHO$_4$ 농도 0.2 g/L 이상에서는 균체량은 약간 감소한다. 1.2% colloidal chitin과 0.2 g/L의 $K_2$PHO$_4$가 포함된 기본 배지에 MgSO$_4$를 0.2-0.25 g/L를 첨가하였을 때 최대의 chitinase 생성을 보이고, 두 균주 모두 K, P, Mg 및 기타 mineral을 영양 요구 인자로서 필요한다. Colloidal chitin을 1.2% 함유하고 있는 기본 배지에 각종 탄소원의 종류에 따른 세포 성장과 chitinase 생성은 colloidal chitin만을 첨가하였을 때가 상대적으로 가장 우수하고, 탄소원을 첨가할 경우 Serratia marcescens는 모든 탄소원에서 chitinase 생성이 억제되었다. 또한 질소원에 따른 세포 성장과 chitinase 생성은 Serratia marcescens KY와 Serratia marcescens ATCC 27117 모두 tryptone이 가장 우수하였고, 2.0 g/L의 질소원 농도까지는 질소원 농도가 증가함에 따라 chitinase 생성은 증가하다가 2.0 g/L 이상의 농도에서는 질소원 농도가 증가함에 따라 chitinase 생성은 감소하였다. 이들 질소원 중 chitinase 생성은 trypotone>yeast extract > beef extract > asparagine 순서로 chitinaserk 생성되므로, Serratia marcescens는 chitinase 생성에 있어 vitamin B군과 같은 질소원을 growth factor로 요구한다.

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.777-780
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• 1995

A strain US50-3 producing water-soluble red pigment was isolated from the pond separating oil from water near the oil storage tanks. The strain US50-3 was identified as a strain of Serratia marcescens considering its morphological and physiological characteristics, and DNA G+C contents. It showed a little difference comparing to the Type strain and was considered to be another biotype strain.

• 한국식품영양학회지
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• 제16권2호
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• pp.152-157
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• 2003

Serratia marcescen ATCC 25419 protease를 ammonium sulfate treatment, DEAE-cellulose anion exchange chromatography등의 방법으로 정제하였는데 최종 단계에서 667.5 unit/mg 이었으며 회수율은 43%이었고 448배 정제되었다. 정제한 S. marcescens protease로부터 아포효소를 만든 후 금속 재활성화에 대해 조사하였다. S. marcescens protease는 EDTA에 의해 완전히 활성을 잃는 metalloenzyme이며 Hg, Fe, Cu 등에 의해서 효소 활성을 70% 이상 잃은 반면, Co는 효소 활성을 약 20% 정도 증가시켰다. 아포효소의 재활성화는 pH 6~8에서 Mn, Co, Zn 등이 효과적이었다. Mn, Co, Zn등을 아포효소에 가하여 만든 효소들 중에서 Zn-효소는 효소 활성도, 알칼리-불활성화, 열-안정성 면에서 원래 protease와 유사하였다.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.288-296
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• 1995

To investigate high-level expression of Serratia marcescens metalloprotease (SMP) in Escherichia coli and S. marcescens, we constructed various recombinant plasmids: pSP2, containing SMP gene and lac promoter; pKSP2, containing SMP gene and tac promoter; pTSP2, containing SMP gene, trc99a promoter, and lacI$^{q}$. The recombinant E. coli (pKSP2) strain expressed SMP to a high-level, about 36% of total cellular proteins but accumulated inactive SMP precursors intracellularly, which indicated that E. coli does not have activation and secretion system for SMP. To overproduce active SMP, we transformed S. marcescens with the recombinant plasmids by a modified CaCl$_{2}$ method. The recombinant S. marcescens ATCC27117 (pSP2) containing lac promoter for SMP transcription produced 530 U/ml of active SMP on LB broth, which is about 5.1 times of the SMP yield, 105 U/ml of a control strain, S. marcescens ATCC27117 (pUC19). However, S. marcescens ATCC27117 (pKSP2) containing tac promoter for SMP transcription did not grow healthy and hardly produced SMP. To overcome a harmful effect of the strong tac promoter, we constructed a regulatory plasmid pTSP2 containing a strong trc99a promoter and its repressor gene lacI$^{q}$. When S. marcescens ATCC27117 (pTSP2) was induced with 1.0 mM IPTG after 9 hr cultivation, 2,200 U/ml of SMP was obtained in LB broth, which is about 21 times of that of a control strain.

• KSBB Journal
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• 제31권4호
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• pp.214-218
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• 2016

Serratia marcescens characterized by the ability to produce red pigments inhabits various ecological niches. A strain Serratia marcescens PYU was isolated from abalone (Haliotis discus) collected at the West Sea in Korea. The isolated strain was gram-negative, motile, rods like coccus, oxidase-negative, and catalase-positive; and formed red pigment. S. marcescens PYU was grown in the presence of 0~10% (w/v) NaCl, at pH 4~9, and at $10{\sim}40^{\circ}C$. The strain PYU produced red pigment, and the extracted pigment showed antibacterial activity against Streptococcus iniae and Lactococcus garviae which has been known as an important fish pathogens. Further studies are underway to elucidate the direct relationship between the red pigment and antibacterial activity.

• 한국미생물·생명공학회지
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• 제20권3호
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• pp.280-288
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• 1992

Serratia marcescens ATCC 21074 균주가 세포밖으로 분비하는 metalloprotease 유전자를 대장균으로 클로닝하고 그 발현을 살펴보았다 Serratia marcescens ATCC 21074 균주의 염색체 DNA를 제한효소 HindIII로 절단하고 아가로스 전기영동 후 32P로 표지된 합성 oligonucleotide를 사용하여 southern hybridization한 결과 4.0Kb의 DNA 절편에 metalloprotease가 존재함을 알 수 있었다. 4.0Kb 염색체 DNA 절ㅊ편을 분리하여 pUC19에 연결한 후 대장균으로 transformation하였다.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.24-30
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• 1995

The effects of amino acids in growth media on the biosynthesis of Serratia marcescens biodegradative threonine dehydratase activity were examined. The enzyme activity was decreased by 44 and 34% by 10 mM isoleucine and valine, respectively, whereas it was increased approximately by 20% by 10 mM threonine. Among several metabolites tested, pyruvate increased the enzyme activity by 60% at 5 mM, but decreased the enzyme activity approximately by 20 to 70% above 20 mM. The enzyme activity was increased by 64% by 5 mM glyoxylate, whereas it decreased the enzyme activity approximately by 40 to 70% above 20 mM glyoxylate. The thiamine, monopyrrole derivative, also increased the enzyme activity by 84% at 50 $\mu $g/ml, but did not affected the enzyme activity above 300 $\mu $g/ml. cAMP increased the enzyme activity by 58% at 0.5 mM, but decreased the enzyme activity by 15% at 2 mM. These data suggested that the biosynthesis of Serratia marcescens biodegradative threonine dehydratase is regulated by concentrations of pyruvate, glyoxylate and cAMP.

• 미생물학회지
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• 제28권4호
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• pp.297-303
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• 1990

Secretion of Serratia marcescens nuclease by E. coli harboring pNUC4 was investigated. 29.2, 54.2 and 16.6% of total nuclease were observed in culture medium, periplasm, and cytoplasm of E. coli, respectively. To investigate the secretion mechanism of Serratia nuclease by E. coli, secretion kinetics of nuclease was examined in the presences of sodium azide, and energy metabolism inhibitor; procaine, an exoprotein processing inhibitor; and chloramphenicol, a protein synthesis inhibitor. In the presence of sodium azide, periplasmic unclease was gradually decreased and the extracellular nyclease was linearly increased according to the incubation time. Similar results were obtained in presences of procaine and chloramphenicol. From these results, we concluded that two transport processes are involved in nuclease secretion: secretion of nuclease through the inner membrane is occurred by an energy-dependent process and probably requiring precusor processing: secretion of nuclease through outer membrane does not require energy, de novo protein synthesis, and precursor processing.

• 한국미생물·생명공학회지
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• 제20권6호
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• pp.693-698
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• 1992

공장 폐수를 비롯한 중금속 오염 환경으로부터 효율적인 중금속 제거를 위해 생물학적 오염제거에 관한 연구가 많이 이루어지고 있다. 본 실험에서는 항생제 내성 유전자를 많이 가지고 있는 것으로 알려진 Serratia marcescens를 대상으로 이 균주가 중금속들에 대해 어떤 영향을 보이는지 조사하였다. 그 결과 lead, iron, magnesium, manganese 등의 처리군에서 24시간내에 1,000ppm 이상의 고농도 처리군에서 최소억제성장농도(MIC)를 나타냈으며, cadmium에서는 600ppm 처리군에서, 구리는 800ppm의 처리군에서 MIC를 보였으며, 아연 처리군에서는 800ppm에서 MIC를 나타냈다. 또한 48시간 배양에 따른 MIC 비교 결과, 중금속의 고농도 처리군에서 매우 긴 적응기를 갖는 것으로 확인하였다. 15가지의 항생체를 대상으로 저항성을 조사한 결과, ampicillin, tetracycline, cefamandole, cephalothin에서 저항성을 보엿으며 다른 S. marcescens 균주들에 비해 chloramphenicol에 대한 특이한 민감성을 보였다. 카드뮴과 납을 대상으로 중금속의 세포내 흡수를 조사한 결과 16.59%와 35.38%의 중금속이 세포내로 흡수되었음을 확인하였다.