• 한국식품영양학회지
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• 제25권3호
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• pp.677-684
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• 2012

Poly-${\gamma}$-glutamic Acid(${\gamma}$-PGA)를 다량 생산하는 균주를 우리나라의 전통발효식품인 청국장으로부터 Bacillus subtilis GS-2를 분리하였다. 이 균은 glutamic acid 의존형 균으로, 이 균에 의한 ${\gamma}$-PGA 생산 최적 조건을 검토한 바, 단순배지(L-glutamic acid 2.0%, glucose 1.0%, $NH_4Cl$ 0.5%, $KH_2PO_4$ 0.05%, $MgSO_4$ $7H_2O$ 0.01%, pH 7.0)로 진탕배양(220 rpm) 하였을 때, 배양시간 48시간, 최적온도 $33^{\circ}C$, 그리고 초기 pH 6.5로 나타났다. 영양원으로 glutamic acid 3%, sucrose 3%, $NH_4Cl$ 0.25%, $KH_2PO_4$ 0.15%, $MgSO_4$ $7H_2O$ 0.015%에서 ${\gamma}$-PGA 최대 생산량이 31.0 $g/{\ell}$이었다.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.798-803
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• 2001

Peptide synthetases produced from various microorganisms are multifunctional enzyme complexes and their substrates are recognized and activated by adenylation domains. To identify the substrate specificity of the peptide synthetase isolated from Bacillus subtilis 713, known to produce an antifungal peptide, two adenylation domains containing the minimal functional portion were expressed and purified. ATP-ppi exchange experiments and kinetic studies revealed that the two adenylation enzymes had a substrate specificity to $_{L}-lysine{\;}and{\;}_{L}-tryptophan$, respectively. In addition, based on a signature sequence comparison, the substrate of the third domain was predicted to be L-glutamic acid. These results suggest that this peptide synthetase is novel because there has been no previous report on a peptide synthetase that uses $_{L}-lysine,{\;}_{L}-tryptophan,{\;}and{\;}_{L}-glutamic$ acid as substrates in that order.

• 한국식품영양학회지
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• 제12권4호
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• pp.421-426
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• 1999

The major flavor compounds of Takju mash which was brewed with a modified Nuruk made by inocu-lation and cultivation of Rhizopus japonicus T2, Aspergillus oryzae L2 and Hansenula sp. BC26 isolated from Nuruk, were analyzed, as compared with those with current fermenting agents such as commerical Nur-uk and rice koji of Aspergillus kawachii. The contents of isoamyl alcohol isobutyl alcohol and ethyl acet-ate which were known as aroma compounds in Takju were much higher in mash of modified Nuruk than in that of commercial Nuruk or ricd koji. The major organic acids were lactic fumalic and succinic acid in mash of modified and lactic and acetic acid in mash of commercial Nuruk and citric lactic and suc-cinic acid in mash of rice koji. The contents of total organic acids were 5,146mg/L, 1,706mg/L and 1, 388 mg/L in mash of commercial Nuruk rice koji and modified Nuruk respectively. The major free amino acids were glutamic acid alanine proline and histidine in mash of modified Nuruk and glutamic acid proline leucine and histidine in mash of commercial Nuruk and arginine proline and glutamic acid in mash of rice koji. The contents of total free amino acids were 14,090mg/L 12,202mg/L and 7,152 mg/L in mash of modified Nuruk commercial Nurcuk and rice koji respectively. Therefore it seemed that the Takju mash of modified Nuruk was better than that of commercial Nuruk or rice koji.

• 한국미생물·생명공학회지
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• 제1권2호
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• pp.105-113
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• 1973

1) 탄소원으로서 glucose medium에서 Brevibacterium flavum을 배양할때 Biotin 5${\gamma}$/1, Desthiobiotin 5${\gamma}$/1, 7.8-Diaminopelargonic acid 10${\gamma}$/l 에서 L-GA생성이 가장 양호하였다. 2) 탄소원으로서 glucose-acetate혼합배지를 4구분하여 사용한 결과 생육도, L-GA생성은glucose 2%-acetate 혼합배지가 가장 양호하였다. 3) 탄소원으로서 Methanol, Ethanol, Ethylacetate, Acetic acid (free acetate), Na-acetate :NH$_4$-acetate=2 : 1의 배지를 사용한 결과 Na-acetate : NH$_4$-acetate=2 : 1 > Acetic acid (free acetate) > Ethylacetate > Ethanol> Methanol 의 순으로 L-GA 생성이 나타났다. 4) 생장촉진제로 각종 Biotin vitamer를 첨가하고 탄소원으로 glucose 또는 Acetate 배지를 사용하였을때 요구되는 농도는 Biotin에 대하여 Desthiobiotin은 대략 동양, 7.8-Diaminopelargonic acid는 3~4배 였으며 Bisnorbiotin은 대체효과가 없었다.

• 대한화학회지
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• 제33권5호
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• pp.504-509
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• 1989

N,N'-dimethylethylenediamine-N,N'-di-${\alpha}$-butyric acid(dmedba)와 세자리 아미노산과의 코발트(III) 착물인 [Co(dmedba)(L-aa)] (L-aa = S-methyl-L-cysteine, L-methionine, L-glutamic acid, L-aspartic acid)는$ s-cis-[Co(dmedba)Cl_2]-^ 착물과 아미노산과의 반응으로부터 얻었다. 아미노산들은 [Co(dmedda)(L-dd)] 착물과 같이 아민과 카르복실그룹을 통하여 배위되었다. 이 착물들의 구조는 ^1H-NMR, IR, UV$ 스펙트럼 데이타와 원소분석으로 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제17권5호
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• pp.433-436
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• 1996

Cobalt(Ⅲ) complexes of trifunctional amino acid and N,N'-diethylethylenediamine-N,N'-di-α-butyrate(deedba), s-cis-[Co(deedba)(L-aa)] (L-aa=S-methyl-L-cysteine, L-aspartic acid, L-glutamic acid) have been prepared from the reaction between the s-cis-[Co(deedba)(Cl2)]- complex and the corresponding amino acid. The amino acids have been found to coordinate through the amine and carboxylate groups. The S-methyl-L-cystene is coordinated not by the sulfur donor atom, but by the nitrogen and oxgen donor atoms, and the L-aspartic and L-glutamic acids are coordinated to the cobalt(Ⅲ) ion via formation of the five-membered glycinate chelate ring. Relatively small optical activity shown by the complexes is due to the chiral center present in the amino acids.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.289-295
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• 2005

In this study, the cultural medium used for the efficient production of $\gamma$-PGA with a newly isolated Bacillus sp. RKY3 was optimized. It was necessary to supplement the culture medium with L-glutamic acid and an additional carbon source in order to induce the effective production of $\gamma$-PGA. The amount of $\gamma$-PGA increased with the addition of L-glutamic acid to the medium. The addition of 90 g/L L-glutamic acid to the medium resulted in the maximal yield of $\gamma$-PGA (83.2 g/L). The optimum nitrogen source was determined to be peptone, but corn steep liquor, a cheap nutrient, was also found to be effective for $\gamma$-PGA production. Both the $\gamma$-PGA production and cell growth increased rapidly with the addition of small amounts of $K_2HPO_4$ and $MgSO_4\cdot7H_{2}O$. Bacillus sp. RKY3 appears to require $Mg^{2+}$, rather than $Mn^{2+}$, for $\gamma$-PGA production, which is distinct from the production protocols associated with other, previously reported bacteria. Bacillus sp. RKY3 may also have contributed some minor $\gamma$-PGA depolymerase activity, resulting in the reduction of the molecular weight of the produced $\gamma$-PGA at the end of fermentation.

• 폴리머
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• 제24권6호
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• pp.802-809
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• 2000

Poly(L-glutamic acid) (PLGA)와 PVA 블렌드막을 제조한 후, ethanol 수용액중에서 막증의 polypeptide 사슬의 2차구조 전이거동에 미치는 용매조성 및 대이온종의 영향과 알칼리 금속 이온 (Li, na, K, Cs)에 대한 투과특성을 조사하였다. 막중 PLG 알칼리 금속염의 helix 형성거동에 있어 대이온 선택성은 Li>Na>K>Cs의 순으로 관찰되었고, 이와 같은 특이성은 탈용매화 에너지와 정전에너지의 감소에 따른 고분자 하전기와 대이온과의 contact ion-pair 형성에 의한 것으로 설명하였다. 또한 PLGA/PVA 블렌드막의 ethanol 수용액 중에서의 알칼리 금속이온의 투과거동을 살펴보면, ethanol 농도가 점차 증가함에 따라 K, Cs의 경우는 투고도가 증가한, Li, Na의 경우에는 감소하였다. K, Cs 이온의 경우 대이온과 염소이온간의 ion-pair (M$^{+}{\cdot}$Cl$^{-}$)형성에 의한 Donnan배제효과의 감소와 중성염 형태로의 분배량 증가때문인 것으로, Li, Na 이온의 경우 막중의 coil-helix 구조전이에 따른 자유체적의 감소와 고분자 하전기와의 상호작용이 증가하여 확산성이 크게 감소하였기 때문인 것으로 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.60-66
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• 2003

Mycelial growth of L. edodes by supplement nutrition of softwood was studied on a sawdust medium. The sawdust used was from the following softwood species : Larix leptolepis, Pinus densiflora and Pinus koraiensis. The added nutritions consisted of carbon nutritions(sucrose, active carbon, xylose, glucose, paper pellet), nitrogen nutritions(potassium nitrate, ammonium chloride, asparagine, glutamic acid) and vegetable oil(rice bran oil). The sawdust medium was a mixture of 76% sawdust, 20% rice bran, 3% carbon nutrition, 0.4% nitrogen nutrition and 0.6% calcium carbonate. Following addition of carbon and nitrogen nutritions on the sawdust medium proved most suitable : L. leptolepis (glucose, glutamic acid), P. densiflora (active carbon, asparagine) and P. koraiensis (xylose, glutamic acid). The highest mycelial growth was obtained from sawdust medium of optimum condition with 97% of L. leptolepis, 110% of P. densiflora and 98% of P. koraiensis. This study has provided useful preliminary information for the cultivation of L. edodes.

• 미생물학회지
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• 제53권2호
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• pp.97-102
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• 2017

포도당과 글루탐산을 함유한 배지에서 시드로포어인 2, 3-dihydroxybenzoic acid (DHB)를 생산하는 Acinetobacter sp. B-W 균주를 글루탐산을 유일한 탄소원과 질소원으로 함유한 배지에 배양한 결과, 상등액에서 2, 3-DHB가 아닌 카테콜 형의 시드로포어를 생산하는 것으로 조사되었다. 글루탐산의 농도는 3%에서 시드로포어 생산이 최고로 나타났으며, 3% 보다 높은 농도에서는 감소하는 것으로 조사되었다. 글루탐산을 유일한 탄소원과 질소원으로 함유한 배지에서 자란 균주 B-W는 배양 온도 $28^{\circ}C$에서는 시드로포어를 생산하지만 $36^{\circ}C$에서는 생산하지 않았다. 또한 $10{\mu}M\;FeCl_3$를첨가한 배지에서는 시드로포어 생산이 완전히 억제되었다. 글루탐산 배지에서 생산된 균주 B-W의 시드로포어는 TLC 전개 용매 butanol: acetic acid: water =12:3:5에서 Rf치가 0.32로 나타나 Rf치가 0.82인 2, 3-DHB와는 다른 것으로 조사되었으며, 또한 항산화 활성도 없는 것으로 나타나 항산화 활성을 가진 2, 3-DHB와는 다른 시드로포어인 것으로 추정되었다.