• 농업과학연구
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• 제36권2호
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• pp.225-232
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• 2009

The ratio of saccharification and formation of furans during the acid hydrolysis of agar with oxalic acid and sulfuric acid were examined base on the contents of the agar and acids. The ratio of saccharification in oxalic acid appeared to be 51~59% somewhat higher than 49~61% of sulfuric acid. Formation of the furans during the acid hydrolysis increased proportional to the contents of agar and acid. The relative formation ratio was high 10~47% for furfural (FUR) and 15~29% for hydroxy-methyl furfural (HMF) in 0.5~1.25% sulfuric acid rather than those of oxalic acid. When comparing the removal efficiency of the furans using an alkali treatment, steam stripping and hydrophobic resins, FUR was eliminated 60% by the alkali treatment, 62~90% by steam stripping and 71~75% by Amberlite XAD4 and 7HP, while HMF was removed to low levels of 10.5%, 4~17% and 13~25%, respectively. The loss of reducing sugar was also observed in process of the removal of furans, and the loss rate was the level of 2~4% in alkali treatment, 11~16% in steam stripping and 7~9% in Amberlite resins.

• KSBB Journal
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• 제29권5호
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• pp.307-315
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• 2014

Recently seaweed polysaccharides have been extensively studied for alternative energy application. Because their producing cost is high and efficiency low, their industrial applications have been limited. The main component of cell wall of red algae represented by Gelidiales and Gracilariales is agar. Red-algae agar or galactan, consisting of D-galactose and 3, 6-anhydro-L-galactose, is suitable for bio-product application if hydrolyzed to monomer unit. For the hydrolysis of algae, chemical or enzymatic treatment can be used. A chemical process using a strong acid is simple and efficient, but it generates together with target sugar and toxic compounds. In an enzymatic hydrolysis process, target sugar without toxic compounds generation. The objective of this review is to summary the recent data of saccharification by chemical and enzymatic means from red seaweed for especially focused on automobile industry.

• 공업화학
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• 제23권3호
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• pp.279-283
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• 2012

화석연료로 인한 환경오염 등의 문제를 해결하기 위해서 다양한 원료를 이용하여 바이오 에탄올 생산에 대한 연구가 진행되고 있다. 해조류 중에 홍조류는 agar, carrageenan, porphyran으로 구성되어 있어 산 처리를 통해 바이오에탄올 생산에 유용한 바이오매스로 전환이 가능하다. 본 연구는 홍조류의 가수분해물을 이용하여 바이오에탄올 생산의 최적 조건을 찾으려고 한다. 바이오에탄올 생산하기 위해 전처리 된 우뭇가사리에 Saccharomyces cerevisiae KCCM112를 접종해 발효하였다. 우뭇가사리 가수분해의 최적조건은 1.5% $H_2SO_4$를 $121^{\circ}C$에서 30 min 반응시켰을 때 7.04 g/L의 galactose와 1.94 g/L의 glucose가 생산되었다. 그리고 $CH_3COOH$의 경우 2.0% 농도로 처리하였을 때, galactose 0.75 g/L가 생산되었다. 이와 반대로 도박에서는 $H_2SO_4$1.5%를 처리하였을 때 galactose를 6.38 g/L 생산하였으며, $CH_3COOH$을 처리했을 때 0.368 g/L이 생산되었다. 우뭇가사리에서 에탄올 생산은 1.0% $H_2SO_4$를 $121^{\circ}C$에서 30 min 간 처리하였을때 가장 높았으며, 96 h 배양하였을 때 3.77 g/L의 에탄올을 생산했다.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1134-1141
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• 2004

A bacterial strain capable of hydrolyzing sulfate ester bonds in p-nitrophenyl sulfate and agar was isolated from the Southeast coast of Korea. The isolated strain (AS6330) is aerobic, Gram-negative, rod-shaped, and motile. Octadecanoic acid was the major cellular fatty acid in the isolate. An almost complete 16S rDNA sequence of the isolate was determined and the sequence similarity of the 16S rDNA with those of known Sphingomonas spp. was found to be at most $96.4\%$, implying that the isolate was a new Sphingomonas species. The organism was grown optimally at NaCl concentration of $1.5-3.5\%$. Optimum culture conditions were determined to be $30^{\circ}C$ and pH 7.0 for 48 h fermentation using a laboratory fermentor under constant culture conditions. Partially purified arylsulfatase through Q-Sepharose and phenyl­Sepharose chromatographies catalyzed hydrolysis of sulfate ester bonds in agar, and $97\%$ of sulfates in agar were removed after 4 h reaction at $45^{\circ}C$ and pH 7.0. The arylsulfatase from the isolated bacterium might be useful for the removal of sulfate groups in agar.

• 한국해양바이오학회지
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• 제8권1호
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• pp.1-9
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• 2016

The hydrolysis of biomass to fermentable sugar (saccharification) and to oligosaccharide is an essential process in biotechnology including biorefinery and biofood. Various macroalgae are commercially cultivated in several Asian countries as a useful resource for food and agar production. Agar is a major component of the cell walls of red algae that can be hydrolyzed by agarase. Agarases are classified into ${\alpha}$-agarase (E.C. 3.2.1.158) and ${\beta}$-agarase (E.C. 3.2.1.81) according to the cleavage pattern and grouped in the glycoside hydrolase (GH) family (GH-16, GH-58, GH-86, GH-96, and GH-118) based on the amino acid sequences of the proteins. Agarases have been isolated from various bacteria found in seawater and marine sediments. To increase productivity of the enzyme, a research on recombinant enzymes has been done. The application of recombinant agarase can be possible in the various filed such as energy, food, cosmetics, medical and so on. This paper reviews the source, biochemical characteristics and production system of recombinant agarases for further study.

• 생명과학회지
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• 제22권5호
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• pp.627-633
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• 2012

본 연구에서는 해수로부터 난소화성 복합다당류를 분해하는 해양미생물 $Microbulbifer$ sp. AJ-3의 효소에 대한 기질 특이성을 분석하고 균주가 생산하는 효소를 이용하여 매생이의 효소분해산물을 조제하여 이에대한 생리활성을 분석하였다. 효소의 활성은 agar에 대한 상대적인 활성으로 나타내었는데 chitin 34.8%, fucoidan 36.8%로 비교적 낮은 활성을 보였고, starch 51.2%, agarose와 laminaran은 agar와 비슷한 수준인 115.6%, 103.1%의 활성을 나타내었다. 이 뿐만 아니라 alginic acid에 대해서는 agar의 2배가 넘는 239.3%의 활성을 나타내었다. 매생이 효소분해산물의 항산화능은 DPPH radical 소거능과 SOD 활성측정으로 분석하였는데 매생이 효소분해산물 2 mg/ml의 농도에서 DPPH 라디칼 소거능은 32%, SOD 활성은 93%로 나타났다. 매생이 효소분해산물의 아질산염 소거능은 pH 1.2에서 82%, pH 3.0에서 53%, pH 6.0에서 12%로 positive control인 비타민C와 유사한 활성을 보였다. 매생이 효소분해산물의 숙취해소 효능은 ADH 활성증진에 미치는 영향을 조사하였는데 효소분해산물 2 mg/ml 농도에서 30%의 증가된 알콜 분해능이 나타났다. 매생이 효소분해산물의 미백 효능에 대해서는 tyrosinase 저해능으로 분석하였으며 2 mg/ml에서 28%의 저해활성을 나타내었고 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1067-1072
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• 2005

A metagenomic library was constructed using a fosmid vector, and total genomic DNA was extracted directly from soil at Cisolok (hot spring area, Indonesia). This library was composed of 10,214 clones and screened for lipolytic enzyme on tributyrin agar plates. An esterase gene (estMa) was subcloned and sequenced from a positive lipolytic active clone. Esterase EstMa was encoded by a 954-bp open reading frame and showed low ($11-33\%$) amino acid similarity to known esterases. The amino acid sequence analysis demonstrated that the enzyme is a new member of lipolytic enzyme family VI. The estMa gene encodes a preprotein of 317 amino acids with a predicted molecular mass of 34,799 Da. The purified enzyme exhibited optimal activity at $50^{\circ}C$ and pH 6.5. The $K_m,\;and\;V_{max}$ values of EstMa for the hydrolysis of p-nitrophenyl valerate were $45.3\;{\mu}M$ and 4.45 U/mg, respectively.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.284-292
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• 2018

A novel ${\beta}$-agarase, AgaJ5, was identified from an agar-degrading marine bacterium, Gayadomonas joobiniege G7. It belongs to the glycoside hydrolase family 86 and is composed of 805 amino acids with a 30-amino-acid signal peptide. Zymogram analysis showed that purified AgaJ5 has agarase activity. The optimum temperature and pH for AgaJ5 activity were determined to be $30^{\circ}C$ and 4.5, respectively. AgaJ5 was an acidic ${\beta}$-agarase that had strong activity at a narrow pH range of 4.5-5.5, and was a cold-adapted enzyme, retaining 40% of enzymatic activity at $10^{\circ}C$. AgaJ5 required monovalent ions such as $Na^+$ and $K^+$ for its maximum activity, but its activity was severely inhibited by several metal ions. The $K_m$ and $V_{max}$ of AgaJ5 for agarose were 8.9 mg/ml and 188.6 U/mg, respectively. Notably, thin-layer chromatography, mass spectrometry, and agarose-liquefication analyses revealed that AgaJ5 was an endo-type ${\beta}$-agarase producing neoagarohexaose as the final main product of agarose hydrolysis. Therefore, these results suggest that AgaJ5 from G. joobiniege G7 is a novel endo-type neoagarohexaose-producing ${\beta}$-agarase having specific biochemical features that may be useful for industrial applications.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.471-475
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• 1998

신생아 분변으로부터 장내세균 127균주를 분리하였다. 각각의 균주들의 배양균체를 검정종양세포들에 대해 항종양활성을 측정한 결과, 항종양활성을 나타내는 분리균주는 27균주였고, 그 중 비교적 강한 항종양활성을 보이는 균주는 5균주였으며, 5균주중 위암세포주, SNU-1에 선택적으로 강한 항종양활성을 나타내는 2B4-1 균주를 최종분리하였다. API 20 S system kit를 이용하여 분리 균주 2B4-1을 동정한 결과, Enterococcus faecalis와 99.9%의 % ID value를 나타내었다. 동정된 분리균주 2B4-1과 type strain, Enterococcus faecalis NCTC 775와의 생리생화학적 특성들을 비교해 본 결과, 온도별대 성장률, 내염성, 내산성, arabinose등의 당 이용성 및 통성혐기 상태에서의 생육 등에서는 일치된 결과를 나타내었으나 hippurate hydrolysis test의 음성반응 및 $\beta$-hemolysis test의 음성반응을 나타낸 것으로 보아 Enterococcus faecalis NCTC 775와 2가지의 다른 특성을 나타내었다. 따라서 분리균주 2B4-1은 Enterococus faecalis NCTC 775와는 약간의 특성이 다른 변종으로 확인되어 Enterococcus faecalis 2B4-1으로 동정하였다.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.83-89
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• 2012

Flavobacterium johnsoniae was isolated from farmed rainbow trout Oncorhynchus mykiss in Korea, and its biochemical and molecular characterization was determined. Yellow-pigmented bacterial colonies were isolated from 18 of 64 fish samples (28.1%) on trypticase soy agar plates, and their biochemical profiles were characterized by API 20E and API 20NE test kits. F. johnsoniae was identified by biochemical phenotyping of factors including rapid gliding motility, Gram-negative condition, oxidase- and catalase-positive status, Congo red absorption, nitrate reduction, ${\beta}$-galactosidase production, acid production from glucose, and gelatin and casein hydrolysis. PCR and subsequent sequencing of 16S rRNA confirmed that the yellow-pigmented colonies were most similar to F. johnsoniae. The alignment analysis of 16S rRNA sequences also showed that all 18 rainbow trout isolates had highly similar homologies (97-99% identity). One isolate was selected and named FjRt09. This isolate showed 98% homology with previously reported F. johnsoniae isolates, and in phylogenetic analysis was more closely grouped with F. johnsoniae than with F. psychrophilum, F. columnare, or F. branchiophilum. This is the first report on the occurrence and biochemical characterization of F. johnsoniae isolated from rainbow trout in Korea.