• Applied Biological Chemistry
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• 제48권1호
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• pp.16-22
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• 2005

키토산분해효소(Chitosanases, EC 3.2.1.132)는 당질가수분해효소군의 하나로, 아미노당인 D-glucosamine polymer인 chitosan의 ${\beta}-1,4-glycoside$ 결합을 가수분해하는 효소이며, 세균, 곰팡이, 식물 등에 널리 분포한다. 본 논문에서는 chitosanase의 N-말단 아미노산의 서열과 입체구조에 근거한 family 및 clan 분류, 작용모형, 절단 유형, subclass 분류, 및 family-subclass 상관성을 검토하였다. 아미노산 서열과 입체구조와 기질의 분해패턴 사이에는 깊은 상관이 있음을 확인 제시하였다. 다양한 종 유래 chitosanase의 1차구조의 해명과 진화적 상관 규명, 나아가 보다 정교한 chitosanase의 정의와 다양한 산업적 응용에의 가능성도 검토하였다.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.165-170
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• 2006

The antifungal activity of crude methanolic extract and fractions from Yucca smalliana Fern. leaves, roots and flowers were investigated in vitro against a panel of plant pathogenic fungi. The minimal inhibitory concentration(MIC) was determined by an agar dilution method. Preliminary liquid culture and agar plate assays showed that the growth of Fu sarium oxysporum, Phytophthora capsici, Rhizoctonia solani and Botrytis cinerea were inhibited by Y. smalliana extracts. The extracts from flowers and leaves showed antifungal activity of 64.0% and 34.0% against F. oxysporum, 66.0% and 62.0% against P. capsici, and 27.0% and 41.0% against B. cinerea, respectively. The methanolic extract from Y. smallina leaves in distilled water was fractionated using solvents of increasing polarity: hexane, ethyl acetate and butanol. These fractions had a broad spectrum of antifungal activity, found to reside entirely in the butanol and aqueous fraction. The aqueous fraction showed inhibition rate of 60.0, 67.8, 84.6 and 58.3% against F. oxysporum, R. solani, C. gloeosporioides, and B. cinerea, respectively, and the butganol fracgtion showed 36.0, 46.0, 66.1 and 58.3%, respectively. Phenolics(e.g. flavonoids, steroids and terpenoids) were observed in the thin layer profile of the different fractions. Leave extract showed a prominent antioxidant activity totally scavenging the free radical of DPPH at a concentration of 1 mg/ml.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.274-280
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• 2005

A chitinase was purified from the culture supernatant of Paenibacillus illinoisensis KJA-424 by protein precipitation, DEAE-Sephadex anion-exchange chromatography, and Sephadex G-150 gel filtration. The molecular weight of the purified chitinase was 54 kDa on SDS-PAGE and activity staining. Optimal pH and temperature were pH 5.0 and 60$^{circ}$C, the presence of 10 ruM Ag$^{+}$ and Hg$^{2+}$ inhibited the activity by $92.1/%$ and $97.7/%$, and the K$_{m}$ and V$_{max}$ values were 1.12 mg chitin mrl and 1.48$\mu$mol GlcNAc min$^{-1}$, respectively. The enzyme hydrolyzed tetramer to dimer, pentamer to dimer and trimer, and hexamer to dimer, trimer and tetramer, indicating an endo-splitting mechanism. The chitinase had no hydrolytic activity toward dimer and trimer. The chitinase inhibited the mycelial growth of Rhizoctonia solani, suggesting an antifungal property.

• 한국식품저장유통학회지
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• 제10권4호
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• pp.506-511
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• 2003

DSC를 이용하여 acom starch와 com starch 및 starch-saccharide-water system 의 겔화와 노화에 관한 열적 메카니즘을 알아보았다. 전분에 fructose와 maltose를 첨가한 starch-saccharide-water 계의 엔탈피를 측정한 결과, 당을 첨가하지 않은 경우의 엔탈피 값보다 컸으며 겔화 온도 역시 증가하였는데 이는 당이 물과 상호 작용하여 비결정성 영역에 흡수된 자유수가 감소하고 결정부분이 안정화되어 겔화가 일어나는 것을 지연시키기 때문이라고 생각되었다. 노화 엔탈피는 acorn starch 와 com starch에 대해 1일 ∼ 14일까지 저장시간에 따르는 변화를 관찰한 결과, 저장시간이 길어짐에 따라 엔탈피 값이 유의성 있게 증가하는 경향을 나타내었으며 이는 amylopectin 의 재결정화가 서서히 일어나기 때문으로 보였다. 또한 s-s-w system의 노화과정을 관찰한 결과, 저장시간이 길어짐에 따라 엔탈피 값이 증가하다가 7일이 지나면서부터는 일정해졌다. 이는 당이 amylopectin의 재결정화를 정지시켜서 노화를 지연시키기 때문으로 판단되었다. 당의 첨가가 노화에 미치는 영향은 fructose와 maltose 중에서 maltose의 노화지연 효과가 더 컸는데 이는 전분 겔 계를 안정시키는 junction zone의 수와 equatorial OH 수 및 활동적인 수화상태가 증가되는 요인을 maltose가 fructose보다 더 많이 갖고 있기 때문인 것으로 설명할 수 있었다.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.346-351
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• 1995

To produce ethanol from Jerusalem artichoke powder efficiently, Kluyveromyces marxianus F043 cells were encapsulated in 2% sodium alginate and were cultured in a countinuous reactor to investigate the fermentation properties. Immobilized K. marxianus F043 cells were activated for 48 hours in a fermentor for continuous ethanol production. The culture in a CSTR using a Jerusalem artichoke substrate treated with 2% cellulase showed a decrease in ethanol concentration and an increase in residual saccharide concentration with a increasing dilution rate. Optimum conditions for high ethanol productivity and low residual saccharide output were clarified to be given at a dilution rate of 0.2 h$^{-1}$ and a Jerusalem artichoke medium concentration of 75 g/l. Ethanol productivity of 3.1 g/l-h and saccharide utilization of 62.6% were obtained under the optimum condition. When the fermentation was performed for 3 weeks under these conditions, the effluent medium showed stable ethanol concentrations of 16.3 - 17.9 g/l and viable cells of 6.60-7.16 log cells/ml without contamination. Trace amounts of methyl, n-propyl, iso-butyl, isoamyl alcohols besides ethanol were detected.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.67-72
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• 2005

To achieve demineralization of crab shell waste by chemical and biological treatments, lactic acid and lactic acid bacterium were applied. In 5.0 and $10\%$ lactic acid, pH rapidly decreased from 6.8 to 4.2 and from 4.5 to 2.4 at day 3, respectively, and thereafter the pH remained at an almost constant level. In a $10\%$ lactic acid bacterium inoculum, pH lowered to 4.6 at day 5. Relative residual ash content rapidly decreased to 49.1 and $16.4\%$ in 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, relative residual ash content rapidly decreased to 55.2, 40.9 and $44.7\%$, respectively, on the first day. Residual dry masses were 76.4, 67.8 and $46.6\%$ in 2.5, 5 and $10\%$ lactic acid treatments, respectively, for the initial 12 h. After a one-time exchange of the lactic acid solution, in the $5.0\%$ lactic acid treatment, residual dry mass rapidly decreased from 66.0 to $41.4\%$. In 2.5, 5 and $10\%$ lactic acid bacterium inoculums, residual dry masses decreased to 67.6, 57.4 and $59.6\%$ respectively, on the first day. Protein contents after demineralization ranged from $51.3{\sim}54.7\%$ in the chemical treatments and decreased to $32.3\%$ in the lactic acid fermentation process. A negative relationship was shown between pH and demineralization rate in lactic acid and lactic acid bacterium treatments. These results suggest that lactic acid fermentation can be an alternative for demineralization of crab shells, even though the rate and efficiency of the demineralization is lower than the chemical treatment.

• 한국당과학회:학술대회논문집
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• 한국당과학회 2006년도 제1회 연례학술대회
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• pp.16-18
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• 2006

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.358-361
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• 2009

The purified endochitosanase(Mw 41 kDa) from bacterium Bacillus cereus D-11 hydrolyzed chitooligomers $(GlcN)_{5-7}$ into chitobiose, chitotriose, and chitotetraose as the final products. The minimal size of the oligosaccharides for enzymatic hydrolysis was a pentamer. To further investigate the cleavage pattern of this enzyme, chitooligosaccharide alcohols were prepared as substrates and the end products of hydrolysis were analyzed by TLC and HPLC. The chitosanase split $(GlcN)_4GlcNOH$ into $(GlcN)_3+(GlcN)_1GlcNOH$, and $(GlcN)_5GIcNOH$ into $(GlcN)_4+(GlcN)_1GlcNOH$ and $(GlcN)_3+(GlcN)_2GlcNOH$. The heptamer $(GlcN)_6GlcNOH$ was split into $(GlcN)_5$ [thereafter hydrolyzed again into $(GlcN_3+(GlcN)2]+(GlcN)_1GlcNOH$, $(GlcN)_4+(GlcN)_2GlcNOH$, and $(GlcN)_3+(GlcN)_3GlcNOH$, whereas $(GlcN)_{1-3}GlcNOH$ was not hydrolyzed. The monomers GlcN and GIcNOH were never detected from the enzyme reaction. These results suggest that D-11 chitosanase recognizes three glucosamine residues in the minus position and simultaneously two residues in the plus position from the cleavage point.

• 대한지역사회영양학회지
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• 제28권3호
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• pp.181-191
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• 2023

Objectives: The incidence of inflammatory bowel disease (IBD) is increasing globally, and excessive added sugar consumption has been identified as one of the contributing factors. In the context of IBD, it is essential to explore functional sweeteners that can improve metabolic health and minimize the risk of IBD-related symptoms. This review article aims to shed light on the effects of natural mono- and di-saccharides as alternative sweeteners, specifically focusing on potential benefits for IBD. Methods: A comprehensive literature review was performed using PubMed and Google Scholar databases with articles published after the year 2000. The search terms 'IBD', 'added sugar', 'sweeteners', 'mono-saccharide', and 'di-saccharide' were combined to retrieve relevant articles. A total of 21 manuscripts, aligning with the objectives of the study, were selected. Papers focusing on artificial or high-intensity sweeteners were excluded to ensure relevant literature selection. Results: Multiple studies have emphasized the association between the high consumption of added sugars such as simple sugars and the increased risk of developing IBD. This is suggested to be attributed to the induction of pro-inflammatory cytokine productions and dysbiosis of the gut microbiota. Consequently, there is a growing demand for safe and functional sweeteners, in particular mono- and di-saccharides, that can serve as alternatives for IBD patients. Those functional sweeteners regulate inflammation, oxidative stress, and Intestinal barrier protection, and restore microbiome profiles in various IBD models including cells, animals, and humans. Conclusions: Understanding these mechanisms resolves the link between how sugar consumption and IBD, and highlights the beneficial effects of natural alternative sweeteners on IBD when they were administered by itself or as a replacement for simple sugar. Further, exploration of this relationship leads us to recognize the necessity of natural alternative sweeteners in dietary planning. This knowledge could potentially lead to more effective dietary strategies for individuals with IBD.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.285-291
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• 1995

Saccharide utilizations for the growth by Bifidobacterium longum and Bifidobacterium breve were compared. B. longum fermented glucose more rapidly than lactose as a carbon source whereas B. breve fermented lactose at a rate higher than that of glucose. The highest cell concentration, in the case of B. longum, was obtained when cultivated in a jar fermentor that contained modified MRS medium that half the beef extract was replaced by the same amount of tuna extract, and that pH was controlled at 6.0. B. breve showed the best growth when grown in a jar fermentor containing the MRS medium with lactose instead of glucose, controlled at pH 6.0. The optimal concentration of peptone in MRS medium for the growth of B. breve was 5 g/l.