• Korean Journal of Food Science and Technology
• /
• v.13 no.3
• /
• pp.241-246
• /
• 1981

A fungal strain which produced high levels of acid protease and amylase was isolated from the atmosphere for application to the manufacture of digestive enzme preparation. This study was carried out to elucidate its microbiological characteristics, environmental conditions for production of the enzymes, and relationships between the enzyme activity and acidity. 1. The isolate was identified as a fungal strain which belonged to Aspergillus niger by the manual of Rafer and Fennel, and was found to be a strain producing high levels of acid protease and amylase. 2. The optimal pH of tile enzymes produced by the strain were: protease, 2.0;, ${\alpha}-amylase$, 4 to 5; and glucoamylase, 3 to 5. 3. The optimal culture conditions for production of the enzymes were: protease (at pH 2.5), 2 to 3 days incubation on wheat bran at $30^{\circ}C$; ${\alpha}-amylase$ and glucoamylase(at pH 3.0), 3 days incubation at $30^{\circ}C$. 4. The production of acid protease and glucoamylase was increased approximately by 20 percent when 2 percent of corn starch was added to the wheat bran medium. 5. The addition of 0.3 percent ammonium sulfate to the wheat bran medium resulted in enhancing the enzyme production, especially of acid prctease.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.6
• /
• pp.482-493
• /
• 2005

Biomass is originally photosynthesized from inorgainic compounds such as $CO_2$, minerals, water and solar energy. Recent studies have shown that anaerobic bacteria have the ability to convert recalcitrant biomass such as cellullosic or chitinoic materials to useful compounds. The biomass containing agricultural waste, unutilized wood and other garbage is expected to utilize as feed, food and fuel by microbial degradation and other metabolic functions. In this study we isolated several anaerobic, cellulolytic and chitinolytic bacteria from rumen fluid, compost and soil to study their related enzymes and genes. The anaerobic and cellulolytic bacteria, Clostridium thermocellum, Clostridium stercorarium, and Clostridium josui, were isolated from compost and the chitinolytic Clostridium paraputrificum from beach soil and Ruminococcus albus was isolated from cow rumen. After isolation, novel cellulase and xylanase genes from these anaerobes were cloned and expressed in Escherichia coli. The properties of the cloned enzymes showed that some of them were the components of the enzyme (cellulase) complex, i.e., cellulosome, which is known to form complexes by binding cohesin domains on the cellulase integrating protein (Cip: or core protein) and dockerin domains on the enzymes. Several dockerin and cohesin polypeptides were independently produced by E. coli and their binding properties were specified with BIAcore by measuring surface plasmon resonance. Three pairs of cohesin-dockerin with differing binding specificities were selected. Two of their genes encoding their respective cohesin polypeptides were combined to one gene and expressed in E. coli as a chimeric core protein, on which two dockerin-dehydrogenase chimeras, the dockerin-formaldehyde dehydrogenase and the dockerin-NADH dehydrogenase are planning to bind for catalyzing $CO_2$ reduction to formic acid by feeding NADH. This reaction may represent a novel strategy for the reduction of the green house gases. Enzymes from the anaerobes were also expressed in tobacco and rice plants. The activity of a xylanase from C. stercorarium was detected in leaves, stems, and rice grain under the control of CaMV35S promoter. The digestibility of transgenic rice leaves in goat rumen was slightly accelerated. C. paraputrificum was found to solubilize shrimp shells and chitin to generate hydrogen gas. Hydrogen productivity (1.7 mol $H_2/mol$ glucos) of the organism was improved up to 1.8 times by additional expression of the own hydrogenase gene in C. paraputrficum using a modified vector of Clostridiu, perfringens. The hydrygen producing microflora from soil, garbage and dried pelletted garbage, known as refuse derived fuel(RDF), were also found to be effective in converting biomass waste to hydrogen gas.

• Applied Biological Chemistry
• /
• v.7
• /
• pp.1-13
• /
• 1966

1) Three ${\beta}-1$, 4-mannanases were isolated from germinated guar bean through extraction, ammonium sulfate fractionation, column chromatography on cellulose derivatives and gel filltration on Sephadex G-100. They were designated as ${\beta}-1$, 4-mannanase A,B and C, respectively, in the order of isolation. 2) These enzymes were different in several aspects such as pH optimum, effect of metal ions, adsorbability on cellulose derivatives, molecular weight, Michaelis constant toward reduced ivory nut mannan A, mode of action and extent of hydrolysis of the mannan. 3) ${\beta}-1$, 4-Mannanases A and C were proposed to be two different endo-enzymes of random-splitting type producing a series of oligosaccharides from ${\beta}-1$, 4-mannans. ${\beta}-1$, 4-Mannanase B was suggested to be possibly an exe-type enzyme catalyzing a stepwise splitting from the non-reducing end of ${\beta}-1$, 4-mannans to produce mannose. 4) Guaran was subjected to hydrolysis by the purified enzymes and the consequence was discussed in connection with structural requirements of the enzymes toward substituted ${\beta}-1$, 4-mannans and their role in germinating guar seeds.

• Applied Biological Chemistry
• /
• v.43 no.1
• /
• pp.72-77
• /
• 2000

The repeated silica gel colum chromatographies of EtOAc fraction, showing anticonvulsant activity, obtained from MeOH extracts of Schizandra chinensis B. fruits led to isolation of a sesquiterpenoid, four lignans and a sterol glycoside. Their chemical structures were determined to be chamigrenal, gomisin A, gomisin H, gomisin N. schizandrin and daucosterol. Among them, schizandrin and daucosterol inhibited GABA degrative enzymes, succinic semialdehyde dehydrogenase and succinic semialdehyde reductase, respectively. It is postulated that the schizandrin and daucosterol are able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on GABA degrative enzymes and act as anticonvulsant drugs.

• Mycobiology
• /
• v.47 no.2
• /
• pp.230-241
• /
• 2019

The Great Sebkha of Oran is a closed depression located in northwestern of Algeria. Despite the ranking of this sebkha among the wetlands of global importance by Ramsar Convention in 2002, no studies on the fungal community in this area have been carried out. In our study, samples were collected from two different regions. The first region is characterized by halophilic vegetation and cereal crops and the second by a total absence of vegetation. The isolated strains were identified morphologically then by molecular analysis. The biotechnological interest of the strains was evaluated by testing their ability to grow at different concentration of NaCl and to produce extracellular enzymes (i.e., lipase, amylase, protease, and cellulase) on solid medium. The results showed that the soil of sebkha is alkaline, with the exception of the soil of cereal crops that is neutral, and extremely saline. In this work, the species Gymnoascus halophilus, Trichoderma gamsii, the two phytopathogenic fungi, Fusarium brachygibbosum and Penicillium allii, and the teleomorphic form of P. longicatenatum observed for the first time in this species, were isolated for the first time in Algeria. The halotolerance test revealed that the majority of the isolated are halotolerant. Wallemia sp. and two strains of G. halophilus are the only obligate halophilic strains. All strains are capable to secrete at least one of the four tested enzymes. The most interesting species presenting the highest enzymatic index were Aspergillus sp. strain A4, Chaetomium sp. strain H1, P. vinaceum, G. halophilus, Wallemia sp. and Ustilago cynodontis.

• Applied Biological Chemistry
• /
• v.33 no.2
• /
• pp.154-160
• /
• 1990

A bacterial strain which was capable of producing extracellular soymilk-clotting enzyme was isolated from soil samples during the course of screening test. The characteristics of the isolated strain K-324-7, indicated that the strain belonged to species of Bacillus cereus. The crude purification of this enzyme was precipitated by salting out with ammonium sulfate of 0.8 saturation. The optimal pH for the enzyme activity was at $6.1{\sim}7.0$ and below $50^{\circ}C$. The optimal culture medium for the production of soymilk-clotting enzyme were consisted of 0.2% glucose, 0.2% peptone, and 0.5% $KH_2PO_4$ with initial pH value of 6.5. The activity of enzyme was maximum when the microbe was cultured for 3 days at $35^{\circ}C$.

• Microbiology and Biotechnology Letters
• /
• v.3 no.2
• /
• pp.69-72
• /
• 1975

Isolation of the toxic substance which was produced by Streptentyces sp. and it's biorhemical characterestics and toxicity to fishes were reported in the previous paper. The present report includes antibiotic activity of the substance, inhibitory activity of the substance on the succinic dehydrogenase of fishes, and its effect on the blood corpuscles of a rabbit. An evident antibiotic activity of this substance was observed on Candida yeasts, but n$ot^1$on molds or bacteria. The substance inhibited the growth of Candida japonica and C. utilis to the 50％ at the concentrations of 7.5 and 10.2ug per ml, respectively. The activity of succinic dehydrogenase obtained from various organs of Cyprinous carpio L. was also found to be inhibited by this substance. Original activities of the enzymes from tht brain, kidney, and liver, were inhibited by 75.4％, 38.2％, and 26.2％, respectively, but not the enzymes from the heart and spleen. Neither leukopenia nor leukocytosis was detected after the intravenous administration of the substince to the rabbit at the level of 6 mg per 2 kg body weight.

• Korean Journal of Food Science and Technology
• /
• v.31 no.1
• /
• pp.219-223
• /
• 1999

Various bacterial strains that secret extracellular fibrinolytic enzyme were screened from kimchi, a traditional vegetable fermented food in Korea. Three microbes of them were identified to be Bacillus amyloliquefaciens, Bacillus brevis and Micrococcus luteus strains according to Bergey's Manual of Systematic Bacteriology. It was found that B. amyloliquefaciens, B. brevis and M. luteus produced 2.58, 1.48 and 2.03 plasmin unit/mL of fibrinolytic enzyme, respectively. All extracellular proteases showing the fibrinolytic activity were confirmed by SDS-PAGE and fibrin zymography assay and we propose that some of the fibrinolytic enzymes from this work are novel enzymes.

• Journal of Life Science
• /
• v.25 no.7
• /
• pp.780-785
• /
• 2015

Dietary intake and bioavailability of phorotannins in abalone was investigated after feeding with the phlorotannin-rich brown seaweed Ecklonia stolonifera after 4 days starvation. Reverse-phase high-performance liquid chromatography (RP-HPLC) affords isolation and quantification of the major phlorotannins of 7-phloroeckol and eckol, which were identified by mass spectrometry and nuclear magnetic resonance. Abalone growth and feed consumption rates were similar when fed either with the E. stolonifera or the common feed seaweed Saccharina japonica for 20 days. Throughout the feeding period, 7-phloroeckolol was accumulated in the abalone flesh tissue up to an average of 0.58±0.13 mg/g dry weight after 6 days. Eckol was reached to 0.25±0.05 mg/g dry tissue after 6 days, and maintained the level until end of feeding period. By feeding S. japonica as a control, no phlorotannins were detected in the abalone tissues. Both of the abalone, fed with E. stolonifera or S. japonica, had enzymes that decomposed 7-phloroeckol and eckol in muscle tissues, with similar degradation rates of −0.05 or less and −0.05 mg/ml/hr, respectively. Phlorotannins were reduced by constitutive enzymes in abalone tissues. Therefore, value-added abalone containing bioactive phlorotannins can be produced by simply changing the feed to the phlorotannin-rich brown seaweed E. stolonifera 6 days before harvest.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.1
• /
• pp.7-11
• /
• 1998

Protoplasts were isolated from the parenchyma supension cultured cells of Streptanthus tortus using hydrolytic enzymes, 0.03% cellulase + 0.02% pectinase. Phloem cells and companion protoplasts were isolated from differentiated suspension cultured cells using hydrolytic enzymes, 0.2% macerase + 0.03% cellulase + 0.02% pectinase + 0.025% rohamet PC. Isolated parenchyma -and companion- protoplasts transported glucose into the cells, but not transported sucrose at all. On the other hand, isolated phloem cells transported sucrose into the cells actively, but not transported glucose. These results show for the first time that loading of sucrose into the phloem cells without nucleus was possible without contributing of companion cells and companion cells had not the ability to transport sucrose directly because of lack of sucrose carriers in the membrane. The sucrose transport into the isolated phloem cells depend on metabolic energy.