• Journal of Microbiology and Biotechnology
• /
• v.24 no.9
• /
• pp.1280-1290
• /
• 2014

In order to obtain the cellulolytic bacterial consortia, sediments from Great Basin hot springs (Nevada, USA) were sampled and enriched with cellulosic biomass as the sole carbon source. The bacterial composition of the resulting anaerobic ethanol-producing celluloytic bacterial consortium, named SV79, was analyzed. With methods of the full-length 16S rRNA library-based analysis and denaturing gradient gel electrophoresis, 21 bacteria belonging to eight genera were detected from this consortium. Clones with closest relation to the genera Acetivibrio, Clostridium, Cellulosilyticum, Ruminococcus, and Sporomusa were predominant. The cellulase activities and ethanol productions of consortium SV79 using different agricultural residues (sugarcane bagasse and spent mushroom substrate) and energy crops (Spartina anglica, Miscanthus floridulus, and Pennisetum sinese Roxb) were studied. During cultivation, consortium SV79 produced the maximum filter paper activity (FPase, 9.41 U/ml), carboxymethylcellulase activity (CMCase, 6.35 U/ml), and xylanase activity (4.28 U/ml) with sugarcane bagasse, spent mushroom substrate, and S. anglica, respectively. The ethanol production using M. floridulus as substrate was up to 2.63 mM ethanol/g using gas chromatography analysis. It has high potential to be a new candidate for producing ethanol with cellulosic biomass under anoxic conditions in natural environments.

• Microbiology and Biotechnology Letters
• /
• v.30 no.2
• /
• pp.172-176
• /
• 2002

A filamentous microorganism, strain FJ1, was isolated from completely rotten wood for the production of cellulolytic enzymes. For the production of the enzymes, cellulolsic wastes were used as carbon sources of strain FJ1 and rice straw showed higher enzyme activities than sawdust and pulp. The activities of CMCase, xylanase, $\beta$-glucosidase, and avicelase were 2.95, 5.89, 0.45, and 0.12 unit/ml by use of rice straw, respectively. To enhance production of the enzymes, the mixture substrate of rice straw and cellulosic materials were investigated as carbon sources. The highest activities of CMCase, $\beta$-glucosidase, and avicelase were found in the mixture of rice straw (0.5%, w/v) and avicel (0.5%, w/v), and the highest xylanase was obtained at the mixture ratio of 0.71%(w/v) and 0.29%(w/v). Addition of 0.1%(w/v) peptone showed enhanced production of the cellulolytic enzymes in which the activities of CMCase, xylanase, $\beta$-glucosidase, and avicelase were 19.23, 27.18, 1.28, and 0.53 unit/ml, respectively. The production of the enzymes using rice straw was efficiently induced in the presence of avicel and pulp containing cellulose. In particular, a medium composed of rice straw (0.5%, w/v) and pulp (0.5%, w/v) yielded larger cellulolytic enzymes: CMCase 24.3 unit/ml, xylanase 38.7 unit/ml, $\beta$-glucosidase 1.5 unit/ml, and avicelase 0.6 unit/ml. The filamentous microorganism, strain FJ1 utilized various cellulosic wastes as carbon sources and will be expected as a favorable candidate for biological saccharification of cellulosic wastes.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.449-452
• /
• 2002

A filamentous microorganism was isolated from completely rotten wood for the production of cellulolytic enzyme. The Trichoderma sp. FJ1 produced a large amount of cellulolytic enzymes, such as CMC, xylanase, ${\beta}-glucosidase$, and avicelase. For the production of the enzymes, when cellulolsic wastes were used as carbon sources of strain FJ1, rice straw showed higher enzyme activities than sawdust and pulp. The activities of CMC, xylanase, ${\beta}-glucosidase$, and avicelase were 2.95, 5.89, 0.45, and 0.12 U/ml in use of rice straw, respectively. To enhance production of the enzymes, the mixture substrate of rice straw and commercial cellulosic materials was investigated as carbon sources. The highest activities of CMCase, ${\beta}-glucosidase$, and avicelase were found in the mixture of rice straw and avicel, particularly rice straw:avicel (50:50), and the highest xylanase was obtained in the mixture ratio of 71:29. Bacto peptone addition of 0.1% showed enhanced production of the cellulolytic enzymes in which the activities of CMCase, xylanase ${\beta}-glucosidase$, and avicelase were 19.23, 27.18, 1.28, and 0.53 U/ml, respectively. The production of the enzymes using rice straw was efficiently induced in present of avicel and pulp containing high content of cellulose. Consequently, the filamentous microorganism, strain FJ1 utilized various cellulosic wastes as carbon sources and cellulases productivities were excellent compared to those of others strains reported previously, suggesting that the strain FJ1 will be expected as a favorable candidate for biological saccharification of cellulosic wastes in further.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.512-516
• /
• 2003

The study was aimed to saccharify callulosic waste by pectinase produced from strain KL34 isolated from soil. The enzyme activity in the culture using 1%(w/v) fruit waste as carbon source reached to 3.8 U/ml. In the enzymatic hydrolysis of cellulosic waste, we obtained 9.5g/L reducing sugar in the condition of supernatant containing 5 U/ml enzyme and 10%(w/v) apple rind as substrate. Additionally, in enzymatic hydrolysis of food waste using pectinase from KL34, reducing sugar of 12.7g/L was obtained, indicating enhancement of 1.6 fold compared with that of only cellulase employment.

• Journal of the Korean Wood Science and Technology
• /
• v.17 no.3
• /
• pp.52-60
• /
• 1989

This study was carried out to know the possibility of simultaneous utilization of laccase from white-rot fungus with cellulase on enzymatic hydrolysis of cellulosic substrate from autohydrolyzed oak wood. Laccases from 3 white-rot fungi, Pleurotus ostreatus. Ganoderma lucidum, and Phanerochaete chrysosporium, were isolated, purified and measured their activities. The highest activity was shown in Pleurotus ostreatus and the lowest in Phanerochaete chrysosporium. Laccase from Pleurotus ostreatus has optimum pH of 5.94, Km value of 3.209 mM and appeared to be stable at relatively wide pH range, 4.7-8.72. Temperature stability showed that 60% activity was preserved after 40 minutes at $50^{\circ}C$. Laccase from Ganoderma lucidum reached to the maximum activity during 15-20 day incubation. This enzyme has optimum pH of 6.45, Km value of 6.71 mM and pH range of 5.0-9.0 for stabilization. 95% activity was preserved at $30^{\circ}C$ and 58% activity at $50^{\circ}C$. Concerned to the enzymatic hydrolysis of cellulosic substrate with both enzymes, cellulase and laccase, simultaneously, mixed culture filtrates and mycellium extracts were shown higher hydrolysis rates than those of Trichoderma viride. There were no significant differences in the extent of hydrolysis among various mixed culture filtrates and mycellium extracts.

• Microbiology and Biotechnology Letters
• /
• v.4 no.4
• /
• pp.152-158
• /
• 1976

Cultivation condition of yeast on the utilization of fermentable substrate from the cellulosic wastes such as rice hull, rice straw and corn starch cake was investigated. The results obtained were summarized as follows；1. Corn starch cake was respectively added to rice hull and rice straw in order to increase sugar concentration in the hydrolyzate, and then hydrolyzed. As the result, concentration of sugar in hydrolyzed solution of rice hull was 9.12％, in that of rice straw was 7.98％. 2. It was found that calcium carbonate as a neutralizer was the most effective to prepare the culture broth of yeast. 3. An optimal growth of Hansenula subpelliculosa GFY-2 was observed in the medium prepared by adding 0.3％ of ammonium sulfate, 0.4％ of potassium phosphate dibasic, 0.02％ of magnesium sulfate, sodium chloride and calcium chloride to hydrolyaed sugar solution, respectively. 4. Hansenula subpellicuiosa GFY-2 cultured in the substrate solution which of rice hull and rice straw added to corn starch cake was assimilated more than 90％ of sugar in the hydrolyzate within 48 hours. The yeast cells yielded in rice hull was 46.5％, and that of rice straw 45.4％ to utilized sugars.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.38-43
• /
• 1998

Application of pervaporative extraction of ethanol to simultaneous saccharification and fermentation(SSF) of cellulose was investigated. From batch experiments, optimum cellulose substrate and enzyme loadings were found to be 10% and 15 IFPU/g cellulose, respectively. The cellulose conversion was lowered in fed-batch system due to the ethanol accumulation. The activity of the yeast Saccharomyces uvarum used in this study was significantly reduced at ethanol concentrations above around 40 g/L. From pervaporation experiments using PDMS membrane, ethanol was efficiently separated at 38$^\circ C$ and 10 mmHg of a down stream pressure. The pervaporation unit with 240 cm$^2$ of surface area was combined into the SSF reactor. The continuous removal of ethanol by pervaporation during SSF resulted in an improved cellulose conversion. Within the scope of this experiment, ethanol yields in the pervaporative SSF and simple SSF were 68.3% and 56.6%, respectively. The permeate flux for SSF broth pervaporation was about one-half that for the pervaporation of aqueous ethanol solution. Accordingly, the development of a membrane with higher ethanol selectivity and flux will increase the feasibility of this technology.

• KSBB Journal
• /
• v.6 no.2
• /
• pp.157-166
• /
• 1991

The structural properties of cellulose are significantly changed with the progress of hydrolysis reaction. The effects of changes on such properties of cellulosic substrate as crystallinity, amicessibility of enzyme to the active site of cellulose surface, and particle size on the kinetics of enzymatic hydrolysis have been studied. Among those physical studies, the apparent surface active site of cellulose particle was found to have the most significant effect on the hydrolysis kinetics. Based on the experimental results, the adsorption affinity of enzyme and hydrolysis rate were mainly influenced by the surface roughness of cellulose particle. The extent of accesssible active site may be expressed as the change of particle diameter. The Langmuir isotherm was proposed in terms of enzyme activity to explain the actual action of enzyme protein.

• Microbiology and Biotechnology Letters
• /
• v.5 no.3
• /
• pp.127-131
• /
• 1977

Various kinds of native herbage grasses like-Miscanthus sinensis, Arundinella hirta, Cymbopogen geirngii, Themeda japonica etc. are widely distributed in every Korean mountain. So we investigated the availability of native grass, Miscanthus sinensis as a substrate for the production of S. C. P. The results were obtained as follows. 1) At the alkali treatment, NaOH was the most effective with the exclusion of lignin, and pretreated Miscanthus with NaOH appeared to be a good substrate for the microbial growth. 2) When Miscanthus was treated with one to 10％ NaOH, the microbial growth increased in proportion to the increased alkali concentration. Beyond 4％ NaOH, a slight increase was observed. 3) Phosphoric acid, as a neutralizer, was the most effective in cell production after alkali treatment. 4) On the effect of incubation time, the productivity was best found at 60 hours, and the cell weight was 9.23 mg per 1 ml, and the microbial digestibility of substrate was 75.2％.

• Microbiology and Biotechnology Letters
• /
• v.2 no.2
• /
• pp.79-82
• /
• 1974

Present experiments were designed to estimate the effects of pretreatments by various kinds of alkalis to the agricultural wastes such as cereal straws as the substrate on the production of cellulosic single-cell protein. Among the various kinds of alkalis NaOH was proved to be the most effective on improving the digestibility of cellulose by the bacteria isolated. NH$_4$OH which is inferior to NaOH in the effectiveness of treatment might have more economic advantage in the price, and the ammonium salt resulted from the neutralization can be used as the nitrogen source by bacteria. The treatment with higher concentration than 1 normality of NH$_4$OH didn't increase the productivility of cell mass. About five per cent of (NH$_4$)$_2$SO$_4$ in medium resulted from the neutralization didn't have any influence in the cell mass productivility. Futhermore, the cell mass productibility was higher in the case of neutralization than alkali free washing. The digestibility of straws was increased from 7.9％ to 46.0％ by NH$_4$OH treatment, and 6.3∼6.45g of dry cell were obtained from 40g of NH$_4$OH treated straws. In the case of NaOH treatment, 8.6g of cell mass was obtained from 40g of substrate.