• The Korean Journal of Mycology
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• 제31권2호
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• pp.77-83
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• 2003

For the purpose of utilizing cellulose resources by cellulolytic enzymes of Roseofomes subflexibilis, it's cultural conditions for the production of cellulolytic enzymes in synthetic media were investigated. The results obtained were summarized as follows : The optimum temperature and pH for the enzyme production were $30^{\circ}C$ and pH 4.0, respectively. Among the carbon sources, glucose was good for the production of cellulase. The optimum concentration of saccharose as 1.2%. As a organic nitrogen source, yeast extract was good for the mycelial growth. The optimum concentration of yeast extract as 1.5%. As a inorganic nitrogen source, $NH_{4}H_{2}PO_{4}$ was good for the mycelial growth. The optimum concentration of $NH_{4}H_{2}PO_{4}$ were 1.1%. The mineral salt of $Al_{2}(SO_{4})_{3}$ was effective and the optimum concentration was 0.1 M.

• Microbiology and Biotechnology Letters
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• 제18권4호
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• pp.383-389
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• 1990

During the cultivation of Penkillium uerrmulosum in the media containing cellobiose octaacetate (COA), avicel, or KC-flock as an inducer and as a sole carbon source for 21 days, cellulolytic activity and SDS-PAGE pattern of proteins in the culture broth were investigated. Protein concentration and cellulolytic activity were highest in the COA medium. As cultivation period was increased, protein content and avicel hydrolytic activity of culture broth were increased as similar extent but neither $\beta$-glucosidase nor CMC hydrolytic activity was correlated to protein content. When crude proteins from the culture broth were separated on DEAE column by HPLC, distribution of avicel-hydrolytic activities were well correlated with that of major proteins. From those results it was suggested that three major proteins having 60 K, 68 K, and 76 K of Mr. were avicel-hydrolytic enzymes.

• Korean Journal of Microbiology
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• 제23권1호
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• pp.25-33
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• 1985

The cell-free cellulolytic enzyme was separated into 3 different enzyme proteins by gel-filtration and ion-exchange chromatography. These fractions were named enzyme A, enzyme B and enzyme C. The mode of action of each of the separated enzymes on crystalline cellulose was examined using infrared spectroscopy and X-ray crystallography. It was concluded that enzyme B is of the $C_1-type$ and reduces the crystallinity of the subatrate by generation an unstable glucopyranose ring structure, whilst enzymes A and C are of the $C_x-type$ and hydrolyse the reaction product of enzyme B to constituent sugars. A reaction scheme for this cellulase system is proposed and discussed.

• Korean Chemical Engineering Research
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• 제52권3호
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• pp.302-306
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• 2014

The present study was carried out to optimize fermentation parameters for the production of cellulolytic enzymes through solid substrate fermentation of Trichoderma reesei and Aspergillus niger grown on wheat straw. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation parameters including temperature, pH, moisture content and particle size. The results of optimization indicated that $40^{\circ}C$, pH 7, moisture content 75% and particle size between 0.25~0.5 mm were found to be the optimum condition at 96 hr fermentation. Under the optimal condition, co-culture of T. reesei and A. niger produced cellulase activities of 10.3 IU, endoglucanase activity of 100.3 IU, ${\beta}$-glucosidase activity of 22.9 IU and xylanase activity of 2261.7 IU/g dry material were obtained. Cellulolytic enzyme production with optimization showed about 72.6, 48.8, 55.2 and 51.9% increase compared to those obtained from control experiment, respectively.

• The Korean Journal of Mycology
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• 제14권3호
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• pp.225-229
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• 1986

Cellulosic substance which plays an important role in carbon cycle is most abundant in the nature world. Some higher fungi are able to digest cellulose directly to satisfy their carbohydrate requirement. Then, in order to investigate the enzymatic components of Lenzites betulina (Fr.) being wood rot, that fungus was collected in Kwangneung area. The carpophore of the fungus was smashed with cool distilled water, extracted and salted out by ammonium sulfate. And then the precipitate was purified by dialysing with visking tube and dissolved with pH 7.8 ammonia water, and the extract was filtrated. The fraction of filtrate was obtained as light brown powder after lyophilization, and determined cellulolytic activity. Cellulolytic potency of Lenzites betulina (Fr.) was 1. 65 unit/ml. The cellulase of Lenzites betulina (Fr.) was stable at below $45^{\circ}C$ and range of pH $4.5{\sim}6.0$ and is completely inactivated at $60^{\circ}C$ for 15 minutes. The optimum condition for the enzymatic reaction was $40^{\circ}C$ and pH 4.0. The enzyme activity was not influenced by the presence of $Ca^{2+}$ and $Fe^{2+}$.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1670-1679
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• 2020

The substantial use of fungal enzymes to degrade lignocellulosic plant biomass has widely been attributed to the extensive requirement of powerful enzyme-producing fungal strains. In this study, a two-step screening procedure for finding cellulolytic fungi, involving a miniaturized culture method with shake-flask fermentation, was proposed and demonstrated. We isolated 297 fungal strains from several cellulose-containing samples found in two different locations in Thailand. By using this screening strategy, we then selected 9 fungal strains based on their potential for cellulase production. Through sequence-based identification of these fungal isolates, 4 species in 4 genera were identified: Aspergillus terreus (3 strains: AG466, AG438 and AG499), Penicillium oxalicum (4 strains: AG452, AG496, AG498 and AG559), Talaromyces siamensis (1 strain: AG548) and Trichoderma afroharzianum (1 strain: AG500). After examining their lignocellulose degradation capacity, our data showed that P. oxalicum AG452 exhibited the highest glucose yield after saccharification of pretreated sugarcane trash, cassava pulp and coffee silverskin. In addition, Ta. siamensis AG548 produced the highest glucose yield after hydrolysis of pretreated sugarcane bagasse. Our study demonstrated that the proposed two-step screening strategy can be further applied for discovering potential cellulolytic fungi isolated from various environmental samples. Meanwhile, the fungal strains isolated in this study will prove useful in the bioconversion of agricultural lignocellulosic residues into valuable biotechnological products.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.482-493
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• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제11권5호
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• pp.538-544
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• 1998

One hundred and twenty-eight finishing pigs (51.3 kg average initial body weight) were used to determine the effects of adding cellulase enzymes and lactobacillus acidophilus to sorghum-based diets on growth performance, carcass merit, and nutrient digestibility in finishing pigs. Treatments were: 1) corn-soybean meal-based positive control; 2) sorghum-soybean meal-based negative control; 3) Diet 2 with celluloytic enzymes; and 4) Diet 2 with a bacterial feed additive (lactobacillus acidophilus). There was a trend for greater average daily gain (ADG) in pigs fed com versus the sorghum treatments for day 0 to 28 (p < .09), but there was no effect of treatment (p > .15) on overall ADG (i.e., day 0 to 63). Feed consumption was not affected by treatment during the experiment (p > .19). Pigs fed the corn-soybean meal-based diet had 3.5% greater overall gain/feed than pigs fed the other diets (p < .009). Dressing percentage was not affected by treatment (p > .22), but there was a trend for backfat thickness at the last rib to be greater for pigs fed com versus the sorghum treatments (p < .09). Pigs fed the sorghum treatments had 1 % greater fat free lean index (p < .10) compared to pigs fed the corn-soybean meal-based positive control. Pigs fed com had greater apparent digestibilities of DM, N, and GE than pigs fed the sorghum treatments (p < .03), and greater DE intake (p < .07) suggesting that the increased carcass fatness for pigs fed the corn-based control diet resulted from greater energy status of those pigs. In conclusion, pigs fed the corn-soybean meal-based control diet had no improved growth performance but tended to be fatter than pigs fed sorghum. Adding cellulolytic enzymes or a bacterial feed additive to diets for finishing pigs did not affect growth performance, carcass merit, or nutrient utilization.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.946-950
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• 2014

Bacillus licheniformis was grown in minimal nutrient medium containing 1% (w/v) of distillers dried grain with soluble (DDGS), palm kernel meal (PKM), wheat bran (WB) or copra meal (CM), and the enzyme activity of endoglucanase, ${\beta}$-glucosidase, xylanase and reducing sugars was measured to investigate a possibility of using cost-effective agricultural residues in producing cellulolytic and hemicellulolytic enzymes. The CM gave the highest endoglucanase activity of 0.68 units/mL among added substrates at 48 h. CM yielded the highest titres of 0.58 units/ml of ${\beta}$-glucosidase, compared to 0.33, 0.23, and 0.16 units/mL by PKM, WB, and DDGS, respectively, at 72 h. Xylanase production was the highest (0.34 units/mL) when CM was added. The supernatant from fermentation of CM had the highest reducing sugars than other additional substrates at all intervals (0.10, 0.12, 0.10, and 0.11 mg/mL respectively). It is concluded that Bacillus licheniformis is capable of producing multiple cellulo- and hemicellololytic enzymes for bioethanol production using cost-effective agricultural residues, especially CM, as a sole nutrient source.

• Mycobiology
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• 제42권2호
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• pp.181-184
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• 2014

To the best of our knowledge, this is the first report on thermophilic fungi isolated in Korea. Three species of thermophiles were isolated from compost and were identified as Myriococcum thermophilum, Thermoascus aurantiacus, and Thermomyces lanuginosus. They can grow at temperatures above $50^{\circ}C$ and produce high levels of cellulolytic and xylanolytic enzymes at high temperatures. Notably, the considerable thermostability of the endo-glucanase produced by T. aurantiacus has made the fungus an attractive source of industrial enzymes.