• Journal of Microbiology and Biotechnology
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• v.23 no.3
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• pp.351-356
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• 2013

A high ${\beta}$-glucosidase (BGL)-producing strain, Stereum hirsutum, was identified and isolated and showed a maximum BGL activity (10.4 U/ml) when cultured with Avicel and tryptone as the carbon and nitrogen sources, respectively. In comparison with other BGLs, BGL obtained from S. hirsutum showed a higher level of activity to cellobiose ($V_{max}$ = 172 U/mg, and $k_{cat}$ = 281/s). Under the optimum conditions (600 rpm, $30^{\circ}C$, and pH 6.0), the maximum BGL activity of 10.4 U/ml with the overall productivity of 74.5 U/l/h was observed. BGL production was scaled up from a laboratory scale (7-L fermenter) to a pilot scale (70-L fermenter). When S. hirsutum was cultured in fed-batch culture with rice straw as the carbon source in a 70-L fermenter, a comparable productivity of 78.6 U/l/h was obtained. Furthermore, S. hirsutum showed high levels of activity of other lignocellulases (cellobiohydrolase, endoglucanase, xylanase, and laccase) that are involved in the saccharification of biomasses. Application of S. hirsutum lignocellulases in the hydrolysis of Pinus densiflora and Catalpa ovata showed saccharification yields of 49.7% and 43.0%, respectively, which were higher than the yield obtained using commercial enzymes.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.490-495
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• 1995

Among the cellulases by Cellulomonas sp. KL-6. CMCase and filter paperase, which were produced as the out enzymes of cell, had been much produced, but very small amounts of ${\beta}-glucosidase $, the enzyme of which is cell bound form, was produced by this organism. The optimal culture times for CMCase and filter paperase productions were 5 days, while that of ${\beta}-glucosidase$ was 4 days. When this strain was cultured under the optimal medium for enzyme production, CMCase, FPase and ${\beta}-glucosidase$ were $82\;units/m{\ell},\;80\;units/m{\ell}\;and\;1.2\;units/m{\ell}$, respectively. Thus these results were showed to increase enzyme productivities as about $60{\sim}70%$ than those produced in basal medium. $CaCO_3$ injected to the medium as the ratio of 0.1% was not only enhanced cellulase activities but also effective as acid neutralizing agent. The production effects of lignase and lactase by this bacterium in filter paper medium was not appeared.

• Journal of Soil and Groundwater Environment
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• v.20 no.2
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• pp.22-31
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• 2015

In the present study, surface of laccase producing Ceriporia lacerata was modified using 4-bromobutyryl chloride and polyethylenimine. The modified biomass was freeze dried and utilized as a biosorbent for the removal of Ni(II) from aqueous solution. The physicochemical properties of the biosorbent were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. Batch experiments were carried out as a function of contact time (0-60 min), pH (2 to 8), adsorbent dosage (25-150 mg), and initial Ni(II) concentration (25-125 mg/L). The results indicate that surface modified biosorbent effectively adsorbed (9.5 mg/0.1 g biomass) Ni(II) present in the solution. The equilibrium adsorption data were modeled with different kinetic and isotherm models. The Ni(II) adsorption followed pseudo-first-order kinetics (R² = 0.998) and Langmuir isotherm (R² = 0.994) model. Hydroxyl and carbonyl functional groups present in biomass play a major role in the adsorption of Ni(II). The adsorbed Ni(II) from the biosorbent was successfully desorbed (85%) by 1M HCl. The results of the study indicate that the surface modified C. lacerate biomass could be used for the treatment of Ni(II) contaminated ground waters.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.242-247
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• 2017

Humic acid (HA) is a complex organic matter found in the environments, especially in grassland soils with a high density. The bioactivity of HA to promote plant growth depends largely on its extraction sources. The quality-control of HA and the quality improvements via an artificial synthesis are thus challenging. We recently reported that a polymeric product from fungal laccase-mediated oxidation of catechol and vanillic acid (CAVA) displays a HA-like activity to enhance seed germination and salt stress tolerance in a model plant, Arabidopsis. Here, we examined whether HA or CAVA enhances the growth of Italian ryegrass seedling. Height and fresh weight of the plant with foliar application of HA or CAVA were bigger than those with only water. Interestingly, enhanced root developments were also observed in spite of the foliar treatments of HA or CAVA. Finally, we proved that HA or CAVA promotes the regrowth of Italian ryegrass after cutting. Collectively, CAVA acts as a HA mimic in Italian ryegrass cultivation, and both as a biostimulant enhanced the early growth and regrowth after cutting of Italian ryegrass, which could improve the productivity of forage crops.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1438-1445
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• 2021

A bifunctional glycoside hydrolase GH78 from the ascomycete Xylaria polymorpha (XpoGH78) possesses catalytic versatility towards both glycosides and esters, which may be advantageous for the efficient degradation of the plant cell-wall complex that contains both diverse sugar residues and esterified structures. The contribution of XpoGH78 to the conversion of lignocellulosic materials without any chemical pretreatment to release the water-soluble aromatic fragments, carbohydrates, and methanol was studied. The disintegrating effect of enzymatic lignocellulose treatment can be significantly improved by using different kinds of hydrolases and phenoloxidases. The considerable changes in low (3 kDa), medium (30 kDa), and high (> 200 kDa) aromatic fragments were observed after the treatment with XpoGH78 alone or with this potent cocktail. Synergistic conversion of rape straw also resulted in a release of 17.3 mg of total carbohydrates (e.g., arabinose, galactose, glucose, mannose, xylose) per gram of substrate after incubating for 72 h. Moreover, the treatment of rape straw with XpoGH78 led to a marginal methanol release of approximately 17 ㎍/g and improved to 270 ㎍/g by cooperation with the above accessory enzymes. In the case of beech wood conversion, the combined catalysis by XpoGH78 and laccase caused an effect comparable with that of fungal strain X. polymorpha in woody cultures concerning the liberation of aromatic lignocellulose fragments.

• Mycobiology
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• v.49 no.1
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• pp.1-14
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• 2021

Pleurotus species are commercially essential mushrooms and widely cultivated throughout the world. The production of Pleurotus mushrooms alone accounts for around 25% of that total cultivated mushrooms globally. In America and Europe, Pleurotus species are considered specialty mushrooms, whereas, in Korea, their cultivation is economically profitable, and it is one of the highly consumed species. Pleurotus species are predominantly found in tropical forests and often grow on fallen branches, dead and decaying tree stumps, and wet logs. Biographical studies have shown that the Pleurotus genus is among the more conspicuous fungi that induce wood decay in terrestrial ecosystems worldwide due to its formidable lignin-modifying enzymes, including laccase and versatile peroxidases. Pleurotus species can be grown easily due to their fast colonization nature on diversified agro-substrates and their biological efficiency 100%. Pleurotus mushrooms are rich in proteins, dietary fiber, essential amino acids, carbohydrates, water-soluble vitamins, and minerals. These mushrooms are abundant in functional bioactive molecules, though to influence health. Pleurotus mushrooms are finding unique applications as flavoring, aroma, and excellent preservation quality. Apart from its unique applications, Pleurotus mushrooms have a unique status delicacy with high nutritional and medicinal values. The present review provides an insight into the cultivation of Pleurotus spp. using different agro-waste as growth substances paying attention to their effects on the growth and chemical composition.

• The Korea Journal of Herbology
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• v.35 no.2
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• pp.1-6
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• 2020

Objectives : Heating process is the traditional processing method that has been applied to reduce the toxicity of dried resin of Toxicodendron vernicifluum (Anacardiacea) used as Geon-chil (乾漆, Lacca Rhois Exsiccata or Toxicodendri Resina). Urushiol, which is found in the plants of Toxicodendron genus, is a toxic compound that is absorbed into the skin and induces allergic dermatitis by being contacted. Hence, the reduction of urushiol level by heating processing of Geon-chil is crucial method for its medicinal application. Methods : Due to lack of Geon-chil processing-related articles, the articles researching the processing of lacquer (漆), as a coating material, were collected and analyzed to investigate the chemical change of urushiol during heating process. Results : The results demonstrate that the resin which was collected from the sap of T. vernicifluum tree was dried under warm and humid conditions repeatedly. During primary drying process, the laccase, a copper-containing enzyme in the resin, participated in the formation of urushiol polymers and thereafter urushiol-related toxicity could be reduced by making a lacquer harder and more stable. Moreover, heating a lacquer over 200℃ could cause thermo-degradation of urushiol polymers, and vaporized thermally degraded urushiol monomers and their by-products, which were determined using pyrolysis/GC-MS. Conclusions : These results support that heating process being performed over 200 ℃, such as stir-frying (炒) or calcination (煅), reduces the urushiol content in Geon-chil and hence, its medicinal use can be more stable without urushiol-related allergic reactions.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.356-371
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• 2024

Novel meat-inspired products, such as cell-cultivated meat and meat analogues, embrace environmental sustainability, food safety and security, animal welfare, and human health, but consumers are still hesitant to accept these products. The appearance of food is often the most persuasive determinant of purchasing decisions for food. Producing cultivated meat and meat analogues with similar characteristics to conventional meat could lead to increased acceptability, marketability, and profitability. Color is one of the sensorial characteristics that can be improved using color-inducing methods and colorants. Synthetic colorants are cheap and stable, but natural pigments are regarded as safer components for novel food production. The complexity of identifying specific colorants to imitate both raw and cooked meat color lies in the differences in ingredients and methods used to produce meat alternatives. Research devoted to improving the sensorial characteristics of meat analogues has noted various color-inducing methods (e.g., ohmic cooking and pasteurization) and additives (e.g., lactoferrin, laccase, xylose, and pectin). Additionally, considerations toward other meat components, such as fat, can aid in mimicking conventional meat appearance. For instance, the use of plant-based fat replacers and scaffolds can produce a marked sensory enhancement without compromising the sustainability of alternative meats. Moving forward, consumer-relevant sensorial characteristics, such as taste and texture, should be prioritized alongside improving the coloration of meat alternatives.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1017-1028
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• 2024

Lignocellulolytic enzymes play a crucial role in efficiently converting lignocellulose into valuable platform molecules in various industries. However, they are limited by their production yields, costs, and stability. Consequently, their production by producers adapted to local environments and the choice of low-cost raw materials can address these limitations. Due to the large amounts of olive stones (OS) generated in Morocco which are still undervalued, Penicillium crustosum, Fusarium nygamai, Trichoderma capillare, and Aspergillus calidoustus, are cultivated under different fermentation techniques using this by-product as a local lignocellulosic substrate. Based on a multilevel factorial design, their potential to produce lignocellulolytic enzymes during 15 days of dark incubation was evaluated. The results revealed that P. crustosum expressed a maximum total cellulase activity of 10.9 IU/ml under sequential fermentation (SF) and 3.6 IU/ml of β-glucosidase activity under submerged fermentation (SmF). F. nygamai recorded the best laccase activity of 9 IU/ml under solid-state fermentation (SSF). Unlike T. capillare, SF was the inducive culture for the former activity with 7.6 IU/ml. A. calidoustus produced, respectively, 1,009 ㎍/ml of proteins and 11.5 IU/ml of endoglucanase activity as the best results achieved. Optimum cellulase production took place after the 5th day under SF, while ligninases occurred between the 9th and the 11th days under SSF. This study reports for the first time the lignocellulolytic activities of F. nygamai and A. calidoustus. Furthermore, it underlines the potential of the four fungi as biomass decomposers for environmentally-friendly applications, emphasizing the efficiency of OS as an inducing substrate for enzyme production.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.667-676
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• 2007

This study was conducted to determine effects of cellulolytic microbes inoculation to sawdust-based spent mushroom substrate(SMS) during deepstacking on fermentation parameters, total microbial counts and cellulolytic enzyme activity and to on SMS nutrients utilization by sheep. For sheep metabolism trials, six sheep(ram, average 54.8kg) were fed a Control diet(70% concentrates, 15% rice straw and 15% SMS with no microbial treatment on a dry basis) and a Treatment diet(the same diet including SMS with a microbial treatment) for 2 trials. Spent mushroom substrates with or without a microbial(4 strains including 1 strain of Enterobacter ludwigii, 1 strain of Bacillus cereus and 2 strains of Bacillus subtillis) treatment (1% of SMS on wet basis) were deepstacked for 7 days. The internal temperatures in 1.2 M/T of SMS deepstacks reached to 50±5℃ within 7 days of storage. Total microbial counts remarkably decreased (P<0.05) with a deepstacking process and were not affected(P>0.05) by the microbial treatment. For fibrolytic enzyme activity, CMCase and xylanase activities were decreased(P<0.05) by a deepstacking process. After deepstacking, the microbial treatment showed about 2.5-times higher(P<0.05) for CMCase activity and about 4-times higher(P<0.05) for xylanase activity than those of the Control. Activities of ligninolytic enzymes such as laccase and MnP were not affected by the microbial treatment. The sheep fed the microbially treated SMS diet had a tendency of greater total tract digestibilities of ash(P=0.051), NFE (P=0.071), hemicellulose(P=0.087) and NDF(P=0.096) than those fed the untreated SMS diet. Nitrogen balance of sheep was not affected(P>0.05) by feeding of microbially treated SMS. Accordingly, these results indicate that cellulolytic microbes inoculation during deepstacking of SMS may improve the bio- utilization of SMS by sheep.