• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.648-657
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• 2008

In this study, we used functional genomic strategies, proteomics and quantitative real-time (qRT)-PCR, to advance our understanding of genes associated with fumonisin production in the fungus Fusarium verticillioides. Earlier studies have demonstrated that deletion of the FCC1 gene, which encodes a C-type cyclin, leads to a drastic reduction in fumonisin production and conidiation in the mutant strain (FT536). The premise of our research was that comparative analysis of F. verticillioides wild-type and FT536 proteomes will reveal putative proteins, and ultimately corresponding genes, that are important for fumonisin biosynthesis. We isolated proteins that were significantly upregulated in either the wild type or FT536 via two-dimensional polyacrylamide gel electrophoresis, and subsequently obtained sequences by mass spectrometry. Homologs of identified proteins, e.g., carboxypeptidase, laccase, and nitrogen metabolite repression protein, are known to have functions involved in fungal secondary metabolism and development. We also identified gene sequences corresponding to the selected proteins and investigated their transcriptional profiles via quantitative real-time (qRT)-PCR in order to identify genes that show concomitant expression patterns during fumonisin biosynthesis. These genes can be selected as targets for functional analysis to further verify their roles in $FB_1$ biosynthesis.

• 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.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.16-16
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• 2015

Ectomycorrhizal (ECM) mushrooms play a major role in plant growth promotion through symbiotic association with roots of forest trees. They also provide an economically important food resource to us and therefore they have been studied for their artificial cultivation for decades in Korea. We have secured bio-resources of ECM mushrooms from Korean forests and performed their physiological studies. To investigate the cultural characteristics, the fungi were cultured under different conditions (medium, temperature, pH of the medium, inorganic nitrogen source). More than 90% of total 160 strains grew on three solid media (potato dextrose agar, PDA; sabouraud dextrose agar, SDA; modified Melin-Norkrans medium, MMN). The rate of mycelial growth on malt extract agar (MEA) was lower than those of three media (PDA, SDA, MMN). None of the Tricholomataceae strains grew on MEA. Many strains of ECM mushrooms were able to grow at the temperature range of $15{\sim}25^{\circ}C$ on PDA, while they showed poor growth at $10^{\circ}C$ or $30^{\circ}C$. In particular, the growth rates of both Gomphaceae and Tricholomataceae were significantly lower at $10^{\circ}C$ than at $30^{\circ}C$. The optimal pH of many strains was pH 5.0 when they cultured in potato dextrose broth (PDB). Fifty-seven percent of tested strains grew well on medium containing ammonium source than nitrate source. Many strains of Tricholomataceae showed a notable growth on ammonium medium than nitrate medium. Twenty-three percent of strains preferred nitrate source than ammonium source for their mycelial growth. The production and activity of two enzymes (cellulase and laccase) by ECM fungi were also assayed on the enzyme screening media containing CMC or ABTS. Each strains exhibited different levels of enzymatic activities as well as enzyme production. The number of laccase-producing strains was less than that of cellulase-producing strains. We found that 77% of tested strains produced both cellulase and laccase, whereas 2% of strains did not produce any enzymes. The morphological characteristics of mycelial colony were also examined on four different solid media. Yellow was a dominant color in mycelial colony and followed by white and brown on all culture media. ECM mushrooms formed mycelial colonies with a single or multiple colors within a culture medium depending on the strains and culture media. The most common shape of mycelial colony was a circular form on all media tested. Other families except for Amanitaceae formed an irregular colony on MMN than PDA. All strains of Tricholomataceae did not form a filamentous colony on all media. The pigmentation of culture media by mycelial colonies was observed in more than 50% of strains tested on both PDA and SDA. The degree of pigmentation on PDA or SDA was higher than MMN and brown color was dominant than yellow color. The production of exudates from mycelial colony was higher on PDA than MMN. Brown exudates were mainly produced by many strains on PDA or SDA, whereas transparent exudates were mainly produced by strains on MMN. We observed the mycelial colonies with a single or multiple textures in just one culture plate. Wrinkled or uneven colony surfaces were remarkably observed in many strains on PDA or SDA, while an even colony surface was observed in many strains on MMN. Sixty percent of Tricholomaceae strains formed wrinkled surface on PDA. However, they did not form any wrinkle on MMN plate. Cottony texture was observed in mycelia colonies of many strains. Velvety texture was often observed in the mycelial colonies on SDA than PDA and accounted for 60% of Suillaceae strains on SDA.

• Journal of Mushroom
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• v.16 no.2
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• pp.74-78
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• 2018

This study was carried out to establish a suitable method for liquid spawn production from Lentinula edodes. The optimum production of liquid spawn (OLS) was achieved using soybean meal medium (SMM) with 0.3% of 850 um oak powder and 10-day incubation period and 0.6 vvm aeration volume. OLS showed activities of laccase on ABTS agar plate and carboxymethyl cellulase (CM-cellulase) on CMC agar plate. In case of liquid spawn, fruiting-body development period was delayed approximately 1 day compared to that of sawdust spawn, however, the yield of 153 g per 1.2 kg polypropylene bag was similar to that of sawdust spawn.

• Mycobiology
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• v.36 no.2
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• pp.114-120
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• 2008

This study was conducted to evaluate the degradation of aromatic dyes and the production of ligninolytic enzymes by 10 white rot fungi. The results of this study revealed that Pycnoporus cinnabarinus, Pleurotus pulmonarius, Ganoderma lucidum, Trametes suaveolens, Stereum ostrea and Fomes fomentarius have the ability to efficiently degrade congo red on solid media. However, malachite green inhibited the mycelial growth of these organisms. Therefore, they did not effectively decolorize malachite green on solid media. However, P. cinnabarinus and P. pulmonarius were able to effectively decolorize malachite green on solid media. T. suaveolens and F. rosea decolorized methylene blue more effectively than any of the other fungi evaluated in this study. In liquid culture, G. lucidum, P. cinnabarinus, Naematoloma fasciculare and Pycnoporus coccineus were found to have a greater ability to decolorize congo red. In addition, P. cinnabarinus, G lucidum and T. suaveolens decolorized methylene blue in liquid media more effectively than any of the other organisms evaluated in this study. Only F. fomentarius was able to decolorize malachite green in liquid media, and its ability to do so was limited. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in naphthalene supple mented liquid media. P. coccineus, Coriolus versicolor and P. cinnabarinus were found to produce a large amount of laccase when grown in medium that contained napthalene.

• 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.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.8-16
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• 2008

Aurofusarin is a polyketide pigment produced by some Fusarium species. The PKS12 and GIP1 genes, which encode a putative type I polyketide synthase (PKS) and a fungal laccase, respectively, are known to be required for aurofusarin biosynthesis in Gibberella zeae (anamorph: Fusarium graminearum). The ten additional genes, which are located within a 30 kb region of PKS12 and GIP1 and regulated by a putative transcription factor (GIP2), organize the aurofusarin biosynthetic cluster. To determine if they are essential for aurofusarin production in G. zeae, we have employed targeted gene deletion, complementation, and chemical analyses. GIP7, which encodes O-methyltransferase, is confirmed to be required for the conversion of norrubrofusarin to rubrofusarin, an intermediate of aurofusarin. GIP1-, GIP3-, and GIP8-deleted strains accumulated rubrofusarin, indicating those gene products are essential enzymes for the conversion of rubrofusarin to aurofusarin. Based on the phenotypic changes in the gene deletion strains examined, we propose a possible pathway for aurofusarin biosynthesis in G. zeae. Our results would provide important information for better understanding of naphthoquinone biosynthesis in other fdarnentous fungi as well as the aurofusarin biosynthesis in G. zeae.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.92-98
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• 2005

This study was performed to get the basic information concerned to the optimum culture condition of Inonotus obliquus. Several solid media, PDA, MEA and Czapek-Dox, and three liquid media were adopted for the in vitro cultivation. Some main features of the fungal morphological characteristics under cultivation conditions were observed and described. Preliminary results showed that appearance of the mycelial mat, hyphal size and substrate pigmentation differed according to the media. The PDA medium was the most favorable substrate for the growth on solid culture, followed by MEA and Czapek-Dox media. Concerned to the addition of amino acids, 5 amino acids, such as alanine, alginine, isoleucine, leucine and threonine, enhanced to the mycelial growth. Isoleucine was shown the best fungal growth. An important morphological hyphal structure for the fungus, the setae, was found in abundance and diverse its shape and size. In liquid culture, fresh potato broth was the best growth stimulant of the fungus, followed by Malt extract and potato broth. Addition of yeast extract to the liquid media had improved the biomass, but not laccase production.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.115-119
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• 1999

During mechanical pulp production and blcaching wood components, such as extractives, carbohydrates and lignin are dissolved and dispersed into the process waters. These components are called dissolved and colloidal substances(DCS). DCS can accumulate during water circulation and can in turn affect paper machine runnability and also the strength and optical properties of the paper. In this work DCS fraction origination from TMP process were treated with enzymes acting on triglycerides. glucomannans, and lignin and the effect of enzymatic treatments on the water composition as well as sheet properies were evaluated. Lipases were found to modify the chemical structure of the extractives resulting in more hydrophilic fibre surface and subsequent improvement in the sheet strength properties. Mannanase treatment, on the other hand, destabilized pitch. As a result, aggregation of pitch to the fibres was observed which in turn resulted in impaired strength properties. Laccase could effectively polymerize lignans and the reaction products seemed to be sorbed onto the fibres.