• Title/Summary/Keyword: Extracellular enzymes

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Environmental Factors and Bioremediation of Xenobiotics Using White Rot Fungi

  • Magan, Naresh;Fragoeiro, Silvia;Bastos, Catarina
    • Mycobiology
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    • v.38 no.4
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    • pp.238-248
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    • 2010
  • This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the differential effect of white rot fungi on the degradation of single and mixtures of pesticides using fungi such as Trametes versicolor and Phanerochaete chrysosporium. We also explore the formulation and delivery of fungal bioremedial inoculants to terrestrial ecosystems as well as the use of spent mushroom compost as an approach. Future areas for research and potential exploitation of new techniques are also considered.

Fungal Secretome for Biorefinery: Recent Advances in Proteomic Technology

  • Adav, Sunil S.;Sze, Siu Kwan
    • Mass Spectrometry Letters
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    • v.4 no.1
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    • pp.1-9
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    • 2013
  • Fungal biotechnology has been well established in food and healthcare sector, and now being explored for lignocellulosic biorefinery due to their great potential to produce a wide array of extracellular enzymes for nutrient recycling. Due to global warming, environmental pollution, green house gases emission and depleting fossil fuel, fungal enzymes for lignocellulosic biomass refinery become a major focus for utilizing renewal bioresources. Proteomic technologies tender better biological understanding and exposition of cellular mechanism of cell or microbes under particular physiological condition and are very useful in characterizing fungal secretome. Hence, in addition to traditional colorimetric enzyme assay, mass-spectrometry-based quantification methods for profiling lignocellulolytic enzymes have gained increasing popularity over the past five years. Majority of these methods include two dimensional gel electrophoresis coupled to mass spectrometry, differential stable isotope labeling and label free quantitation. Therefore, in this review, we reviewed more commonly used different proteomic techniques for profiling fungal secretome with a major focus on two dimensional gel electrophoresis, liquid chromatography-based quantitative mass spectrometry for global protein identification and quantification. We also discussed weaknesses and strengths of these methodologies for comprehensive identification and quantification of extracellular proteome.

Enzyme Production Related to Alcohol Metabolism from Thermophilic Fungus Thermoascus aurantiacus (호열성 사상균 Thermoascus aurantiacus의 알코올분해대사 관련 효소학적 특성)

  • Ko Hee-Sun;Kim Hyun-Soo
    • Microbiology and Biotechnology Letters
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    • v.34 no.3
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    • pp.216-220
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    • 2006
  • Thermophillic fungus Thermoascus aurantiacus showed excellent growth and produced high amount of alcohol oxidase and catalase in a pectin medium. Besides, the strain produced enzymes which related with pectin or alcohol decomposition. We detected extracellular pectin esterase (EC 3.1.1.11) activity and, both intracellular and extracellular pectinase (EC 4.2.2.10) activity, as pectinolytic enzymes produced by T. aurantiacus. The production of methanol decomposition enzymes, such as alcohol oxidase (AOD, EC 1.1.3.13), alcohol dehydrogenase (ADH, EC 1.1.1.1), formaldehyde dehydrogenase (FADH, EC 1.2.1.1) and formate dehydrogenase (FDH, EC 1.2.1.2) follows by pectin esterase reaction which is converted to methanol. We concluded that T. aurantiacus has pectinolytic and alcohol - oxidative enzymological mechanism which produced carbon dioxide as a final material, started from pectin.

Characterization of Three Extracellular β-Glucosidases Produced by a Fungal Isolate Aspergillus sp. YDJ14 and Their Hydrolyzing Activity for a Flavone Glycoside

  • Oh, Jong Min;Lee, Jae Pil;Baek, Seung Cheol;Jo, Yang Do;Kim, Hoon
    • Journal of Microbiology and Biotechnology
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    • v.28 no.5
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    • pp.757-764
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    • 2018
  • A cellulolytic fungus, YDJ14, was isolated from compost and identified as an Aspergillus sp. strain. Three extracellular ${\beta}$-glucosidases, BGL-A1, BGL-A2, and BGL-A3, were separated using ultrafiltration, ammonium sulfate fractionation, and High-Q chromatography. The molecular masses of the three enzymes were estimated to be 100, 45, and 40 kDa, respectively, by SDS-PAGE. The optimum pH and temperature of BGL-A3 were 5.0 and $50^{\circ}C$, respectively, whereas the optimum pH and temperature of BGL-A1 and BGL-A2 were identical (4.0 and $60^{\circ}C$, respectively). The half-life of BGL-A3 at $70^{\circ}C$ (2.8 min) was shorter than that of BGL-A1 and BGL-A2 (12.1 and 8.8 min, respectively). All three enzymes preferred p-nitrophenyl-${\beta}$-$\text\tiny{D}$-glucopyranoside (pNPG) and hardly hydrolyzed cellobiose, suggesting that these enzymes were aryl ${\beta}$-glucosidases. The $K_m$ of BGL-A3 (1.26 mM) for pNPG was much higher than that of BGL-A1 and BGL-A2 (0.25 and 0.27 mM, respectively). These results suggested that BGL-A1 and BGL-A2 were similar in their enzymatic properties, whereas BGL-A3 differed from the two enzymes. When tilianin (a flavone glycoside of acacetin) was reacted with the three enzymes, the inhibitory activity for monoamine oxidase, a target in the treatment of neurological disorders, was similar to that shown by acacetin. We conclude that these enzymes may be useful in the hydrolysis of flavone glycosides to improve their inhibitory activities.

Industrial utilization of spent mushroom substrate (버섯 수확 후 배지의 산업적 활용)

  • Kang, Hee-Wan
    • Journal of Mushroom
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    • v.17 no.3
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    • pp.85-92
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    • 2019
  • Over a million tons of spent mushroom substrate (SMS) are generated as by-products of mushroom cultivation every year in Korea. Disposal of SMS by mushroom farmers is difficult, therefore, recycling solutions that do not harm the environment are necessary. SMS consists of mushroom mycelia and residues of fruiting bodies, containing a variety of bioactive substances, such as extracellular enzymes, antimicrobial compounds, and secondary metabolites. This paper reviews utility of SMS for bioremediation, controlling plant disease, and production of lignocellulytic enzymes, organic fertilizer, and animal feed.

Bioconversion of Lignocellulose Materials

  • Pothiraj, C.;Kanmani, P.;Balaji, P.
    • Mycobiology
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    • v.34 no.4
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    • pp.159-165
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    • 2006
  • One of the most economically viable processes for the bioconversion of many lignocellulosic waste is represented by white rot fungi. Phanerochaete chrysosporium is one of the important commercially cultivated fungi which exhibit varying abilities to utilize different lignocellulosic as growth substrate. Examination of the lignocellulolytic enzyme profiles of the two organisms Phanerochaete chrysosporium and Rhizopus stolonifer show this diversity to be reflected in qualitative variation in the major enzymatic determinants (ie cellulase, xylanase, ligninase and etc) required for substrate bioconversion. For example P. chrysosporium which is cultivated on highly lignified substrates such as wood (or) sawdust, produces two extracellular enzymes which have associated with lignin deploymerization. (Mn peroxidase and lignin peroxidase). Conversely Rhizopus stolonifer which prefers high cellulose and low lignin containg substrates produce a family of cellulolytic enzymes including at least cellobiohydrolases and ${\beta}-glucosidases$, but very low level of recognized lignin degrading enzymes.

Effect of Various Culture Conditions on the Activity of Extracellular Enzymes from Fomitopsis palustris, Brown Rot Fungi (침엽수 혼합목분에서 배양조건을 달리한 Fomitopsis palustris 의 균체외효소 활성 변화)

  • Lee, Young-Min;Choi, Doo-Yul;Kim, Hyun-Jung;Yoon, Jeoung-Jun;Kim, Yeong-Suk
    • Journal of Forest and Environmental Science
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    • v.24 no.1
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    • pp.53-59
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    • 2008
  • Extracellular enzyme activities of Fomitopsis palustris were determined by the particle sizes, culture periods and concentrations of wood particle substrate which was mixture of 4 domestic coniferous woods, such as Pinus densiflora, Larix leptolepsis, Pinus koraiensis, and Pinus rigida. The results showed that the culture conditions had an effect on the secretion of most of the extracellular enzymes from Fomitopsis palustris in the mixed wood particle substrate. :The optimal culture conditions for enzyme activities were 80~100 mesh in wood particle size, 7.5% in concentrations of wood substrate, and 4~8 weeks in culture period.

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Extracellular Proteome Profiling of Bacillus pumilus SCU11 Producing Alkaline Protease for Dehairing

  • Wang, Chao;Yu, Shiqiang;Song, Ting;He, Tingting;Shao, Huanhuan;Wang, Haiyan
    • Journal of Microbiology and Biotechnology
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    • v.26 no.11
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    • pp.1993-2005
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    • 2016
  • Bacillus pumilus is one of the most characterized microorganisms that are used for high-level production of select industrial enzymes. A novel B. pumilus SCU11 strain possessing high alkaline protease activity was obtained in our previous work. The culture supernatant of this strain showed efficient dehairing capability with minimal collagen damage, indicating promising potential applications in the leather industry. In this study, the strain's extracellular proteome was identified by LC-MS/MS-based shotgun proteomic analysis, and their related secretory pathways were characterized by BLAST searches. A total of 513 proteins, including 100 actual secreted and 413 intracellular proteins, were detected in the extracellular proteome. The functions of these secreted proteins were elucidated and four complete secretory systems (Sec, Tat, Com, and ABC transporter) were proposed for B. pumilus. These data provide B. pumilus a comprehensive extracellular proteome profile, which is a valuable theoretical and applicative basis for future genetic modifications and development of industrial enzymes.

Hydrolysis of Agricultural Residues and Kraft Pulps by Xylanolytic Enzymes from Alkaliphilic Bacillus sp. Strain BK

  • Kaewintajuk Kusuma;Chon Gil-Hyong;Lee Jin-Sang;Kongkiattikajorn Jirasak;Ratanakhanokchai Khanok;Kyu Khin Lay;Lee John-Hwa;Roh Min-Suk;Choi Yun-Young;Park Hyun;Lee Yun-Sik
    • Journal of Microbiology and Biotechnology
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    • v.16 no.8
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    • pp.1255-1261
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    • 2006
  • An alkaliphilic bacterium, Bacillus sp. strain BK, was found to produce extracellular cellulase-free xylanolytic enzymes with xylan-binding activity. Since the pellet-bound xylanase is eluted with 2% TEA from the pellet of the culture, they contain a xylan-binding region that is stronger than the xylan-binding xylanase of the extracellular enzyme. The xylanases had a different molecular weight and xylan-binding ability. The enzyme activity of xylanase in the extracellular fraction was 6 times higher than in the pellet-bound enzyme. Among the enzymes, xylanase had the highest enzyme activity. When Bacillus sp. strain BK was grown in pH 10.5 alkaline medium containing xylan as the sole carbon source, the bacterium produced xylanase, arabinofuranosidase, acetyl esterase, and $\beta$-xylosidase with specific activities of 1.23, 0.11, 0.06, and 0.04 unit per mg of protein, respectively. However, there was no cellulase activity detected in the crude enzyme preparation. The hydrolysis of agricultural residues and kraft pulps by the xylanolytic enzymes was examined at 50$^{\circ}C$ and pH 7.0. The rate of xylan hydrolysis in com hull was higher than those of sugarcane bagasse, rice straw, com cop, rice husk, and rice bran. In contrast, the rate of xylan hydrolysis in sugarcane pulp was 2.01 and 3.52 times higher than those of eucalyptus and pine pulp, respectively. In conclusion, this enzyme can be used to hydrolyze xylan in agricultural residues and kraft pulps to breach and regenerate paper from recycled environmental resources.