Displaying publications 81 - 100 of 125 in total

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  1. Fulltext Development of an amperometric-based glucose biosensor to measure the glucose content of fruit
    Ang LF, Por LY, Yam MF
    PLoS One, 2015;10(3):e0111859.
    PMID: 25789757 DOI: 10.1371/journal.pone.0111859
    An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant ([Formula: see text]) of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable.
    Matched MeSH terms: Fungal Proteins/chemistry*
  2. Phylogenetic relationships and morphological evolution in Lentinus, Polyporellus and Neofavolus, emphasizing southeastern Asian taxa
    Seelan JS, Justo A, Nagy LG, Grand EA, Redhead SA, Hibbett D
    Mycologia, 2015 May-Jun;107(3):460-74.
    PMID: 25661717 DOI: 10.3852/14-084
    The genus Lentinus (Polyporaceae, Basidiomycota) is widely documented from tropical and temperate forests and is taxonomically controversial. Here we studied the relationships between Lentinus subg. Lentinus sensu Pegler (i.e. sections Lentinus, Tigrini, Dicholamellatae, Rigidi, Lentodiellum and Pleuroti and polypores that share similar morphological characters). We generated sequences of internal transcribed spacers (ITS) and partial 28S regions of nuc rDNA and genes encoding the largest subunit of RNA polymerase II (RPB1), focusing on Lentinus subg. Lentinus sensu Pegler and the Neofavolus group, combined these data with sequences from GenBank (including RPB2 gene sequences) and performed phylogenetic analyses with maximum likelihood and Bayesian methods. We also evaluated the transition in hymenophore morphology between Lentinus, Neofavolus and related polypores with ancestral state reconstruction. Single-gene phylogenies and phylogenies combining ITS and 28S with RPB1 and RPB2 genes all support existence of a Lentinus/Polyporellus clade and a separate Neofavolus clade. Polyporellus (represented by P. arcularius, P. ciliatus, P. brumalis) forms a clade with species representing Lentinus subg. Lentinus sensu Pegler (1983), excluding L. suavissimus. Lentinus tigrinus appears as the sister group of Polyporellus in the four-gene phylogeny, but this placement was weakly supported. All three multigene analyses and the single-gene analysis using ITS strongly supported Polyporus tricholoma as the sister group of the Lentinus/Polyporellus clade; only the 28S rRNA phylogeny failed to support this placement. Under parsimony the ancestral hymenophoral configuration for the Lentinus/Polyporellus clade is estimated to be circular pores, with independent transitions to angular pores and lamellae. The ancestral state for the Neofavolus clade is estimated to be angular pores, with a single transition to lamellae in L. suavissimus. We propose that Lentinus suavissimus (section Pleuroti) should be reclassified as Neofavolus suavissimus comb. nov.
    Matched MeSH terms: Fungal Proteins/genetics
  3. A facile enzymatic synthesis of geranyl propionate by physically adsorbed Candida rugosa lipase onto multi-walled carbon nanotubes
    Mohamad NR, Buang NA, Mahat NA, Lok YY, Huyop F, Aboul-Enein HY, et al.
    Enzyme Microb Technol, 2015 May;72:49-55.
    PMID: 25837507 DOI: 10.1016/j.enzmictec.2015.02.007
    In view of several disadvantages as well as adverse effects associated with the use of chemical processes for producing esters, alternative techniques such as the utilization of enzymes on multi-walled carbon nanotubes (MWCNTs), have been suggested. In this study, the oxidative MWCNTs prepared using a mixture of HNO3 and H2SO4 (1:3 v/v) were used as a supportive material for the immobilization of Candida rugosa lipase (CRL) through physical adsorption process. The resulting CRL-MWCNTs biocatalysts were utilized for synthesizing geranyl propionate, an important ester for flavoring agent as well as in fragrances. Enzymatic esterification of geraniol with propionic acid was carried out using heptane as a solvent and the efficiency of CRL-MWCNTs as a biocatalyst was compared with the free CRL, considering the incubation time, temperature, molar ratio of acid:alcohol, presence of desiccant as well as its reusability. It was found that the CRL-MWCNTs resulted in a 2-fold improvement in the percentage of conversion of geranyl propionate when compared with the free CRL, demonstrating the highest yield of geranyl propionate at 6h at 55°C, molar ratio acid: alcohol of 1:5 and with the presence of 1.0g desiccant. It was evident that the CRL-MWCNTs biocatalyst could be reused for up to 6 times before a 50% reduction in catalytic efficiency was observed. Hence, it appears that the facile physical adsorption of CRL onto F-MWCNTs has improved the activity and stability of CRL as well as served as an alternative method for the synthesis of geranyl propionate.
    Matched MeSH terms: Fungal Proteins/metabolism*
  4. Fulltext Chemoenzymatic epoxidation of alkenes and reusability study of the phenylacetic acid
    Abdulmalek E, Arumugam M, Mizan HN, Abdul Rahman MB, Basri M, Salleh AB
    ScientificWorldJournal, 2014;2014:756418.
    PMID: 24587751 DOI: 10.1155/2014/756418
    Here, we focused on a simple enzymatic epoxidation of alkenes using lipase and phenylacetic acid. The immobilised Candida antarctica lipase B, Novozym 435 was used to catalyse the formation of peroxy acid instantly from hydrogen peroxide (H2O2) and phenylacetic acid. The peroxy phenylacetic acid generated was then utilised directly for in situ oxidation of alkenes. A variety of alkenes were oxidised with this system, resulting in 75-99% yield of the respective epoxides. On the other hand, the phenylacetic acid was recovered from the reaction media and reused for more epoxidation. Interestingly, the waste phenylacetic acid had the ability to be reused for epoxidation of the 1-nonene to 1-nonene oxide, giving an excellent yield of 90%.
    Matched MeSH terms: Fungal Proteins/chemistry
  5. Thermokinetic comparison of trypan blue decolorization by free laccase and fungal biomass
    Razak NN, Annuar MS
    Appl Biochem Biotechnol, 2014 Mar;172(6):2932-44.
    PMID: 24464534 DOI: 10.1007/s12010-014-0731-7
    Free laccase and fungal biomass from white-rot fungi were compared in the thermokinetics study of the laccase-catalyzed decolorization of an azo dye, i.e., Trypan Blue. The decolorization in both systems followed a first-order kinetics. The apparent first-order rate constant, k1', value increases with temperature. Apparent activation energy of decolorization was similar for both systems at ∼ 22 kJ mol(-1), while energy for laccase inactivation was 18 kJ mol(-1). Although both systems were endothermic, fungal biomass showed higher enthalpy, entropy, and Gibbs free energy changes for the decolorization compared to free laccase. On the other hand, free laccase showed reaction spontaneity over a wider range of temperature (ΔT = 40 K) as opposed to fungal biomass (ΔT = 15 K). Comparison of entropy change (ΔS) values indicated metabolism of the dye by the biomass.
    Matched MeSH terms: Fungal Proteins/chemistry*
  6. Fulltext Development of a pyrG mutant of Aspergillus oryzae strain S1 as a host for the production of heterologous proteins
    Ling SO, Storms R, Zheng Y, Rodzi MR, Mahadi NM, Illias RM, et al.
    ScientificWorldJournal, 2013;2013:634317.
    PMID: 24381522 DOI: 10.1155/2013/634317
    The ease with which auxotrophic strains and genes that complement them can be manipulated, as well as the stability of auxotrophic selection systems, are amongst the advantages of using auxotrophic markers to produce heterologous proteins. Most auxotrophic markers in Aspergillus oryzae originate from chemical or physical mutagenesis that may yield undesirable mutations along with the mutation of interest. An auxotrophic A. oryzae strain S1 was generated by deleting the orotidine-5'-monophosphate decarboxylase gene (pyrG) by targeted gene replacement. The uridine requirement of the resulting strain GR6 pyrGΔ0 was complemented by plasmids carrying a pyrG gene from either Aspergillus nidulans or A. oryzae. β -Galactosidase expression by strain GR6 pyrGΔ0 transformed with an A. niger plasmid encoding a heterologous β -galactosidase was at least 150 times more than that obtained with the untransformed strain. Targeted gene replacement is thus an efficient way of developing auxotrophic mutants in A. oryzae and the auxotrophic strain GR6 pyrGΔ0 facilitated the production of a heterologous protein in this fungus.
    Matched MeSH terms: Fungal Proteins/physiology*
  7. Efficient removal of lignin with the maintenance of hemicellulose from kenaf by two-stage pretreatment process
    Wan Azelee NI, Md Jahim J, Rabu A, Abdul Murad AM, Abu Bakar FD, Md Illias R
    Carbohydr Polym, 2014 Jan;99:447-53.
    PMID: 24274529 DOI: 10.1016/j.carbpol.2013.08.043
    The enhancement of lignocellulose hydrolysis using enzyme complexes requires an efficient pretreatment process to obtain susceptible conditions for the enzyme attack. This study focuses on removing a major part of the lignin layer from kenaf (Hibiscus cannabinus) while simultaneously maintaining most of the hemicellulose. A two-stage pretreatment process is adopted using calcium hydroxide, Ca(OH)₂, and peracetic acid, PPA, to break the recalcitrant lignin layer from other structural polysaccharides. An experimental screening of several pretreatment chemicals, concentrations, temperatures and solid-liquid ratios enabled the production of an optimally designed pretreatment process for kenaf. Our results showed that the pretreatment process has provide 59.25% lignin removal while maintaining 87.72% and 96.17% hemicellulose and cellulose, respectively, using 1g of Ca(OH)₂/L and a 8:1 (mL:g) ratio of liquid-Ca(OH)₂ at 50 °C for 1.5 h followed by 20% peracetic acid pretreatment at 75 °C for 2 h. These results validate this mild approach for aiding future enzymatic hydrolysis.
    Matched MeSH terms: Fungal Proteins/chemistry
  8. Identification of immunogenic proteins of Candida parapsilosis by serological proteome analysis
    Lee PY, Gam LH, Yong VC, Rosli R, Ng KP, Chong PP
    J Appl Microbiol, 2014 Apr;116(4):999-1009.
    PMID: 24299471 DOI: 10.1111/jam.12408
    Systemic candidiasis is the leading fungal bloodstream infection, and its incidence has been on the rise. Recently, Candida parapsilosis has emerged as an increasingly prevalent fungal pathogen, but little is known about its antigenic profile. Hence, the current work was performed to discover immunogenic proteins of C. parapsilosis using serological proteome analysis.
    Matched MeSH terms: Fungal Proteins/immunology*
  9. Fluorene biodegradation and identification of transformation products by white-rot fungus Armillaria sp. F022
    Hadibarata T, Kristanti RA
    Biodegradation, 2014 Jun;25(3):373-82.
    PMID: 24114532 DOI: 10.1007/s10532-013-9666-x
    A diverse surfactant, including the nonionic Tween 80 and Brij 30, the anionic sodium dodecyl sulphate, the cationic surfactant Tetradecyltrimethylammonium bromide, and biosurfactant Rhamnolipid were investigated under fluorine-enriched medium by Armilaria sp. F022. The cultures were performed at 25 °C in malt extract medium containing 1 % of surfactant and 5 mg/L of fluorene. The results showed among the tested surfactants, Tween-80 harvested the highest cell density and obtained the maximum specific growth rate. This due Tween-80 provide a suitable carbon source for fungi. Fluorane was also successfully eliminated (>95 %) from the cultures within 30 days in all flasks. During the experiment, laccase production was the highest among other enzymes and Armillaria sp. F022-enriched culture containing Non-ionic Tween 80 showed a significant result for laccase activity (1,945 U/L). The increased enzyme activity was resulted by the increased biodegradation activity as results of the addition of suitable surfactants. The biotransformation of fluorene was accelerated by Tween 80 at the concentration level of 10 mg/L. Fluorene was initially oxidized at C-2,3 positions resulting 9-fluorenone. Through oxidative decarboxylation, 9-fluorenone subjected to meta-cleavage to form salicylic acid. One metabolite detected in the end of experiment, was identified as catechol. Armillaria sp. F022 evidently posses efficient, high effective degrader and potential for further application on the enhanced bioremediation technologies for treating fluorene-contaminated soil.
    Matched MeSH terms: Fungal Proteins/biosynthesis
  10. Fulltext Characterisation of a New Fungal Immunomodulatory Protein from Tiger Milk mushroom, Lignosus rhinocerotis
    Pushparajah V, Fatima A, Chong CH, Gambule TZ, Chan CJ, Ng ST, et al.
    Sci Rep, 2016 07 27;6:30010.
    PMID: 27460640 DOI: 10.1038/srep30010
    Lignosus rhinocerotis (Tiger milk mushroom) is an important folk medicine for indigenous peoples in Southeast Asia. We previously reported its de novo assembled 34.3 Mb genome encoding a repertoire of proteins including a putative bioactive fungal immunomodulatory protein. Here we report the cDNA of this new member (FIP-Lrh) with a homology range of 54-64% to FIPs from other mushroom species, the closest is with FIP-glu (LZ-8) (64%) from Ganoderma lucidum. The FIP-Lrh of 112 amino acids (12.59 kDa) has a relatively hydrophobic N-terminal. Its predicted 3-dimensional model has identical folding patterns to FIP-fve and contains a partially conserved and more positively charged carbohydrates binding pocket. Docking predictions of FIP-Lrh on 14 glycans commonly found on cellular surfaces showed the best binding energy of -3.98 kcal/mol to N-acetylgalactosamine and N-acetylglucosamine. Overexpression of a 14.9 kDa soluble 6xHisFIP-Lrh was achieved in pET-28a(+)/BL21 and the purified recombinant protein was sequence verified by LC-MS/MS (QTOF) analysis. The ability to haemagglutinate both mouse and human blood at concentration ≥0.34 μM, further demonstrated its lectin nature. In addition, the cytotoxic effect of 6xHisFIP-Lrh on MCF-7, HeLa and A549 cancer cell lines was detected at IC50 of 0.34 μM, 0.58 μM and 0.60 μM, respectively.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/immunology*
  11. Influence of agitation speed on tannase production and morphology of Aspergillus niger FETL FT3 in submerged fermentation
    Darah I, Sumathi G, Jain K, Lim SH
    Appl Biochem Biotechnol, 2011 Dec;165(7-8):1682-90.
    PMID: 21947762 DOI: 10.1007/s12010-011-9387-8
    Agitation speed was found to influence the tannase production and fungal growth of Aspergillus niger FETL FT3. The optimal agitation speed was at 200 rpm which produced 1.41 U/ml tannase and 3.75 g/l of fungal growth. Lower or higher agitation speeds than 200 rpm produced lower enzyme production and fungal growth. Based on the SEM and TEM micrograph observation, there was a significant correlation between agitation speed and the morphology of the fungal mycelia. The results revealed an increase of the enzyme production with the change of the fungal growth morphology from filamentous to pelleted growth forms. However, the exposure to higher shear stress with an increasing agitation speed of the shaker also resulted in lower biomass yields as well as enzyme production.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism*
  12. Cgl-SLT2 is required for appressorium formation, sporulation and pathogenicity in Colletotrichum gloeosporioides
    Yong HY, Bakar FD, Illias RM, Mahadi NM, Murad AM
    Braz J Microbiol, 2013 Dec;44(4):1241-50.
    PMID: 24688518
    The mitogen-activated protein (MAP) kinase pathways has been implicated in the pathogenicity of various pathogenic fungi and plays important roles in regulating pathogenicity-related morphogenesis. This work describes the isolation and characterization of MAP kinase gene, Cgl-SLT2, from Colletotrichum gloeosporioides. A DNA sequence, including 1,633 bp of Cgl-SLT2 open-reading frame and its promoter and terminator regions, was isolated via DNA walking and cloned. To analyze gene function, a gene disruption cassette containing hygromycin-resistant gene was constructed, and Cgl-SLT2 was inactivated via gene deletion. Analysis on Cgl-slt2 mutant revealed a defect in vegetative growth and sporulation as compared to the wild-type strain. When grown under nutrient-limiting conditions, hyperbranched hyphal morphology was observed in the mutant. Conidia induction for germination on rubber wax-coated hard surfaces revealed no differences in the percentage of conidial germination between the wild-type and Cgl-slt2 mutant. However, the percentage of appressorium formation in the mutant was greatly reduced. Bipolar germination in the mutant was higher than in the wild-type at 8-h post-induction. A pathogenicity assay revealed that the mutant was unable to infect either wounded or unwounded mangoes. These results suggest that the Cgl-SLT2 MAP kinase is required for C. gloeosporioides conidiation, polarized growth, appressorium formation and pathogenicity.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism*
  13. Purification and comparison of intracellular proteinase A in Candida spp. isolates from Malaysian and Iranian patients and infected mice
    Amri Saroukolaei S, Pei Pei C, Shokri H, Asadi F
    J Mycol Med, 2012 Jun;22(2):149-59.
    PMID: 23518017 DOI: 10.1016/j.mycmed.2012.01.002
    To compare the specific intracellular proteinase A activity in clinical isolates of Candida species isolated from Iranian and Malaysian patients, the blood and kidneys of mice infected by Candida cells isolated from these human patients.
    Matched MeSH terms: Fungal Proteins/isolation & purification*; Fungal Proteins/metabolism
  14. Fulltext Inhibition of hyphae formation and SIR2 expression in Candida albicans treated with fresh Allium sativum (garlic) extract
    Low CF, Chong PP, Yong PV, Lim CS, Ahmad Z, Othman F
    J Appl Microbiol, 2008 Dec;105(6):2169-77.
    PMID: 19120662 DOI: 10.1111/j.1365-2672.2008.03912.x
    The aims of the present study were to determine whether Allium sativum (garlic) extract has any effect on the morphology transformation of Candida albicans, and to investigate whether it could alter the gene expression level of SIR2, a morphogenetic control gene and SAP4, a gene encoding secreted aspartyl proteinase.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism*
  15. Fulltext Saccharification of rice straw by cellulase from a local Trichoderma harzianum SNRS3 for biobutanol production
    Rahnama N, Foo HL, Abdul Rahman NA, Ariff A, Md Shah UK
    BMC Biotechnol, 2014;14:103.
    PMID: 25496491 DOI: 10.1186/s12896-014-0103-y
    Rice straw has shown to be a promising agricultural by-product in the bioconversion of biomass to value-added products. Hydrolysis of cellulose, a main constituent of lignocellulosic biomass, is a requirement for fermentable sugar production and its subsequent bioconversion to biofuels such as biobutanol. The high cost of commercial enzymes is a major impediment to the industrial application of cellulases. Therefore, the use of local microbial enzymes has been suggested. Trichoderma harzianum strains are potential CMCase and β-glucosidase producers. However, few researches have been reported on cellulase production by T. harzianum and the subsequent use of the crude cellulase for cellulose enzymatic hydrolysis. For cellulose hydrolysis to be efficiently performed, the presence of the whole set of cellulase components including exoglucanase, endoglucanase, and β-glucosidase at a considerable concentration is required. Biomass recalcitrance is also a bottleneck in the bioconversion of agricultural residues to value-added products. An effective pretreatment could be of central significance in the bioconversion of biomass to biofuels.
    Matched MeSH terms: Fungal Proteins/isolation & purification; Fungal Proteins/chemistry*
  16. Fulltext Insight into different environmental niches adaptation and allergenicity from the Cladosporium sphaerospermum genome, a common human allergy-eliciting Dothideomycetes
    Yew SM, Chan CL, Ngeow YF, Toh YF, Na SL, Lee KW, et al.
    Sci Rep, 2016 05 31;6:27008.
    PMID: 27243961 DOI: 10.1038/srep27008
    Cladosporium sphaerospermum, a dematiaceous saprophytic fungus commonly found in diverse environments, has been reported to cause allergy and other occasional diseases in humans. However, its basic biology and genetic information are largely unexplored. A clinical isolate C. sphaerospermum genome, UM 843, was re-sequenced and combined with previously generated sequences to form a model 26.89 Mb genome containing 9,652 predicted genes. Functional annotation on predicted genes suggests the ability of this fungus to degrade carbohydrate and protein complexes. Several putative peptidases responsible for lung tissue hydrolysis were identified. These genes shared high similarity with the Aspergillus peptidases. The UM 843 genome encodes a wide array of proteins involved in the biosynthesis of melanin, siderophores, cladosins and survival in high salinity environment. In addition, a total of 28 genes were predicted to be associated with allergy. Orthologous gene analysis together with 22 other Dothideomycetes showed genes uniquely present in UM 843 that encode four class 1 hydrophobins which may be allergens specific to Cladosporium. The mRNA of these hydrophobins were detected by RT-PCR. The genomic analysis of UM 843 contributes to the understanding of the biology and allergenicity of this widely-prevalent species.
    Matched MeSH terms: Fungal Proteins/genetics*; Fungal Proteins/immunology
  17. Fulltext Genome analysis of Daldinia eschscholtzii strains UM 1400 and UM 1020, wood-decaying fungi isolated from human hosts
    Chan CL, Yew SM, Ngeow YF, Na SL, Lee KW, Hoh CC, et al.
    BMC Genomics, 2015 Nov 18;16:966.
    PMID: 26581579 DOI: 10.1186/s12864-015-2200-2
    BACKGROUND: Daldinia eschscholtzii is a wood-inhabiting fungus that causes wood decay under certain conditions. It has a broad host range and produces a large repertoire of potentially bioactive compounds. However, there is no extensive genome analysis on this fungal species.

    RESULTS: Two fungal isolates (UM 1400 and UM 1020) from human specimens were identified as Daldinia eschscholtzii by morphological features and ITS-based phylogenetic analysis. Both genomes were similar in size with 10,822 predicted genes in UM 1400 (35.8 Mb) and 11,120 predicted genes in UM 1020 (35.5 Mb). A total of 751 gene families were shared among both UM isolates, including gene families associated with fungus-host interactions. In the CAZyme comparative analysis, both genomes were found to contain arrays of CAZyme related to plant cell wall degradation. Genes encoding secreted peptidases were found in the genomes, which encode for the peptidases involved in the degradation of structural proteins in plant cell wall. In addition, arrays of secondary metabolite backbone genes were identified in both genomes, indicating of their potential to produce bioactive secondary metabolites. Both genomes also contained an abundance of gene encoding signaling components, with three proposed MAPK cascades involved in cell wall integrity, osmoregulation, and mating/filamentation. Besides genomic evidence for degrading capability, both isolates also harbored an array of genes encoding stress response proteins that are potentially significant for adaptation to living in the hostile environments.

    CONCLUSIONS: Our genomic studies provide further information for the biological understanding of the D. eschscholtzii and suggest that these wood-decaying fungi are also equipped for adaptation to adverse environments in the human host.

    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism
  18. Fulltext Comparative chemical screening and genetic analysis reveal tentoxin as a new virulence factor in Cochliobolus miyabeanus, the causal agent of brown spot disease on rice
    De Bruyne L, Van Poucke C, Di Mavungu DJ, Zainudin NA, Vanhaecke L, De Vleesschauwer D, et al.
    Mol Plant Pathol, 2016 Aug;17(6):805-17.
    PMID: 26456797 DOI: 10.1111/mpp.12329
    Brown spot disease, caused by Cochliobolus miyabeanus, is currently considered to be one of the most important yield reducers of rice (Oryza sativa L.). Despite its agricultural importance, little is known about the virulence mechanisms deployed by the fungus. Therefore, we set out to identify novel virulence factors with a role in disease development. This article reports, for the first time, the production of tentoxin by C. miyabeanus as a virulence factor during brown spot disease and the identification of the non-ribosomal protein synthetase (NRPS) CmNps3, responsible for tentoxin biosynthesis. We compared the chemical compounds produced by C. miyabeanus strains differing in virulence ability using ultra-high-performance liquid chromatography (UHPLC) coupled to high-resolution Orbitrap mass spectrometry (HRMS). The production of tentoxin by a highly virulent strain was revealed by principal component analysis of the detected ions and confirmed by UHPLC coupled to tandem-quadrupole mass spectrometry (MS/MS). The corresponding NRPS was identified by in silico genome analysis and confirmed by gene deletion. Infection tests with wild-type and Cmnps3 mutants showed that tentoxin acts as a virulence factor and is correlated with chlorosis development during the second phase of infection. Although rice has previously been classified as a tentoxin-insensitive plant species, our data demonstrate that tentoxin production by C. miyabeanus affects symptom development.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism
  19. Crystal structure of fuculose aldolase from the Antarctic psychrophilic yeast Glaciozyma antarctica PI12
    Jaafar NR, Littler D, Beddoe T, Rossjohn J, Illias RM, Mahadi NM, et al.
    Acta Crystallogr F Struct Biol Commun, 2016 11 01;72(Pt 11):831-839.
    PMID: 27827354
    Fuculose-1-phosphate aldolase (FucA) catalyses the reversible cleavage of L-fuculose 1-phosphate to dihydroxyacetone phosphate (DHAP) and L-lactaldehyde. This enzyme from mesophiles and thermophiles has been extensively studied; however, there is no report on this enzyme from a psychrophile. In this study, the gene encoding FucA from Glaciozyma antarctica PI12 (GaFucA) was cloned and the enzyme was overexpressed in Escherichia coli, purified and crystallized. The tetrameric structure of GaFucA was determined to 1.34 Å resolution. The overall architecture of GaFucA and its catalytically essential histidine triad are highly conserved among other fuculose aldolases. Comparisons of structural features between GaFucA and its mesophilic and thermophilic homologues revealed that the enzyme has typical psychrophilic attributes, indicated by the presence of a high number of nonpolar residues at the surface and a lower number of arginine residues.
    Matched MeSH terms: Fungal Proteins/genetics; Fungal Proteins/metabolism; Fungal Proteins/chemistry*
  20. Modeling and optimization of lipase-catalyzed production of succinic acid ester using central composite design analysis
    Abdul Rahman MB, Jarmi NI, Chaibakhsh N, Basri M
    J Ind Microbiol Biotechnol, 2011 Jan;38(1):229-34.
    PMID: 20803246 DOI: 10.1007/s10295-010-0817-3
    Esterification of succinic acid with oleyl alcohol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was investigated in this study. Response surface methodology (RSM) based on a five-level, four-variable central composite design (CCD) was used to model and analyze the reaction. A total of 21 experiments representing different combinations of the four parameters including temperature (35-65°C), time (30-450 min), enzyme amount (20-400 mg), and alcohol:acid molar ratio (1:1-8:1) were generated. A partial cubic equation could accurately model the response surface with a R(2) of 0.9853. The effect and interactions of the variables on the ester synthesis were also studied. Temperature was found to be the most significant parameter that influenced the succinate ester synthesis. At the optimal conditions of 41.1°C, 272.8 min, 20 mg enzyme amount and 7.8:1 alcohol:acid molar ratio, the esterification percentage was 85.0%. The model can present a rapid means for estimating the conversion yield of succinate ester within the selected ranges.
    Matched MeSH terms: Fungal Proteins
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