1. |
Wang L,
Zhuang WY,
( 2007 ) Phylogenetic analyses of penicillia based on partial calmodulin gene sequences. PMID : 16860929 : DOI : 10.1016/j.biosystems.2006.04.008 Abstract >>
Partial sequences (about 600 nucleotides) of the calmodulin gene were used for the phylogenetic studies on Eupenicillium, Talaromyces and Penicillium. This region is from the 3rd base of the codon for the 9th amino acid Gln to the 3rd base of the codon for the 122th amino acid Val, flanking parts of the 2nd and 5th exons with complete sequences of two exons and three introns. Seventy-six isolates of 56 taxa of penicillia were involved. The nucleotide sequences with and without introns were analyzed respectively using the neighbor-joining (NJ) and maximum parsimony (MP) methods. The cluster analysis on relative synonymous codon usage (RSCU) of each sequence was also carried out. The fact that species of penicillia belong to the two subfamilies of the Trichocomaceae proposed by Malloch based on traditional methods is supported by our molecular data, whereas, the development of asci and patterns of penicilli show little phylogenetic information. Nine groups in the lineage of Eupenicillium and two in that of Talaromyces were recognized in our studies. In addition to the teleomorph-holomorph-anamorph evolutionary model of penicillia suggested by LoBuglio et al., and Pitt, we proposed that a mutation bias of holomorphs/anamorphs with or without selection is another evolutionary path of these organisms.
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2. |
López-Villavicencio M,
Aguileta G,
Giraud T,
de Vienne DM,
Lacoste S,
Couloux A,
Dupont J,
( 2010 ) Sex in Penicillium: combined phylogenetic and experimental approaches. PMID : 20460164 : DOI : 10.1016/j.fgb.2010.05.002 Abstract >>
We studied the mode of reproduction and its evolution in the fungal subgenus Penicillium Biverticillium using phylogenetic and experimental approaches. We sequenced mating type (MAT) genes and nuclear DNA fragments in sexual and putatively asexual species. Examination of the concordance between individual trees supported the recognition of the morphological species. MAT genes were detected in two putatively asexual species and were found to evolve mostly under purifying selection, although high substitution rates were detected at some sites in some clades. The first steps of sexual reproduction could be induced under controlled conditions in one of the two species, although no mature cleistothecia were produced. Altogether, these findings suggest that the asexual Penicillium species may have lost sex only very recently and/or that the MAT genes are involved in other functions. An ancestral state reconstruction analysis indicated several events of putative sex loss in the genus. Alternatively, it is possible that the supposedly asexual Penicillium species may have retained a cryptic sexual stage.
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3. |
Zhang T,
Zhao S,
Liao LS,
Li CX,
Liao GY,
Feng JX,
( 2017 ) Deletion of TpKu70 facilitates gene targeting in Talaromyces pinophilus and identification of TpAmyR involvement in amylase production. PMID : 28849313 : DOI : 10.1007/s11274-017-2331-5 Abstract >>
Talaromyces pinophilus is a promising filamentous fungus for industrial production of biomass-degrading enzymes used in biorefining, and its genome was recently sequenced and reported. However, functional analysis of genes in T. pinophilus is rather limited owing to lack of genetic tools. In this study, a putative TpKu70 encoding the Ku70 homolog involved in the classic non-homologous end-joining pathway was deleted in T. pinophilus 1-95. �GTpKu70 displayed no apparent defect in vegetative growth and enzyme production, and presented similar sensitivity to benomyl, bleomycin, and UV, when compared with the wild-type T. pinophilus strain 1-95. Seven genes that encode putative transcription factors, including TpAmyR, were successfully knocked out in �GTpKu70 at 61.5-100% of homologous recombination frequency, which is significantly higher than that noted in the wild-type. Interestingly, �GTpAmyR produced approximately 20% of amylase secreted by the parent strain �GTpKu70 in medium containing soluble starch from corn as the sole carbon source. Real-time quantitative reverse transcription PCR showed that TpAmyR positively regulated the expression of genes encoding �\-amylase and glucoamylase. Thus, this study provides a useful tool for genetic analysis of T. pinophilus, and identification of a key role for the transcription factor TpAmyR in amylase production in T. pinophilus.
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4. |
Xian L,
Wang F,
Luo X,
Feng YL,
Feng JX,
( 2015 ) Purification and characterization of a highly efficient calcium-independent �\-amylase from Talaromyces pinophilus 1-95. PMID : 25811759 : DOI : 10.1371/journal.pone.0121531 PMC : PMC4374950 Abstract >>
Alpha-amylase is a very important enzyme in the starch conversion process. Most of the �\-amylases are calcium-dependent and exhibit poor performance in the simultaneous saccharification and fermentation process of industrial bioethanol production that uses starch as feedstock. In this study, an extracellular amylolytic enzyme was purified from the culture broth of newly isolated Talaromyces pinophilus strain 1-95. The purified amylolytic enzyme, with an apparent molecular weight of 58 kDa on SDS-PAGE, hydrolyzed maltopentaose, maltohexaose, and maltoheptaose into mainly maltose and maltotriose and minor amount of glucose, confirming the endo-acting mode of the enzyme, and hence, was named Talaromyces pinophilus �\-amylase (TpAA). TpAA was most active at pH 4.0-5.0 (with the temperature held at 37�XC) and 55�XC (at pH 5.0), and stable within the pH range of 5.0-9.5 (at 4�XC) and below 45�XC (at pH 5.0). Interestingly, the Ca2+ did not improve its enzymatic activity, optimal temperature, or thermostability of the enzyme, indicating that the TpAA was Ca2+-independent. TpAA displayed higher enzyme activity toward malto-oligosaccharides and dextrin than other previously reported �\-amylases. This highly active Ca2+-independent �\-amylase may have potential applications in starch-to-ethanol conversion process.
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5. |
Rojas JD,
Sette LD,
de Araujo WL,
Lopes MS,
da Silva LF,
Furlan RL,
Padilla G,
( 2012 ) The diversity of polyketide synthase genes from sugarcane-derived fungi. PMID : 21938508 : DOI : 10.1007/s00248-011-9938-0 Abstract >>
The chemical ecology and biotechnological potential of metabolites from endophytic and rhizosphere fungi are receiving much attention. A collection of 17 sugarcane-derived fungi were identified and assessed by PCR for the presence of polyketide synthase (PKS) genes. The fungi were all various genera of ascomycetes, the genomes of which encoded 36 putative PKS sequences, 26 shared sequence homology with �]-ketoacyl synthase domains, while 10 sequences showed homology to known fungal C-methyltransferase domains. A neighbour-joining phylogenetic analysis of the translated sequences could group the domains into previously established chemistry-based clades that represented non-reducing, partially reducing and highly reducing fungal PKSs. We observed that, in many cases, the membership of each clade also reflected the taxonomy of the fungal isolates. The functional assignment of the domains was further confirmed by in silico secondary and tertiary protein structure predictions. This genome mining study reveals, for the first time, the genetic potential of specific taxonomic groups of sugarcane-derived fungi to produce specific types of polyketides. Future work will focus on isolating these compounds with a view to understanding their chemical ecology and likely biotechnological potential.
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6. |
Liao GY,
Zhao S,
Zhang T,
Li CX,
Liao LS,
Zhang FF,
Luo XM,
Feng JX,
( 2018 ) The transcription factor TpRfx1 is an essential regulator of amylase and cellulase gene expression in Talaromyces pinophilus. PMID : 30337955 : DOI : 10.1186/s13068-018-1276-8 PMC : PMC6174557 Abstract >>
Perfect and low cost of fungal amylolytic and cellulolytic enzymes are prerequisite for the industrialization of plant biomass biorefinergy to biofuels. Genetic engineering of fungal strains based on regulatory network of transcriptional factors (TFs) and their targets is an efficient strategy to achieve the above described aim. Talaromyces pinophilus produces integrative amylolytic and cellulolytic enzymes; however, the regulatory mechanism associated with the expression of amylase and cellulase genes in T. pinophilus remains unclear. In this study, we screened for and identified novel TFs regulating amylase and/or cellulase gene expression in T. pinophilus 1-95 through comparative transcriptomic and genetic analyses. Comparative analysis of the transcriptomes from T. pinophilus 1-95 grown on media in the presence and absence of glucose or soluble starch as the sole carbon source screened 33 candidate TF-encoding genes that regulate amylase gene expression. Thirty of the 33 genes were successfully knocked out in the parental strain T. pinophilus ?TpKu70, with seven of the deletion mutants firstly displaying significant changes in amylase production as compared with the parental strain. Among these, ?TpRfx1 (TpRfx1: Talaromyces pinophilus Rfx1) showed the most significant decrease (81.5%) in amylase production, as well as a 57.7% reduction in filter paper cellulase production. Real-time quantitative reverse transcription PCR showed that TpRfx1 dynamically regulated the expression of major amylase and cellulase genes during cell growth, and in vitro electrophoretic mobility shift assay revealed that TpRfx1 bound the promoter regions of genes encoding �\-amylase (TP04014/Amy13A), glucoamylase (TP09267/Amy15A), cellobiohydrolase (TP09412/cbh1), �]-glucosidase (TP05820/bgl1), and endo-�]-1,4-glucanase (TP08514/eg1). TpRfx1 protein containing a regulatory factor X (RFX) DNA-binding domain belongs to RFX family. We identified a novel RFX protein TpRFX1 that directly regulates the expression of amylase and cellulase genes in T. pinophilus, which provides new insights into the regulatory mechanism of fungal amylase and cellulase gene expression.
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7. |
Moroz OV,
Sobala LF,
Blagova E,
Coyle T,
Peng W,
Mørkeberg Krogh KBR,
Stubbs KA,
Wilson KS,
Davies GJ,
( 2018 ) Structure of a Talaromyces pinophilus GH62 arabinofuranosidase in complex with AraDNJ at 1.25 ? resolution. PMID : 30084398 : DOI : 10.1107/S2053230X18000250 PMC : PMC6096477 Abstract >>
The enzymatic hydrolysis of complex plant biomass is a major societal goal of the 21st century in order to deliver renewable energy from nonpetroleum and nonfood sources. One of the major problems in many industrial processes, including the production of second-generation biofuels from lignocellulose, is the presence of `hemicelluloses' such as xylans which block access to the cellulosic biomass. Xylans, with a polymeric �]-1,4-xylose backbone, are frequently decorated with acetyl, glucuronyl and arabinofuranosyl `side-chain' substituents, all of which need to be removed for complete degradation of the xylan. As such, there is interest in side-chain-cleaving enzymes and their action on polymeric substrates. Here, the 1.25 ? resolution structure of the Talaromyces pinophilus arabinofuranosidase in complex with the inhibitor AraDNJ, which binds with a Kd of 24 �� 0.4 ?M, is reported. Positively charged iminosugars are generally considered to be potent inhibitors of retaining glycosidases by virtue of their ability to interact with both acid/base and nucleophilic carboxylates. Here, AraDNJ shows good inhibition of an inverting enzyme, allowing further insight into the structural basis for arabinoxylan recognition and degradation.
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8. |
Crutcher FK,
Puckhaber LS,
Stipanovic RD,
Bell AA,
Nichols RL,
Lawrence KS,
Liu J,
( 2017 ) Microbial Resistance Mechanisms to the Antibiotic and Phytotoxin Fusaric Acid. PMID : 28986689 : DOI : 10.1007/s10886-017-0889-x Abstract >>
Fusaric acid (FA) produced by Fusarium oxysporum plays an important role in disease development in plants, including cotton. This non-specific toxin also has antibiotic effects on microorganisms. Thus, one expects a potential pool of diverse detoxification mechanisms of FA in nature. Bacteria and fungi from soils infested with Fusarium and from laboratory sources were evaluated for their ability to grow in the presence of FA and to alter the structure of FA into less toxic compounds. None of the bacterial strains were able to chemically modify FA. Highly FA-resistant strains were found only in Gram-negative bacteria, mainly in the genus of Pseudomonas. The FA resistance of the Gram-negative bacteria was positively correlated with the number of predicted genes for FA efflux pumps present in the genome. Phylogenetic analysis of predicted FA resistance proteins (FUSC, an inner membrane transporter component of the efflux pump) revealed that FUSC proteins having high sequence identities with the functionally characterized FA resistance protein FusC or Fdt might be the major contributors of FA resistance. In contrast, most fungi converted FA to less toxic compounds regardless of the level of FA resistance they exhibited. Five derivatives were detected, and the detoxification of FA involved either oxidative reactions on the butyl side chain or reductive reactions on the carboxylic acid group. The production of these metabolites from widely different phyla indicates that resistance to FA by altering its structure is highly conserved. A few FA resistant saprophytic or biocontrol strains of fungi were incapable of altering FA, indicating a possible involvement of efflux transporters. Deployment of both efflux and derivatization mechanisms may be a common feature of fungal FA resistance.
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