The Brevicompactum clade is recognized as a separate lineage in Trichoderma/Hypocrea. This includes T. brevicompactum and the new species T. arundinaceum, T. turrialbense, T. protrudens and Hypocrea rodmanii. The closest relative of the Brevicompactum clade is the Lutea clade. With the exception of H. rodmanii, all members of this clade produce the simple trichothecene-type toxins harzianum A or trichodermin. All members of the clade produce peptaibiotics, including alamethicins. Strains previously reported as T. harzianum (ATCC 90237), T. viride (NRRL 3199) or Hypocrea sp. (F000527, CBS 113214) to produce trichothecenes are reidentified as T. arundinaceum. The Brevicompactum clade is not closely related to species that have biological application.
Two primary alcohols (1-butanol and ethanol) are major fermentation products of several clostridial species.In addition to these two alcohols, the secondary alcohol 2-propanol is produced to a concentration of about 100 mM by some strains of Clostridium beyerinckii. An alcohol dehydrogenase (ADH) has been purified to homogeneity from two strains (NRRL B593 and NESTE 255) of 2-propanol-producing C. bejerinckii. When exposed to air, the purified ADH was stable, whereas the partially purified ADH was inactivated. The ADHs from the two strains had similar structural and kinetic properties. Each had a native Mr of between 90,000 and 100,000 and a subunit Mr of between 38,000 and 40,000. The ADHs were NADP(H) dependent, but a low level of NADW-linked activity was detected. They were equally active in reducing aldehydes and 2-ketones, but a much lower oxidizing activity was obtained with primary alcohols than with secondary alcohols. The kc,./Km value for the alcohol-forming reaction appears to be a function of the size of the larger alkyl substituent on the carbonyl group. ADH activities measured in the presence of both acetone and butyraldehyde did not exceed activities measured with either substrate present alone, indicating a common active site for both substrates. There was no similarity in the N-terminal amino acid sequence between that of the ADH and those of fungi and several other bacteria. However, the N-terminal sequence had 67% identity with those of two other anaerobes, T7hermoanaerobium brockii and Methanobacterium palustre. Furthermore, conserved glycine and tryptophan residues are present in ADHs of these three anaerobic bacteria and ADHs of mammals and green plants. Alcohol dehydrogenase (ADH) is widespread in nature.The ADHs of human and horse liver and baker's yeast are well characterized (7,15,30). Although the metabolism of ethanol is a recognized physiological role of ADH, isozymes of ADH often show higher levels of activity toward other substrates. ADHs react with normal and branched-chain aliphatic and aromatic alcohols, both primary and secondary, as well as the corresponding aldehydes and ketones. The broad substrate range has led to suggestions for other roles for ADH (42), and it remains difficult to determine the physiological reaction and significance of an ADH when multiple ADHs are present in an organism. In anaerobic bacteria that produce alcohols as major end products (27) or that grow on alcohols (e.g., references 5 and 16), the physiological role of the predominant ADH is the formation or oxidation of the pertinent alcohols.Although ADHs generally have a broad substrate range, few are equally reactive toward both primary and secondary alcohols. For example, the liver ADHs react with both primary and secondary alcohols (12). Among the liver ADHs, the human aa isozyme (class I) is far more efficient than the others in oxidizing secondary alcohols (49). Nevertheless, the human wx ADH is still considered a primary ADH because it reacts with primary alcohols more efficiently than with sec...
Dollar spot is one of the most destructive and economically important fungal diseases of amenity turfgrasses. The causal agent was first described in 1937 as the ascomycete Sclerotinia homoeocarpa. However, the genus-level taxonomic placement of this fungus has been the subject of an ongoing debate for over 75 y. Existing morphological and rDNA sequence evidence indicates that this organism is more appropriately placed in the family Rutstroemiaceae rather than the Sclerotiniaceae. Here we use DNA sequence data from samples of the dollar spot fungus and other members of the Rutstroemiaceae (e.g. Rutstroemia, Lanzia, Lambertella) collected throughout the world to determine the generic identity of the turfgrass dollar spot pathogen. Phylogenetic evidence from three nucleotide sequence markers (CaM, ITS and Mcm7; 1810-bp) confirmed that S. homoeocarpa is not a species of Sclerotinia; nor is it a member of any known genus in the Rutstroemiaceae. These data support the establishment of a new genus, which we describe here as Clarireedia gen. nov. The type species for the genus, Clarireedia homoeocarpa comb. nov., is described to accommodate the dollar spot fungus, and a neotype is designated. Three new species in this clade, Clarireedia bennettii sp. nov., Clarireedia jacksonii sp. nov., and Clarireedia monteithiana sp. nov. that also cause dollar spot disease are described. Clarireedia homoeocarpa and C. bennettii occur primarily on Festuca rubra (C3 grass) hosts and appear to be restricted to the United Kingdom. Clarireedia jacksonii and C. monteithiana occur on a variety of C3 and C4 grass hosts, respectively, and appear to be globally distributed. This resolved taxonomy puts to rest a major controversy amongst plant pathologists and provides a foundation for better understanding the nature and biology of these destructive pathogens.
Highlights► Longibrachiatum clade consists of at least 26 phylogenetic species. ► Many species are allopatric although sympatric species are also present. ► The majority of species lost their ability to sexual reproduction. ► The K/θ method is a useful measure to delineate species in the Longibrachiatum clade. ► The combination of the GCPSR and K/θ method gives the most adequate result for species delineation.
Analysis of a worldwide collection of strains of Trichoderma asperellum sensu lato using multilocus genealogies of four genomic regions (tef1, rpb2, act, ITS1, 2 and 5.8s rRNA), sequence polymorphism-derived (SPD) markers, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) of the proteome and classical mycological techniques revealed two morphologically cryptic sister species within T. asperellum, T. asperellum, T. asperelloides sp. nov. and a third closely related but morphologically distinct species. T. yunnanense. Trichoderma asperellum and T. asperelloides have wide sympatric distribution on multiple continents; T. yunnanense is represented by a single strain from China. Several strains reported in the literature or represented in GenBank as T. asperellum are re-identified as T. asperelloides. Four molecular SPD typing patterns (I-IV) were found over a large geographic range. Patterns I-III were produced only by T. asperellum and pattern IV by T. asperelloides and T. yunnanense. Pattern I was found in North America, South America, Africa and Europe and Asia (Saudi Arabia). Pattern III was found in Africa, North America, South America and Asia, not in Europe. Pattern II was found only in Cameroon (central Africa) and Peru. Pattern IV was found in all continents. All SPD II pattern strains formed a strongly supported subclade within the T. asperellum clade in the phylogenetic tree based on rpb2 and MLS (combined multilocus sequence). The diversity of DNA sequences, SPD markers and polypeptides in T. asperellum suggests that further speciation is under way within T. asperellum. MALDI-TOF MS distinguished T. yunnanense from related taxa by UPGMA clustering, but separation between T. asperellum and T. asperelloides was less clear.
The Longibrachiatum Clade of Trichoderma is revised. Eight new species are described (T. aethiopicum, T. capillare, T. flagellatum, T. gillesii, T. gracile, T. pinnatum, T. saturnisporopsis, T. solani). The twenty-one species known to belong to the Longibrachiatum Clade are included in a synoptic key. Trichoderma parareesei and T. effusum are redescribed based on new collections or additional observations. Hypocrea teleomorphs are reported for T. gillesii and T. pinnatum. Previously described species are annotated.
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