Talaromyces Thermophilus Research Articles

Highly Thermostable Xylanase of the Thermophilic Fungus Talaromyces thermophilus: Purification and Characterization

A thermostable xylanase from a newly isolated thermophilic fungus Talaromyces thermophilus was purified and characterized. The enzyme was purified to homogeneity by ammonium sulfate precipitation, diethylaminoethyl cellulose anion exchange chromatography, P-100 gel filtration, and Mono Q chromatography with a 23-fold increase in specific activity and 17.5% recovery. The molecular weight of the xylanase was estimated to be 25 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration. The enzyme was highly active over a wide range of pH from 4.0 to 10.0. The relative activities at pH5.0, 9.0, and 10.0 were about 80%, 85.0%, and 60% of that at pH7.5, respectively. The optimum temperature of the purified enzyme was 75 degrees C. The enzyme showed high thermal stability at 50 degrees C (7 days) and the half-life of the xylanase at 100 degrees C was 60 min. The enzyme was free from cellulase activity. K (m) and V (max) values at 50 degrees C of the purified enzyme for birchwood xylan were 22.51 mg/ml and 1.235 micromol min(-1) mg(-1), respectively. The enzyme was activated by Ag(+), Co(2+), and Cu(2+); on the other hand, Hg(2+), Ba(2+), and Mn(2+) inhibited the enzyme. The present study is among the first works to examine and describe a secreted, cellulase-free, and highly thermostable xylanase from the T. thermophilus fungus whose application as a pre-bleaching aid is of apparent importance for pulp and paper industries.

Talaromyces thermophilus β-d-Xylosidase: Purification, Characterization and Xylobiose Synthesis

When grown on wheat bran as the only carbon source, the filamentous fungus Talaromyces thermophilus produces large amounts of beta-xylosidase activity. The presence of glucose drastically decreases the beta-xylosidase production level. The beta-xylosidase of T. thermophilus was purified by ammonium sulfate precipitation, DEAE-cellulose chromatography, and gel filtration (high-performance liquid chromatography). The molecular mass of the enzyme was estimated to be 97 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration. The enzyme activity was optimum at 50 degrees C and pH 7. The apparent Michaelis constant K(m) of the beta-xylosidase was 2.37 mM for p-nitrophenyl-beta-D-xylopyranoside, with a V(max) of 0.049 micromol min(-1) per milligram protein. Enzyme activity was inhibited by Cu(2+), Hg(2+), and Zn(2+) and activated by Ca(2+), Mn(2+), and Co(+) at a concentration of 5 mM. At high xylose concentration, this enzyme catalyses the condensation reaction leading to xylobiose production.

Bioconversion of Straw Into Improved Fodder: Mycoprotein Production and Cellulolytic Acivity of Rice Straw Decomposing Fungi

Sixty two out of the sixty four species of fungal isolates tested could produce both wxo-β1,4-gluconasc (C1) and endo-β1 ,4-glueonase (Cx on pure cellulose and rice straw as carbon source in Czapek’s medium. Fifty-eight and fifteen species were able to grow at 25°C and at 45°C, respectively. Eleven species could grow at both 25°C and 45°C while, four species appeared only at 45°C. The most cellulolytic species at 25°C was Trichoderma koningii producing 1.164 C1 (mg glueose/1 ml culture filtrate/1 hr) and 2.690 Cx on pure cellulose, and 0.889 C1 and 1.810 C1 on rice straw, respectively. At 45°C, the most active thermotolerant species were Aspergillus terreus, followed by A. fumigatus. Talaromyces thermophilus was the highest active thermophilic species followed by Malbranchea sulfurea. Most of these species were also active in fermentation of rice straw at 25 and 45°C (P<0.05). The most active ones were T. koningii, A. ochraceus and A. terreus, which produced 201.5, 193.1 and 188.1 mg crude protein/g dry straw, respectively.

Microbial, chemical and physical aspects of citrus waste composting

Citrus waste supplemented with calcium hydroxide and with a C/N ratio of 24:1, pH of 6.3 and moisture content of 60% was composted by piling under shelter. With regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65–70 days and composting was completed after 3 months. Compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l −1 , bulk density of 1.05 g cm −3 and conductivity of 480 mS m −1 . Phosphorus content (in mg l −1) was 15, potassium 1170, calcium 362, magnesium 121, sodium 32, chloride 143, boron 0.31, and water-soluble nitrogen and organic matter 126 and 4788, respectively. Total carbon amounted to 8.85% and total nitrogen to 1.26% of the dry weight, giving a C/N ratio of 7. Mature compost showed some, but acceptable, levels of phytotoxicity. Raw citrus waste was predominantly colonised by mesophilic yeasts. Thermophilous microorganisms present during the thermic phase mainly comprised the bacterial species Bacillus licheniformis, B. macerans and B. stearothermophilus and, to a lesser extent, fungi such as Absidia corymbifera, Aspergillus fumigatus, Emericella nidulans, Penicillium diversum, Paecilomyces variotii, Rhizomucor pusillus, Talaromyces thermophilus and Thermomyces lanuginosus. Bacteria prevalent in the final product included B. licheniformis, B. macerans, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens, P. luteola and Serratia marcescens, whereas fungi isolated most frequently comprised Aspergillus puniceus, A. ustus, E. nidulans, Paecilomyces lilacinus, T. lanuginosus, yeasts and a basidiomycetous species, probably Coprinus lagopus.

Cloning of the phytases from Emericella nidulans and the thermophilic fungus Talaromyces thermophilus

Phytases (EC 3.1.3.8) belong to the family of histidine acid phosphatases. We have cloned the phytases of the fungi Emericella nidulans and Talaromyces thermophilus. The putative enzyme encoded by the E. nidulans sequence consists of 463 amino acids and has a M r of 51785. The protein deduced from the T. thermophilus sequence consists of 466 amino acids corresponding to a M r of 51450. Both predicted amino acid sequences exhibited high identity (48% to 67%) to known phytases. This high level of identity allowed the modelling of all available fungal phytases based on the three-dimensional structure coordinates of the Aspergillus niger phytase. By this approach we identified 21 amino acids which are conserved in fungal phyA phytases and are part of the residues forming the substrate pocket. Furthermore, potential glycosylation sites were identified and compared between the aforementioned phytases and the A. niger phytase.

Thermophilic and thermotolerant fungi isolated from cultivated and desert soils, exposed continuously to cement dust particles in Egypt

Summary Thermophilic and thermotolerant fungi of forty soil samples collected from cultivated and desert soils, exposed continuously to cement dust particles were studied. Ten genera and 16 species in addition to two varieties of Aspergillus flavus and Malbranchia pulchella were recovered from all soil samples, on three types of media at 45 °C. From cultivated soils, 11 species and 2 varieties representing 7 genera were collected on yeast starch agar; on glucose- (3 genera and 3 species) and on cellulose-Czapek's agar (2 genera and 2 species). From desert soils, 12 species and 1 variety which belong to 8 genera were isolated on yeast starch agar and on both glucose- and cellulose Czapek's agar (1 genus and 1 species). In this investigation, the most dominant species was A. fumigatus . Truly thermophilic fungi were encountered and these were: Chaetomium thermophile, Malbranchea pulchella var. sulfurea, Rhizomucor pusillus, Myriococcum albomyces, Talaromyces thermophilus and Torula thermophila . Yeast starch agar was the best medium for isolation of thermophilic and thermotolerant fungi in the present study.

Fungal flora associated with combine harvester wheat and sorghum dusts from Egypt

107 species and 8 species varieties belonging to 44 genera were collected from combine harvester wheat and sorghum dusts (35 genera and 91 species + 4 varieties) and from the atmosphere of their hay sites (26 genera and 69 species + 4 varieties) on glucose- and cellulose-Czapek's Dox agar at 28 degrees C and 45 degrees C. The mycoflora of wheat and sorghum dusts were basically similar on the two types of media and the most common fungi were: Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. ochraceus, A. sydowii, A. terreus, Cochliobolus spicifer, Emericella nidulans, Fusarium moniliforme, Penicillium chrysogenum, P. duclauxii, P. funiculosum and P. oxalicum. Truly thermophilic species were frequently encountered from the two substrates: Chaetomium thermophilum, Humicola grisea var. thermoidae, H. insolens, Malbranchea pulchella var., sulphurea, Rhizomucor pusillus, Sporotrichum thermophilum, Talaromyces thermophilus, Thermoascus thermophilus and Thermomyces lanuginosus. The airborne fungi in the two atmospheres were basically similar and the most prevalent species were members of Alternaria (1 species), Aspergillus (18 species + 2 varieties), Chaetomium (2 species), Cochliobolus(3 species), Emericella (3 species + 2 varieties), Fusarium (3 species), Mucor (1 species), Penicillium (14 species) and Stachybotrys (1 species).

Eucaryote thermophily: role of lipids in the growth of Talaromyces thermophilus.

The effects of growth temperature on the fatty acid composition of the phospholipids of the fungus Talaromyces thermophilus were investigated. This thermophilic organism was unable to increase the degree of unsaturation of its fatty acids when shifted from high to low growth temperatures. Inhibition of fatty acid synthesis by the antibiotic cerulenin was reversed by the addition of a mixture of palmitic, stearic, and oleic acids and ergosterol. The data obtained were consistent with the hypothesis that the thermophilic character of T. thermophilus is due to metabolic limitations that restrict its ability to regulate membrane fluidity.

Microflora of heat-damaged rapeseed

Microfloral components present on two sound lots (1 and 2) and three sample grade, heat-damaged lots (3 to 5) of stored Canadian rapeseed (Brassica campestris L. and B. napus L.) were determined with and without surface disinfection. Lots 1 and 2 were from a granary and a warehouse, respectively, and lots 3 to 5 were from primary elevators. Seed in lots 4, 5, and 3 showed progressively increased effects of heat damage as shown by the crush test. Sound lots 1 and 2 had mainly Alternaria and Cladosporium spp. with traces of Eurotium amstelodami, E. repens, and Penicillium spp. Lot 4 seed had low–medium levels of Alternaria alternata, Absidia ramosa, E. amstelodami, and Mucor pusillus. Lot 5 had high levels of E. amstelodami and low levels of Talaromyces thermophilus but A. alternata and M. pusillus were largely absent. Lot 3 had deeper-seated E. amstelodami, T. thermophilus, and Penicillium spp. than lots 4 and 5. Eurotium amstelodami was the predominant storage fungus in the heat-damaged lots. During the early stages of heating, E. amstelodami was often accompanied by the primary sugar fungi M. pusillus and A. ramosa, and after severe heating, by T. thermophilus. The thermal death point was between 50 and 60 °C for moist seed and between 80 and 90 °C for dry seed after 30-min exposure. With the exception of E. amstelodami, heat resistance of the fungal flora did not exceed that of the seed.

Thermophilic Fungi in Sun-Heated Soils

Thermophilic and thermotolerant fungi were isolated from soils of south-central Indiana (U.S.A.) in the following order of decreasing frequency: Myriococcum albomyces Cooney et Emerson, Aspergillus fumigatus Fres., Talaromyces thermophilus Stolk, Humicola lanuginosa (Griff. et Maubl.) Bunce, Allescheria terrestris Apinis, Malbranchea pulchella var. sulfurea (Miehe) Cooney et Emerson, Thielavia heterothallica Klopotek, Mucor pusillus Lindt, Chaetomium thermophile var. dissitum Cooney et Emerson, Thielavia minor (Rays et Borut) Malloch et Cain, Thermoascus aurantiacus Miehe sensu Apinis, Mucor miehei Cooney et Emerson, Torula thermophila Cooney et Emerson, Humicola stellata Bunce, Acrophialophora nainana Edward, Thielavia sepedonium Emmons, Dactylomyces thermophilus Sopp, and Talaromyces emersonii Stolk. Four unidentified thermophilic fungi were also isolated. Thermophilic and thermotolerant fungi were isolated most frequently from sun-heated soil, less so from grass-shaded soil, and still less so from tree-shaded soil. Isolates were more frequently obtained from a depth of 0-5 cm than from 10-20 cm. Data concerning numerical values for population numbers and soil pH, moisture, temperature, and percent organic matter are given for samples from the two soil levels for each of 15 consecutive months. Results of special procedures for enrichment of thermophilic and theromotolerant fungi are described, as well as results of air sampling.

Effect of Temperature on Growth Rate of Seven Thermophilic Fungi

Thermophilic fungi, those with a minimum temperature required for growth of 20 C or above and a maximum temperature for growth of 50 C or above, are important in the decomposition of organic matter (3). These and similar organisms are involved in the preparation of mushroom compost (1, 3, 5, 6). Furthermore, thermophilic fungi apparently take part in thermogenesis and spontaneous combustion which cause appreciable financial losses (3). Some diseases affecting animals, including man, involve the thermophilic fungi (3). Cooney and Emerson (3), Cochrane (2), Tansey (8) and Fergus (5) have shown a need for further investigation of the influence of temperature on growth rate and development of thermophilic fungi. Of the thermophilic fungi that have been studied in this regard, only a few have been investigated in detail. Preliminary investigations (good growth and reproduction on YpSs agar at 45 C) indicated that Huimicola insolens Cooney et Emerson, Talaromyces thermophilus Stolk, Humicola grisea (Traaen) var. therm oidea Cooney et Emerson, Sporotrichtu thermophile Apinis, Malbranchea pulchella Sacc. et Penzig var. sulfurea (Miehe) Cooney et Emerson, Mucor miehei Cooney et Emerson and Papulaspora thermophila Fergus would be excellent subjects for an investigation that might extend our knowledge about the effects of temperature on growth rate and reproduction of thermophilic fungi. The organisms were supplied by Dr. C. L. Fergus. A variation of YpSs (3) medium of the following composition was used for the experiment: yeast extract, 2 g; K2HPO4, 1 g; MgSO47H20, 0.5 g; soluble starch, 4 g; distilled water, 1,000 ml; agar (Difco 542

Isolation of Thermophilic Fungi from Alligator Nesting Material

Thermophilic fungi isolated from partially decomposed vegetation from the interior of a recently used alligator (Alligator mississipiensis) nest included Chaetomium thermophile var. coprophile Cooney & Emerson, C. thermophile var. dissitum Cooney & Emerson, Humicola lanuginosa (Griffon & Maublanc) Bunce, Talaromyces thermophilus Stolk, and Thermoascus aurantiacus Miehe sensu Apinis. The thermotolerant fungi Aspergillus fumigatus Fresenius and Burgoa-Papulaspora sp. were also isolated. The ontogeny of bulbils of the latter isolate is described. Alligator nesting material provides a habitat suitable for the thermophilic fungi, where the heat required for growth of these fungi is not provided by the body heat of the nest builder. These data suggest that habitats suitable for the origin and evolutionary survival of obligately thermophilic fungi have existed for long periods of time.

Isolation of Thermophilic Fungi from Alligator Nesting Material

SUMMARYThermophilic fungi isolated from partially decomposed vegetation from the interior of a recently used alligator (Alligator mississipiensis) nest included Chaetomium thermophile var. coprophile Cooney & Emerson, C. thermophile var. dissitum Cooney & Emerson, Humicola lanuginosa (Griffon & Maublanc) Bunce, Talaromyces thermophilus Stolk, and Thermoascus aurantiacus Miehe sensu Apinis. The thermotolerant fungi Aspergillus fumigatus Fresenius and Burgoa-Papulaspora sp. were also isolated. The ontogeny of bulbils of the latter isolate is described. Alligator nesting material provides a habitat suitable for the thermophilic fungi, where the heat required for growth of these fungi is not provided by the body heat of the nest builder. These data suggest that habitats suitable for the origin and evolutionary survival of obligately thermophilic fungi have existed for long periods of time.