Characterisation and application of glycanases secreted by Aspergillus terreus CCMI 498 and Trichoderma viride CCMI 84 for enzymatic deinking of mixed office wastepaper.

Two enzymatic extracts obtained from xylan-grown Aspergillus terreus CCMI 498 and cellulose-grown Trichoderma viride CCMI 84 were characterised for different glycanase activities. Both strains produce extracellular endoxylanase and endoglucanase enzymes. The enzymes optimal activity was found in the temperature range of 45-60 degrees C. Endoglucanase systems show identical activity profiles towards temperature, regardless of the strain and inducing substrate. Conversely, the endoxylanases produced by both strains showed maximal activity at different pH values (from 4.5 to 5.5), being the more acidic xylanase produced by T. viride grown on cellulose. The endoglucanase activities have an optimum pH at 4.5-5.0. The endoxylanase and endoglucanase activities exhibited high stability at 50 degrees C and pH 5.0. Mannanase, beta-xylosidase, and amylase activities were also found, being the first two activities only present for T. viride extract. These two enzymatic extracts were used for mixed office wastepaper (MOW) deinking. When the enzymatic extract from T. viride was used, a further increase of 24% in ink removal was obtained by comparison with the control. Both enzymes contributed to the improvement of the paper strength properties and the obtained results clearly indicate that the effective use of enzymes for deinking can also contribute to the pulp and paper properties improvement.

Diversity of microfungi in the phylloplane of plants growing in a Mediterranean ecosystem.

Mediterranean ecosystems have not been investigated as natural habitats for microorganisms in general, and microfungi in particular. Plants harvested in "Serra da Arrábida" (38 degrees 27' N, 9 degrees 02' W), a Mediterranean ecosystem in Portugal, were analyzed for the filamentous microfungi inhabiting their surface. Two field locations with distinct climatic characteristics were studied: 'Fonte do Veado' (38 degrees 28'50" N, 9 degrees 0'17" W; 300 m elevation) located on the northern slope, and 'Mata do Solitário' (38 degrees 27'55" N, 8 degrees 59'35" W; 50 m elevation), on the southern slope. From Veado zone, leaf samples yielded a total of 3,049 isolates, ranging from 317 to 1,328/sample (mean = 762). The number of species/sample ranged from 12 to 24. From Solitario zone, leaf samples yielded a total of 1,337 isolates, ranging from 189 to 528/sample (mean = 334). The number of species/sample, in this case, ranged from 10 to 17. Veado zone showed a wider range of species. The fungal species more frequently isolated from both zones (Aureobasidium pullulans (De Bary) Arnaud, Cladosporium cladosporioides (Fresen.) De Vries, C. sphaerospermum Penzig and Alternaria alternata (Fr.) Keissler) were found in all plant samples and represents 80% (Veado) and 85% (Solitario) of the total isolates.

Estimation and diversity of phylloplane mycobiota on selected plants in a Mediterranean-type ecosystem in Portugal.

Mediterranean ecosystems have not been consistently investigated as natural habitats for microbes in general, and fungi in particular. Here we present the results of a survey of epiphytic mycobiota (filamentous fungi and yeasts) on the phylloplane of selected plants in the Arrábida Natural Park, an ecosystem of Mediterranean characteristics in Portugal, using conventional culture-dependent isolation methods. Leaves from the species Acer monspessulanum and Quercus faginea (deciduous trees) and Cistus albidus, Pistacia lentiscus, and Osyris quadripartita (evergreen shrubs) were collected twice a year for two consecutive years, at two distinct locations of Serra da Arrábida: the more humid northern slope and the drier southern slope. A total of 1029 strains of filamentous fungi and 540 strains of yeasts were isolated, which represented at least 36 and 46 distinct species, respectively. Total counts were higher on the plants from the northern slope and there was a general increase from spring to autumn, notably on the deciduous trees for the yeasts. Plant species that had higher numbers of leaf colonists (A. monspessulanum, C. albidus, and Q. faginea) also yielded a wider range of species. Among the filamentous fungi there was a predominance of species of ascomycetous affinity, whereas basidiomycetous species dominated among yeast isolates. Some of the taxa recovered were common to other phylloplane studies (e.g., ubiquitous molds and yeasts such as Cladosporium spp. and Cryptococcus spp., respectively), but less common species were also found, some of which appeared to represent undescribed taxa. Interestingly, a few species seemed to be associated with a particular plant, notably in the case of the evergreen shrub C. albidus. However, for a considerable number of fungi and yeasts the same taxon was recovered throughout the year from more than one plant and at both sites, suggesting that such species might be genuine phylloplane inhabitants (or at least of aerial plant surfaces) even though they appeared not to display host specificity.