Abstract
Laccases of fungi attract considerable attention due to their possible involvement in the transformation of a wide variety of phenolic compounds including the polymeric lignin and humic ...substances. So far, more than a 100 enzymes have been purified from fungal cultures and characterized in terms of their biochemical and catalytic properties. Most ligninolytic fungal species produce constitutively at least one laccase isoenzyme and laccases are also dominant among ligninolytic enzymes in the soil environment. The fact that they only require molecular oxygen for catalysis makes them suitable for biotechnological applications for the transformation or immobilization of xenobiotic compounds.
The purpose of this study was to evaluate the natural durability of Cupressus lusitanica, Cryptomeria japonica and Pinus taeda woods subjected to a rotting field trial, through mass loss and ...deterioration index. The trial was conducted in an open field in the city of Curitibanos, State of Santa Catarina, Brazil, for a 24-month period, with evaluations carried out every 6 months. For developing the study, we used the woods of Cupressus lusitanica (16 years), Cryptomeria japonica (16 years) and Pinus taeda (juvenile=15 years and mature wood>30 years) species, from which test specimens were made with the dimensions of 2.5 x 5.0 x 50.0 cm in thickness, width and length, respectively, following the standards suggested by IUFRO. After 24 months of exposure to the rotting field the woods of C. japonica and C. lusitanica species showed a deterioration index that reflected an evident but moderate attack of fungi and termites, while the woods of P. taeda (juvenile) and P. taeda (mature) showed deterioration index that reflected an intense rotting and intense attack of termites. Regarding the mass loss the woods of C. japonica and C. lusitanica were classified as highly resistant, while P. taeda (juvenile) was considered resistant and P. taeda (mature) was considered moderately resistant. In general, the woods of C. lusitanica and C. japonica showed greater natural durability when used in contact with the soil.
This study investigated the diversity of yeast species associated with rotting wood in Brazilian Amazonian rainforests. A total of 569 yeast strains were isolated from rotting wood samples collected ...in three Amazonian areas (Universidade Federal do Amazonas‐Universidade Federal do Amazonas UFAM, Piquiá, and Carú) in the municipality of Itacoatiara, Amazon state. The samples were cultured in yeast nitrogen base (YNB)‐d‐xylose, YNB‐xylan, and sugarcane bagasse and corncob hemicellulosic hydrolysates (undiluted and diluted 1:2 and 1:5). Sugiyamaella was the most prevalent genus identified in this work, followed by Kazachstania. The most frequently isolated yeast species were Schwanniomyces polymorphus, Scheffersomyces amazonensis, and Wickerhamomyces sp., respectively. The alpha diversity analyses showed that the dryland forest of UFAM was the most diverse area, while the floodplain forest of Carú was the least. Additionally, the difference in diversity between UFAM and Carú was the highest among the comparisons. Thirty candidates for new yeast species were obtained, representing 36% of the species identified and totaling 101 isolates. Among them were species belonging to the clades Spathaspora, Scheffersomyces, and Sugiyamaella, which are recognized as genera with natural xylose‐fermenting yeasts that are often studied for biotechnological and ecological purposes. The results of this work showed that rotting wood collected from the Amazonian rainforest is a tremendous source of diverse yeasts, including candidates for new species.
To explore the diversity of the Amazonian rainforest by targeting the group of yeasts with the ability to assimilate lignocellulosic sugars, the authors collected rotting wood samples in three sites of the forest, including both drylands and floodplain areas. Dryland areas in the Brazilian Amazonian rainforest has higher diversity of yeasts associated with rooting wood than floodplain areas. Also, a high number of candidates for novel species is present in rotting wood samples.
Take‐away
Rotting wood is a great source of yeast species that can assimilate lignocellulosic sugars.
Dryland areas in the Brazilian Amazonian rainforest has higher diversity of culturable yeasts associated with rooting wood than floodplain areas.
A great number of candidates for novel species is present in rotting wood samples.
Universidade Federal do Amazonas and yeast nitrogen base (YNB)‐xylose were the area and medium, respectively, in which the highest number of new species candidates were recovered.
This study investigated the diversity of yeast species associated with rotting wood in Brazilian Amazonian rainforests. Herein, a total of 569 yeast strains were isolated from rotting wood samples ...collected in three Amazonian areas (Universidade Federal do Amazonas-Universidade Federal do Amazonas UFAM, Piquiá, and Carú) in the municipality of Itacoatiara, Amazon state. The samples were cultured in yeast nitrogen base (YNB)-d-xylose, YNB-xylan, and sugarcane bagasse and corncob hemicellulosic hydrolysates (undiluted and diluted 1:2 and 1:5). Sugiyamaella was the most prevalent genus identified in this work, followed by Kazachstania. The most frequently isolated yeast species were Schwanniomyces polymorphus, Scheffersomyces amazonensis, and Wickerhamomyces sp., respectively. The alpha diversity analyses showed that the dryland forest of UFAM was the most diverse area, while the floodplain forest of Carú was the least. Additionally, the difference in diversity between UFAM and Carú was the highest among the comparisons. Thirty candidates for new yeast species were obtained, representing 36% of the species identified and totaling 101 isolates. Among them were species belonging to the clades Spathaspora, Scheffersomyces, and Sugiyamaella, which are recognized as genera with natural xylose-fermenting yeasts that are often studied for biotechnological and ecological purposes. The results of this work showed that rotting wood collected from the Amazonian rainforest is a tremendous source of diverse yeasts, including candidates for new species.
The aim of this study was to evaluate the chemical compounds of garlic essential oil (EO), and determine the antifungal efficacy of garlic EO and its major components, diallyl trisulfide and its ...nanoemulsions against wood-rotting fungi,
and
. GC-MS analysis revealed that the major constituents of garlic EO were diallyl trisulfide (39.79%), diallyl disulfide (32.91%), and diallyl sulfide (7.02%). In antifungal activity, the IC
value of garlic EO against
and
were 137.3 and 44.6 μg/mL, respectively. Results from the antifungal tests demonstrated that the three major constituents were shown to have good antifungal activity, in which, diallyl trisulfide was the most effective against
and
, with the IC
values of 56.1 and 31.6 μg/mL, respectively. The diallyl trisulfide nanoemulsions showed high antifungal efficacy against the examined wood-rotting fungi, and as the amount of diallyl trisulfide in the lipid phase increases, the antifungal efficacy of the nanoemulsions increases. These results showed that the nanoemulsions and normal emulsion of diallyl trisulfide have potential to develop into a natural wood preservative.
Phylogenetic analyses inferred from the nuc rDNA ITS1-5.8S-ITS2 (ITS) data set and the combined 2-locus data set 5.8S + nuc 28S rDNA (nLSU) of taxa of Trechisporales around the world show that
family ...forms a monophyletic lineage within Trechisporales. Bayesian evolutionary and divergence time analyses on two data sets of 5.8S and nLSU sequences indicate an ancient divergence of
family from Hydnodontaceae during the Triassic period (224.25 Mya).
family is characterized by resupinate and thin basidiomata, smooth, verruculose, or odontoid-semiporoid hymenophore, a monomitic hyphal structure, and generative hyphae bearing clamp connections, the presence of cystidia and hyphidia in some species, thin-walled, smooth, inamyloid, and acyanophilous basidiospores. In addition, four new species, namely,
,
,
, and
, are described and illustrated. In addition, three new combinations, namely,
,
, and
, are also proposed.
1. Wood-decaying fungi are crucial for the functioning of forest ecosystems. We tested the hypotheses that on coarse woody debris (CWD), the abundance, diversity and composition of fungi depend more ...on the amount of available resource than on macro- or microclimate, and that on fine woody debris (FWD) more on the microclimate because of the rapid desiccation of thin woody debris. 2. We sampled 7183 dead wood objects with 10 818 fungal samples on 290 plots along four transects, from 650 to 1450 m a.s.l., in the Bavarian Forest National Park, Germany, Overall, we recorded 263 species (54 only on FWD and 71 only on CWD). 3. For each plot, we characterized the macroclimate using field data and a terrain model. Microclimate variables were extracted from remote-sensing and ground surveys. Resource availability was characterized by measuring the amount, tree species composition, diameter and rotting stage of all dead wood objects. We extracted principal components from each of the three data sets for further analyses. 4. The number of species found per sampled surface area of woody debris indicated that the fungal community on FWD needs a much lower surface area than that on CWD; FWD probably provides more niches per unit surface area than CWD. The abundance of fungi (and therefore also species density) living on FWD and CWD as well as the fungal community composition on CWD were clearly driven by variables characterizing the amount and diversity of the resource. In general, the surface area was the most important factor for abundance of species. In contrast, the community composition on FWD was better predicted by variables characterizing the microclimate. 5. Synthesis. Our results supported the hypotheses that the amount of available resources is more important than macroclimate for fungi living on CWD, and microclimate is more important for fungi living on FWD. Therefore, both dead wood removal and silviculture, which, like logging, open the canopy and increases sunlight exposure, will strongly affect the diversity of wood-decaying fungi in forests. For the conservation of this important group of organisms in forests, silvicultural strategies are more important than climate.
ABSTRACT The yerba-mate (Ilex paraguariensis) has great socioeconomic importance on family farming in Southerm Brazil. One of the main yerba-mate disease is root rotting, caused by Fusarium spp. ...Little is known about the pathogen physiology, especially regarding the aggressiveness associated with the production of extracellular enzymes. On this work, the aggressiveness of isolates of F. oxysporum and F. solani pathogenic to yerba-mate was evaluated and it was determined the activities of extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases produced by Fusarium spp. in culture medium. Six isolates of F. solani and one isolate of F. oxysporum pathogenic to yerba-mate were used. The F. oxysporum isolate proved to be less aggressive in relation to the other F. solani isolates. All isolates of Fusarium spp. produced, on a semiquantitative manner, the extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases (polygalacturonase and pectate lyase). However, the quantity produced for each enzyme was significantly different among the isolates. With the exception of the laccase and polygalacturonase enzymes, the M7C1 isolate showed the highest enzymatic index and was also responsible for the highest percentage of yerba-mate seedlings death.
RESUMO A erva-mate (Ilex paraguariensis) tem grande importância socioeconômica na agricultura familiar do Sul do Brasil. A principal doença da erva-mate é a podridão-de-raízes causada por Fusarium spp. Pouco se sabe a respeito da fisiologia deste patógeno, principalmente quanto à agressividade associada à produção de enzimas extracelulares. Neste trabalho, avaliou-se a agressividade de isolados de F. oxysporum e F. solani patogênicos à erva-mate e determinou-se as atividades das enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases produzidas por Fusarium spp. em meio de cultura. Foram utilizados seis isolados de F. solani e um isolado de F. oxysporum patogênicos à erva-mate. O isolado de F. oxysporum mostrou-se menos agressivo em relação aos demais isolados de F. solani. Todos os isolados de Fusarium spp. produziram, de maneira semiquantitativa, as enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases (poligalacturonase e pectato liase). Entretanto, a quantidade produzida de cada enzima foi significativamente diferente entre os isolados. Com exceção das enzimas lacase e poligalacturonase o isolado M7C1 de F. solani exibiu as maiores médias do índice enzimático e foi também o responsável pelo maior percentual de morte de mudas de erva-mate.
We studied degradation patterns and microorganisms preserved in permineralized stems of Rhexoxylon piatnitzky, Protojuniperoxylon ischigualastense, and Agathoxylon argentinum from the Valle de la ...Luna Member of the Ischigualasto Formation (Upper Triassic, San Juan, Argentina). All three species show loss of middle lamella, thinning, and whitening of tracheid cell walls, and detachment of the S3 layer, consistent with selective delignification by white rot. This type of rot is the product of lignin and cellulosic degradation by Basidiomycetes and Ascomycetes. Rhexoxylon piatnitzkyi also shows small cavities, more or less circular in outline, on the wall of tracheids. This is known as soft rot and can be produced by some Ascomycetes, the anamorphic phases of diverse fungi, and tunneling bacteria. Additionally, abundant and diverse microorganisms were found. Rhexoxylon piatnitzkyi shows fragments of septate hyphae, evidence of bacterial activity, and structures of unknown affinity. Protojuniperoxylon ischigualastense presents structures common to anamorphic phases of diverse fungi, such as chlamydospores and conidiophores. Lastly, Agathoxylon argentinum bears coiled and septate hyphae, and a fan-shaped mycelium, whose significance is discussed. The microbiological study was complemented by the assessment of sedimentary and taphonomic data of the fossil-bearing beds. A gradual increment in humidity for the Valle de la Luna Member is interpreted, which concludes with a humidity peak in its upper section. This contribution represents the first detailed study of xylophagous and saprophyte micro-communities for the Ischigualasto Formation. The abundance and diversity of microorganisms described illustrate the complexity of wood-inhabiting micro-communities from the Carnian-Norian interval of Argentina.
•Triassic woods from Ischigualasto Formation with soft, white, and white-pocket rot.•Fossil fungi and fungi-like microorganisms are described in stem tissues.•Dark globules are interpreted as evidence of bacterial activity.•Microorganisms correspond to abundant and diverse saprophytes and parasites.•A seasonal humid to subhumid climate with periodic droughts is inferred.
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•Turning has the main effect on the formation of microplastic during composting.•Microplastics 2–0.2 mm form mainly during the first weeks.•The majority of plastic pollutants are thin ...film materials from polyolefins.•Microplastics are only partially removed during the final sieving step.
The quantity and type of macro- and microplastics was investigated in rotting material during the composting process of two state-of-the-art composting plants in Austria. Microplastics >0.2 mm, were found already after the first turning event in both facilities. The generation of microplastics was more extensive in the plant that used shorter turning intervals during the first four weeks and generated approx. 21 particles per week and kg−1 DM. After 4 weeks of operation less microplastic particles were detected, which suggested that particles were fractionated to smaller sizes during processing. In addition, a total of nine composts from three different facilities that were operated in various settlement structures were compared. 7 to 232 macro- and microplastic particles per kg DM were found, whereas the highest plastic burden was observed in the composts made from biowaste that originated from the most densely populated area.
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