Candida Distribution in Onychomycosis and in vitro Susceptibility to Antifungal Agents

The aim of this study was to determine distribution of the Candida (C.) species in onychomycosis and analyses in vitro susceptibility to fluconazole and itraconazole. In recent years, cases of onychomycosis in Lithuania caused by Candida have increased significantly. In the period between 2009 and 2016, a total of 8149 clinical cases (outpatients and inpatients) were investigated at the Vilnius University Hospital Santaros Clinics (VUH SC). Candida yeasts were identified using VITEK 2 (BioMerieux, France) and IVD Maldi biotyper 2.3 (Bruker Daltonik GmbH, Germany), automated systems for identification of yeasts. The antifungal susceptibility to the Candida species were determined by disc diffusion. Candida spp. were the most frequently isolated pathogens in onychomycosis during the investigation period. The main species in onychomycosis were C. albicans (38.6%), followed by C. krusei (33.7%), C. tropicalis (11.1%), C. parapsilosis (7.9%), and other Candida (8.7%). The different antifungal susceptibility patterns among Candida species confirm the need to perform antifungal susceptibility in vitro testing of yeasts from patients with onychomycosi

Candida Distribution in Onychomycosis and in vitro Susceptibility to Antifungal Agents

The aim of this study was to determine distribution of the Candida (C.) species in onychomycosis and analyses in vitro susceptibility to fluconazole and itraconazole. In recent years, cases of onychomycosis in Lithuania caused by Candida have increased significantly. In the period between 2009 and 2016, a total of 8149 clinical cases (outpatients and inpatients) were investigated at the Vilnius University Hospital Santaros Clinics (VUH SC). Candida yeasts were identified using VITEK 2 (BioMerieux, France) and IVD Maldi biotyper 2.3 (Bruker Daltonik GmbH, Germany), automated systems for identification of yeasts. The antifungal susceptibility to the Candida species were determined by disc diffusion. Candida spp. were the most frequently isolated pathogens in onychomycosis during the investigation period. The main species in onychomycosis were C. albicans (38.6%), followed by C. krusei (33.7%), C. tropicalis (11.1%), C. parapsilosis (7.9%), and other Candida (8.7%). The different antifungal susceptibility patterns among Candida species confirm the need to perform antifungal susceptibility in vitro testing of yeasts from patients with onychomycosi

Fungi Surviving on Treated Wood and Some of Their Physiological Properties

Wood is still widely used as a construction material but in spite of great assortment of antifungal chemicals, incidents of treated-wood damage still happen. The objective of the present investigation was to identify the fungal species that survived after wood treatment and make a primary screening of some physiological properties important for fungi in wood colonization. Fungal strains from <em>Alternaria, Cladosporium, Fusarium, Penicillium</em><em>, Phoma, Trichoderma </em>and <em>Ulocladium</em> genera were isolated and identified. The primary endoglucanase and phenoloxidase activity discoloration assays showed that wood colonization ability of fungi isolated from treated wood differed among the strains and some of them had not only cellulolytic but even ligninolytic activity as well. The spectrophothometric analysis of fungal enzymatic activity on wood showed that <em>Alternaria alternata</em> 8/15-2 was most active tyrosinase producer and <em>Cladosporium herbarum </em>8/15-1 – laccase producer whereas peroxidase activity level and variation tendency of all strains was alike. Among studied strains only <em>Penicillium </em>genus representatives had medium acidification ability. <em>Alternaria alternata </em>8/15-2 was the hardiest to wood preservatives fungal strain. The study of fungal physiological properties could help in selecting wood preservatives, in elucidation of reasons of their inefficiency and creating of new ones.<p>DOI: <a href="http://dx.doi.org/10.5755/j01.ms.19.1.3824">http://dx.doi.org/10.5755/j01.ms.19.1.3824</a></p

Enzymatic Biodegradation of Lignin-Cellulose Complex in Plant Origin Material

Lignin and cellulose are chemically hardly destructible complex polymeric materials of organic origin. The main enzymes of fungi taking part in lignin degradation are phenoloxidases: lignin peroxidase, Mn-peroxidase and lacase, while in cellulose - endoglucanase. The aim of the investigation was to define the degradation of lignin and cellulose in the later stages of fungi cultivation, to determine the activity of phenoloxidases and endoglucanase and their abilities to degrade this complex. It was shown that the greatest lignin and cellulose degradation was measured after Galactomyces geotrichum 012 30 and 60 cultivation days. Galactomyces geotrichum 012 showed the greatest peroxidase (68.13 a.u./g) and tyrosinase (0.33 c.u./g) activity, meanwhile laccase activity reached its peak (0.068 ext. coef.) after Sporotrichum pruinosum 60 cultivation days. The greatest endoglucanase activity was observed after Galactomyces geotrichum and Sporotrichum pruinosum in the course of whole cultivation period.http://dx.doi.org/10.5755/j01.ms.17.1.258</p

The composites of poly(vinyl alcohol), horn meal and glycerol as mulching materials

Gamtos tyrimų centrasVytauto Didžiojo universitetasŽemės ūkio akademij

Biodegradation of woodt reated with copper based preservative by two Dematiaceous fungi: Alternaria tenuissima and Ulocladium consortiale

As cases of treated wood colonization by fungi still happen, the understanding of fungal survival abilities could contribute in the creation of new efficient preservatives. For that reason, two dematiaceous fungi Alternaria tenuissima and Ulocladium consortiale isolated from treated wooden joists with discolorations were tested for their wood decomposition ability and tolerance to a copper based preservative. Our results indicated that the copper based preservative failed to suppress completely cellulose and lignin biodegradation by discoloring fungi studied in wood. Moreover, cellulose degradation was higher in the treated sawdust for both fungi after 30 days than in the untreated. Comparing the results of two strains U. consortiale that is little studied as a wood decomposer, was stronger lignin degrader than A. tenuissima in treated and untreated sawdust. The copper sulphate tolerance test showed that both fungi were able to grow up to 7 mM concentration in a solid medium

Mechanical, thermal properties and stability of high renewable content liquefied residual biomass derived bio-polyurethane wood adhesives

Bio-polyurethane adhesives bio-PU of high renewable content up to 87 % were produced using biomass biopolyols obtained previously via crude-glycerol mediated solvothermal liquefaction of three industrial biomass residue feedstocks: digested sewage sludge, hemp stalk hurds and sugar beet pulp, and commercial pentamethylene diisocyanate. The produced adhesives were capable of exhibiting tensile strength values within the threshold of two commercially available polyurethane PU wood adhesives 5.77-11.03 MPa. Varying biomass feedstock particle size and dry matter content, adhesive formulation isocyanate to hydroxyl group ratios and biomass biopolyol blending with blank crude glycerol biopolyol showed varying effects on the adhesives produced. Although bio-PU adhesives exhibited lower thermal stability, the non-flame retarded adhesives showed lower potential for fire spread and nearly identical flammability with lower heat release rates in the cone calorimeter. In terms of fire toxicity, biopolyol adhesives were found to be less toxic in well-ventilated flaming fire scenarios, with significantly lower smoke and CO production than the commercial formulation. However, both commercial and biopolyol adhesives yielded significant quantities of CO and HCN toxicants when tested in under-ventilated and post-flashover fire scenarios. Here, the tested bio-PU bound wood system exhibited 25-30 % higher fractional effective doses compared to the commercial PU adhesive analogue. The biopolyol adhesives were much more hydrophilic water uptake of up to 119 %, less stable dimensionally max. elongation of 3 %, contained significantly more water soluble components up to 43 %, and biodegraded at higher rates up to 0.89 %/month, compared to commercial PU. They were, nonetheless, hydrolytically stable as their tensile strengths did not decrease below levels after water soaking and drying. Overall, the adhesives produced show promise as sustainable alternatives in applications where high thermal stability and low water uptake are not crucial parameters

Mechanical, thermal properties and stability of high renewable content liquefied residual biomass derived bio-polyurethane wood adhesives

Bio-polyurethane adhesives bio-PU of high renewable content up to 87 % were produced using biomass biopolyols obtained previously via crude-glycerol mediated solvothermal liquefaction of three industrial biomass residue feedstocks: digested sewage sludge, hemp stalk hurds and sugar beet pulp, and commercial pentamethylene diisocyanate. The produced adhesives were capable of exhibiting tensile strength values within the threshold of two commercially available polyurethane PU wood adhesives 5.77-11.03 MPa. Varying biomass feedstock particle size and dry matter content, adhesive formulation isocyanate to hydroxyl group ratios and biomass biopolyol blending with blank crude glycerol biopolyol showed varying effects on the adhesives produced. Although bio-PU adhesives exhibited lower thermal stability, the non-flame retarded adhesives showed lower potential for fire spread and nearly identical flammability with lower heat release rates in the cone calorimeter. In terms of fire toxicity, biopolyol adhesives were found to be less toxic in well-ventilated flaming fire scenarios, with significantly lower smoke and CO production than the commercial formulation. However, both commercial and biopolyol adhesives yielded significant quantities of CO and HCN toxicants when tested in under-ventilated and post-flashover fire scenarios. Here, the tested bio-PU bound wood system exhibited 25-30 % higher fractional effective doses compared to the commercial PU adhesive analogue. The biopolyol adhesives were much more hydrophilic water uptake of up to 119 %, less stable dimensionally max. elongation of 3 %, contained significantly more water soluble components up to 43 %, and biodegraded at higher rates up to 0.89 %/month, compared to commercial PU. They were, nonetheless, hydrolytically stable as their tensile strengths did not decrease below levels after water soaking and drying. Overall, the adhesives produced show promise as sustainable alternatives in applications where high thermal stability and low water uptake are not crucial parameters

Copolymers of glycerol and propylene glycol diglycidyl ethers with aromatic dithiols

Monomers derived from renewable recourses have the potential to become the biobased alternatives for petroleum derived chemicals in the production of polymers. Glycerol, the byproduct of biodiesel refining, and propylene glycol derived from glycerol are promising candidates which can be used in the synthesis of polymers as they are or after chemical modification. The new copolymers of glycerol and propylene glycol diglycidyl ethers with aromatic dithiols were synthesized and investigated in this study. Their chemical structures were confirmed by IR, 1H-NMR spectroscopy, and gel permeation chromatography. The dependencies of the mechanical, thermal properties, swelling in the different solvents, biodegradability, and bioresistance of synthesized copolymers on their chemical structures were studied. The properties of some synthesized copolymer films were found to be comparable with those of commodity polymer filmsVytauto Didžiojo universitetasŽemės ūkio akademij

A comparative investigation of the biodegradation behaviour of linseed oil-based cross-linked composites filled with industrial waste materials in two different soils

The biodegradation of polymeric biocomposites formed from epoxidized linseed oil and various types of fillers (pine needles, pine bark, grain mill waste, rapeseed cake) and a control sample without filler was studied during 180 days of exposure to two types of forest soil: deciduous and coniferous. The weight loss, morphological, and structural changes of polymer composites were noticed after 180 days of the soil burial test. The greatest weight loss of all tested samples was observed in coniferous forest soil (41.8%–63.2%), while in deciduous forest soil, it ranged between 37.7% and 42.3%. The most significant changes in the intensities of the signals evaluated by attenuated total reflectance infrared spectroscopy, as well as morphological changes determined by scanning electron microscopy, were assessed for polymer composite with rapeseed cake and specimen without filler in coniferous forest soil and are in a good agreement with weight loss results. Whereas significantly lower changes in weight loss, morphology, and structure of polymeric film with pine bark were noticed in both soils. It was suggested that fungi of Trichoderma, Penicillium, Talaromyces and Clonostachys genera are the possible soil microorganisms that degrade linseed oil-based cross-linked polymer composites. Moreover, the novel polymer composites have the potential to be an environmentally friendly alternative to petroleum-based mulching films