New Insights on Environmental Occurrence of Pathogenic Fungi Based on Metagenomic Data from Brazilian Cerrado Biome

Abstract: Cerrado is the second largest biome in Brazil and majorly contributes to the country's grain production. Previous studies on soil metagenomics from the Cerrado revealed an outstanding microbial diversity. In this study, the abundance of pathogenic fungi was analyzed using metagenomic sequences of the Cerrado soils under native vegetation, and under agriculture with no-tillage and conventional tillage. In total, 128,627 sequences of fungi were identified, with 43,439 representing pathogenic fungi and were distributed as follows: native 17,301 (40%), no-tillage 13,780 (32%), and conventional tillage 12,358 (28%). We identified 41 pathogenic fungal species associated with human and animal infections. The data analysis revealed that the native soils had a higher relative abundance of fungal sequences, similar to pathogenic species sequences, in relation to the total eukaryotic sequences, than the conventional tillage and no-tillage treatments, which observed a reduction in fungal abundance because of anthropogenic activities.

Unveiling Xylanolytic Enzymes Production of Talaromyces wortmannii DR49 on Industrial Agro Wastes

Abstract Xylan degradation is an important step in different industries, such as in biorefinery for biomass hydrolysis. Talaromyces wortmannii is a known fungus due to second metabolite production but only few works showed the xylanolytic potential of this fungus. In this way, the aim of this study was to evaluate the production of xylanolytic enzymes from T. wortmannii DR49 on industrial agro wastes. Cultivation in shake flask showed highest xylanase titration (10.3 U/mL; 9.5 U/mL) for wheat bran (WB) and hydrothermal pretreated sugar cane bagasse (HB); in β-xylosidase production WB and xylose were the best carbon sources (0.57 U/mL; 0.34 U/mL) respectively. STR cultivation revealed that 29°C and pH 6.0 were the best conditions for xylanase (14.5 U/mL) and β-xylosidase (1.7 U/mL) production. T. wortmannii DR49 showed to be a potential candidate for xylanolytic enzymes production using agro wastes in bioreactors, which has never been previously reported in this fungus.

Endophytic Actinomycetes as Potential Producers of Hemicellulases and Related Enzymes for Plant Biomass Degradation

Abstract Tailor made enzymatic preparation must be design to hydrolyze efficiently plant biomass, once that each plant biomass possesses a distinct cell wall composition. Most of actinomycetes used for plant cell wall degradation are focused on the cellulases and xylanases production. However, a wide range of enzymes must be produced for an efficient degradation of lignocellulose materials. During the last decade several unusual environments were studied to obtain strains that produce glycohydrolases with innovator characteristics. In this context, the present work concerned the selection of endophytic actinomycetes as producers of hemicellulases and related enzymes with different enzymatic profiles, for use in the deconstruction of lignocellulosic biomass. A total of 45 Brazilian actinomycetes previously isolated from plants (endophytics) and soil were prospected for hemicellulases and β-glucosidase production. Four strains highlighted for hemicellulase production (DR61, DR63, DR69 and DR66) and were selected for cultivation under other inductors substrates (xylan and pectin). All strains belong to Streptomyces genera and have their extracts tested for degradation of several hemicellulolytic substrates. The strains presented different glicohydrolyse enzymes profiles mainly for xylans and glucans that can be used for specific formulations of enzymes applied on the biomass deconstruction, principally on sugar cane bagasse.

Occurrence of sulphate reducing bacteria (SRB) associated with biocorrosion on metallic surfaces in a hydroelectric power station in Ibirama (SC) - Brazil

The aim of this study was evaluate, two methods for the detection and identification of sulphate reducing bacteria (SRB): ML medium and PCR with specific primers for SRB groups. SRB were detected through the selective medium only on carbon steel, which showed corrosion. Employing specific PCR primer, SBR were detected from all the metallic components assayed, even those that did not present visible corrosion spots, such stainless steel and copper alloys. Despite the presence or absence of corrosion at the later stages effectively by using the selective medium,, the initial stages of the corrosion could only be detected by the amplification of total DNA with SRB specific primers. The early detection of SRB could be employed for preventing the damages on metal surfaces before the installation of corrosion processes. Strategies for reducing the time spent on SRB isolation and identification could be auxiliary tools for controlling the corrosion of materials.

Spore production in Paecilomyces lilacinus (Thom. ) samson strains on agro-industrial residues / Produção de esporos em linhagens de Paecilomyces lilacinus (Thom. ) samson em resíduos agro-industriais

Paecilomyces lilacinus has potential for pests control. We aimed to analyze mycelial growth and spore production in P. lilacinus strains in several agro-industrial residues and commercial media. This study suggests alternative nutrient sources for fungi production and that the biotechnological potential of agro-industrial refuses could be employed in byproducts development.

Paecilomyces lilacinus apresenta potencial para controle de pragas. O objetivo deste trabalho foi analisar o crescimento micelial e a produção de esporos de linhagens de P. lilacinus em resíduos agro-industriais e meios comerciais. Este estudo sugere fontes alternativas para produção de fungos com potencial biotecnológico para desenvolvimento de bioprodutos.