Bioprospecting Aspergillus section Nigri in Atlantic Forest soil and plant litter

Tatiana Faria Maia,Marcelo Elias Fraga

doi:10.1590/1808-1657000502015

Tatiana Faria Maia, Marcelo Elias Fraga

Open Access

https://doi.org/10.1590/1808-1657000502015

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Abstract

ABSTRACT: The use of fungi as a source of enzymes has become widespread in various industrial and commercial areas, and Aspergillus section Nigri has significant potential for producing enzymes. The aim of this study was to isolate Aspergillus section Nigri from plant litter and soil from the Atlantic Forest biome and evaluate it with regards to hydrolytic enzyme production. The trials for producing the enzymes were carried out in Petri dishes, using different culture mediums adapted for microbial growth and with the respective substrates for inducing enzyme production - cellulase (carboxymethyl cellulose), protease (skimmed milk), amylase (soluble starch), pectinase (citrus pectin), and phytase (Pikovskaya medium). Forty-two fungi were isolated, 16.7% derived from the plant litter layer and 83.3% derived from soil at a depth of 0 to 5 cm and 5 to 10 cm. All of the isolated lineages presented amylase, protease, and phytase production, with 90.4% producing cellulase and no lineage producing pectinase. From the results, the significant potential for Atlantic Forest fungi as hydrolytic enzyme producers could be perceived. The enzymatic activity evaluations presented a satisfactory result when compared with the scientific literature.

Highlights

Brazil contains the greatest biodiversity on the planet
1,854 fungal lineages from the plant litter and soil samples were isolated, 907 lineages in the wet period and 947 lineages in the dry period. Of this total number of isolates, 42 were Aspergillus section Nigri, 16.7% derived from the plant litter layer and 83.3% derived from soil at depths of 0 to 5 cm and 5 to 10 cm
In order to evaluate the cellulase production potential, it was observed that, of the lineages isolated from Aspergillus section Nigri, 38 of them produced cellulase; that is, 90.4% presented a halo of hydrolysis

Summary

Introduction

Brazil contains the greatest biodiversity on the planet. Among the country’s various biomes, the Atlantic Forest features as one of the 34 global “hotspots”. Its climatic conditions enable the existence of microorganisms that decompose and degrade forest biomass, making the soil in this biome very rich in nutrients. Among these microorganisms, fungi are of crucial importance to the functioning of this ecosystem. Fungi of the Aspergillus genus are filamentous, cosmopolitan, saprophytes, and are mainly found in regions with tropical and subtropical climates (KLICH, 2002). Some species of this genus are used in biotechnology, in which they produce a diversity of biocompounds such as antibiotics, microtoxins, enzymes, organic acids, and phenolic compounds, among other substances (DAGENAIS; KELLER, 2009)

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