Solubilization of diabase and phonolite dust by filamentous fungus

• Published in: Revista Ceres 2014-10, Vol.61 (5), p.740-745
• Main Authors: Brandão, Juliana Andréia Vrba, Lopes-Assad, Maria Leonor Ribeiro Casimiro, Ceccato-Antonini, Sandra Regina
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; Aspergillus niger; biossolubilização; pó de rocha; rochagem
• ISSN: 0034-737X; 2177-3491; 0034-737X
• DOI: 10.1590/0034-737X201461050018

The objective of this study was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 in the release of nutrients contained in two types of rock powder (diabase and phonolite) by means of in vitro solubilization trials. The experimental design was completely randomized in a 5 x 4 factorial design with three replications. It was evaluated five treatments (phonolite dust + culture medium; phonolite dust + fungus + culture medium; diabase powder + culture medium; diabase powder + fungus + culture medium and fungus + culture medium) and four sampling dates (0, 10, 20 and 30 days). Rock dust (0.4% w/v) was added to 125 mL Erlenmeyer flasks containing 50 mL of liquid culture medium adapted to A. niger. The flasks were incubated at 30°C for 30 days, and analysis of pH (in water), titratable acidity, and concentrations of soluble potassium, calcium, magnesium, zinc, iron and manganese were made. The fungus A. niger was able to produce organic acids that solubilized ions. This result indicates its potential to alter minerals contained in rock dust, with the ability to interact in different ways with the nutrients. A significant increase in the amount of K was found in the treatment with phonolite dust in the presence of the fungus. The strain CCT4355 of A. niger can solubilize minerals contained in these rocks dust. Este trabalho objetivou avaliar o efeito do fungo Aspergillus niger, linhagem CCT4355, na liberação de nutrientes contidos em pós de dois tipos de rocha (fonolito e diabásio), por meio de ensaios de solubilização in vitro. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 5x4, com três repetições. Foram avaliados cinco tratamentos (pó de fonolito + meio; pó de fonolito + fungo + meio, pó de diabásio + meio, pó de diabásio + fungo + meio e fungo + meio) e quatro épocas de amostragens (0, 10, 20 e 30 dias). Adicionou-se pó de rocha (0,4% m/v) a Erlenmeyers de 125 mL, com 50 mL de meio de cultura líquido adaptado para A. niger. Os frascos foram incubados a 30 °C, por 30 dias, e foram feitas análises de pH em água, acidez titulável e teores de potássio, cálcio, magnésio, zinco, ferro e manganês solúveis. O A. niger foi capaz de produzir ácidos orgânicos que solubilizaram íons. Este resultado indica o potencial de A. niger para alterar minerais contidos em pós de rocha, com capacidade de interagir de diferentes formas com os nutrientes. Houve aumento significativo da quantidade de K solúvel, no tratamento com pó