COMPATIBILITY OF P-SOLUBILIZING ASPERGILLUS NIGER WITH BIOEFFECTORS

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 601-608 pp, DOI: 10.5593/sgem2017/61/S25.079

ABSTRACT

In this work, the filamentous fungus Aspergillus niger was tested for its compatibility with different media compositions, other plant growth promoting microorganisms, and plant growth stimulators. As a first step, a medium selection was carried out employing as a criterion the P-solubilizing activity of A. niger. The highest soluble P concentration of 136,92 mg/L and 394,93 mg/L was registered on Potato-Dextrose and Czapek-Dox medium in conditions of submerged and solid-state fermentation processes, respectively.

Experiments on Petri plates showed that A. niger demonstrates high compatibility with the yeast Yarrowia lipolytica, low compatibility with the filamentous fungi Trichoderma harzianum and Trichoderma viride, and was between low and neutral with the mycorrhiza-like fungus Piriformospora indica and the bacteria Bacillus subtilis and Pseudomonas fluorescens. Four biostimulants were tested for their effect on A. niger growth containing algal extract, humic acids, amino acids, and plant extracts. All products were compatible with A. niger but the highest mycelial growth in liquid culture was measured in the presence of humic acids and plant extracts.

These results can be further used to formulate A. niger based inoculants combined with other microorganisms and/or biostimulants to be used in alternative fertilisation strategies such as organic and low-input farming.

Keywords: Aspergillus niger, plant beneficial microorganisms, biostimulants, compatibility, fermentation experiments