Mora-Lugo R, Zimmermann J, Rizk AM, Fernandez-Lahore M. Development of a transformation system for Aspergillus sojae based on the Agrobacterium tumefaciens-mediated approach.
BMC Microbiol 2014;
14:247. [PMID:
25253558 PMCID:
PMC4186950 DOI:
10.1186/s12866-014-0247-x]
[Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/15/2014] [Indexed: 11/30/2022] Open
Abstract
Background
Aspergillus sojae has been an important filamentous fungus in Biotechnology due to its use in diverse fermentative processes for the production of various food products. Furthermore, this fungus is a common expression system for the production of enzymes and other metabolites. The availability of molecular genetic tools to explore its biology is thus of big interest. In this study, an Agrobacterium tumefaciens-mediated transformation (ATMT) system for A. sojae was developed and its applicability evaluated.
Results
The donor plasmid named pRM-eGFP was constructed for ATMT of A. sojae. This plasmid contains the ble and egfp genes in its transfer DNA element (T-DNA) to confer phleomycin resistance and express the enhanced green fluorescent protein (EGFP) in A. sojae, respectively. Agrobacterium tumefaciens (LBA4404) harboring the donor plasmid and A. sojae (ATCC 20235) were co-cultured under diverse conditions to achieve ATMT. The maximum number of transformed fungi was obtained after three days of co-culturing at 28°C, and selection with 50 μg/ml phleomycin. Polymerase chain reaction (PCR), fluorescence microscopy and Western Blot analysis for EGFP expression confirmed successful genomic integration of the T-DNA element in A. sojae. The T-DNA was mitotically stable in approximately 40% of the fungal transformants after four generations of sub-culturing under phleomycin pressure.
Conclusion
We successfully established a new ATMT protocol for A. sojae. This transformation system should enable further protein expression studies on this filamentous fungus.
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