Effect of Lactic Acid Bacteria on the Fermentation Quality and Mycotoxins Concentrations of Corn Silage Infested with Mycotoxigenic Fungi

Abstract

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) on fermentation quality, mycotoxin concentrations, and microbial communities of whole-crop corn silages infested with mycotoxigenic fungi. Cultured spores (106 cfu/mL) of mycotoxigenic Aspergillus flavus and Fusarium graminearum were sprayed (5 mL) on corn forage on 27 July and 10 August 2018. On 21 August 2018, sprayed (FI; 3 plots) and unsprayed (NFI; 3 plots) corn forage were harvested at the 1/2 kernel milk line stage, followed by chopping and ensiling without inoculants (CON), or with Lactobacillus buchneri (LB, 1 × 106 cfu/g FW), Lactobacillus plantarum (LT, 1 × 106 cfu/g FW), or L. buchneri + L. plantarum (BT: both L. buchneri and L. plantarum applied at 0.5 × 106 cfu/g FW). After 90 d of ensiling, FI silages had a higher (p p 1 (AFB1) was only detected in FI fresh corn and silages; ensiling decreased (p 1 concentration compared with fresh corn, and LB and BT decreased AFB1 concentration compared with CON. The zearalenone (ZEN), deoxynivalenol (DON), and fumonisin B1 (FB1) concentrations were similar (p p 1 concentrations in LB, LT, and BT silages were significantly lower (p Lactobacillus, Weissella, Wickerhamomyces, Pichia, and Epicoccum than the corresponding NFI silages. The RA of Aspergillus and Fusarium markedly decreased after 90 d of ensiling, and the inoculation expanded this trend irrespective of fungal infestation. The Penicillium in FI silages survived after 90 d of ensiling, while the inoculants decreased the RA of Penicillium. Inoculants mitigate the adverse effects of fungal infestation on corn silage quality by changing the bacterial and fungal communities.

Keywords

• corn silage
• microbial community
• fungi infestation
• mycotoxins