Evaluating the effects of cellulolytic enzymes and Lactobacillus bulgaricus on mycotoxins production and the quality of maize silage

Abstract

Fungal spoilage and mycotoxin contamination are two of the greatest hazards of silage. The present work was carried out to evaluate the impact of Lactobacillus bulgaricus and cellulolytic enzymes on the maize silage (MS) quality. Fungal analysis of different MS samples showed different mycotoxigenic fungi. The highest frequency (62.8%) was associated with Fusarium spp. Four species with different relative densities were found: F. graminearum (71.1%), F. culmorum (15.2%), F. proliferatum (11.2%), and F. oxysporum (2.50 %). High-performance liquid chromatography analysis showed the presence of trichothecene, nivalenol, zearalenone, and fumonisins mycotoxins in MS inoculated by F. graminearum. The inhibition % of trichothecene, nivalenol, and zearalenone synthesis was 50.2%, 47.5%, and 23.5%, respectively, in MS inoculated by Lactobacillus bulgaricus after a 30 d incubation period. Trichoderma harzianum succeeded in producing cellulolytic enzymes, i.e., carboxymethyl cellulase, manganase peroxidase, and laccase, with a maximum production of 350 µg/mL, 5.47 µg/mL, and 16.0 µg/mL, respectively, after 21 d using MS as the substrate. Treatment by the extracted cellulolytic enzyme with L. bulgaricus enhanced unfavorable conditions for MS fungal contamination, i.e., the production of lactic acid, a lowered pH, and increased L. bulgaricus colony-forming units, compared to the addition of enzyme extract or L. bulgaricus alone.

Fusarium verticillioides of maize plant: Potentials of propitious phytomicrobiome as biocontrol agents

“…Hence, the application of this fungus as microbial inoculants to plants would help to modify and degrade fumonisin thus preventing its invasion of crops. From the study of Bakri (2021) which evaluated the effect of T. harzianum and other cellulolytic enzymes on divers mycotoxin, it was found that this fungus together with Lactobacillus bulgaricus greatly inhibited the production of fumonisin and other mycotoxins.…”

Mycotoxins associated with maize wastes treated with comprised capsule of Spirulina platensis biomass

“…The identification approaches documented the occurrence of three filamentous fungi on maize silage: Aspergillus flavus, A. niger, and Fusarium sp. Bakri (2021) demonstrated the presence of Aspergillus sp., Fusarium sp., Penicillium, Mucor sp., and Rhizopus sp. on maize silage.…”