Combination of Sodium Bicarbonate (SBC) with Bacterial Antagonists for the Control of Brown Rot Disease of Fruit

Abstract

Simultaneous treatment with antagonistic bacteria Bacillus amylolquefaciens (SF14), Alcaligenes faecalis (ACBC1), and the food additive sodium bicarbonate (SBC) to control post-harvest brown rot disease caused by Monilinia fructigena, and their effect on the post-harvest quality of nectarines were evaluated. Four concentrations of SBC (0.5, 2, 3.5, and 5%) were tested. Results showed that bacterial antagonists displayed remarkable compatibility with different concentrations of SBC and that their viability was not affected. The results obtained in vitro and in vivo bioassays showed a strong inhibitory effect of all treatments. The combination of each bacterial antagonist with SBC revealed a significant improvement in their biocontrol efficacies. The inhibition rates of mycelial growth ranged from 60.97 to 100%. These results also indicated that bacterial antagonists (SF14 or ACBC1) used at 1 × 108 CFU/ mL in combination with 2, 3.5, or 5% SBC significantly improved the control of M. fructigina by inhibiting the germination of spores. Interestingly, disease incidence and lesion diameter in fruits treated with SF14, ACBC1 alone, or in combination with SBC were significantly lower than those in the untreated fruits. In vivo results showed a significant reduction in disease severity ranging from 9.27 to 64.83% compared to the untreated control, while maintaining the appearance, firmness, total soluble solids (TSS), and titratable acidity (TA) of fruits. These results suggested that the improved disease control by the two antagonistic bacteria was more likely due to the additional inhibitory effects of SBC on the mycelial growth and spore germination of the pathogenic fungus. Overall, the combination of both bacteria with SBC provided better control of brown rot disease. Therefore, a mixture of different management strategies can effectively control brown rot decay on fruits.

Isolation, identification, biological characteristics, and antifungal efficacy of sodium bicarbonate combined with natamycin on Aspergillus niger from Shengzhou nane (Prunus salicina var. taoxingli) fruit

“… Castro-Ríos et al (2021) reported that 3.0 g/L SBC presented a significant reduction in A. niger growth 72 h after inoculation. Some researchers speculated that pH may be involved in the inhibitory activity of SBC since SBC could change the pH of the growth environment of microbes ( Lyousfi et al, 2022 ). Lai et al (2015) found that pH could induce different expressions of some genes, resulting in the inhibition of the growth of P. expansum .…”

“…Several previous studies have demonstrated that SBC plays an important role in the inhibition of postharvest diseases in several fruits. For example, SBC controls postharvest diseases caused by P. digitatum ( Zhu et al, 2012 ), Penicillium italicum , Geotrichum citri-aurantii ( Hong et al, 2014 ), and Monilinia fructigena ( Lyousfi et al, 2022 ). Nonetheless, similar to other alternative treatments, its application alone shows much lower effectiveness compared to synthetic fungicides.…”

“…Nonetheless, similar to other alternative treatments, its application alone shows much lower effectiveness compared to synthetic fungicides. Thus, the antibacterial effect of the combined treatments of SBC with other bactericides has been reported ( Ippolito et al, 2005 ; Casals et al, 2010 ; Lyousfi et al, 2022 ). Natamycin (NT), a natural antifungal substance, is a polyene macrolide produced by Streptomyces spp.…”

Assess the Efficacy of Combination Therapy for Fungal Otitis Externa

“…Finally, the combined use of sodium bicarbonate and a bacterial antagonist demonstrated signi cant inhibitory effects on both mycelial growth and spore germination of M. fructigina, resulting in a fungal inhibition rate ranging from 60.97% to 100%. Conversely, when sodium bicarbonate or a bacterial antagonist was used individually, the inhibition rates were lower, ranging from 9.27% to 64.83% [9] .…”

Biocontrol of bacterial seedling rot of rice plants using combination of Cytobacillus firmus JBRS159 and silicon

“…A combination of microbial biocontrol agents and other chemical components has been reported to increase biocontrol efficacy. For instance, many salt additives, such as calcium chloride, sodium carbonate, and sodium bicarbonate, along with microbial biocontrol agents efficiently controlled diseases in fruits and vegetables [ 18 , 19 ]. Silicon, the second most abundant element (27%) in the earth’s crust, is usually present in unavailable forms of silicates that cannot be readily used by plants [ 20 ].…”