Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i>
This study investigated whether viable cells, dead cells or cell-free supernatants (CFS) were responsible for the biocontrol effect of strains from two important bacterial genera, <i>Pseudomonas</i> and <i>Lactobacillus</i>, known for their antifungal properties against plant...
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2025-01-01
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| author | Francesca Di Rico Francesco Vuolo Edoardo Puglisi |
| author_facet | Francesca Di Rico Francesco Vuolo Edoardo Puglisi |
| author_sort | Francesca Di Rico |
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| description | This study investigated whether viable cells, dead cells or cell-free supernatants (CFS) were responsible for the biocontrol effect of strains from two important bacterial genera, <i>Pseudomonas</i> and <i>Lactobacillus</i>, known for their antifungal properties against plant pathogens and food spoilage microorganisms. Specifically, the capability of these strains to produce extracellular hydrolytic enzymes on specified media was assessed, along with their effectiveness in inhibiting the mycelial growth of several phytopathogenic fungi (<i>Fusarium oxysporum</i>, <i>Botrytis cinerea</i>, <i>Pythium ultimum</i> and <i>Rhizoctonia solani</i>) using dual culture plate assays. Results from these inhibition assays revealed that <i>P. fluorescens</i> PF05 and <i>L. plantarum</i> LMG 23520 strains were the most effective in suppressing fungal growth, especially <i>F. oxysporum</i>. Therefore, further experiments were carried out to investigate the antifungal potential of the viable cells, heat-killed cells (HKC) and CFS from these strains against the germination of <i>F. oxysporum</i> spores. The viable cell trial proved successful, whereas HKC from the two bacterial isolates were ineffective against fungal spore germination. Conversely, the CFS of <i>L. plantarum</i> LMG 23520 was able to prevent fungal spore development for up to six days. The CFS of <i>P. fluorescens</i> PF05, instead, did not yield positive results. Additional studies are required to evaluate the potential inhibitory effects of the CFS from <i>P. fluorescens</i> PF05 and the HKC from both strains. |
| format | Article |
| id | doaj-art-80e486a43c554217b2d9fcae34fab3b5 |
| institution | Kabale University |
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| language | English |
| publishDate | 2025-01-01 |
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| series | Microorganisms |
| spelling | doaj-art-80e486a43c554217b2d9fcae34fab3b52025-01-24T13:42:39ZengMDPI AGMicroorganisms2076-26072025-01-0113110510.3390/microorganisms13010105Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i>Francesca Di Rico0Francesco Vuolo1Edoardo Puglisi2Department of Food Science and Technologies for Sustainable Agro-Food Chain (DiSTAS), Università Cattolica del Sacro Cuore, 29122 Piacenza, PC, ItalySacco System, 22071 Cadorago, CO, ItalyDepartment of Food Science and Technologies for Sustainable Agro-Food Chain (DiSTAS), Università Cattolica del Sacro Cuore, 29122 Piacenza, PC, ItalyThis study investigated whether viable cells, dead cells or cell-free supernatants (CFS) were responsible for the biocontrol effect of strains from two important bacterial genera, <i>Pseudomonas</i> and <i>Lactobacillus</i>, known for their antifungal properties against plant pathogens and food spoilage microorganisms. Specifically, the capability of these strains to produce extracellular hydrolytic enzymes on specified media was assessed, along with their effectiveness in inhibiting the mycelial growth of several phytopathogenic fungi (<i>Fusarium oxysporum</i>, <i>Botrytis cinerea</i>, <i>Pythium ultimum</i> and <i>Rhizoctonia solani</i>) using dual culture plate assays. Results from these inhibition assays revealed that <i>P. fluorescens</i> PF05 and <i>L. plantarum</i> LMG 23520 strains were the most effective in suppressing fungal growth, especially <i>F. oxysporum</i>. Therefore, further experiments were carried out to investigate the antifungal potential of the viable cells, heat-killed cells (HKC) and CFS from these strains against the germination of <i>F. oxysporum</i> spores. The viable cell trial proved successful, whereas HKC from the two bacterial isolates were ineffective against fungal spore germination. Conversely, the CFS of <i>L. plantarum</i> LMG 23520 was able to prevent fungal spore development for up to six days. The CFS of <i>P. fluorescens</i> PF05, instead, did not yield positive results. Additional studies are required to evaluate the potential inhibitory effects of the CFS from <i>P. fluorescens</i> PF05 and the HKC from both strains.https://www.mdpi.com/2076-2607/13/1/105microbial biocontrol agentsplant pathogens<i>Pseudomonas fluorescens</i><i>Lactiplantibacillus plantarum</i><i>Fusarium oxysporum</i>cell-free supernatants |
| spellingShingle | Francesca Di Rico Francesco Vuolo Edoardo Puglisi Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> Microorganisms microbial biocontrol agents plant pathogens <i>Pseudomonas fluorescens</i> <i>Lactiplantibacillus plantarum</i> <i>Fusarium oxysporum</i> cell-free supernatants |
| title | Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> |
| title_full | Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> |
| title_fullStr | Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> |
| title_full_unstemmed | Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> |
| title_short | Evaluating the Role of Viable Cells, Heat-Killed Cells or Cell-Free Supernatants in Bacterial Biocontrol of Fungi: A Comparison Between Lactic Acid Bacteria and <i>Pseudomonas</i> |
| title_sort | evaluating the role of viable cells heat killed cells or cell free supernatants in bacterial biocontrol of fungi a comparison between lactic acid bacteria and i pseudomonas i |
| topic | microbial biocontrol agents plant pathogens <i>Pseudomonas fluorescens</i> <i>Lactiplantibacillus plantarum</i> <i>Fusarium oxysporum</i> cell-free supernatants |
| url | https://www.mdpi.com/2076-2607/13/1/105 |
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