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Wu Y, Duan B, Lin Q, Liang Y, Du X, Zheng M, Zhu Y, Jiang Z, Li Q, Ni H, Li Z, Chen J. Fermentation of waste water from agar processing with Bacillus subtilis by metabolomic analysis. Appl Microbiol Biotechnol 2024; 108:15. [PMID: 38170310 DOI: 10.1007/s00253-023-12891-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/01/2023] [Accepted: 11/22/2023] [Indexed: 01/05/2024]
Abstract
Fungal infection has become a major threat to crop loss and affects food safety. The waste water from agar processing industries extraction has a number of active substances, which could be further transformed by microorganisms to synthesize antifungal active substances. In this study, Bacillus subtilis was used to ferment the waste water from agar processing industries extraction to analyze the antifungal activity of the fermentation broth on Alternaria alternata and Alternaria spp. Results showed that 25% of the fermentation broth was the most effective in inhibited A. alternata and Alternaria spp., with fungal inhibition rates of 99.9% and 96.1%, respectively, and a minimum inhibitory concentration (MIC) was 0.156 μg/mL. Metabolomic analysis showed that flavonoid polyphenols such as coniferyl aldehyde, glycycoumarin, glycitin, and procyanidin A1 may enhance the inhibitory activity against the two pathogenic fungal strains. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that polyphenols involved in the biosynthesis pathways of isoflavonoid and phenylpropanoid were upregulated after fermentation. The laser confocal microscopy analyses and cell conductivity showed that the cytoplasm of fungi treated with fermentation broth was destroyed. This study provides a research basis for the development of new natural antifungal agents and rational use of seaweed agar waste. KEY POINTS: • Bacillus subtilis fermented waste water has antifungal activity • Bacillus subtilis could transform active substances in waste water • Waste water is a potential raw material for producing antifungal agents.
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Affiliation(s)
- Yanyan Wu
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
| | - Boyan Duan
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
| | - Qiaoyan Lin
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
| | - Yingying Liang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
| | - Xiping Du
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
| | - Mingjing Zheng
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
| | - Yanbing Zhu
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
| | - Zedong Jiang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
| | - Qingbiao Li
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
| | - Hui Ni
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China
- Xiamen Ocean Vocational College, Xiamen, 361021, Fujian, China
| | - Zhipeng Li
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China.
- Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, Fujian, China.
- Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, Fujian, China.
| | - Jinfang Chen
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, Fujian, China.
- College of Harbour and Coastal Engineering, Jimei University, Xiamen, 361021, Fujian, China.
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Han J, Zhu J, Liu S, Sun X, Wang S, Miao G. Enhancing tomato disease resistance through endogenous antifungal proteins and introduced nematode-targeting dsRNA of biocontrol agent Bacillus velezensis HS-3. PEST MANAGEMENT SCIENCE 2024; 80:3839-3851. [PMID: 38511614 DOI: 10.1002/ps.8087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 02/21/2024] [Accepted: 03/21/2024] [Indexed: 03/22/2024]
Abstract
BACKGROUND As a type of biological control agent (BCA), Bacillus velezensis possesses the efficacy of inhibiting pathogenic microorganisms, promoting plant growth, and overcoming continuous cropping obstacles (CCOs). However, there is limited reporting on the optimization of the cultivation conditions for such biocontrol agents and their role as double-stranded RNA (dsRNA) delivery vectors. RESULTS In this study, a Bacillus velezensis strain HS-3 was isolated from the root zone of tomato plants with in vitro anti-Botrytis cinerea activity. The investigation into active compounds revealed that HS-3 predominantly employs proteins with molecular weights greater than 3 kDa for its antifungal activity. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis identified various proteases and chitosanase, further suggesting that HS-3 most likely employs these enzymes to degrade fungal cell walls for its antifungal effect. To optimize the production of extracellular proteins, fermentation parameters for HS-3 were systematically optimized, leading to an optimized medium (OP-M). HS-3 cultured in OP-M demonstrated enhanced capacity to assist tomato plants in withstanding CCOs. However, the presence of excessive nematodes in diseased soil resulted in the disease severity index (DSI) remaining high. An RNA interference mechanism was further introduced to HS-3, targeting the nematode tyrosine phosphatase (TP) gene. Ultimately, HS-3 expressing dsRNA of TP in OP-M effectively assisted tomatoes in mitigating CCOs, reducing DSI to 2.2% and 17.8% of the control after 45 and 90 days of growth, respectively. CONCLUSION The advantages of Bacillus velezensis in crop disease management and the mitigation of CCOs become even more pronounced when utilizing both optimized levels of endogenous enzymes and introduced nematode-targeting dsRNA. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Juan Han
- Department of Bioengineering, Huainan Normal University, Huainan, China
- Institute of Digital Ecology and Health, Huainan Normal University, Huainan, China
| | - Jinchi Zhu
- Department of Bioengineering, Huainan Normal University, Huainan, China
| | - Shuyuan Liu
- Department of Bioengineering, Huainan Normal University, Huainan, China
| | - Xuehan Sun
- Department of Bioengineering, Huainan Normal University, Huainan, China
| | - Shunchang Wang
- Department of Bioengineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Guopeng Miao
- Department of Bioengineering, Huainan Normal University, Huainan, China
- Institute of Digital Ecology and Health, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
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Li W, Sun L, Wu H, Gu W, Lu Y, Liu C, Zhang J, Li W, Zhou C, Geng H, Li Y, Peng H, Shi C, Wang D, Peng G. Bacillus velezensis YXDHD1-7 Prevents Early Blight Disease by Promoting Growth and Enhancing Defense Enzyme Activities in Tomato Plants. Microorganisms 2024; 12:921. [PMID: 38792750 PMCID: PMC11124510 DOI: 10.3390/microorganisms12050921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 04/20/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024] Open
Abstract
Bacillus velezensis is well known as a plant growth-promoting rhizobacteria (PGPR) and biocontrol agent. Nevertheless, there are very few reports on the study of B. velezensis on tomato early blight, especially the biocontrol effects among different inoculation concentrations. In this study, an IAA-producing strain, Bacillus velezensis YXDHD1-7 was isolated from the tomato rhizosphere soil, which had the strongest inhibitory effect against Alternaria solani. Inoculation with bacterial suspensions of this strain promoted the growth of tomato seedlings effectively. Furthermore, inoculations at 106, 107, and 108 cfu/mL resulted in control efficacies of 100%, 83.15%, and 69.90%, respectively. Genome sequencing showed that it possesses 22 gene clusters associated with the synthesis of antimicrobial metabolites and genes that are involved in the production of IAA. Furthermore, it may be able to produce spermidine and volatile compounds that also enhance plant growth and defense responses. Our results suggest that strain YXDHD1-7 prevents early blight disease by promoting growth and enhancing the defense enzyme activities in tomato plants. This strain is a promising candidate for an excellent microbial inoculant that can be used to enhance tomato production.
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Affiliation(s)
- Wangxi Li
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China;
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Lili Sun
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Hangtao Wu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Wenjie Gu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Yusheng Lu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Chong Liu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Jiexin Zhang
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Wanling Li
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Changmin Zhou
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Haoyang Geng
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Yaying Li
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Huanlong Peng
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Chaohong Shi
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Dan Wang
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Key Laboratory of Nutrient Cycling and Farmland Conservation of Guangdong Province, Guangzhou 510640, China; (L.S.); (H.W.); (W.G.); (Y.L.); (C.L.); (J.Z.); (W.L.); (C.Z.); (H.G.); (Y.L.); (H.P.); (C.S.)
| | - Guixiang Peng
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China;
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Zhang X, Xin Y, Wang J, Dhanasekaran S, Yue Q, Feng F, Gu X, Li B, Zhao L, Zhang H. Characterization of a Bacillus velezensis strain as a potential biocontrol agent against soft rot of eggplant fruits. Int J Food Microbiol 2024; 410:110480. [PMID: 37977077 DOI: 10.1016/j.ijfoodmicro.2023.110480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/24/2023] [Accepted: 11/04/2023] [Indexed: 11/19/2023]
Abstract
Postharvest soft rot of eggplant fruits caused by Pectobacterium carotovorum is a bacterial disease with a high disease incidence and produces substantial economic losses. This study aimed to control postharvest soft rot of eggplant fruits by Bacillus velezensis and investigate the possible control mechanisms based on the effects of B. velezensis on P. carotovorum subsp. carotovorum (Pcc) and eggplant fruits, respectively. B. velezensis effectively controlled postharvest soft rot of eggplant fruits and directly inhibited Pcc growth in vitro. The volatile metabolites produced by B. velezensis showed no inhibition on Pcc. Whereas the cell-free filtrate of B. velezensis significantly inhibited the growth of Pcc in vitro and in vivo. Notably, methanol-soluble precipitates obtained from cell-free filtrate showed significant inhibition on Pcc, and the primary inhibitory substances were identified as surfactin isoforms. Besides, iturin and fengycin isoforms with much lower relative abundance were also detected in the methanol-soluble precipitates. Furthermore, B. velezensis enhanced the activities of reactive oxygen species (ROS) scavenging enzymes in eggplant fruits that alleviated ROS and oxidative damage; thereby, B. velezensis enhanced the fruits' disease resistance.
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Affiliation(s)
- Xiaoyun Zhang
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Yu Xin
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Junyi Wang
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Solairaj Dhanasekaran
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Qingrong Yue
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Faping Feng
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Xiangyu Gu
- School of Grain Science and Technology, Jiangsu University of Science and Technology, 2 Mengxi Road, Zhenjiang 212003, China
| | - Bo Li
- School of Grain Science and Technology, Jiangsu University of Science and Technology, 2 Mengxi Road, Zhenjiang 212003, China
| | - Lina Zhao
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China
| | - Hongyin Zhang
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
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Ma S, Wang Y, Teng W. Bacillus velezensis K-9 as a Potential Biocontrol Agent for Managing Potato Scab. PLANT DISEASE 2023; 107:3943-3951. [PMID: 37337440 DOI: 10.1094/pdis-12-22-2829-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Crop pathogen infections can lead to substantial economic losses, but biocontrol, an environmentally friendly approach, can be used to control infections. For the biological management of potato scab disease, we assessed the potential use of Bacillus velezensis as a biocontrol agent. B. velezensis K-9 inhibited up to 44.90% of the infection caused by Streptomyces scabies, the causative agent of potato scab. Treatment of the S. scabies-infected potato plants with B. velezensis K-9 resulted in a significant reduction in the depth of the disease lesions compared with the untreated infected potato plants. In a radish seedling test, the B. velezensis K-9 culture and cell-free filtrate significantly reduced (P < 0.05) potato scab disease symptoms, suggesting that the strain K-9 was able to reduce S. scabies pathogenesis on potatoes. In a field test, the disease and scab indexes for B. velezensis K-9 against potato scab were significantly different from the control. In 2021, the potato yield for the B. velezensis K-9-treated plants was 12.44% higher than that for the control plants. In 2022, the potato yield following B. velezensis K-9 treatment increased by 12.65% compared with the control. In conclusion, B. velezensis K-9 prevented potato scab and increased potato yield. Thus, B. velezensis K-9 substantially reduced the occurrence of potato scab and could be used as a potential biocontrol agent for the management of potato scab.
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Affiliation(s)
- Shuang Ma
- College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Yanjie Wang
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Wang Teng
- College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China
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Wang L, Zhu T. Strong Opponent of Walnut Anthracnose- Bacillus velezensis and Its Transcriptome Analysis. Microorganisms 2023; 11:1885. [PMID: 37630445 PMCID: PMC10456653 DOI: 10.3390/microorganisms11081885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Walnut is a significant economic tree species worldwide. Walnut anthracnose, caused by the pathogen Colletotrichum gloeosporioides, greatly reduces walnut production and economic benefits. Our study showed that Bacillus velezensis effectively halted the growth of C. gloeosporioides, inducing noticeable abnormalities such as hyphal breakage and distortion, thereby curtailing the pathogen's virulence. A 50-100 times dilution of B. velezensis fermentation broth, applied every two to three days, served as an efficient protective layer for walnut leaves and fruits against C. gloeosporioides infection. Transcriptomic analysis of B. velezensis unveiled its dynamic response against C. gloeosporioides. On the second day, B. velezensis upregulated a significant number of differentially expressed genes related to the synthesis of metabolic products, amino acid biosynthesis, and motility. On the fourth day, continuous synthesis of metabolic products and amino acids, along with differential expression of spore-related genes, was observed. By the sixth day, the focus shifted towards environmental adaptation and carbon source utilization. Throughout the process, B. velezensis likely employed strategies such as the release of metabolic products, increased chemotaxis, and nutrient competition to exert its antagonistic effect on C. gloeosporioides. Fluorescence quantitative results showed that 15 primer pairs were up-regulated and 15 were down-regulated, with a 100% similarity rate to transcriptome sequencing results, confirming their authenticity. These findings provided a foundation for the widespread application of B. velezensis as a biocontrol agent in agriculture and forestry.
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Affiliation(s)
| | - Tianhui Zhu
- College of Forestry, Sichuan Agricultural University, Yaan 625000, China
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Zheng L, Gu X, Sun L, Dong M, Gao A, Han Z, Pan H, Zhang H. Adding Metal Ions to the Bacillus mojavensis D50 Promotes Biofilm Formation and Improves Ability of Biocontrol. J Fungi (Basel) 2023; 9:jof9050526. [PMID: 37233237 DOI: 10.3390/jof9050526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/27/2023] Open
Abstract
Bacillus mojavensis D50, a biocontrol strain, is used to prevent and treat the fungal plant pathogen Botrytis cinerea. Bacillus mojavensis D50's biofilms can affect its colonization; thus, the effects of different metal ions and culture conditions on biofilm formation were determined in this study. The results of medium optimization showed that Ca2+ had the best ability to promote biofilm formation. The optimal medium composition for the formation of biofilms contained tryptone (10 g/L), CaCl2 (5.14 g/L), and yeast extract (5.0 g/L), and the optimal fermentation conditions included pH 7, a temperature of 31.4 °C, and a culture time of 51.8 h. We found that the antifungal activity and abilities to form biofilms and colonize roots were improved after optimization. In addition, the levels of expression of the genes luxS, SinR, FlhA, and tasA were up-regulated by 37.56-, 2.87-, 12.46-, and 6.22-fold, respectively. The soil enzymatic activities which related biocontrol-related enzymes were the highest when the soil was treated by strain D50 after optimization. In vivo biocontrol assays indicated that the biocontrol effect of strain D50 after optimization was improved.
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Affiliation(s)
- Lining Zheng
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Xuehu Gu
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Liangpeng Sun
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Meiqi Dong
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Ao Gao
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Zhe Han
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
| | - Hongyu Pan
- College of Plant Sciences, Jilin University, Changchun 130062, China
| | - Hao Zhang
- College of Plant Protection, Jilin Agricultural University, Changchu 130118, China
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Kang K, Niu Z, Zhang W, Wei S, Lv Y, Hu Y. Antagonistic Strain Bacillus halotolerans Jk-25 Mediates the Biocontrol of Wheat Common Root Rot Caused by Bipolaris sorokiniana. PLANTS (BASEL, SWITZERLAND) 2023; 12:828. [PMID: 36840176 PMCID: PMC9965128 DOI: 10.3390/plants12040828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Common root rot caused by Bipolaris sorokiniana infestation in wheat is one of the main reasons for yield reduction in wheat crops worldwide. The bacterium strain JK-25 used in the current investigation was isolated from wheat rhizosphere soil and was later identified as Bacillus halotolerans based on its morphological, physiological, biochemical, and molecular properties. The strain showed significant antagonism to B. sorokiniana, Fusarium oxysporum, Fusarium graminearum, and Rhizoctonia zeae. Inhibition of B. sorokiniana mycelial dry weight and spore germination rate by JK-25 fermentation supernatant reached 60% and 88%, respectively. The crude extract of JK-25 was found, by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), to contain the surfactin that exerted an inhibitory effect on B. sorokiniana. The disruption of mycelial cell membranes was observed under laser scanning confocal microscope (LSCM) after treatment of B. sorokiniana mycelium with the crude extract. The antioxidant enzyme activity of B. sorokiniana was significantly reduced and the oxidation product malondialdehyde (MDA) content increased after treatment with the crude extract. The incidence of root rot was significantly reduced in pot experiments with the addition of JK-25 culture fermentation supernatant, which had a significant biological control effect of 72.06%. Its ability to produce siderophores may help to promote wheat growth and the production of proteases and pectinases may also be part of the strain's role in suppressing pathogens. These results demonstrate the excellent antagonistic effect of JK-25 against B. sorokiniana and suggest that this strain has great potential as a resource for biological control of wheat root rot strains.
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