Esteban-Herrero Guillermo, Álvarez Belén, Santander Ricardo D, Biosca Elena G
Departamento de Microbiología y Ecología, Universitat de València (UV), 46100 Valencia, Spain.
Departamento de Investigación Aplicada y Extensión Agraria, Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario (IMIDRA), 28805 Madrid, Spain.
Microorganisms. 2023 Jul 13;11(7):1795. doi: 10.3390/microorganisms11071795.
, the bacterial species responsible for fire blight, causes major economic losses in pome fruit crops worldwide. Chemical control is not always effective and poses a serious threat to the environment and human health. Social demands for eco-sustainable and safe control methods make it necessary to search for new biocontrol strategies such as those based on antagonists. A bacterial collection from different fire blight-free Mediterranean environments was tested for antagonistic activity against Spanish strains of . Antagonistic assays were carried out in culture medium and in immature loquat and pear fruits. Results revealed that 12% of the 82 bacterial isolates tested were able to inhibit the growth of several strains of the pathogen. Some of the isolates also maintained their antagonistic activity even after chloroform inactivation. Selected isolates were further tested , with several of them being able to delay and/or reduce fire blight symptom severity in both loquats and pears and having activity against some strains. The isolates showing the best antagonism also produced different hydrolases linked to biocontrol (protease, lipase, amylase, and/or DNAse) and were able to fix molecular nitrogen. Based on this additional characterization, four biocontrol strain candidates were further selected and identified using MALDI-TOF MS. Three of them were Gram-positive bacteria belonging to and genera, and the fourth was a strain. Results provide promising prospects for an improvement in the biological control strategies against fire blight disease.
引起火疫病的细菌物种在全球范围内给仁果类作物造成了重大经济损失。化学防治并不总是有效，且对环境和人类健康构成严重威胁。社会对生态可持续和安全防治方法的需求使得有必要寻找新的生物防治策略，例如基于拮抗微生物的策略。对来自不同无火疫病地中海环境的细菌菌株进行了测试，以检测其对西班牙 的菌株的拮抗活性。在培养基以及未成熟的枇杷和梨果实中进行了拮抗试验。结果显示，在所测试的82株细菌分离物中，有12%能够抑制该病原菌的多个菌株的生长。一些分离物即使在经氯仿灭活后仍保持其拮抗活性。对筛选出的分离物进一步进行了测试，其中有几种能够延缓和/或减轻枇杷和梨中火疫病症状的严重程度，并且对一些 菌株具有活性。表现出最佳拮抗作用的分离物还产生了与生物防治相关的不同水解酶（蛋白酶、脂肪酶、淀粉酶和/或脱氧核糖核酸酶），并且能够固定分子态氮。基于这一进一步的特性分析，使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）进一步筛选和鉴定了4株生物防治候选菌株。其中3株为革兰氏阳性菌，属于 和 属，第4株为 菌株。研究结果为改进火疫病的生物防治策略提供了有希望的前景。
