The use of compost extracts is steadily increasing, offering an attractive way for plant growth enhancement and disease management replacing chemical pesticides. In this study, potential mechanisms involved in plant growth promotion and suppressive activity against fungal diseases, of a compost extract produced from poultry manure/olive husk compost, were investigated. Results of physico-chemical and microbiological investigations showed high ability to reduce Fusarium oxysporum, Alternaria alternata, Aspergillus niger and Botrytis cinerea growth. The suppressive ability detected using confrontation test and the phytostimulatory effect tested on tomato seeds were related mainly to its microbial population content. Among 150 bacterial strains, isolated from the compost extract, 13 isolates showed antifungal activity against the four tested plant pathogenic fungi. Their identification based on 16S rRNA gene sequence revealed they belonged to different species of the genus Bacillus, Alcaligenes, Providencia and Ochrobactrum. When tested for their ability to produce cell wall degradation enzymes using specific media, the majority of the 13 isolates were shown to synthesize proteases, lipases and glucanases. Similarly, the best part of them showed positive reaction for plant growth promoting substances liberation, biosurfactant production and biofilm formation. In vivo tests were carried out using tomato seeds and fruits and proved that 92% of strains improved tomato plants vigor indexes when compared to the control and 6 among them were able to reduce decay severity caused by B. cinerea over 50%. Principal component analysis showed an important correlation between in vitro and in vivo potentialities and that Bacillus siamensis CEBZ11 strain was statistically the most effective strain in protecting tomato plants from gray mould disease. This study revealed the selected strains would be useful for plant pathogenic fungi control and plant growth promotion.

堆肥提取物的使用正在稳步增加，为替代化学杀虫剂的植物生长促进和疾病管理提供了一种有吸引力的方式。在这项研究中，研究了从家禽粪便/橄榄壳堆肥中生产的堆肥提取物促进植物生长和抑制真菌疾病的潜在机制。物化的结果和微生物学研究表现出较高的能力，可以降低尖孢镰刀菌，链格孢，黑曲霉和灰霉病增长。对抗试验检测的抑制能力和番茄种子的植物刺激作用主要与其微生物种群含量有关。在从堆肥提取物中分离的 150 种细菌菌株中，13 种分离物对四种测试的植物病原真菌显示出抗真菌活性。他们基于 16S rRNA 基因序列的鉴定表明它们属于芽孢杆菌属、产碱杆菌属、普罗维登西亚属和Ochrobactrum属的不同物种。当使用特定培养基测试它们产生细胞壁降解酶的能力时，13 个分离株中的大多数被证明可以合成蛋白酶、脂肪酶和葡聚糖酶。同样，它们中最好的部分对植物促生长物质的释放、生物表面活性剂的产生和生物膜的形成都表现出积极的反应。使用番茄种子和果实进行了体内试验，结果证明与对照相比，92% 的菌株提高了番茄植株活力指数，其中 6 个菌株能够将B. cinerea引起的腐烂严重程度降低50% 以上。主成分分析表明体外和体内潜力与暹罗芽孢杆菌之间存在重要的相关性。CEBZ11 菌株在统计上是保护番茄植物免受灰霉病的最有效菌株。该研究表明，所选择的菌株可用于控制植物病原真菌和促进植物生长。