背景:土壤传播的植物病害是一个严重的问题,对粮食作物的生产产生负面影响。放线菌在土壤真菌的生物防治中起着至关重要的作用。
目的:本研究的目的是测试产生几丁质酶的纤维素链霉菌48的拮抗活性(登录号,MT573878)抗枯萎病。随后,在搅拌釜生物反应器中使用不同的发酵工艺最大化Actino48的生产。最后,使用滑石粉(TP)和膨润土以天然和纳米形式作为载体,从Actino48的培养液中制备生物友好型制剂。同时,调查它们在减少花生植物的阻尼和根腐病方面的活动,在温室条件下被R.solani感染。
结果:发现Actino48在p≤0.05时是最显著的拮抗分离株,对真菌菌丝体生长的抑制百分比最高,达到97%。扫描电子显微镜(SEM)图像分析的结果表明,茄子菌丝体质量大大降低。此外,发现了许多像差变化和真菌菌丝损伤。分批发酵编号.2,使用200rpm的搅拌速度进行,获得了0.1163UmL-1min-1的高几丁质酶活性,产量系数为0.004UmL-1min-1几丁质酶活性/g几丁质。与其他配方相比,Actino48的纳米滑石配方在减少阻尼和根腐病的百分比方面具有更显著的效果,分别为19.05%和4.76%,减少百分比分别为60%和80%,分别。花生植株的健康成活率为76.19%。此外,Actino48的纳米滑石配方足以增加花生植株的干重,根系,花生豆荚总数增加了47.62%,55.62%,38.07%,分别。
结论:这项研究得出的放线菌生物友好型制剂可能在管理土壤传播疾病方面发挥积极作用。
BACKGROUND: Soil-borne plant diseases represent a severe problem that negatively impacts the production of food crops. Actinobacteria play a vital role in biocontrolling soil-borne fungi.
OBJECTIVE: The target of the present study is to test the antagonistic activity of
chitinase-producing Streptomyces cellulosae Actino 48 (accession number, MT573878) against Rhizoctonia solani. Subsequently, maximization of Actino 48 production using different fermentation processes in a stirred tank bioreactor. Finally, preparation of bio-friendly formulations prepared from the culture broth of Actino 48 using talc powder (TP) and bentonite in a natural as well as nano forms as carriers. Meanwhile, investigating their activities in reducing the damping-off and root rot diseases of peanut plants, infected by R. solani under greenhouse conditions.
RESULTS: Actino 48 was found to be the most significant antagonistic isolate strain at p ≤ 0.05 and showed the highest inhibition percentage of fungal mycelium growth, which reached 97%. The results of scanning electron microscope (SEM) images analysis showed a large reduction in R. solani mycelia mass. Additionally, many aberrations changes and fungal hypha damages were found. Batch fermentation No. 2, which was performed using agitation speed of 200 rpm, achieved high
chitinase activity of 0.1163 U mL- 1 min- 1 with a yield coefficient of 0.004 U mL- 1 min- 1
chitinase activity/g chitin. Nano-talc formulation of Actino 48 had more a significant effect compared to the other formulations in reducing percentages of damping-off and root rot diseases that equal to 19.05% and 4.76% with reduction percentages of 60% and 80%, respectively. The healthy survival percentage of peanut plants recorded 76.19%. Furthermore, the nano-talc formulation of Actino 48 was sufficient in increasing the dry weight of the peanut plants shoot, root systems, and the total number of peanut pods with increasing percentages of 47.62%, 55.62%, and 38.07%, respectively.
CONCLUSIONS: The bio-friendly formulations of actinobacteria resulting from this investigation may play an active role in managing soil-borne diseases.