## 1 Introduction  
Postharvest diseases cause considerable losses of fruits and vegetables during handling, transportation, and storage [1]. Spoilage caused by fungi is primarily responsible for significant losses during storage. Fruit infections caused by fungal pathogens both in the field and after harvest result in postharvest deterioration or decay [2]. High levels of losses due to fungal pathogens are related to high levels of moisture, nutrients, low pH valuesto the presence of mycotoxins. Indeed, some species of postharvest genera, i.e., _Botrytis_, _Aspergillus_, _Penicillin_, and _Alternaria_, produce toxic secondary metabolites, which pose a health risk to humans and animals [4]. Synthetic fungicides were the first products to be used to control postharvest decay; however, they are not the most appropriate option since they pollute the atmosphere, damage the environment, leave harmful residues, and can lead to the development of resistant strains, with the potential to harm consumer health [5]. According to reports from the World Health Organization (WHO), there are about 20,000 unintentional deaths and 2 million poisonings each year, mostly caused by the mishandling of synthetic fungicides in third-world countries. The use of synthetic fungicides in the storage of food products has had numerous adverse effects on human health, such as carcinogenicity, teratogenicity, and hormonal imbalances, among others [6]. Mexico is the world's fourth-largest producer of berries. At the national level, 248,512 tons of blackberries are produced, of which Michoacan contributes more than 90% (238,832 tons). Strawberry production nationwide is 468,000 tons and Michoacan contributes more than 60% (341,130 tons). The blueberry production in Michoacan is positioned in second place nationally, with an annual production of 6000 tons (SEDRUA, 2017). Therefore, searching for agroecological alternatives to reduce postharvest pathogens is imperative and urgent for producers. A viable, effective, and economical alternative to synthetic fungicides is the use of microbial antagonists, also called biocontrol agents. These are microorganisms that decrease the damaging effects of pathogens. [PERSON] [7] described plant-growth-promoting bacteria (PGPB), and, as their name suggests, they stimulate plant growth, either through direct mechanisms, such as facilitating the acquisition of resources or modulating the levels of plant hormones, or through indirect mechanisms, therefore reducing the effects of pathogens acting as biocontrol bacteria. Due to this biocontrol activity, these microorganisms have the potential to control or reduce the effects of pathogens that affect postharvest fruits and vegetables, without the harmful side effects associated with fungicides. There are several modes of action of microbial antagonists. Some of these include competition for space and nutrients, antibiosis, induced resistance, and direct parasitism [1,8,9]. Other authors have also described mechanisms of action such as the production of biofilms and quorum sensing [10]. Several studies have been carried out in which PGPB have been effective in controlling the growth of pathogenic fungi, in both in vitro and in vivo experiments, demonstrating their ability as biocontrol agents. _Bacillus_ sp. strain E25 is an endophytic strain isolated from husk tomato roots in Michoacan, Mexico, that has displayed excellent biocontrol and plant-growth-promoting activities. In silico analysis showed that this strain has 17 gene clusters to produce active antagonistic compounds, including bacteriocins, siderophores, lanthipeptides, lipopeptides, ladderanes, and terpenes [11]. [PERSON] et al., 2018 [12] evaluated the antagonistic capacity of the bacterial strains _B. thuringiensis_ CR71 and _Basillus_ sp. E25 against _B. cinerea_. They found that both bacterial strains inhibit the growth of _B. cinerea_. Through the production of volatile organic compounds (VOCs), E25 inhibits mycelial growth by 40%, while strain CR71 inhibits it by 52%.