Contents lists available at ScienceDirect Postharvest Biology and Technology journal homepage: www.elsevier.com/locate/postharvbio Identification of lipopeptides from Bacillus strain Q11 with ability to inhibit the germination of Penicillium expansum, the etiological agent of postharvest blue mold disease José Luis Rodríguez-Chávez a,1 , Yara Suhan Juárez-Campusano a , Guillermo Delgado b , Juan Ramiro Pacheco Aguilar a, ⁎ a Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario (CU) Cerro de las Campanas, Cerro de las Campanas s/n, Querétaro 76100, Mexico b Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico ARTICLE INFO Keywords: Iturins Fengycins MALDI-TOF Biological control Conidia ABSTRACT The genus Bacillus produces secondary metabolites among which stand out compounds of polypeptide nature for their versatility of applications, one of them is the activity against fungal phytopathogens of agricultural im- portance. In the present work was evaluated the effectiveness of the crude lipopeptide from Bacillus subtilis Q11 against common soil borne pathogens, additionally in vitro and in vivo assays were carried out to determine the ability to inhibit the germination of conidia and reduce the blue mold rot induced by Penicillium expansum in apple (Malus domestica Borkh) fruit. In antagonistic test, the lipopeptide fraction of Q11 was able to limit the mycelial growth of Rhizoctonia solani, Sclerotium rolfsii, Penicillium expansum, Fusarium stilboides, Colletotrichum gleosporides and Botrytis cinerea, showing higher inhibition at higher lipopeptide concentrations (10, 20, and 30 μg disk -1 ); however, it was ineffective against Pseudomonas syrigae, Xanthomonas campestris, and Clavibacter michiganensis. On the other hand, the conidia of P. expansum after being exposed to a concentration of 800 mg L -1 of lipopeptide for 16 h, showed swelling and germination reduction greater than 90%. In fruit assay with apples inoculated with a droplet of conidia suspension (200 conidia) of P. expansum, the treatment with the lipopeptide fraction reduced rot lesion severity, registering the greatest effects at 80 μg, which reduced the size of the lesion by more than 60%. The analysis by infrared spectroscopy, HPLC and MALDI-TOF established that the crude lipopeptide is a complex formed primarily by iturin-type compounds with fatty acid chain length of C14–C17 and small proportion of compounds of fengycin A and B type that differ in the length of the fatty acid chain. These compounds could be useful in the development of products for biological control of postharvest blue mold disease in apple. 1. Introduction The genus Penicillium includes several species of post-harvest pa- thogens that affect the quality of fruit around the world (Guerrero- Prieto et al., 2013; Sánchez et al., 2008). During harvest, transport and storage practices, fruit are exposed to mechanical damage (peel and internal injuries) and they become susceptible to infection by Peni- cillium expansum, P. digitatum, and P. italicum that colonize fruit sur- faces (Shen et al., 2018a) due to nutrients and volatiles of the damaged area that stimulate conidial germination (Buron-Moles et al., 2014; Juhnevica-Radenkova et al., 2016). Particularly, Penicillium expansum causes postharvest decay of Malus domestica Borkh (apple), Pyrus communis L. (pear), Prunus persica L. (peach) fruit and others (Julca et al., 2015), disease known as blue mold. The rapid spread of P. ex- pansum during improper or long-term storage causes significant eco- nomic losses in the different stages of the post-harvest supply chain. In addition, under cold storage increases the fruit damage and the con- tamination with mycotoxin patulin (Shen et al., 2018b), due to its po- tential health risks to consumers, regulatory health care organizations of many developed countries have established limits in foods (50 μg kg -1 )(Loi et al., 2017). The application of synthetic chemical fungi- cides represents the main strategy for the control of postharvest decay of apple fruit in packaging companies unfortunately, the repeated ap- plication of synthetic fungicides has been associated with a strong https://doi.org/10.1016/j.postharvbio.2019.05.011 Received 13 November 2018; Received in revised form 17 April 2019; Accepted 15 May 2019 ⁎ Corresponding author at: Facultad de Química, Universidad Autónoma de Querétaro, Mexico. E-mail address: ramiro.pacheco@uaq.mx (J.R. Pacheco Aguilar). 1 Postdoctoral researcher fellowship-CONACYT. Postharvest Biology and Technology 155 (2019) 72–79 0925-5214/ © 2019 Published by Elsevier B.V. T