**3. Results**

Results of the assessment showed the presence of some toxigenic mold species, such as *Aspergillus flavus*, *Fusarium* spp., and *Penicillium* spp., as well as deteriorative molds such as *Aspergillus niger* and *Rhizopus oryzae*, as well as innocuous mold species such as *Phoma* spp. and *Cladosporium* spp. In general, mycobiota of the sampled seeds is consistent with reports for dried fruits from a tropical region, with a predominance of molds adapted to warm, humid climates such as *R. oryzae*, *A. flavus*, and *A. niger* [7].

A comprehensive list of the identified molds can be seen in **Tables 1**–**3**, along with the main characteristics that allowed their identification. A greater diversity of mold species was found in peanut samples, whereas squash seed mycobiota was largely dominated by *R. oryzae* and *A. niger*. Mold species identified in peanuts have been previously reported by other authors: *A. flavus*, *A. niger*, *Fusarium* spp., *Alternatia alternata*, *Rhizopus* spp., *Cladosporium* spp., and *Mucor* spp. which are ubiquitous in shelled peanut samples, both raw and roasted [2, 3, 8–10].

Valle-Garcia *et al*. [11] reported *A. niger*, *Fusarium* spp., *Rhizopus* spp., and a variety of *Penicillium* species in pecans from Rio Grande do Sul State in Brazil. The particular species of *Penicillium* found in the aforementioned study were different from those encountered in this study; however, *Penicillium* is an extremely diverse genus, and species are bound to be different in separate geographic areas.

The mycobiota of the seeds of *C. argyrosperma* remains poorly studied. Phytopathogenic molds such as *Phytophthora capsici*, *Rhizoctonia solani*, and *Sclerotium rolfsii* have been reported to cause fruit rot in silver-seed gourd [12]; however, no such studies exist about the mycology of the seeds themselves, which is, presumably, different from that of the rest of the fruit. It can be assumed that the mycobiota of *C. argyrosperma* seeds is similar to that of the seeds of *C. pepo*. In that regard, *R. oryzae* and *A. niger* have also been reported in the seeds of *C. pepo* [13]. Furthermore, *Penicillium* species have also been reported in *C. pepo* seeds [14], although data concerning squash seeds in that study is deficient.

Morphological characteristics of *A. alternata* are in accordance with those described by Armitage *et al*. [15], except for colony diameter in PDA culture, which was reported as a maximum of 68 mm by these authors. Other authors [16] have also reported the *Aspergillus candidus* morphology encountered in this study. Its distinctive features are the characteristic white color of its colonies and the smooth texture of its conidia. Conidium diameter was smaller than reported in other studies, at 2.0 μm.

*A. flavus* was differentiated from similar species such as *A. oryzae* and *A. parasiticus* by the texture of its stipe (rough) and its conidia (slightly roughened), as reported by Diba *et al.* [17] and Samson *et al.* [7]. *A. niger* was identified by its characteristic black, extensive colonies, as well as by its small conidia (<6 μm in diameter), borne in conidiophores bearing both phialides and metulae, as outlined by Pitt & Hocking [1]. *A. tamarii* was identified by its characteristic brown colonies across different culture media, its large (>3 μm diameter), rough-walled conidia, and its radiate conidiophores [1, 18].

Two unidentified *Aspergillus* species were encountered in peanut samples. Morphological characteristics were insufficient for identification with the means available, and further testing would be necessary.

For the differentiation of some *Penicillium* species, creatine sucrose neutral agar proved useful, as macroscopic colony characteristics and microscopic morphology of *Penicillium* species are often too similar to allow for speciation. A wide variety of *Penicillium* species were recovered from peanut kernels and pecan nuts, which is in accordance with other studies of the microbiota of both dried fruits [11, 19, 20]; however, the particular blend of species identified in this study was different than

### *Isolation and Identification of Molds in Selected Dried Fruits and Seeds Sold in Bulk in México DOI: http://dx.doi.org/10.5772/intechopen.99973*



## *Isolation and Identification of Molds in Selected Dried Fruits and Seeds Sold in Bulk in México DOI: http://dx.doi.org/10.5772/intechopen.99973*



*\*PDA: potato dextrose agar, MEA: malt extract agar, CZD: Czapek Dox agar, CYA: Czapek yeast extract agar.*

**Table 1.**

*Identification of isolated non-Penicillium molds in peanut samples.*

*Isolation and Identification of Molds in Selected Dried Fruits and Seeds Sold in Bulk in México DOI: http://dx.doi.org/10.5772/intechopen.99973*



*\*PDA: potato dextrose agar, MEA: malt extract agar, CZD: Czapek Dox agar, CYA: Czapek yeast extract agar.*

**Table 2.**

*Identification of isolated non-Penicillium molds in pecan samples.*


*Isolation and Identification of Molds in Selected Dried Fruits and Seeds Sold in Bulk in México DOI: http://dx.doi.org/10.5772/intechopen.99973*


