Unveiling microbial oxidizers in Chihuahuan Desert rock varnish (Mexico): a pioneer study
Desvelando los oxidantes microbianos en barnices del desierto de Chihuahua (México): un estudio pionero
Marisela Aguirre Ramírez1, Pável Ulianov Martínez-Pabello2,*, María Colín-García2, Víctor Antonio López Ruiz1, Iris Suárez Quijada2, María Del Pilar Ortega Larrocea2, Paulina Del Valle Pérez3, Aldo Izaguirre Pompa4, Héctor Mario Munguía Peña1
1 Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, C.P. 32310, Ciudad Juárez, Chihuahua, México.
2 Instituto de Geología, Universidad Nacional Autónoma de México, C.P. 04510, Ciudad de México, México.
3 Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, C.P. 04510, Ciudad de México, México.
4 Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, C.P. 32310, Ciudad Juárez, Chihuahua, México.
* Corresponding author: (P.U. Martínez-Pabello) This email address is being protected from spambots. You need JavaScript enabled to view it.
How to cite this article:
Aguirre Ramírez, M., Martínez-Pabello, P.U., Colín-García, M., López Ruiz, V.A., Suárez Quijada, I., Ortega Larrocea, M.P., Del Valle Pérez, P., Izaguirre Pompa, A., Munguía Peña, H.M., 2025, Unveiling microbial oxidizers in Chihuahuan Desert rock varnish (Mexico): a pioneer study: Boletín de la Sociedad Geológica Mexicana, 77(1), A261224. http://dx.doi.org/10.18268/BSGM2025v77n1a261224
Manuscript received: September 12, 2024; Corrected manuscript received: November 27, 2024; Manuscript accepted: December 6, 2024.
ABSTRACT
Arid and semi-arid desert areas characterized by extreme conditions, including northern Mexico, have rocks with micrometric coatings. These coatings are known as desert varnish, an often dark-red microlayer deposited over millennia and developed on different rock types. These microlaminations, rich in clay minerals and Fe/Mn-oxides, can serve as habitats for various microorganisms, mainly fungi and bacteria. However, the role of microorganisms in these varnish formations is still under debate. In the Chihuahuan desert (Mexico), particularly in the Samalayuca ridge, extensive areas are covered by rocks with desert varnish Here we present a research effort focused on isolating Feand Mn-oxidising microorganisms in different culture media, along with directed sequencing. Using a benzidine spot test to detect oxidant species revealed the presence of bacteria and fungi inhabiting these layers. Likewise, we contribute to a better understanding of the formation of desert varnish, representing the first report of specific microorganisms isolated from rock vanish of the Chihuahuan desert.
Keywords: desert varnish, oxidising microorganisms, Chihuahuan desert, benzidine test
