Biology subjects

Batista-Garcia, R. A.

Publications and source records attributed to Batista-Garcia, R. A..

4 recordsLinked to original sources

bioRxiv2026

Chaotropic Ions Reshape the Cell Wall of the Obligate Halophile Aspergillus atacamensis: Insight from Solid-State NMR

Fungal survival in hypersaline environments requires exceptional adaptation of polysaccharide-based cell walls, yet the molecular principles underlying these adaptations remain largely unknown due to the extreme rarity of obligate halophilic fungi. Aspergillus atacamensis is an obligate halophile and chaotolerant fungus capable of growth at saturating NaCl concentrations and unusually high levels of MgCl2. Here, we used multidimensional solid-state NMR spectroscopy to investigate the molecular organization, hydration, and dynamics of cell wall polysaccharides in intact, uniformly 13C-labeled A. atacamensis cells grown under kosmotropic NaCl and chaotropic MgCl2 conditions. Under NaCl conditions, the rigid cell wall core was dominated by {beta}-1,3-glucan and chitin across all salinities. Hyperosmotic NaCl induced thinner, dehydrated walls with increased polysaccharide mobility. In contrast, MgCl2 exposure resulted in marked remodeling of wall carbohydrates, including the emergence of chitosan, incorporation of mannan into the rigid phase, increased wall thickness, and enhanced hydration and dynamics. Together, these findings reveal fundamentally distinct polysaccharide remodeling strategies in response to kosmotropic versus chaotropic stress and establish a molecular framework for understanding fungal survival in extreme ionic environments. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/700186v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@a38e89org.highwire.dtl.DTLVardef@1e2f7fdorg.highwire.dtl.DTLVardef@71a94org.highwire.dtl.DTLVardef@61f2c4_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LISolid-state NMR reveals salt-dependent remodeling of fungal cell wall polysaccharides C_LIO_LIKosmotropic and chaotropic salts drive distinct cell wall adaptation strategies C_LIO_LINaCl stress promotes dehydration and compaction of the {beta}-1,3-glucan-chitin framework C_LIO_LIMgCl2 induces chitosan emergence and alters mannan organization in the rigid phase C_LIO_LIPolysaccharide hydration and dynamics encode fungal adaptation to extreme environments C_LI

biophysics↗

bioRxiv2023

Structural Organization of the Cell Wall of Halophilic Fungi

Halophilic fungi, which thrive in hypersaline habitats and face a range of extreme conditions. These fungal species have gained considerable attention due to their potential applications in harsh industrial processes, such as bioremediation and fermentation under unfavorable conditions of hypersalinity, low water activity, and extreme pH. However, the role of the cell wall in surviving these environmental conditions remains unclear. Here we employ solid-state NMR spectroscopy to compare the cell wall architecture of Aspergillus sydowii across salinity gradients. Analyses of intact cells reveal that A. sydowii cell walls contain a rigid core comprising chitin, {beta}-glucan, and chitosan, shielded by a surface shell composed of galactomannan and galactosaminogalactan. When exposed to hypersaline conditions, A. sydowii enhances chitin biosynthesis and incorporates -glucan to create thick, stiff, and hydrophobic cell walls. Such structural rearrangements enable the fungus to adapt to both hypersaline and salt-deprived conditions, providing a robust mechanism for withstanding external stress. These molecular principles can aid in the optimization of halophilic strains for biotechnology applications.

biophysics↗

bioRxiv2020

Transcriptional profiling reveals conserved and species-specific plant defense responses during the interaction of the early divergent plant Physcomitrium patens with Botrytis cinerea

Bryophytes were among the first plants that colonized earth and they evolved key defense mechanisms to counteract microbial pathogens present in the new environment. Although great advances have been made on pathogen perception and subsequent defense activation in angiosperms, limited information is available in early divergent land plants. In this study, a transcriptomic approach uncovered the molecular mechanisms underlying the defense response of the bryophyte Physcomitrium patens against the important plant pathogen Botrytis cinerea. A total of 3.072 differentially expressed genes were significantly affected during B. cinerea infection, including genes encoding proteins with known function in angiosperm immunity and involved in pathogen perception, signaling, transcription, hormonal signaling, metabolic pathways such as shikimate and phenylpropanoid, and proteins with diverse role in defense against biotic stress. Similarly as in other plants, B. cinerea infection leads to downregulation of genes involved in photosynthesis and cell cycle progression. These results highlight the existence of evolutionary conserved defense responses to pathogens throughout the green plant lineage, suggesting that they were probably present in the common ancestors of land plants. Moreover, several genes acquired by horizontal transfer from prokaryotes and fungi, and a high number of P. patens-specific orphan genes were differentially expressed during B. cinerea infection, indicating that they are part of the moss immune response and probably played an ancestral role related to effective adaptation mechanisms to cope with pathogen invasion during the conquest of land. Key MessageEvolutionary conserved defense mechanisms present in extant bryophytes and angiosperms, as well as moss-specific defenses are part of the immune response of the early divergent land plant Physcomitrium patens.

plant biology↗

bioRxiv2019

Bioremediation of soils contaminated with petroleum solid wastes and drill cuttings by Pleurotus sp. strains under different treatment scales

Wastes from the oil industry represent one of the sources of soil pollution with the greatest environmental impact. Both drill cuttings and crude residues are delivered to the soil and produce severe toxic effects, mainly due to the presence of polycyclic aromatic hydrocarbons. Various bioremediation technologies have been implemented in order to restore the soil quality and the natural auto depuration capabilities, amongst them: composting, bioaugmentation and biostimulation. All of these bioremediation techniques promise to be eco-friendlier and cheaper alternatives than other approaches. In this work we have evaluated several strains of Pleurotus sp. for their effect on the bioremediation of oil-contaminated wastes and drill cuttings disposed in storage tanks or in open-air soil lots for many years. Our results suggest that combined natural attenuation mechanism and directed fungal biodegradation activities, could be promising strategies to remediate heavily petroleum polluted soils and drilling wastes both at the laboratory and in field conditions. Furthermore, we present new data that supporting Pleurotus genera as able to degrade asphaltenes, the most recalcitrant fraction of petroleum. This study proposes an approach that at the same time can treat soils contaminated with waste from drill cuttings and bottoms of crude storage tanks.

microbiology↗