Biology subjects

Zavafer, A.

Publications and source records attributed to Zavafer, A..

3 recordsLinked to original sources

bioRxiv2026

COMPARATIVE PHENOMICS IN Limnospira platensis STRAINS REVEALS PHOTOBIOENERGETIC SIMILARITIES AND DIFFERENCES IN AMERICAN AND AFRICAN STRAINS

This study addresses the functional diversity of wild Limnospira platensis strains from two continents. Wild strains retain regulatory and metabolic flexibility often lost during domestication, making them essential for exploring natural adaptation within the species evolutionary history. We investigated the comparative growth performance of five Limnospira strains under controlled temperature and light regimes to identify phenotypic differences attributable to single environmental variables. We then evaluated their biochemical and biophysical responses under naturally fluctuating light conditions, linking energy use strategies to phylogenetic relationships. Our analyses reveal that while certain traits, such as fine-tuning of photosynthetic reactions, are shared among closely related strains, overall growth performance is highly variable even within phylogenetically similar groups. For example, photosensitive strains (e.g., UTEX 3086) differ markedly from high light tolerant strains (e.g., UTEX LB 2342) in their mechanisms of coping with light stress. Together, these comparative analyses highlight how environmental sensitivity and energy-use strategies vary across strains of the same species, reflecting broader patterns of diversification within Limnospira.

bioengineering↗

bioRxiv2026

A DEVICE THAT COMBINES LIGHT ATTENUATION AND SCATTERING FOR THE MEASUREMENTS OF OPTICALLY DENSE ALGAL CULTURES IN CELL CULTURE FLASKS.

Studying algae requires specialized equipment to characterize culture growth and physiological performance and non-invasive monitoring of these cultures typically relies on optical density (OD) measurements. Currently, OD is often measured using standard spectrometers that suffer from detector saturation at high cell densities, which requires time consuming sample dilutions and lacks compatibility with flat-walled cell culture flasks like Roux bottles. Here we describe a 3D-printable device to measure optically dense algal cultures directly within these cultivation vessels. This instrument combines light attenuation and scattering, resulting in a dual-sensor system that utilizes near-infrared light (950 nm) to precisely quantify biomass without interference from changing photosynthetic pigments. Cultures that reach high cell densities can be assumed to be accurately quantified in situ using the scattered signal, preserving the integrity of the culture and eliminating the need for subsampling. This method is adaptable to the most common geometries of Roux bottles (T-25, T-75, and T-175) and could be used to monitor small-scale batch cultures without contamination risks. A cyanobacteria algal species (Limnospira platensis) and three flask sizes were analysed on light attenuation linearity and scattering detection limits at different cell concentration, demonstrating that the light attenuation module can reliably measure biomass up to an OD of 3.1 (equivalent to >1.5 g/L) without requiring dilution.

bioengineering↗

bioRxiv2026

MUTALISM BETWEEN Ambystoma maculatum AND Oophila amblystomatis IS DEPENDENT ON LIGHT INTENISTY DURING PHOTOSYNTHETIC GROWTH

The most studied symbiosis between land vertebrates and algae, is the one between Ambystoma maculatum and Oophila amblystomatis, where the latter colonizes the amphibian''s eggs. Although clear benefit given by algal growth for the salamander embryo has been observed, mutualism is not widely accepted. Mutualistic hypotheses posit benefits from the host to the algae which include protection, N- and C-sources, but no experimental evidence has been obtained. In fact, recent studies suggest that the algae are stressed during this relationship and propose fermentation rather than photosynthesis as main driver for algal growth. In this work, we analyzed embryonic host developmental rate, algal and embryo growth and photosynthetic function of eggs housed at different light intensities. We provide evidence that photosynthetic growth is the main driver for Oophila and that higher algal growth yields faster developmental rate and embryo size. Also, we provide strong evidence that rates of photosynthetic electron transport (and the concomitant O2 evolution) must be higher than those of consumption by the embryo for this symbiosis to be mutualistic. Since photosynthetic rate is dependent on light, this work illustrates the importance of light intensity in this symbiotic relationship.

ecology↗