Novel Cyanobacterial Diversity Found in Costa Rican Thermal Springs Associated with Rincon de la Vieja and Miravalles Volcanoes: A Polyphasic Approach

Abstract

Central America is one of the most important biodiversity hot spots in the world, and Costa Rican microbial communities from thermal springs are the best characterized in the isthmus. Miravalles is an inactive quaternary stratovolcano, and the Rincón de la Vieja is a unique active volcano, in whose slopes diverse hydrothermal springs, such as Las Lilas, are located. These springs harbor extensive microbial mats, whose diversity has been studied. Based on their importance as primary producers, in this study we focused on cultured cyanobacterial diversity from two geothermal environments of northern Costa Rica. Several cultural, molecular and taxonomic techniques were employed to maximize the results of a polyphasic approach. Sample collection sites were physicochemically described, and strains were isolated and characterized by light and electron microscopy. Phylogenetic analysis was performed using 16S rRNA gene sequences and amplified ribosomal DNA restriction analysis (ARDRA). Fifty‐six phylotypes were isolated and classified into 21 morphotypes and identified in 14 genera, some of them might be new species within these genera. Furthermore, according to phylogenetic analysis, there are three possible new genera in our collection. Miravalles and Las Lilas thermal springs are reservoirs of novel phylogeographic lineages of phototrophic microorganisms. This study is the first report of strains that belong to the genera Gloeocapsa, Stanieria, Microseira, Klisinema and Oculatella isolated from thermal springs and growing at temperatures above 50°C. We also obtained isolates assigned to Synechococcus, Leptolyngbya spp., and Fischerella, which are considered typical strains in these environments.

Using simulated wildland fire to assess microbial survival at multiple depths from biocrust and bare soils

“…The genus Oculatella is widely distributed in both arid and temperate environments, often in biocrusts (Becerra-Absalón et al, 2020). Previous studies have isolated Oculatella from thermal springs above 50°C (Brenes-Guillén et al, 2021) which suggests this genera is thermotolerant, and may respond positively to fire as indicated by the ASVs detected in the present study. The genus Timaviella is also in a clade with Trichotorquatus.…”

Draft Genome Sequences of Two Cyanobacteria Leptolyngbya spp. Isolated from Microbial Mats in Miravalles Thermal Spring, Costa Rica

“…They were cultivated in BG11 medium ( 3 ) and maintained at 25°C. The location, sampling methods, and isolation protocol details were the same as those provided in reference 4 . Genomic DNA (gDNA) was isolated using the Plant II kit (Macherey-Nagel) and purified using the NucleoSpin gDNA cleanup kit (Macherey-Nagel), according to the manufacturer’s protocol.…”

“…strain 7M was assembled into nonoverlapping scaffolds totaling 6,990,850 bp, with a G+C content of 49.92%, and it contains 7,020 coding sequences and 88 non-protein-coding genes; the final coverage was 10×. According to the 16S rRNA gene-based sequencing approach ( 4 ), isolate 7M was 98.59% identical to the siderophilic Oscillatoriales cyanobacterium JSC1. The draft genome sequence of Leptolyngbya sp.…”

<italic>Geminocystis urbisnovae</italic> sp. nov. (Chroococcales, Cyanobacteria): polyphasic description complemented with a survey of the family <italic>Geminocystaceae</italic>

“…had spherical or ellipsoidal 1.5−7.0 µm cells (Andreote et al 2014, Bravakos et al 2016, Hirose et al 2017, Ma et al 2019, Brenes-Guillén et al 2021 (Table 1). The majority of described strains (Table 1) can reorient division plane by 90° producing double pairs, or tetrads (Korelusová et al 2009, Andreote et al 2014, Bravakos et al 2016, Brito et al 2017, Brenes-Guillén et al 2021. Tetrads have been also observed in Synechocystis spp.…”

“…Cyanobacterium spp. cells were from spherical to rodlike (Moro et al 2007, Andreote et al 2014, Deepa 2018, Brenes-Guillén et al 2021) (Table 2). Cell form and dimensions depended on growth conditions, temperature, and salinity, in particular (Moro et al 2007, Bravakos et al 2016.…”