Evaluation of prokaryotic diversity of five hot springs in Eritrea

Abstract

BackgroundTotal community rDNA was used to determine the diversity of bacteria and archaea from water, wet sediment and microbial mats samples of hot springs in the Eastern lowlands of Eritrea. The temperatures of the springs range from 49.5 °C to 100 °C while pH levels varied from 6.97 to 7.54. Akwar and Maiwooi have high carbonate levels. The springs near the seashore, Garbanabra and Gelti, are more saline with higher levels of sodium and chlorides. Elegedi, situated in the Alid volcanic area, has the highest temperature, iron and sulfate concentrations.ResultsThe five hot springs shared 901 of 4371 OTUs recovered while the three sample types (water, wet sediment and microbial mats) also shared 1429 OTUs. The Chao1 OTU estimate in water sample was significantly higher than the wet sediment and microbial mat samples. As indicated by NMDS, the community samples at genus level showed location specific clustering. Certain genera correlated with temperature, sodium, carbonate, iron, sulfate and ammonium levels in water. The abundant phyla included Proteobacteria (6.2–82.3%), Firmicutes (1.6–63.5%), Deinococcus-Thermus (0.0–19.2%), Planctomycetes (0.0–11.8%), Aquificae (0.0–9.9%), Chlorobi (0.0–22.3%) and Bacteroidetes (2.7–8.4%).ConclusionThere were significant differences in microbial community structure within the five locations and sample types at OTU level. The occurence of Aquificae, Deinococcus-Thermus, some Cyanobacteria and Crenarchaeota were highly dependent on temperature. The Halobacterium, unclassified Thaumarchaeota, Actinobacteria and Cyanobacteria showed significant correlation with salinity occurring abundantly in Garbanabra and Gelti. Firmicutes and unclassified Rhodocylaceae were higher in the microbial mat samples, while Archaea were prominent in the wet sediment samples.Electronic supplementary materialThe online version of this article (10.1186/s12866-017-1113-4) contains supplementary material, which is available to authorized users.

The Chemical Characteristic and Microbial Diversity of the Hot Spring at Phusang National Park

“…Phylum Proteobacteria and Chloroflexi were most commonly found in samples from Tato Field, Tatta Pani, and Murtazaabad according to this study (Ghilamicael et al, 2017;Chaudhuri et al, 2017;Amin et al, 2017). In the Murtazaabad hot springs (90-95 °C), phylum Thermotogae was favored with the higher temperature, whereas the phylum Proteobacteria has favored growth in the Tatta Pani thermal spring (60 °C) (Amin et al, 2017).…”

“…Similarly, a study of the Bor Khlueng hot spring (Ratchaburi Province, Thailand) found Crenarahaeota (Kanokratana et al, 2004). A significant correlation with abundant salinity occurring was found between Halobacteria, Actinobacteria and Cyanobacteria in Garbanabra and Gelti (Ghilamicael et al, 2017). The occurrence of some Cyanobacteria was highly dependent on temperature (Strunecky et al, 2018).…”

“…Moreover, the results suggest that Actinobacteria might be producing antimicrobial molecules and biopharmaceuticals more than other bacteria. Thermophilic Actinobacteria was a producer of several enzymes such as DNA polymerases, amylases, xylanases, lipases and proteases (Valeriani et al, 2018;Ghilamicael et al, 2017) or lipolytic enzymes from Jae Sawn hot spring (Thailand), which lead to the isolation of a novel esterase (Est1) and patatin-like phospholipase (PLP) with potential use in industrial applications (Tirawongsaroj et al, 2008). This study found Bacillus licheniformis is a potential producer of a thermostable enzyme such as amylase, cellulose, gelatins, lecithin, and protease.…”

“…Phylum Proteobacteria (6.2-82.3%), Firmicutes (1.6-63.5%), Deinococcus-Thermus (0.0-19.2%) and Bacteroidetes (2.7-8.4%) were abundant. These generacorrelate with the temperature, carbonate, iron, sodium and sulfate levels in the water (Ghilamicael et al, 2017). In India, the Bakreshwar hot spring (54 °C) in West Bengal predominantly included the bacterial phylum Firmicutes (65.85%) and Synergistetes (27.24%) and water from the hot spring (65 °C) exhibited the diversity of the phylum Firmicutes (96.10%) and Proteobacteria (3.36%) based on sequencingV3 hypervariable 16S rRNA fragments (Chaudhuri et al, 2017).…”

Screening of Bacteria Producing Asparaginase Free of Glutaminase and Urease from Hot Springs in West Sulawesi

“…Several published reports on bacteria from hot springs, stated that three Proteobacteria subclass, i.e. Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria existed in high abundance (Ghilamicael, et al, 2017;Hussein et al, 2017;Rozanov, et al, 2017;Song et al, 2013).…”