Diversity and enzymatic potential of thermophilic bacteria associated with terrestrial hot springs in Algeria

Abstract

This study aims to determine the diversity of culturable thermophilic bacteria isolated from eight terrestrial hot springs in Northeastern of Algeria using the conventional methods, SDS-PAGE fingerprinting of whole-cell proteins and 16S rRNA gene sequencing. In addition, their hydrolytic enzyme activities were also investigated. A total of 293 strains were isolated from the hot springs' water and sediment using different culture media. Overall, five distinct bacterial groups were characterized by whole-cell protein pattern analysis. Based on the 16S rRNA gene sequencing of 100 selected strains, the isolates were assigned to the following three major phyla: Firmicutes (93%), Deinococcus-Thermus (5%), and Actinobacteria (2%), which included 27 distinct species belonging to 12 different phylotypes, Aeribacillus, Aneurinibacillus, Anoxybacillus, Bacillus, Brevibacillus, Geobacillus, Laceyella, Meiothermus, Saccharomonospora, Thermoactinomyces, Thermobifida, and Thermus. The screening for nine extracellular enzymes showed that 65.87% of the isolates presented at least five types of enzyme activities, and 6.48% of strains combined all tested enzymes (amylase, cellulase, pectinase, esculinase, protease, gelatinase, lipase, lecithinase, and nuclease). It was found that Bacillus, Anoxybacillus, Aeribacillus, and Aneurinibacillus were the genera showing the highest activities. Likewise, the study showed an abundant and diverse thermophilic community with novel taxa presenting a promising source of thermozymes with important biotechnological applications. This study showed that a combined identification method using SDS-PAGE profiles of whole-cell proteins and subsequent 16S rRNA gene sequence analysis could successfully differentiate thermophilic bacteria from Algerian hot springs.

Genome mining, phylogenetic, and functional analysis of arsenic (As) resistance operons in Bacillus strains, isolated from As-rich hot spring microbial mats

“…When analyzing the genome of strain KNP, genes that code for proteins involved in the reduction and resistance to As were also detected, such as thioredoxin, arsA, and arsB (Arora et al, 2021). Other strains of B. paralicheniformis have also been isolated from Espinazo Hot springs in Nuevo Leon, México (Silva-Salinas et al, 2021), Morocco (Maski et al, 2021), and Algeria (Benammar et al, 2020). Interestingly, all these B. altitudinis strains were associated with diverse biotechnological applications.…”

Unraveling the enzymatic and antibacterial potential of rare halophilic actinomycetes from Algerian hypersaline wetland ecosystems

“…Members of Actinopolyspora and Nocardiopsis form an ecologically versatile and biotechnologically important group of rare actinomycetes. Most species are halotolerant or halophilic where they thrive in saline soils, marine environments, and other hypersaline ecosystems [2], and to ensure their survival under these conditions, they mainly produce extremozymes, compatible solutes, and bioactive compounds [48].…”

Genome mining, phylogenetic, and functional analysis of arsenic (As) resistance operons in Bacillus strains, isolated from As-rich hot spring microbial mats

“…The copyright holder for this preprint this version posted March 21, 2022. ; https://doi.org/10.1101/2022.03.20.485026 doi: bioRxiv preprint genome of strain KNP, genes that code for proteins involved in the reduction and resistance to As were also detected, such as thioredoxin, arsA, and arsB (Arora et al, 2021). Other strains of B. paralicheniformis have also been isolated from Espinazo Hot springs in Nuevo Leon, México (Silva-Salinas et al, 2021), Morocco (Maski et al, 2021), and Algeria (Benammar et al, 2020). Interestingly, all these B. altitudinis strains were associated with diverse biotechnological applications.…”