ExtremophilesPub Date : 2025-08-01DOI: 10.1007/s00792-025-01398-y
Ishfaq Ahmad Baba, Zubair Ahmad Wani, Mohamad Mosa Mubarak, Zahoor Ahmad
{"title":"Actinomycetes from high altitude salt lake Tso-Kar of Ladakh offers bright prospects for antimycobacterial drug discovery especially for drug resistant mycobacteria.","authors":"Ishfaq Ahmad Baba, Zubair Ahmad Wani, Mohamad Mosa Mubarak, Zahoor Ahmad","doi":"10.1007/s00792-025-01398-y","DOIUrl":"https://doi.org/10.1007/s00792-025-01398-y","url":null,"abstract":"<p><p>The rise of multidrug-resistant (MDR) strains of Mycobacterium tuberculosis (M. tb) has driven the search for new antimycobacterial agents. Our study focused on isolation and characterization of actinomycetes from the hypersaline Tso-Kar Salt lake in Ladakh, India, to explore their antibacterial potential. We isolated 145 bacterial isolates from various soil, salt and water samples and found 23 actinomycete isolates effective against Mycobacterium smegmatis through cross-streak screening. Molecular identification confirmed that these isolates belonged to 14 genera of actinomycetes. Out of 23 extracts from these isolates, 15 ethyl acetate organic extracts exhibited strong antimycobacterial activities against M. smegmatis, M. tb H37Ra, and M. tb H37Rv, with MIC values between 125 and 31.25 µg/mL. Importantly, all 15 extracts demonstrated bactericidal activities at their respective MICs against M. tb H37Rv. The other 8 extracts displayed comparatively weaker MIC and MBC ranging 500-250 µg/mL and 1000-500 µg/mL respectively. These extracts were equally effective against drug-resistant and drug-susceptible M. tb clinical isolates. Furthermore, they showed broad antibacterial activity against both gram-positive and gram-negative bacteria, with MICs ranging from 500 to 31.25 µg/mL. The GC-MS analysis of the potent extracts revealed that a wide range of compounds including Phenolics, Peptides, Ergot alkaloids and their derivates may have contributed to anti-mycobacterial activity. The genetic diversity and significant antimicrobial properties of these actinomycetes from extreme environments highlight their potential for developing new antituberculosis and general antibiotic agents, particularly against MDR infections.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"33"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144759590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural insight into the unique substrate specificity of glutamate dehydrogenase from Saccharolobus solfataricus.","authors":"Itsuki Okabe, Masashi Hirano, Taketo Ohmori, Minako Segawa, Kazunari Yoneda, Toshihisa Ohshima, Haruhiko Sakuraba","doi":"10.1007/s00792-025-01395-1","DOIUrl":"https://doi.org/10.1007/s00792-025-01395-1","url":null,"abstract":"<p><p>The gene (SSO1457) encoding a L-glutamate dehydrogenase (GDH) homolog from the thermoacidophilic archaeon Saccharolobus solfataricus P2 was overexpressed in Escherichia coli. At a substrate concentration of 50 mM, the enzyme (SSO1457) produced exhibited much higher specific activity toward L-norvaline than L-glutamate at temperatures between 55 and 75°C, whereas the enzyme showed higher activity for L-glutamate than L-norvaline at 85°C. The crystal structures of both NAD<sup>+</sup>/2-oxovalerate-bound and NAD<sup>+</sup>/2-oxoglutarate-bound SSO1457 were determined. Comparison of the two structures showed that the positioning of the substrate molecules and the surrounding residues is nearly identical in the two complexes. In the 2-oxoglutarate-bound structure, the C5-carboxylate group of 2-oxoglutarate is hydrogen-bonded with the side chains of Lys72, Arg188, and Ser351, as observed in other GDHs. By contrast, in the 2-oxovalerate-bound structure, the C01, C02, and C03 atoms of 2-oxovalerate are anchored via hydrophobic interactions to the side chains of Met93 and Val348. Site-directed mutagenesis shows that the side chain of Met93 mainly mediates the reactivity of SSO1457 towards L-norvaline and contributes to high specific activities for L-norvaline.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"32"},"PeriodicalIF":2.6,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144698007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-21DOI: 10.1007/s00792-025-01399-x
Christian Hintersatz, Luis Antonio Rojas, Sean Ting-Shyang Wei, Sabine Kutschke, Angela Thewes, Falk Lehmann, Rohan Jain, Katrin Pollmann
{"title":"Idiomarina aminovorans sp. nov., a halophilic bacterium isolated from the Llamara salt pan in the Atacama Desert of northern Chile.","authors":"Christian Hintersatz, Luis Antonio Rojas, Sean Ting-Shyang Wei, Sabine Kutschke, Angela Thewes, Falk Lehmann, Rohan Jain, Katrin Pollmann","doi":"10.1007/s00792-025-01399-x","DOIUrl":"10.1007/s00792-025-01399-x","url":null,"abstract":"<p><p>The Atacama Desert, one of the most extreme environments on our planet, harbors a plethora of unique microbial communities adapted to the harsh conditions of the habitat. In this study, strain ATCH4<sup>T</sup>, a novel Gram-stain-negative, curved rod-shaped bacterium, was isolated from the Llamara salt pan, located in the Atacama Desert in the north of Chile. ATCH4<sup>T</sup> was capable of growth within a range of 3-12% (w/v) NaCl, 4-40 °C, and pH 6-9. Comparative 16S rRNA analysis placed the strain within the genus Idiomarina, with its closest related type species being I. loihiensis, I. ramblicola, and I. abyssalis. Genomic analysis revealed the presence of several genes linked to halophilicity as well as unique metabolic pathways, including the ability to synthesize C5 and C10-C20 isoprenoids, which may contribute to the isolate's survival in hypersaline conditions. The observed isoprenoid biosynthesis pathways suggest potential applications in various biotechnological fields, including the production of biofuels, pharmaceuticals, and other valuable chemicals. Levels of DNA-DNA relatedness, average nucleotide identity, and several phenotypic and chemotaxonomic markers clearly indicate that strain ATCH4<sup>T</sup> represents a novel species of the genus Idiomarina, for which the designation Idiomarina aminovorans sp. nov. (type strain ATCH4<sup>T</sup> = DSM 114475 = LMG 32710) is proposed.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"31"},"PeriodicalIF":2.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12279604/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144674268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-10DOI: 10.1007/s00792-025-01390-6
Lydia M Dimattia, Naim Saglam, Ralph Saunders, Daniel H Shain
{"title":"An ice inhabiting bdelloid rotifer from North America.","authors":"Lydia M Dimattia, Naim Saglam, Ralph Saunders, Daniel H Shain","doi":"10.1007/s00792-025-01390-6","DOIUrl":"10.1007/s00792-025-01390-6","url":null,"abstract":"<p><p>Bdelloid rotifers are major components of zooplankton worldwide and have been reported in glacier ice in both Northern and Southern Hemispheres. Curiously, no reports of psychrophilic bdelloids have surfaced in North America despite exhaustive surveys of other ice-dwelling invertebrates, e.g., glacier ice worms. This distribution gap may be partially explained by a predator-prey relationship between these two animals, but the current study suggests that ice worms and bdelloids can co-inhabit at least some glacial ecosystems over geological time. Here we report the first ice-inhabiting bdelloid rotifer from North America, collected from the northern aspect of Mt. Deception, WA, USA. Nuclear and mitochondrial genotyping identified sister-species relationships within a clade of Nordic ice-dwelling bdelloids, and close evolutionary relationships with Antarctic/New Zealand specimens. Intrapopulation genetic divergences suggest that bdelloids arrived in North America near the onset of the Pleistocene (2.58 myr BP), but their circumpolar dispersal capabilities and robustness (e.g., freeze-thaw tolerance, ability to propagate at elevated temperatures and under extreme laboratory conditions) cannot rule out multiple transoceanic dispersal events throughout the Quaternary.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"30"},"PeriodicalIF":2.6,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12246028/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144599870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-08DOI: 10.1007/s00792-025-01394-2
Dezhi Wang, Han Li, Yu Zhao, Bailin Cong, Pengying Zhang
{"title":"Structural characteristics and immunomodulatory activity of an exopolysaccharide from Antarctic Pseudoalteromonas sp. LP6-12-2.","authors":"Dezhi Wang, Han Li, Yu Zhao, Bailin Cong, Pengying Zhang","doi":"10.1007/s00792-025-01394-2","DOIUrl":"https://doi.org/10.1007/s00792-025-01394-2","url":null,"abstract":"<p><p>Natural polysaccharides from microorganisms have various biological activities. However, those from psychrophiles with immunomodulatory properties have rarely been found. In this study, an immunoactive exopolysaccharide was extracted from Antarctic Pseudoalteromonas sp. LP6-12-2 (EPS1-1), which isolated using DEAE-Sepharose Fast Flow, Sephadex G-75, and Sephadex G-100. EPS1-1, with a molecular weight 23.47 kDa, was composed of mannose, glucose, galactose, glucosamine, and galactosamine in the ratio of 83.1:7.2:4.3:4.2:1.2. Furthermore, EPS1-1 was found to have a main chain composed of α-D-Manp (1→2) and side chains composed of α-D-Manp (1→6) by FT-IR, methylation, and NMR analyses. Besides, through the Congo red test and I<sub>2</sub>-KI reaction analyses, it was revealed that EPS1-1 lacked triple-helix structure and had more branches. Additionally, EPS1-1 could significantly advance the proliferation, phagocytosis, acid phosphatase activity, and cytokines production of macrophage cells. Data suggested EPS1-1 demonstrated potential as an immunomodulator for functional food or pharmaceutical development.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"29"},"PeriodicalIF":2.6,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144583505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-03DOI: 10.1007/s00792-025-01392-4
Noha M Mesbah
{"title":"Natranaerobius thermophilus: an anaerobic, polyextremophilic microorganism with unique properties and adaptive mechanisms.","authors":"Noha M Mesbah","doi":"10.1007/s00792-025-01392-4","DOIUrl":"https://doi.org/10.1007/s00792-025-01392-4","url":null,"abstract":"<p><p>Natranaerobius thermophilus is an obligately anaerobic, halophilic alkalithermophilic microorganism that was isolated from the sediment of Lake Fazda of the Wadi An Natrun, Egypt. It can grow optimally at 3.3-3.9 M Na<sup>+</sup>, 53℃ and pH 9.5 (measured at 55℃). N. thermophilus has several properties that distinguish it from other halophilic anaerobes; it is simultaneously adapted to alkaline pH and high temperature and adopts a combined salt-in-compatible solute strategy for osmoadaptation, accumulating glycine betaine, proline and potassium in its cytoplasm. The F<sub>1</sub>F<sub>0</sub>-ATPase of N. thermophilus is Na<sup>+</sup>-coupled and functions primarily as a Na<sup>+</sup> pump, expelling Na<sup>+</sup> from the cytoplasm at the expense of ATP. N. thermophilus has a large cohort of electrogenic Na<sup>+</sup>(K<sup>+</sup>)/ H<sup>+</sup> antiporters for cytoplasm acidification and has an acidic proteome. This minireview discusses the phylogeny and metabolism of N. thermophilus. Adaptive mechanisms employed by N. thermophilus to combat multiple extreme growth conditions will be presented.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"27"},"PeriodicalIF":2.6,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-03DOI: 10.1007/s00792-025-01396-0
Adriely Vital de Souza Silva, Averlane Vieira da Silva, Adeildo Júnior de Oliveira, Rafaela Ferreira da Silva Costa, Rodrigo Paidano Alves, Luiz Henrique Rosa, Valéria Maia de Oliveira, Marcela Eugênia da Silva Cáceres, Janice Gomes Cavalcante, Sabrina Barros Cavalcante, Michel Rodrigo Zambrano Passarini, Aline Cavalcanti de Queiroz, Alysson Wagner Fernandes Duarte
{"title":"Phosphate solubilization by filamentous fungi from Antarctic lichens and sediments.","authors":"Adriely Vital de Souza Silva, Averlane Vieira da Silva, Adeildo Júnior de Oliveira, Rafaela Ferreira da Silva Costa, Rodrigo Paidano Alves, Luiz Henrique Rosa, Valéria Maia de Oliveira, Marcela Eugênia da Silva Cáceres, Janice Gomes Cavalcante, Sabrina Barros Cavalcante, Michel Rodrigo Zambrano Passarini, Aline Cavalcanti de Queiroz, Alysson Wagner Fernandes Duarte","doi":"10.1007/s00792-025-01396-0","DOIUrl":"https://doi.org/10.1007/s00792-025-01396-0","url":null,"abstract":"<p><p>We aimed to investigate the phosphate solubilization by filamentous fungi isolated from Antarctic lichen and sediment. The results yielded a total of 80 strains, 9 of which were positive for phosphate solubilization in solid NBRIP medium. Cladosporium sp. 1EM.P1 and Penicillium steckii 5Y.P4 showed the largest halos, indicating their potential in phosphate solubilization. Cladosporium sp. 1EM.P1 was the most efficient phosphorus (P) solubilizer with maximum P levels of 106.14 mg/L at 15 °C and 80.89 mg/L at 25 °C. This strain also showed solubilization activity at 0.5 M NaCl with P levels of 127.93 mg/L. At pH 8.0, the P content was 137.93 mg/L, and glucose was the best carbon source (P 146.55 mg/L). Moreover, the isolated fungus showed activity only with tricalcium phosphate as an inorganic phosphate source. During the solubilization process, Cladosporium sp. 1EM.P1 released formic, malic, and succinic acids by the 15th day of incubation (P 208.99 mg/L). These findings indicate that Cladosporium sp. 1EM.P1 from Antarctic sediment has the potential to solubilize phosphate and thus unveils new possibilities for the agricultural sector, aimed to reducing reliance on chemical fertilizers.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"26"},"PeriodicalIF":2.6,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-07-03DOI: 10.1007/s00792-025-01397-z
Alberto León-Lemus, Martha Martínez-García, Nathalie Cabirol, Jorge E Campos, Alejandro Monsalvo-Reyes
{"title":"Draft genome sequence and comparative genomic analysis of Halomonas salifodinae strain A2 isolated from the Zapotitlán Salinas Valley, Puebla, Mexico.","authors":"Alberto León-Lemus, Martha Martínez-García, Nathalie Cabirol, Jorge E Campos, Alejandro Monsalvo-Reyes","doi":"10.1007/s00792-025-01397-z","DOIUrl":"10.1007/s00792-025-01397-z","url":null,"abstract":"<p><p>In this study, we report the draft genome sequence of strain A2. The genome size was 3.8 Mbp, the GC content was 67.4%, and it was predicted to contain 3520 protein-coding genes, 62 tRNA genes, 8 rRNA genes, and 4 snRNA genes. Phylogenetic analysis of the 16S rRNA gene in different databases suggests that strain A2 belongs to Halomonas salifodinae. Also, Multilocus Sequence Typing analysis confirms that A2 is closely related to H. salifodinae. Phylogenomic of the core genes and comparative genomic analysis using the Average Nucleotide Identity, digital DNA-DNA Hybridization, Average Amino acid Identity, the Percentage of Conserved Proteins values indicators, and the Genome Taxonomy Database indicates that strain A2 is identified as H. salifodinae and suggest that this species has a closer phylogenetic relationship with the genus Bisbaumannia than with Halomonas. The pangenomic analysis of A2 against 100 reference genomes of described Halomonas and another related genus shows 136,122 genes that comprise the pangenome with 317 core genes, 3457 shell genes, 132,332 accessory genome genes, and 691 unique genes. A2 has 261 signature genes that it shares only with Bisbaumannia and Halomonas salifodinae. For strain A2 we found 29 genes for secretion systems, 23 genes for Na<sup>+</sup> and K<sup>+</sup> ion transport, 6 Biosynthetic Gene Clusters groups, a total of 12 genomic islands, an 8.2 kb gene prophage region, 15 regions associated with CRISPR and one CAS-TypeIF cas gene cluster region, 12 genes of biotechnological importance, 38 unique genes essential for adaptability and biotechnological relevance, as well as, 35 genes for the synthesis of compatible solutes. Comparative genomics analysis shows that strain A2 has multiple unique genetic features that could be useful for biotechnological applications. The result of this study places the species Halomonas salifodinae in a very close relationship with the genus Bisbaumannia than with Halomonas, so its reclassification to the genus Bisbaumannia is proposed for future validation.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"28"},"PeriodicalIF":2.6,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12226641/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Identification and characterization of a novel halolysin from Halostella sp. PRR32 with two C-terminal extensions.","authors":"Yu Jin, Juntao Ke, Yuling Hao, Aodi Zhang, Han Wu, Yue Ding, Shengda Zhao, Jing Han, Aimin Liu, Shaoxing Chen","doi":"10.1007/s00792-025-01389-z","DOIUrl":"https://doi.org/10.1007/s00792-025-01389-z","url":null,"abstract":"<p><p>Extracellular proteases produced by haloarchaea, termed halolysins, possess potential applications in diverse fields including food fermentation and bio-remediation. In this study, an extracellular protease encoding gene, hly32<sup>PRR32</sup>, from Halostella sp. PRR32 isolated from a salt mine in Anhui, China, was identified and expressed in Escherichia coli. The expressed protein MBP-Hly32 was purified and biochemically characterized. The results indicate that Hly32 belongs to the S8 family of serine proteases (halolysin). A BLAST search on NCBI reveals that Hly32 has an amino acid sequence identity of 68.87% with serine protease Hly176B from Haloarchaeobius sp. FL176. MBP-Hly32 contains a catalytic triad of Asp<sup>159</sup>-His<sup>198</sup>-Ser<sup>350</sup> and two C-terminal extensions which are crucial for its activity. The optimal conditions for its enzyme activity are 50 °C, pH 8.0, and 4.0 M NaCl. Under these conditions, the K<sub>m</sub>, V<sub>max</sub> and K<sub>cat</sub> for the MBP-Hly32 were determined to be 2.34 mM, 935.50 U·mg<sup>-1</sup> and 1472.40 s<sup>-1</sup>, respectively. Metal ions and organic reagents affect its activity differently from the typical halolysins; for example, Ca<sup>2+</sup>, which enhances the activity of other halolysin enzymes, has no effect on MBP-Hly32. Furthermore, the activity of Hly32 was inhibited by the presence of PMSF, DTT, and EDTA. Furthermore, a three-dimensional structure prediction based on functional domains was obtained in this study which will facilitate modification and protein engineering halolysins to generate mutants with new physiological activities.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"25"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ExtremophilesPub Date : 2025-06-28DOI: 10.1007/s00792-025-01393-3
Laura Biessy, Jack Sissons, Joseph Kanyi Kihika, Susanna A Wood, John K Pearman
{"title":"Microbial adaptations to acidic, nutrient- and metal-rich lakes in Aotearoa New Zealand.","authors":"Laura Biessy, Jack Sissons, Joseph Kanyi Kihika, Susanna A Wood, John K Pearman","doi":"10.1007/s00792-025-01393-3","DOIUrl":"10.1007/s00792-025-01393-3","url":null,"abstract":"<p><p>Four lakes in the same region of Aotearoa New Zealand were investigated to characterize sediment microbial communities and functions under contrasting environmental conditions. Two lakes, an acidic lake (Rototai) and a lake with elevated metals and nutrients (Killarney) were impacted by extreme stressors, while the lowland mesotrophic lake (Kaihoka East) and an alpine lake (Peel) were used as reference lakes. Using metabarcoding and metagenomics analysis, we profiled community composition, functional pathways, and resistance mechanisms in the lake sediments. Rototai contained high abundances of genes involved in sulfur cycling (assimilatory and dissimilatory sulfate reduction, sulfur oxidation) and acid tolerance (kdp potassium-transport system, ClcA antiporters). In contrast, Killarney had elevated abundances of genes involved in methanogenesis, however despite high metal concentrations, no enrichment of metal-resistance genes was detected. Kaihoka East contained the highest prokaryotic diversity and an elevated abundance of genes involved in nitrification. Although community taxonomic differences were modest across lakes, functional analyses revealed distinct metabolic adaptations. These findings highlight the utility of using metagenomic approaches to identify biogeochemical processes and stress-response strategies in lakes. Improved understanding of microbial functional diversity in surface sediments has implications for lake management, particularly in systems impacted by acidification, high nutrient loading, and metal contamination.</p>","PeriodicalId":12302,"journal":{"name":"Extremophiles","volume":"29 2","pages":"24"},"PeriodicalIF":2.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12206176/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144527110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}