Taxonomically-linked growth phenotypes during arsenic stress among arsenic resistant bacteria isolated from soils overlying the Centralia coal seam fire

Arsenic (As), a toxic element, has impacted life since early Earth. Thus, microorganisms have evolved many As resistance and tolerance mechanisms to improve their survival outcomes given As exposure. We isolated As resistant bacteria from Centralia, PA, the site of an underground coal seam fire that has been burning since 1962. From a 57.4°C soil collected from a vent above the fire, we isolated 25 unique aerobic arsenic resistant bacteria spanning six genera. We examined their diversity, resistance gene content, transformation abilities, inhibitory concentrations, and growth phenotypes. Although As concentrations were low at the time of soil collection (2.58 ppm), isolates had high minimum inhibitory concentrations (MICs) of arsenate and arsenite (>300 mM and 20 mM respectively), and most isolates were capable of arsenate reduction. We screened isolates (PCR and sequencing) using 12 published primer sets for six As resistance genes (AsRG). Genes encoding arsenate reductase (arsC) and arsenite efflux pumps (arsB, ACR3(2)) were present, and phylogenetic incongruence between 16S rRNA genes and AsRG provided evidence for horizontal gene transfer. A detailed investigation of differences in isolate growth phenotypes across As concentrations (lag time to exponential growth, maximum growth rate, and maximum OD590) showed a relationship with taxonomy, providing information that could help to predict an isolate’s performance given arsenic exposure in situ. Our results suggest that considering taxonomically-linked tolerance and potential for resistance transferability from the rare biosphere will inform strategies for microbiological management and remediation of environmental As and contribute to a larger consideration of As-exposed microbial ecology.

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Isolasi Bakteri Resisten Arsen pada Sedimen Tanah di Muara Sungai Buyat

Jurnal e-Biomedik ◽

10.35790/ebm.6.2.2018.21994 ◽

2018 ◽

Vol 6 (2) ◽

Author(s):

Ivana C. Nainggolan ◽

. Fatimawali ◽

Widdhi Bodhi

Keyword(s):

River Sediment ◽

Mining Waste ◽

The Body ◽

Resistant Bacteria ◽

Bacterial Identification ◽

Bacterial Isolates ◽

Biochemical Tests ◽

Arsenic Stress ◽

Arsenic Resistant Bacteria ◽

Physiological And Biochemical

Abstract: Arsenic, a toxic element to the body, is commonly found in mining waste. Buyat is known as a mining location (especially gold mine) which dumps mining waste in the form of tailings into the sea through the Buyat River. A mine should process the degradation of waste from a very toxic form into a less toxic form before disposing the waste into the sea. However, this process is often overlooked by artisanal miner because it consumes considerable production cost. Waste containing toxic arsenic gradually accumulates into sediments in the ocean, so bacteria in the environment begin to develop a mechanism of resistance to arsenic. This study was aimed to determine the types of arsenic-resistant bacteria isolated from sediment at Buyat estuary using conventional bacterial identification methods, including morpho-logical, physiological, and biochemical tests. Nine bacterial isolates were treated with arsenic stress at 5 ppm, 10 ppm, 20 ppm, 40 ppm, 80 ppm, 100 ppm, 300 ppm, 500 ppm, and 1000 ppm. The results showed several bacteria that could grow even in conditions containing as much as 1000 ppm of arsenic, namely Klebsiella, Staphylococcus, Aeromonas, Clostridium, Bacillus, Hafnia, and Escherichia. Conclusion: In the sediment of Buyat estuary we found seven genera of bacteria, as follows: Klebsiella, Staphylococcus, Aeromonas, Clostridium, Bacillus, Hafnia and Escherichia.Keywords: Arsenic-resistant bacteria, Buyat River, sediment, As2O3Abstrak: Arsen ialah salah satu jenis unsur yang bersifat toksik bagi tubuh dan merupakan salah satu hasil limbah pertambangan. Buyat merupakan salah satu lokasi pertambangan (terutama tambang emas) yang membuang limbah pertambangannya berupa tailings ke laut. Limbah tersebut dialirkan melalui Sungai Buyat. Pertambangan yang resmi harus melakukan proses degradasi arsen dari yang sangat toksik menjadi kurang toksik terlebih dahulu sebelum membuang limbah ke laut, namun proses ini sering diabaikan oleh pertambangan rakyat karena memakan biaya produksi yang cukup besar. Limbah yang mengandung arsen toksik lama-kelamaan terakumulasi menjadi sedimen di laut, sehingga bakteri di lingkungan tersebut mulai mengembangkan mekanisme resistensi terhadap arsen. Penelitian ini bertujuan untuk mengetahui jenis bakteri resisten arsen yang diisolasi dari sedimen di muara Sungai Buyat menggunakan metode identifikasi bakteri konvensional. Terdapat 9 isolat bakteri yang diberi perlakuan stres arsen pada 5 ppm, 10 ppm, 20 ppm, 40 ppm, 80 ppm, 100 ppm, 300 ppm, 500 ppm, dan 1000 ppm. Hasil penelitian mendapatkan beberapa jenis bakteri yang dapat bertumbuh bahkan pada kondisi mengandung arsen sebanyak 1000 ppm, yaitu genus Klebsiella, Staphylococcus, Aeromonas, Clostridium, Bacillus, Hafnia, dan Escherichia. Simpulan: Pada sedimen tanah di muara Sungai Buyat diidentifikasi tujuh genus bakteri, yaitu Klebsiella, Staphylococcus, Aeromonas, Clostridium, Bacillus, Hafnia, dan Escherichia.Kata kunci: bakteri resisten arsen, Sungai Buyat, sedimen, As2O3

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Improving soybean growth under arsenic stress by inoculation with native arsenic-resistant bacteria

Plant Physiology and Biochemistry ◽

10.1016/j.plaphy.2020.07.015 ◽

2020 ◽

Vol 155 ◽

pp. 85-92

Author(s):

Ana Laura Wevar Oller ◽

Sofía Regis ◽

Ana Laura Armendariz ◽

Melina Andrea Talano ◽

Elizabeth Agostini

Keyword(s):

Resistant Bacteria ◽

Arsenic Stress ◽

Arsenic Resistant Bacteria

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Taxonomically-linked growth phenotypes during arsenic stress among arsenic resistant bacteria isolated from soils overlying the Centralia coal seam fire

10.7287/peerj.preprints.2451 ◽

2017 ◽

Author(s):

Taylor K Dunivin ◽

Justine Miller ◽

Ashley Shade

Keyword(s):

Coal Seam ◽

Arsenic Exposure ◽

Maximum Growth ◽

Maximum Growth Rate ◽

16S Rrna Genes ◽

Rrna Genes ◽

Resistant Bacteria ◽

Rare Biosphere ◽

Genes Encoding ◽

Arsenic Resistant Bacteria

Arsenic (As), a toxic element, has impacted life since early Earth. Thus, microorganisms have evolved many As resistance and tolerance mechanisms to improve their survival outcomes given As exposure. We isolated As resistant bacteria from Centralia, PA, the site of an underground coal seam fire that has been burning since 1962. From a 57.4°C soil collected from a vent above the fire, we isolated 25 unique aerobic arsenic resistant bacteria spanning six genera. We examined their diversity, resistance gene content, transformation abilities, inhibitory concentrations, and growth phenotypes. Although As concentrations were low at the time of soil collection (2.58 ppm), isolates had high minimum inhibitory concentrations (MICs) of arsenate and arsenite (>300 mM and 20 mM respectively), and most isolates were capable of arsenate reduction. We screened isolates (PCR and sequencing) using 12 published primer sets for six As resistance genes (AsRG). Genes encoding arsenate reductase (arsC) and arsenite efflux pumps (arsB, ACR3(2)) were present, and phylogenetic incongruence between 16S rRNA genes and AsRG provided evidence for horizontal gene transfer. A detailed investigation of differences in isolate growth phenotypes across As concentrations (lag time to exponential growth, maximum growth rate, and maximum OD590) showed a relationship with taxonomy, providing information that could help to predict an isolate’s performance given arsenic exposure in situ. Our results suggest that considering taxonomically-linked tolerance and potential for resistance transferability from the rare biosphere will inform strategies for microbiological management and remediation of environmental As and contribute to a larger consideration of As-exposed microbial ecology.

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Isolation and Molecular Characterization of Arsenic Resistant Bacteria from Brahmaputra River Basin of Assam, India

Bioscience Biotechnology Research Communications ◽

10.21786/bbrc/13.3/77 ◽

2020 ◽

Vol 13 (3) ◽

pp. 1502-1509

Author(s):

Bhaba Kumar Pegu

Keyword(s):

Molecular Characterization ◽

River Basin ◽

Resistant Bacteria ◽

Brahmaputra River ◽

Arsenic Resistant Bacteria

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A Gnotobiotic Model to Examine Plant and Microbiome Contributions to Survival under Arsenic Stress

Microorganisms ◽

10.3390/microorganisms9010045 ◽

2020 ◽

Vol 9 (1) ◽

pp. 45

Author(s):

María del Carmen Molina ◽

James F. White ◽

Sara García-Salgado ◽

M. Ángeles Quijano ◽

Natalia González-Benítez

Keyword(s):

Seedling Growth ◽

Endophytic Bacteria ◽

Root Hairs ◽

Resistant Bacteria ◽

Relative Importance ◽

Early Stages ◽

Bacterial Interaction ◽

Arsenic Stress ◽

Free Media

So far, the relative importance of the plant and its microbiome in the development of early stages of plant seedling growth under arsenic stress has not been studied. To test the role of endophytic bacteria in increasing plant success under arsenic stress, gnotobiotic seeds of J. montana were inoculated with two endophytic bacteria: Pantoea conspicua MC-K1 (PGPB and As resistant bacteria) and Arthrobacter sp. MC-D3A (non-helper and non-As resistant bacteria) and an endobacteria mixture. In holobiotic seedlings (with seed-vectored microbes intact), neither the capacity of germination nor development of roots and lateral hairs was affected at 125 μM As(V). However, in gnotobiotic seedlings, the plants are negatively impacted by absence of a microbiome and presence of arsenic, resulting in reduced growth of roots and root hairs. The inoculation of a single PGPB (P. conspicua-MCK1) shows a tendency to the recovery of the plant, both in arsenic enriched and arsenic-free media, while the inoculation with Arthrobacter sp. does not help in the recovery of the plants. Inoculation with a bacterial mixture allows recovery of plants in arsenic free media; however, plants did not recover under arsenic stress, probably because of a bacterial interaction in the mixture.

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