Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria
A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora, and the...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-01-01
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| Series: | Microorganisms |
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| Online Access: | http://www.mdpi.com/2076-2607/6/1/8 |
| _version_ | 1828230010210615296 |
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| author | George E. Mustoe |
| author_facet | George E. Mustoe |
| author_sort | George E. Mustoe |
| collection | DOAJ |
| description | A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora, and the desmid Cosmarium. Biologic activity is evidenced by measured levels of chlorophyll and lipids. Bioassay methods confirm the ability of these microbes to dissolve and metabolize Fe from ferruginous minerals. Chromatographic analysis reveals citric acid as the likely chelating agent; this low molecular weight organic acid is detectable in interstitial fluid in the sandstone, measured as 0.0756 mg/mL. Bioassays using a model organism, Synechoccus elongates strain UTEX 650, show that Fe availability varies among different ferruginous minerals. In decreasing order of Fe availability: magnetite > limonite > biotite > siderite > hematite. Biotite was selected for detailed study because it is the most abundant iron-bearing mineral in the sandstone. SEM images support the microbiologic evidence, showing weathering of biotite compared to relatively undamaged grains of other silicate minerals. |
| first_indexed | 2024-04-12T18:42:43Z |
| format | Article |
| id | doaj.art-ce951e4d989f45e29ec9000183118486 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-04-12T18:42:43Z |
| publishDate | 2018-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj.art-ce951e4d989f45e29ec90001831184862022-12-22T03:20:44ZengMDPI AGMicroorganisms2076-26072018-01-0161810.3390/microorganisms6010008microorganisms6010008Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and CyanobacteriaGeorge E. Mustoe0Geology Department, Western Washington University, Bellingham, WA 98225, USAA sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora, and the desmid Cosmarium. Biologic activity is evidenced by measured levels of chlorophyll and lipids. Bioassay methods confirm the ability of these microbes to dissolve and metabolize Fe from ferruginous minerals. Chromatographic analysis reveals citric acid as the likely chelating agent; this low molecular weight organic acid is detectable in interstitial fluid in the sandstone, measured as 0.0756 mg/mL. Bioassays using a model organism, Synechoccus elongates strain UTEX 650, show that Fe availability varies among different ferruginous minerals. In decreasing order of Fe availability: magnetite > limonite > biotite > siderite > hematite. Biotite was selected for detailed study because it is the most abundant iron-bearing mineral in the sandstone. SEM images support the microbiologic evidence, showing weathering of biotite compared to relatively undamaged grains of other silicate minerals.http://www.mdpi.com/2076-2607/6/1/8algaebioassaybiogenic weatheringbiotitechelationcyanophyteepilithiciron minerals |
| spellingShingle | George E. Mustoe Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria Microorganisms algae bioassay biogenic weathering biotite chelation cyanophyte epilithic iron minerals |
| title | Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria |
| title_full | Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria |
| title_fullStr | Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria |
| title_full_unstemmed | Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria |
| title_short | Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria |
| title_sort | biogenic weathering solubilization of iron from minerals by epilithic freshwater algae and cyanobacteria |
| topic | algae bioassay biogenic weathering biotite chelation cyanophyte epilithic iron minerals |
| url | http://www.mdpi.com/2076-2607/6/1/8 |
| work_keys_str_mv | AT georgeemustoe biogenicweatheringsolubilizationofironfrommineralsbyepilithicfreshwateralgaeandcyanobacteria |