Inhibited growth of Clostridium butyricum in efficient H2-producing co-culture with Rhodobacter sphaeroides
| Autor: | Kestutis S. Laurinavichius, Anatoly A. Tsygankov, Evgeny Shastik, Tatyana V. Laurinavichene |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
biology Starch Rhodospirillum rubrum 02 engineering and technology General Medicine 021001 nanoscience & nanotechnology biology.organism_classification Applied Microbiology and Biotechnology Purple bacteria Clostridia 03 medical and health sciences Rhodobacter sphaeroides chemistry.chemical_compound 030104 developmental biology chemistry Biochemistry Yeast extract 0210 nano-technology Bacteria Clostridium butyricum Biotechnology |
| Zdroj: | Applied Microbiology and Biotechnology. 100:10649-10658 |
| ISSN: | 1432-0614 0175-7598 |
| Popis: | Cell number of Clostridium butyricum and Rhodobacter sphaeroides in co-culture was measured using q-PCR approach. During efficient H2 photoproduction from starch (6.2 mol H2/mol glucose), Clostridia growth and starch-hydrolyzing activity was partly suppressed. Apparently, the effect of R. sphaeroides towards C. butyricum was not attributed to altered Eh or pH values in the presence of purple bacteria. Further, disk-diffusion test proved that R. sphaeroides was capable of producing inhibitors against another purple bacterium, Rhodospirillum rubrum, but not against C. butyricum. We suggested that at initial cell number ratio C. butyricum:R. sphaeroides 1:1 purple bacteria outcompeted C. butyricum for yeast extract at its low concentration (80 mg/L). Under these conditions, the H2 yield was rather high (5.7 mol/mol). When the yeast extract concentration increased to 320 mg/L, this process was replaced by the low-yield H2 production (1.8 mol/mol) characteristic of Clostridia. However, increased percentage of purple bacteria in inoculum under these conditions prevented this shift. The outcome of competition depended on both the yeast extract concentration and cell number ratio. Apparently, the competition for yeast extract helped to maintain balance between fast-growing C. butyricum and slower-growing R. sphaeroides for efficient H2 photoproduction. |
| Databáze: | OpenAIRE |
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