Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture
In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterili...
| Main Authors: | , |
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| Format: | Journal Article |
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Springer Link
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/56070 |
| _version_ | 1848759779530375168 |
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| author | Cheng, Liang Cord-Ruwisch, R. |
| author_facet | Cheng, Liang Cord-Ruwisch, R. |
| author_sort | Cheng, Liang |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterility to avoid contaminant microbes overgrowing the production strain. The current paper describes the sustainable, non-sterile production of an industrial enzyme using activated sludge as inoculum. By using selective conditions (high pH, high ammonia concentration, and presence of urea) for the target bacterium, highly active ureolytic bacteria, physiologically resembling Sporosarcina pasteurii were reproducibly enriched and then continuously produced via chemostat operation of the bioreactor. When using a pH of 10 and about 0.2 M urea in a yeast extract-based medium, ureolytic bacteria developed under aerobic chemostat operation at hydraulic retention times of about 10 h with urease levels of about 60 µmol min -1 ml -1 culture. For cost minimization at an industrial scale the costly protein-rich yeast extract medium could be replaced by commercial milk powder or by lysed activated sludge. Glutamate, molasses, or glucose-based media did not result in the enrichment of ureolytic bacteria by the chemostat. The concentration of intracellular urease was sufficiently high such that the produced raw effluent from the reactor could be used directly for biocementation in the field. © 2013 Society for Industrial Microbiology and Biotechnology. |
| first_indexed | 2025-11-14T10:05:18Z |
| format | Journal Article |
| id | curtin-20.500.11937-56070 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:05:18Z |
| publishDate | 2013 |
| publisher | Springer Link |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-560702017-09-13T16:11:12Z Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture Cheng, Liang Cord-Ruwisch, R. In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterility to avoid contaminant microbes overgrowing the production strain. The current paper describes the sustainable, non-sterile production of an industrial enzyme using activated sludge as inoculum. By using selective conditions (high pH, high ammonia concentration, and presence of urea) for the target bacterium, highly active ureolytic bacteria, physiologically resembling Sporosarcina pasteurii were reproducibly enriched and then continuously produced via chemostat operation of the bioreactor. When using a pH of 10 and about 0.2 M urea in a yeast extract-based medium, ureolytic bacteria developed under aerobic chemostat operation at hydraulic retention times of about 10 h with urease levels of about 60 µmol min -1 ml -1 culture. For cost minimization at an industrial scale the costly protein-rich yeast extract medium could be replaced by commercial milk powder or by lysed activated sludge. Glutamate, molasses, or glucose-based media did not result in the enrichment of ureolytic bacteria by the chemostat. The concentration of intracellular urease was sufficiently high such that the produced raw effluent from the reactor could be used directly for biocementation in the field. © 2013 Society for Industrial Microbiology and Biotechnology. 2013 Journal Article http://hdl.handle.net/20.500.11937/56070 10.1007/s10295-013-1310-6 Springer Link restricted |
| spellingShingle | Cheng, Liang Cord-Ruwisch, R. Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title | Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title_full | Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title_fullStr | Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title_full_unstemmed | Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title_short | Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| title_sort | selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture |
| url | http://hdl.handle.net/20.500.11937/56070 |