Evaluation of the effects of various culture condition on Cr (VI)reduction by Shewanella oneidensis MR-1 in a novel high-throughputmini-bioreactor

Journal Article · Thu Mar 16 04:00:00 EST 2006 · Biotechnology and Bioengineering

DOI:https://doi.org/10.1002/bit.21002· OSTI ID:919764

Tang, Yinjie J.; Laidlaw, David; Gani, Kishen; Keasling, Jay D.

The growth and Cr(VI) reduction by Shewanella oneidensisMR-1 was examined using a mini-bioreactor system that independentlymonitors and controls pH, dissolved oxygen, and temperature for each ofits 24, 10-mL reactors. Independent monitoring and control of eachreactor in the cassette allows the exploration of a matrix ofenvironmental conditions known to influence S. oneidensis chromiumreduction. S. oneidensis MR-1 grew in minimal medium without amino acidor vitamin supplementation under aerobic conditions but required serineand glycine supplementation under anaerobic conditions. Growth wasinhibited by dissolved oxygen concentrations>80 percent. Lactatetransformation to acetate was enhanced by low concentration of dissolvedoxygen during the logarithmic growth phase. Between 11 and 35oC, thegrowth rate obeyed the Arrhenius reaction rate-temperature relationship,with a maximum growth rate occurring at 35oC. S. oneidensis MR-1 was ableto grow over a wide range of pH (6-9). At neutral pH and temperaturesranging from 30-35oC, S. oneidensis MR-1 reduced 100 mu M Cr(VI) toCr(III) within 20 minutes in the exponential growth phase, and the growthrate was not affected by the addition of chromate; it reduced chromateeven faster at temperatures between 35 and 39oC. At low temperatures(<25oC), acidic (pH<6.5), or alkaline (pH>8.5) conditions, 100mu M Cr(VI) strongly inhibited growth and chromate reduction. Themini-bioreactor system enabled the rapid determination of theseparameters reproducibly and easily by performing very few experiments.Besides its use for examining parameters of interest to environmentalremediation, the device will also allow one to quickly assess parametersfor optimal production of recombinant proteins or secondarymetabolites

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Biological andEnvironmental Research
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 919764
• Report Number(s): LBNL--59868; BnR: KP1102010
• Journal Information: Biotechnology and Bioengineering, Journal Name: Biotechnology and Bioengineering Journal Issue: 1 Vol. 95; ISSN 0006-3592; ISSN BIBIAU
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROBIC CONDITIONS
AMINO ACIDS
ANAEROBIC CONDITIONS
BIOREACTORS
DISSOLVED GASES
EVALUATION
OXYGEN
pH temperature dissolved oxygen chromium reduction highthroughput cultivation