ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Enhanced production of α-amylase in fed-batch cultures of Bacillus subtilis TN106[pAT5] (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 1142-1150 
    Details
    ISSN: 0006-3592
    Keywords: Bacillus subtilis ; recombinant species ; recombinant protein ; fed-batch culture ; arginine limitation ; α-amylase ; hydrolysis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Growth of Bacillus subtilis TN106[pAT5] and synthesis of plasmid-encoded protein (α-amylase) are investigated in batch, continuous, and fed-batch cultures using a defined medium containing glucose and/or starch as the carbohydrate source. The batch culture studies reveal that reduced availability of arginine hampers growth of recombinant cells (which lack an arginine synthesis gene) but promotes production of α-amylase and substitution of glucose by starch as the carbohydrate source leads to slower growth of recombinant cells and increased production of α-amylase per unit cell mass. Retention of recombinant cells over prolonged periods in continuous cultures is not possible without continuous application of antibiotic selection pressure owing to segregational plasmid instability. Fed-batch experiments with constant volumetric feed rate demonstrate that α-amylase production is enhanced at lower feed concentration of starch (sole carbohydrate source) and lower volumetric feed rate. Such slow addition of starch is however not conducive for growth of recombinant cells. The expression of the thermostable α-amylase gene carried on the recombinant plasmid pAT5 (derived from a plasmid isolated from a thermophilic bacterium) is promoted at higher temperatures, while growth of recombinant cells is depressed. In all batch and fed-batch experiments, production of α-amylase is observed to be inversely related to growth of recombinant cells. The efficacy of two-stage bioreactor operations, with growth of recombinant cells being promoted in the first stage and α-amylase production in the second stage, in attaining increased bulk α-amylase activity is demonstrated. © 1993 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260421003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    An alternate method for estimation of cell growth kinetics from batch cultures (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 26-34 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An alternative to estimation of cell growth kinetics via continuous culture experiments is proposed in this article. The method employed is based on batch culture experiments with very small inocula (initial cell concentrations being typically less than 5000 cells/mL). Such low initial cell concentrations result in extended exponential cell growth phase during which culture conditions remain unchanged, thereby permitting precise estimation of specific cell growth rates from batch experiments especially for fast-growing microorganisms such as Bacillus species. The effectiveness and utility of this approach are demonstrated via several experiments conducted with a wild-type strain (Bacillus subtilis TN106) and a recombinant strain (B. subtilis TN106[pAT5]). True establishment of exponential growth phase requires insignificant variance of most of the culture conditions during the initial growth phase. Satisfaction of this requirement is demonstrated for microbial systems investigated here. This approach is especially well suited for recombinant microorganisms containing segregationally unstable plasmids, since estimation of growth kinetics of these from continuous cultures is very difficult and highly unreliable due to continual reversion of recombinant ceils to plasmid-free host cells unless some selection pressure is applied at levels sufficient to keep the presence of plasmid-free cells minimal.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260370106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...