ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    ISSN: 1476-5535
    Keywords: Nocardia lactamdurans ; Secondary metabolism ; Protease ; Lipase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary An efrotomycin fermentation was characterized through physical, chemical and biochemical studies. Growth of the actinomycete,Nocardia lactamdurans occurred during the first 50 h of the fermentation cycle at the expense of glucose, protein, and triglycerides. The initiation of efrotomycin biosynthesis was observed when glucose dropped to a low concentration. Upon glucose depletion, cell growth ceased and a switch in the respiratory quotient occurred. Efrotomycin biosynthesis was supported by the utilization of soybean oil and starch. Analysis of triglyceride metabolism showed that no diglycerides or monoglycerides accumulated during the fermentation. The activity of extracellular enzymes (lipase, protease, and amylase) increase during the cell growth phase and decreased significantly after 150 h. The concentrations of DNA, tetrahydro-vitamin K2 (a membrane component), and free amino acids in the supernatant increased dramatically late in the fermentation cycle (225 h), indicating massive cell lysis. During this same time period, a reduction in cellular respiratory activity and efrotomycin biosynthesis were observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1476-5535
    Keywords: Lipase ; Bioconversion ; Biocatalysis ; Leukotriene receptor antagonist ; Verlukast ; Screening ; Pseudomonas aeruginosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A search was implemented for a microbial lipase capable of bioconverting a diester (dimethyl 5-(3-(2-(7-chloroquinolin-2-yl)ethyl)phenyl)4,6-dithianon to its S-ester acid, an intermediate in the production of Verlukast (a leukotriene receptor antagonist). Required properties of the sought-after enzyme included a high enantiomeric selectivity (e.e. 〉98%), the formation of only trace amounts of diacid and a high bioconversion rate. This search yielded 57 lipase-producing microorganisms, 18 of which presented detectable bioconversion activity. Thirteen of these microbes were selected for further study based upon their lipase production level and enzyme stability at harvest. Despite their common enzymatic property, namely the hydrolysis of triglycerides, these lipase preparations presented diverse ester acid specific synthesis rates (from 〈0.01 μg/unit/h to 0.98 μg/unit/h) and diacid formation levels (from 0% to 35%). One of these microbes, identified asPseudomonas aeruginosa (strain MB 5001), was found to produce a lipase having all of the above-listed required properties. The initial fermentation process developed in shake flasks was rapidly and successfully scaled up in 23-liter labora bioreactors, achieving a maximum production of 35 units/ml of lipase after 48 h of cultivation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...