ISSN:
1573-0972
Keywords:
Amino-acid assimilation
;
amino-acid over-production
;
cyanobacteria
;
enzyme de-regulation
;
microbial cell protein
;
Phormidium uncinatum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Mutant strains of Phormidium uncinatum resistant to fluoro-phenylalanine, aztryptophan, fluorotyrosine and azaleucine accumulated a wide range of amino acids, notably glutamic acid, lysine, tyrosine and phenylalanine, and exhibited de-regulated valine and phenylalanine transport. While acetohydroxy acid synthase in azaleucine-resistant mutants lost valine- and leucine-sensitivity, 3-deoxy-Dxxx-arabinoheplulosonate-7-phosphate (DAHP) synthase and prephenate dehydratase in aromatic analogue-resistant strains became phenylalanine-insensitive and shikimate and prephenate dehydrogenases were activated by tyrosine. In addition, activities of nitrate-assimilating enzymes were higher in the mutants, which also exhibited increased nitrogen, protein and phycocyanin contents. The proteins in the mutants were better digested upon enzymatic-treatments and feeding trials than those of the wild type, indicating that they are usable as single-cell protein.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00361013
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