Because most flavour compounds (and, often, their precursors) tend to be inhibitory or even toxic to microorganisms, this challenges is even greater than it first appears. For example , typical fatty acid flavor precursors , especially in the undissociated forms that are prevalent below pH 4.5-5, are significantly cytotoxic , and cellular uptake is limited. Different organism- specific mechanisms account for this limitation. Different organism specific mechanisms account for this limitation. In bacteria, for exsample, specific uptake proteins restrict transmembrans transport of fatty acid precursory.
However,in yeast cells fatty acids addcd to the growth medium diffuse freely across cell menbranes,Theefficncy of this uptake system allows yeast species such as Yarrowai,Rhodotorual,and sporodiobolus to sue a wide variety of fatty acids or derivatives as the sole source of nutricnt carbon .infilamentores fungi,the uptake mechanissms are not yet well understood.
Seriousprecsrsor toxicity aiso sccurs for many microorganisms when supplied with fatty acid esters that are hydrophobic at nonacidic pH values.This problem was described as the factor limiting production of y-decalactong from the corresponding fatty acid ethyl and methyl esters in a patent granted to the German company BASF.
Because most flavour compounds (and, often, their precursors) tend to be inhibitory or even toxic to microorganisms, this challenges is even greater than it first appears. For example , typical fatty acid flavor precursors , especially in the undissociated forms that are prevalent below pH 4.5-5, are significantly cytotoxic , and cellular uptake is limited. Different organism- specific mechanisms account for this limitation. Different organism specific mechanisms account for this limitation. In bacteria, for exsample, specific uptake proteins restrict transmembrans transport of fatty acid precursory.
However,in yeast cells fatty acids addcd to the growth medium diffuse freely across cell menbranes,Theefficncy of this uptake system allows yeast species such as Yarrowai,Rhodotorual,and sporodiobolus to sue a wide variety of fatty acids or derivatives as the sole source of nutricnt carbon .infilamentores fungi,the uptake mechanissms are not yet well understood.
Seriousprecsrsor toxicity aiso sccurs for many microorganisms when supplied with fatty acid esters that are hydrophobic at nonacidic pH values.This problem was described as the factor limiting production of y-decalactong from the corresponding fatty acid ethyl and methyl esters in a patent granted to the German company BASF.
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