strain 59 [80] by addition of clomiphene which decreases the contents of sterol
in yeast and algae and increases the percentage of shorter saturated and
monoene fatty acids. Clomiphene increased both oxidation and cyclization.
Nystatin, which damages the membrane structure by binding to ergosterol,
increases the membrane rigidity, and causes its permeabilization, was found to
increase oxidation and decrease cyclization. The cultivation temperature was
also strongly correlated to the oxidation and cyclization. The ancestral strain of
strains 59, 129, and 35, producing mainly tetracyclic clavines, changed only the
quantity, not the quality, of the clavines produced after addition of clomiphene
[81]. The effect of triadimefon, a triazole inhibitor of ergosterol biosynthesis,
was tested with Claviceps purpurea strain 59. The culture growth decreased and
specific clavine production increased [82].
The effect of soybean peptones as stimulants of clavine alkaloid production
has also been studied [83]. Soybean peptones type III (Sigma) were found to be
excellent nutrients in the production media of the fungus C. fusiformis and gave
higher alkaloid yields than meat peptones. Chromatography on Sephadex G-25
was used to resolve soybean peptone type III (Sigma) into seven fractions
which exhibited different effects on the biosynthesis of clavine ergot alkaloids.
One fraction proved to be the best nutrient for the fungus [84]. The effect of
peptones from Difco Bacto and Torlak P-2 was also reported [85]. They found
that low molecular weight fractions from Torlak P-2 had the strongest promoting effect on clavine production.
It was reported [86] that addition of some surfactants of polyglycol structure
and Tweens to the submerged cultures of a highly productive strain of C. paspali
caused a change in the intensity of alkaloid synthesis. Pluronik (polyethoxypolypropoxypolymer) added in the range of 0.25–0.75% enhanced the alkaloid
production. Not only was the amount of alkaloid formed in the Pluronik supplemented media double the amount formed in the control without this antifoam, but the maximal yield was also reached earlier by 1–2 days as compared
to the control. The effect of vitamins on the fermentative production ergot
alkaloids was studied [87]. Biotin, folic acid, and riboflavin enhanced the
production while pyridoxine inhibited the production.
The ergot alkaloid elaboration by the fungus is highly dependent on the level
of dissolved oxygen in the medium. It has been shown that the final conidial
concentration in batch fermentation depends on the end of the vegetative phase
which occurs when glucose is exhausted. The vegetative cells are then converted
into conidia. This process can be regulated by oxygen input [88]. In another
study [89] it has been shown that, for optimal fungal development and alkaloid
production, a balance between the uptake of oxygen from the liquid and
gaseous phase has to be established by a defined ratio between aeration and
agitation. Recently there has been efforts made to increase the transfer of
oxygen to the cells by the use of hydrocarbons in the fermentation media [90].
In our laboratory we are trying to improve the oxygen transfer by the use of
other oxygen vectors such as hydrogen peroxide and perfluorocarbons.
Use of solid state fermentation for the production of ergot alkaloids is an
attractive proposition. It was reported that the production of total ergot
alkaloids by Claviceps fusiformis in solid state fermentation was 3.9 times
14
J. Mukherjee · M. Menge
in yeast and algae and increases the percentage of shorter saturated and
monoene fatty acids. Clomiphene increased both oxidation and cyclization.
Nystatin, which damages the membrane structure by binding to ergosterol,
increases the membrane rigidity, and causes its permeabilization, was found to
increase oxidation and decrease cyclization. The cultivation temperature was
also strongly correlated to the oxidation and cyclization. The ancestral strain of
strains 59, 129, and 35, producing mainly tetracyclic clavines, changed only the
quantity, not the quality, of the clavines produced after addition of clomiphene
[81]. The effect of triadimefon, a triazole inhibitor of ergosterol biosynthesis,
was tested with Claviceps purpurea strain 59. The culture growth decreased and
specific clavine production increased [82].
The effect of soybean peptones as stimulants of clavine alkaloid production
has also been studied [83]. Soybean peptones type III (Sigma) were found to be
excellent nutrients in the production media of the fungus C. fusiformis and gave
higher alkaloid yields than meat peptones. Chromatography on Sephadex G-25
was used to resolve soybean peptone type III (Sigma) into seven fractions
which exhibited different effects on the biosynthesis of clavine ergot alkaloids.
One fraction proved to be the best nutrient for the fungus [84]. The effect of
peptones from Difco Bacto and Torlak P-2 was also reported [85]. They found
that low molecular weight fractions from Torlak P-2 had the strongest promoting effect on clavine production.
It was reported [86] that addition of some surfactants of polyglycol structure
and Tweens to the submerged cultures of a highly productive strain of C. paspali
caused a change in the intensity of alkaloid synthesis. Pluronik (polyethoxypolypropoxypolymer) added in the range of 0.25–0.75% enhanced the alkaloid
production. Not only was the amount of alkaloid formed in the Pluronik supplemented media double the amount formed in the control without this antifoam, but the maximal yield was also reached earlier by 1–2 days as compared
to the control. The effect of vitamins on the fermentative production ergot
alkaloids was studied [87]. Biotin, folic acid, and riboflavin enhanced the
production while pyridoxine inhibited the production.
The ergot alkaloid elaboration by the fungus is highly dependent on the level
of dissolved oxygen in the medium. It has been shown that the final conidial
concentration in batch fermentation depends on the end of the vegetative phase
which occurs when glucose is exhausted. The vegetative cells are then converted
into conidia. This process can be regulated by oxygen input [88]. In another
study [89] it has been shown that, for optimal fungal development and alkaloid
production, a balance between the uptake of oxygen from the liquid and
gaseous phase has to be established by a defined ratio between aeration and
agitation. Recently there has been efforts made to increase the transfer of
oxygen to the cells by the use of hydrocarbons in the fermentation media [90].
In our laboratory we are trying to improve the oxygen transfer by the use of
other oxygen vectors such as hydrogen peroxide and perfluorocarbons.
Use of solid state fermentation for the production of ergot alkaloids is an
attractive proposition. It was reported that the production of total ergot
alkaloids by Claviceps fusiformis in solid state fermentation was 3.9 times
14
J. Mukherjee · M. Menge