Abstract
Calli of Tagetes patula, subcultured one or two times, were used to start liquid cultures. Calli of both
subcultures contained thiophene-biocides, mainly 5-(but-3-en-1-ynyl)-2,2′-bithiophene
(BBT) and 5-(4-acetoxy-1-butynyl)-2,2′-bithiophene (BBTOAc). Secondary calli contained
about 3 times higher concentrations of thiophenes than tertiary calli. The liquid
batch cultures consisted of coarse cell aggregates (3-8 mm), the volume of which was
doubled each 15 days. In contrast to callus cultures grown on solid medium, cell aggregates
grown in liquid medium released thiophenes. The release into the medium was at least
2.3 mg.dm-3 in 90 days by an average amount of 100 g of fresh cell aggregates and occurred mainly
as 5-(4-hydroxy-1-butynyl)-2,2′-bithiophene (BBTOH). In callus BBTOH did hardly occur.
The amount of thiophenes recovered in the medium corresponded to 0.02% of the cell
dry weight. The productivity of the liquid cultures was not related to the productivity
of the original calli, neither was the thiophene production related to the growth
rate of the biomass in the liquid cultures. The results indicate that not the selection
of calli for thiophene content, but rather the selection of calli with the ability
to form cell aggregates is of relevance for the production of thiophenes in liquid
cultures.
