Whole-cell fungal transformation of precursors into dyes

Table 4 The ability of the tested strains to modify the pH of the transformation medium during cultivation

Strain	2A3HP	2,5DABS	ANS	AHBS	DHN	Control I (without precursor)
	*initial pH*
	8.6	6.9	6.7	5.2	8.6	6.7
	*after 24 hours*
*TV7*	5.3	5.0	4.8	4.9	6	4.8
*FF25*	5.8	6.3	5.5	5.1	nd	5.0
*AB123*	5.0	5.2	5.2	4.9	5.6	5.0
*CU139*	6.5	6.7	6.2	8.0	7.0	6.7
Control II (without strain)	7.9	6.8	6.5	5.2	7.9	6.7
	*after 7 days*
*TV7*	6.5	4.6	4.6	4.8	6.0	4.8
*FF25*	6.0	6.4	6.2	5.4	nd	5.4
*AB123*	5.7	5.6	5.9	5.6	5.6	4.9
*CU139*	8.3	8.3	8.3	8.1	7.0	8.3
Control II (without strain)	7.5	7.0	6.8	5.2	7.9	6.7

The pH values of transformation mixtures containing 1 mM precursors (2A3HP, 2,5DABS, ANS, AHBS, and DHN) were tested during 7 days of incubation with or without the presence of immobilized fungal biomass. Changes in the initial pH of the transformation mixtures (directly after precursor addition) were monitored after 24 hours and after 7 days of incubation in the presence of the four tested strains (TV7, FF25, AB123, and CU139). In addition the pH of culture liquids without a precursor (control I as biotic control) and without fungal biomass (control II as abiotic control) was monitored.

ISSN: 1475-2859