Effect of oxidative stress and exogenous beta-carotene on sclerotial differentiation and carotenoid yield of Penicillium sp. PT95

Abstract

Aims:To determine the effect of oxidative stress and exogenous b-carotene on sclerotial differentiation and carotenoid yield of Penicillium sp. PT95. Methods and Results: In this experiment, high oxidative stress was applied by inclusion of FeCl 3 (10 lmol l )1 ) in the growth medium and by light exposure. Low oxidative stress was applied by omitting iron from the growth medium and by incubation in the dark. Supplementation of exogenous b-carotene (as antioxidant) to the basal medium caused a concentration-dependent delay of sclerotial differentiation (up to 72 h), decrease of sclerotial biomass (up to 43%) and reduction of carotenoid yield (up to 92%). On the contrary, the exogenous b-carotene also caused a concentration-dependent decrease of lipid peroxidation in colonies of this fungus.Conclusions: Under high oxidative stress growth condition, the sclerotial biomass and carotenoid yield of PT95 strain in each plate culture reached 141 mg and 30AE03 lg, which were 1AE53 and 3AE51 times higher respectively, than that at low oxidative stress growth condition. Significance and Impact of the Study: These data prompted us to consider that in order to attain higher sclerotial biomass and pigment yield, the strain PT95 should be grown under high oxidative stress and in the absence of antioxidants.

Oxidative Stress Response and Morphological Changes of Blakeslea trispora Induced by Butylated Hydroxytoluene During Carotene Production

“…Gessler et al [5] studied the changes in the activities of SOD and CAT induced by light, menadione and SOD inhibitors in the fungi Blakeslea trispora and Neurospora crassa. Han et al [10] examined the effect of oxidative stress in Penicillium sp. PT95 induced by FeCl 3 .…”

Effect of copper−induced oxidative stress on sclerotial differentiation, endogenous antioxidant contents, and antioxidative enzyme activities of Penicillium thomii PT95

“…Our previous experiments (Han et al 2005;Li et al 2006) showed that the sclerotial biomass produced by strain PT95 grown under a high oxidative stress condition was 1.23-fold greater than that produced when grown under a low oxidative stress condition. The data of this study provide additional evidence in support of Georgiou's theory and are also in accordance with the general theory of microbial differentiation, which also postulates that the latter is induced by oxidative stress (Burton and Ingold 1984).…”

“…Carotenoids are antioxidants and reduce oxidative stress by acting as scavengers of ROS (mainly singlet oxygen) (Stratton and Liebler 1997). β-Carotene and other carotenoids have been associated with fungal photomorphogenesis and development (Mohr and Schopfer 1995;Georgiou and Petropoulou 2001a, b, c;Georgiou et al 2001a, b;Zervoudakis et al 2003;Han et al 2005). In most organisms, ascorbic acid has important functions in biochemical reactions, such as in cell growth and differentiation.…”

“…In earlier studies, we examined the effect of iron-induced oxidative stress on sclerotial differentiation in strain PT95 (Han et al 2005;Li et al 2006). The aim of the study reported here was to investigate the effects of Cu-induced oxidative stress on sclerotial differentiation, sclerotia biomass, the level of lipid peroxidation [based on malondialdehyde (MDA level)], activities of enzymatic antioxidants (SOD, CAT, APX, GR), and the contents of endogenous antioxidants (such as carotenoids, glutathione, ascorbate).…”

Carotenoids

“…[ 15 ], Sclerotium rolfsii [ 16 ], Sclerotinia sclerotiorum [ 17 ], Sporidiobolus pararoseus [ 18 ], Ustilago maydis [ 19 ], and other Ustilago species [ 20 , 21 ], ascomycetes as Aspergillus giganteus [ 22 ], Cercospora nicotianae [ 23 ], and Penicillium sp. [ 24 ], or the "imperfect fungus" Aschersonia aleyroides [ 25 ]. β-carotene production is also found in mutants of fungal species usually producing xanthophylls, such as Xanthophyllomyces dendrorhous [ 26 ], formerly Phaffi a rhodozyma , or Rhodotorula glutinis [ 27 ].…”