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Indian Journal of Biotechnology (IJBT) >
IJBT Vol.02 [2003] >
IJBT Vol.02(3) [July 2003] >
| Title: | Autolysis of Penicillium chrysogenum-A Holistic Approach |
| Authors: | Pocsi, Istvan
Pusztahelyi, Tunde
Sami, Laszlo
Emri, Tamas |
| Keywords: | Autolysis
Apoptosis
Ageing
Fragmentation
Vacuolation
Chitinase
Respiration |
| Issue Date: | Jul-2003 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Despite
of its biotechnological significance, the autolysis of filamentous fungi is a
poorly studied and understood
area
of fungal physiology. The autolysis of 13-lactam producing fungus, Penicillium
chrysogenum shares some similarities
with
the apoptosis of higher eukaryotes. For example, the biosynthesis and
processing of age-related hydrolases
were
highly regulated in carbon-depleted cultures. The in vivo inhibition of
autolytic chitinase activity hindered
considerably
the disintegration of pelleted structures that are typical of the exponential
growth phase. In the absence
of
conidiation, round-ended "yeast-like" hyphal fragments were the
dominant surviving morphological forms, which
were
characterised with decreasing total respiration, increasing cyanide-resistant
respiration, intracellular accumulation
of
reactive oxygen species (ROS) and declining viability in the autolytic and
post-autolytic phases of growth.
The
term "ageing" was used to describe these physiological changes, and
the surviving fragments may undergo oxidative-
stress
induced programmed cell death. Although variations in oxygen tension and
extracellular ROS concentrations
are
key elements in the initiation of morphological changes, the genomic expression
programmes of fungi
governing
morphological transitions including autolysis are likely to be activated by
different kinds of environmental
stress
and signal transduction pathways. The glutathione (GSH) and ROS metabolisms of P.
chrysogenum were influenced
by
many extrinsic and intrinsic factors in each growth phase studied. As a
consequence, no firm correlation
was
found between the GSHIglutathione disulphide (GSSG) redox status, the
intracellular ROS levels and the observed
morphological and physiological characteristics of the
cells. |
| Page(s): | 293-301 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0967 (Online); 0972-5849 (Print) |
| Source: | IJBT Vol.02(3) [July 2003]
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