The removal of color residues is a major
challenge in paper and textile industries. Effluents from such plants can possess alkaline pH
and high salt content. Marine fungi may be
ideally suited for the bioremediation of such
effluents (Verma et al. 2010): White-rot fungi
containing laccase and other enzymes capable
of decolorization were isolated from mangroves. Laccase production was shown in several marine fungi in the presence of sea water
(D’Souza-Ticlo et al. 2009). However, salttolerant lignin-degrading enzymes have not
been sufficiently explored for their biotechnological applications.
Marine fungi have also been discussed as
source for enzymes or for whole cell application
in the degradation of polycyclic aromatic
hydrocarbons (PAHs). PAHs are widely
distributed in the environment and may persist
for extended periods of time with toxic, mutagenic, and carcinogenic effects (for review see
Bonugli-Santos et al. 2015). The ligninolytic
and the monooxygenase system of cytochrome
P-450 may be involved in PAH degradation by
filamentous fungi (Haritash and Kaushik 2009).
The use of marine-derived fungi for the bioremediation of polluted saline environments will
be facilitated by their tolerance to saline conditions.
Additionally, deep-sea fungi growing under
extreme conditions are a good source for industrially useful enzymes with novel properties
(Synnes 2007). Proteases constitute one group
of the several extracellular enzymes being produced by these fungi; elevated pressure resistance, high pH stability and activity in the
presence of several commercial detergents and
high salt content were shown for fungal proteases from deep-sea sediments. These features
are desirable for commercial application, e.g.,
as detergents additive for cold wash (Raghukumar 2008).
C. Compatible Solutes
All organisms in marine environments have to
adapt to the high salinity of seawater causing
significant osmotic pressure. Seawater organisms therefore need to maintain water potentials lower than that of their environment in
their cells to enable water uptake. Cells developed a number of strategies to deal with salts:
effective efflux machineries, antiporter proteins, and the production of compatible solutes
(Forsyth et al. 1971; Ahmadi et al. 2016). The
latter strategy is frequently observed in marine
fungi. They accumulate osmolytes such as glycerol, mannitol, polyol, and trehalose (Blomberg and Adler 1992). These compounds are
of technological interest due to their stabilizing
effects, stress-protective and therapeutic activities in cosmeceuticals and pharmaceuticals but
also as cryoprotectants (Jadhav et al. 2018).
D. “Detox” Activities
Deep-sea hot vent systems are often characterized by high heavy metal concentration. Fungi
thriving in these habitats need to cope with
these conditions by producing detoxification
compounds, often extracellular sugars such as
chitosan-like molecules. These can be applied
in cosmetic industry (Brown et al. 2016). Also,
enzymes from these fungi show high resistance
against heavy-metal intoxication. For instance,
deep sea Cryptococcus strain was tolerant to
CuSO 4 up to a concentration of 50 mM and
showed high activity of superoxide dismutase,
an enzyme responsible for scavenging superoxide radicals (Miura et al. 2002).
V. How to Design Biotechnological
Processes for True Marine Fungi
Bonugli-Santos et al. (2015) reviewed the biotechnological production of marine enzymes
including bioprocess strategies adopted for the
cultivation of marine organisms for enzyme
production. Large-scale production (e.g., in
bioreactors) of glucoamylase, superoxide dismutase, lignin peroxidase, chitinase, protease,
and glutaminase by marine fungal strains
including, e.g., Aureobasidium pullulans, Penicillium janthinellum, and others, has been
reported in the literature (Sarkar et al. 2010).
These enzymes are produced in bioreactors
406
A. Kramer and A. Labes
challenge in paper and textile industries. Effluents from such plants can possess alkaline pH
and high salt content. Marine fungi may be
ideally suited for the bioremediation of such
effluents (Verma et al. 2010): White-rot fungi
containing laccase and other enzymes capable
of decolorization were isolated from mangroves. Laccase production was shown in several marine fungi in the presence of sea water
(D’Souza-Ticlo et al. 2009). However, salttolerant lignin-degrading enzymes have not
been sufficiently explored for their biotechnological applications.
Marine fungi have also been discussed as
source for enzymes or for whole cell application
in the degradation of polycyclic aromatic
hydrocarbons (PAHs). PAHs are widely
distributed in the environment and may persist
for extended periods of time with toxic, mutagenic, and carcinogenic effects (for review see
Bonugli-Santos et al. 2015). The ligninolytic
and the monooxygenase system of cytochrome
P-450 may be involved in PAH degradation by
filamentous fungi (Haritash and Kaushik 2009).
The use of marine-derived fungi for the bioremediation of polluted saline environments will
be facilitated by their tolerance to saline conditions.
Additionally, deep-sea fungi growing under
extreme conditions are a good source for industrially useful enzymes with novel properties
(Synnes 2007). Proteases constitute one group
of the several extracellular enzymes being produced by these fungi; elevated pressure resistance, high pH stability and activity in the
presence of several commercial detergents and
high salt content were shown for fungal proteases from deep-sea sediments. These features
are desirable for commercial application, e.g.,
as detergents additive for cold wash (Raghukumar 2008).
C. Compatible Solutes
All organisms in marine environments have to
adapt to the high salinity of seawater causing
significant osmotic pressure. Seawater organisms therefore need to maintain water potentials lower than that of their environment in
their cells to enable water uptake. Cells developed a number of strategies to deal with salts:
effective efflux machineries, antiporter proteins, and the production of compatible solutes
(Forsyth et al. 1971; Ahmadi et al. 2016). The
latter strategy is frequently observed in marine
fungi. They accumulate osmolytes such as glycerol, mannitol, polyol, and trehalose (Blomberg and Adler 1992). These compounds are
of technological interest due to their stabilizing
effects, stress-protective and therapeutic activities in cosmeceuticals and pharmaceuticals but
also as cryoprotectants (Jadhav et al. 2018).
D. “Detox” Activities
Deep-sea hot vent systems are often characterized by high heavy metal concentration. Fungi
thriving in these habitats need to cope with
these conditions by producing detoxification
compounds, often extracellular sugars such as
chitosan-like molecules. These can be applied
in cosmetic industry (Brown et al. 2016). Also,
enzymes from these fungi show high resistance
against heavy-metal intoxication. For instance,
deep sea Cryptococcus strain was tolerant to
CuSO 4 up to a concentration of 50 mM and
showed high activity of superoxide dismutase,
an enzyme responsible for scavenging superoxide radicals (Miura et al. 2002).
V. How to Design Biotechnological
Processes for True Marine Fungi
Bonugli-Santos et al. (2015) reviewed the biotechnological production of marine enzymes
including bioprocess strategies adopted for the
cultivation of marine organisms for enzyme
production. Large-scale production (e.g., in
bioreactors) of glucoamylase, superoxide dismutase, lignin peroxidase, chitinase, protease,
and glutaminase by marine fungal strains
including, e.g., Aureobasidium pullulans, Penicillium janthinellum, and others, has been
reported in the literature (Sarkar et al. 2010).
These enzymes are produced in bioreactors
406
A. Kramer and A. Labes