Marine Enzymes – Production and Applications 14.3 Examples of Marine Enzymes 417
Part B | 14.3
14.3 Examples of Marine Enzymes
An important factor concerning the application of marine enzymes in industry and academic research is their
amenability. Thus, cultivation of the enzyme-producing
microorganism as well as identification (by molecular
phylogenetic methods) and optimization of the enzymes’ expression are crucial factors which must be
addressed concerning the supply of the respected enzyme. However, as mentioned before molecular biology
in terms of heterologous expression can be beneficial
for reproducible (over)expression and production of
enzymes on the requested scale. However, the symbiotic nature of the marine strains should be also taken
into account, since marine microorganisms are often
found in close association with various sponges, corals,
and other species). Therefore mixed-cultures such as
biofilms can be helpful to produce and identify the
desired enzyme or, for example, bioactive secondary
metabolites.
In the following sections some enzymes of marine
origin, which are applicable in academic and industrial
research/production, respectively, are highlighted.
14.3.1 Polysaccharide-Degrading Enzymes
Polysaccharolytic enzymes have well-known applications in the food processing, detergent, paper and textile
industries. Furthermore, they have potential applications in the biofuel industry and in waste management.
Cellulase, xylanase, and amylase are used in baking,
brewing, and the production of natural sweeteners. Xylanases are also useful in the prebleaching of paper pulp
and amylases are reported to be components of several
laundry detergents. Carrageenolytic enzymes are used
for liquefaction of carrageenan for applications in the
food, pharmaceutical, and cosmetic industries. In addition to food, pharmaceutical, and cosmetic applications
agarases have potential applications in biotechnological research. Cellulolytic and lignolytic enzymes are
beneficial in the production of biofuels, since degradation of polysaccharide biomasses is the major challenge
in the development of plant-derived biofuels. Plant
biomasses often contain complex polysaccharides that
need to be converted into simple fermentable sugars
for bioethanol production. Cellulose, xylan, and lignocellulose are major groups of polysaccharides that
are abundant in nature and they are major components of almost all biowaste and some industrial waste.
Degradation of these materials is essential for pollution control. Various polysaccharolytic enzymes may
be used for their degradation and conversion to valueadded products.
Amylases
Amylase is an enzyme that catalyzes starch hydrolysis
and is broadly used for the production of simple sugars. Versatile amylases have been reported from marine
organisms. Legin et al. reported 70 amylase producing
microorganisms while screening 269 thermophilic isolates from deep-sea hydrothermal vents [14.30]. Most
thermostable enzymes were produced by several hyperthermophilic archaea belonging to the genus Thermococcus. Four of the archaeal strains showed pullulanase
and ˛-glucosidase activity in addition to ˛-amylase
activity. In another screening, several amylase producing psychrophilic bacteria were reported from deep-sea
sediments of Antarctica [14.31]. Molecular phylogeny
identified the amylase producing strains as members
of the genera Pseudomonas, Rhodococcus, and Nocardiopsis. The two most active amylases were purified
from two Pseudomonas strains and the enzymes were
characterized. Both enzymes were optimally produced
at low temperatures (1520
ı C), but their optimum
activity was reported at a remarkably high temperature (40
ı C), which is contradictory to their natural
habitat. Both the enzymes retained almost 50% activity at 5
ı C. However, the enzymes were unstable
at a temperature above 30
ı C and retained only half
of their maximum activity after 5 min incubation at
60
ı C [14.32]. An amylase encoding gene was isolated
from a marine metagenomic library and overexpressed
in E. coli [14.33]. The enzyme exhibited 72% identity of amino acid sequence to a putative glycosidase
of the deep-sea bacterium Photobacterium profundum,
followed by 67% and 53% identity to putative glycosidases of marine Vibrio splendidus and Hahella
chejuensis. It showed about 50% sequence similarity to
the putative glycoside hydrolase from the marine fish
pathogen Aeromonas salmonicida. All these putative
glycosidases were identified by genome sequences of
marine bacteria and formed a new subfamily of glycoside hydrolase GH13, which is closely related to the
bacterial ˛-amylases. The authors proposed that the
subfamily may be an independent clade of ancestral
marine bacterial ˛-amylases. Instead of low similarity
of the full length sequence of any known ˛-amylases
this enzyme showed a catalytic domain correlated with
the ˛-amylase superfamily. A similar observation was
reported in novel ˛-amylases isolated from Thermo-
Part B | 14.3
14.3 Examples of Marine Enzymes
An important factor concerning the application of marine enzymes in industry and academic research is their
amenability. Thus, cultivation of the enzyme-producing
microorganism as well as identification (by molecular
phylogenetic methods) and optimization of the enzymes’ expression are crucial factors which must be
addressed concerning the supply of the respected enzyme. However, as mentioned before molecular biology
in terms of heterologous expression can be beneficial
for reproducible (over)expression and production of
enzymes on the requested scale. However, the symbiotic nature of the marine strains should be also taken
into account, since marine microorganisms are often
found in close association with various sponges, corals,
and other species). Therefore mixed-cultures such as
biofilms can be helpful to produce and identify the
desired enzyme or, for example, bioactive secondary
metabolites.
In the following sections some enzymes of marine
origin, which are applicable in academic and industrial
research/production, respectively, are highlighted.
14.3.1 Polysaccharide-Degrading Enzymes
Polysaccharolytic enzymes have well-known applications in the food processing, detergent, paper and textile
industries. Furthermore, they have potential applications in the biofuel industry and in waste management.
Cellulase, xylanase, and amylase are used in baking,
brewing, and the production of natural sweeteners. Xylanases are also useful in the prebleaching of paper pulp
and amylases are reported to be components of several
laundry detergents. Carrageenolytic enzymes are used
for liquefaction of carrageenan for applications in the
food, pharmaceutical, and cosmetic industries. In addition to food, pharmaceutical, and cosmetic applications
agarases have potential applications in biotechnological research. Cellulolytic and lignolytic enzymes are
beneficial in the production of biofuels, since degradation of polysaccharide biomasses is the major challenge
in the development of plant-derived biofuels. Plant
biomasses often contain complex polysaccharides that
need to be converted into simple fermentable sugars
for bioethanol production. Cellulose, xylan, and lignocellulose are major groups of polysaccharides that
are abundant in nature and they are major components of almost all biowaste and some industrial waste.
Degradation of these materials is essential for pollution control. Various polysaccharolytic enzymes may
be used for their degradation and conversion to valueadded products.
Amylases
Amylase is an enzyme that catalyzes starch hydrolysis
and is broadly used for the production of simple sugars. Versatile amylases have been reported from marine
organisms. Legin et al. reported 70 amylase producing
microorganisms while screening 269 thermophilic isolates from deep-sea hydrothermal vents [14.30]. Most
thermostable enzymes were produced by several hyperthermophilic archaea belonging to the genus Thermococcus. Four of the archaeal strains showed pullulanase
and ˛-glucosidase activity in addition to ˛-amylase
activity. In another screening, several amylase producing psychrophilic bacteria were reported from deep-sea
sediments of Antarctica [14.31]. Molecular phylogeny
identified the amylase producing strains as members
of the genera Pseudomonas, Rhodococcus, and Nocardiopsis. The two most active amylases were purified
from two Pseudomonas strains and the enzymes were
characterized. Both enzymes were optimally produced
at low temperatures (1520
ı C), but their optimum
activity was reported at a remarkably high temperature (40
ı C), which is contradictory to their natural
habitat. Both the enzymes retained almost 50% activity at 5
ı C. However, the enzymes were unstable
at a temperature above 30
ı C and retained only half
of their maximum activity after 5 min incubation at
60
ı C [14.32]. An amylase encoding gene was isolated
from a marine metagenomic library and overexpressed
in E. coli [14.33]. The enzyme exhibited 72% identity of amino acid sequence to a putative glycosidase
of the deep-sea bacterium Photobacterium profundum,
followed by 67% and 53% identity to putative glycosidases of marine Vibrio splendidus and Hahella
chejuensis. It showed about 50% sequence similarity to
the putative glycoside hydrolase from the marine fish
pathogen Aeromonas salmonicida. All these putative
glycosidases were identified by genome sequences of
marine bacteria and formed a new subfamily of glycoside hydrolase GH13, which is closely related to the
bacterial ˛-amylases. The authors proposed that the
subfamily may be an independent clade of ancestral
marine bacterial ˛-amylases. Instead of low similarity
of the full length sequence of any known ˛-amylases
this enzyme showed a catalytic domain correlated with
the ˛-amylase superfamily. A similar observation was
reported in novel ˛-amylases isolated from Thermo-