are able to modify their physical and chemical nature, making them bioavailable for
hydrocarbons-degrading bacteria.
7.4 Synergistic Action Algae-Bacteria in Oil-Polluted
Marine Environment
7.4.1 Algae Bacteria Mutual Benefits During Degradation
Processes
The oil input in marine environment induces a shift in the bacterial community
structure with a consequent increase of the relative cell density of hydrocarbondegrading bacteria (Yakimov et al. 2005; McKew et al. 2007; Yakimov et al. 2007).
However, the natural occurring oilbiodegradation is a concerted action resulting
from the interaction between hydrocarbon-degrading bacteria and other microorganisms, such as fungi or microalgae and cyanobacteria (Coulon et al. 2012; Bovio et al.
2017). The association of algae-bacteria can be defined as a “microbial module”
(McGenity et al. 2012) that can contribute to the success of Bioremediation in
marine environment. For this reason,knowledge about algae–bacteria interaction as
physiological, biochemical, and ecological aspects will be fundamental to exploit
this biotechnological potential.
In general, the interaction between algae and bacteria can generate both, positive
or negative effects for the two components of the consortium and consequently
for the biodegradation processes. The crucial events of algae–bacteria interaction
occur within the phycosphere, the region that surrounds phytoplankton cells
enriched in organic substrates and algal exudates. It may also include associated
bacterial communities (Seymour et al. 2017). In a mixed algae/bacteria consortium
as it occurs in the natural environment, a cooperation was reported between
algae and bacteria in the biodegradation of available organic substrate, including
hydrocarbons (McGenity et al. 2012; Tang et al. 2012). The success of such
cooperation depends, among several biotic and abiotic factors, also on the type of
interaction between algae and bacteria that can be synergic or antagonist (Fig. 7.1).
With special attention to the synergic action within the phycosphere, the
interexchange of gases for mutual benefits can significantly improve the biodegradation processes (Cole 1982; Gutierrez et al. 2012; Amin et al. 2015; Palacios et al.
2016). In general, oxygen produced by algae enhances bacterial growth and in turn
CO 2 deriving from bacteria promotes microalgae growth (Ramanan et al. 2016).
During bioremediation processes, the oxygen demand increases and its limitation
can reduce the yield of biocatalyses. Within the phycosphere, algae can provide
sufficient amount of oxygen, reducing the total energy requirement of the process
(Sforza et al. 2018). The same benefit could be determinant to enhance the natural
occurring biodegradation processes as for example within marine aggregates such as
marine oily snow (Suja et al. 2019). Moreover, further advantages of algae–bacteria
7 Biodegradation of Hydrocarbons in Marine Environment
209
hydrocarbons-degrading bacteria.
7.4 Synergistic Action Algae-Bacteria in Oil-Polluted
Marine Environment
7.4.1 Algae Bacteria Mutual Benefits During Degradation
Processes
The oil input in marine environment induces a shift in the bacterial community
structure with a consequent increase of the relative cell density of hydrocarbondegrading bacteria (Yakimov et al. 2005; McKew et al. 2007; Yakimov et al. 2007).
However, the natural occurring oilbiodegradation is a concerted action resulting
from the interaction between hydrocarbon-degrading bacteria and other microorganisms, such as fungi or microalgae and cyanobacteria (Coulon et al. 2012; Bovio et al.
2017). The association of algae-bacteria can be defined as a “microbial module”
(McGenity et al. 2012) that can contribute to the success of Bioremediation in
marine environment. For this reason,knowledge about algae–bacteria interaction as
physiological, biochemical, and ecological aspects will be fundamental to exploit
this biotechnological potential.
In general, the interaction between algae and bacteria can generate both, positive
or negative effects for the two components of the consortium and consequently
for the biodegradation processes. The crucial events of algae–bacteria interaction
occur within the phycosphere, the region that surrounds phytoplankton cells
enriched in organic substrates and algal exudates. It may also include associated
bacterial communities (Seymour et al. 2017). In a mixed algae/bacteria consortium
as it occurs in the natural environment, a cooperation was reported between
algae and bacteria in the biodegradation of available organic substrate, including
hydrocarbons (McGenity et al. 2012; Tang et al. 2012). The success of such
cooperation depends, among several biotic and abiotic factors, also on the type of
interaction between algae and bacteria that can be synergic or antagonist (Fig. 7.1).
With special attention to the synergic action within the phycosphere, the
interexchange of gases for mutual benefits can significantly improve the biodegradation processes (Cole 1982; Gutierrez et al. 2012; Amin et al. 2015; Palacios et al.
2016). In general, oxygen produced by algae enhances bacterial growth and in turn
CO 2 deriving from bacteria promotes microalgae growth (Ramanan et al. 2016).
During bioremediation processes, the oxygen demand increases and its limitation
can reduce the yield of biocatalyses. Within the phycosphere, algae can provide
sufficient amount of oxygen, reducing the total energy requirement of the process
(Sforza et al. 2018). The same benefit could be determinant to enhance the natural
occurring biodegradation processes as for example within marine aggregates such as
marine oily snow (Suja et al. 2019). Moreover, further advantages of algae–bacteria
7 Biodegradation of Hydrocarbons in Marine Environment
209