12
M. Al-Sahari et al.
According to Table 1.2, there was a confirmed high efficiency of algicidal bacteria
to inactivate HABs, where the previous studies showed a removal ratio of HABs estimated between 75 and 99.9999%. Furthermore, the bio-algicidal treatment method
was employed in both marine and freshwater to investigate the algicidal activities
of different isolated bacteria and algal blooms species. Algicidal bacterium is one
of the most common biodegradation methods of HABs at the laboratory scales.
However, there are urgent needs to investigate and assess the algicidal activities and
efficiency in the large scale as well as the toxicological and health effect studies are
compulsory before large-scale implementation (Ge et al. 2014). The investigation of
algicidal activities of bacteria will lead to identify a clear concept of the algicidal
bacteria mechanisms and specify the factors affecting the inactivation process.
1.4.3 Inactivation Mechanisms
Surviving competition may be the main mechanism for the bio-control of HABs. To
survive, various allelochemicals are secreted by competing microorganisms (algicidal bacteria/fungi, plankton, aquatic plants, etc.) against algae to fight for light, nutrient substances, living spaces (Uronen et al. 2007). Some of bacteria strains inhibit the
bloom-forming growth of Cyanobacteria in highly eutrophic lakes, through the production of allelochemicals (Li et al. 2015a, b). According to Eckersley and Berger
(2018), the inactivation of HABs by algicidal bacteria was investigated by using
Scanning Electron Microscopy (SEM), where the study has showed the difference of
M. aeruginosa cells under the SEM before and after the inactivation process which
occurred due to the algicidal activities of bacteria. HABs cells mostly have a spherical shape which contain the cell wall and nucleus. The study considered that any
changes on the spherical shape of HABs cells indicate inactivation or deformation
of HABs cells Eckersley and Berger (2018).
1.5 Conclusion
Fresh market wastewater needs an advanced environmental management system to
minimize the health risk associated with the infectious agents. Storage period represents the critical point in the management system, among factors which contribute to
the increase of infection agents risk is the temperature between 25 and 37 °C and pH
between 4 and 5.5. Therefore, the storage of fresh market wastes should not be more
than 24 h. Moreover, the treatment technologies should also be focused on removing
the nutrient to prevent the occurrence of eutrophication and harmful algae blooms.
Acknowledgements The authors would like to thank the Ministry of Education Malaysia for
providing FRGS vot K090 (An Insight Of Xenobiotic Organic Compounds) as a financial support
for this research project.
M. Al-Sahari et al.
According to Table 1.2, there was a confirmed high efficiency of algicidal bacteria
to inactivate HABs, where the previous studies showed a removal ratio of HABs estimated between 75 and 99.9999%. Furthermore, the bio-algicidal treatment method
was employed in both marine and freshwater to investigate the algicidal activities
of different isolated bacteria and algal blooms species. Algicidal bacterium is one
of the most common biodegradation methods of HABs at the laboratory scales.
However, there are urgent needs to investigate and assess the algicidal activities and
efficiency in the large scale as well as the toxicological and health effect studies are
compulsory before large-scale implementation (Ge et al. 2014). The investigation of
algicidal activities of bacteria will lead to identify a clear concept of the algicidal
bacteria mechanisms and specify the factors affecting the inactivation process.
1.4.3 Inactivation Mechanisms
Surviving competition may be the main mechanism for the bio-control of HABs. To
survive, various allelochemicals are secreted by competing microorganisms (algicidal bacteria/fungi, plankton, aquatic plants, etc.) against algae to fight for light, nutrient substances, living spaces (Uronen et al. 2007). Some of bacteria strains inhibit the
bloom-forming growth of Cyanobacteria in highly eutrophic lakes, through the production of allelochemicals (Li et al. 2015a, b). According to Eckersley and Berger
(2018), the inactivation of HABs by algicidal bacteria was investigated by using
Scanning Electron Microscopy (SEM), where the study has showed the difference of
M. aeruginosa cells under the SEM before and after the inactivation process which
occurred due to the algicidal activities of bacteria. HABs cells mostly have a spherical shape which contain the cell wall and nucleus. The study considered that any
changes on the spherical shape of HABs cells indicate inactivation or deformation
of HABs cells Eckersley and Berger (2018).
1.5 Conclusion
Fresh market wastewater needs an advanced environmental management system to
minimize the health risk associated with the infectious agents. Storage period represents the critical point in the management system, among factors which contribute to
the increase of infection agents risk is the temperature between 25 and 37 °C and pH
between 4 and 5.5. Therefore, the storage of fresh market wastes should not be more
than 24 h. Moreover, the treatment technologies should also be focused on removing
the nutrient to prevent the occurrence of eutrophication and harmful algae blooms.
Acknowledgements The authors would like to thank the Ministry of Education Malaysia for
providing FRGS vot K090 (An Insight Of Xenobiotic Organic Compounds) as a financial support
for this research project.