MOSCOW, March 21Russian scientists from Far Eastern research institutes have found a way to use substances secreted by bacteria to protect ship hulls from harmful fouling by microorganisms and algae, the Russian Ministry of Science and Higher Education said.
A big problem, leading to significant economic losses, is biofouling in the marine environment — the accumulation of microorganisms, plants, algae or even small animals on the hulls of ships.
Biofouling enhances the corrosion processes of structural materials and leads to early decommissioning of various equipment. Both mobile and stationary structures are susceptible to damage — ships, hydraulic structures, oil and gas platforms, oceanographic equipment, etc. On ships, fouling increases friction between the ship's hull and water, which results in an increase in fuel consumption (up to 40-50% ), as well as reduced maneuverability.
The most common method of surface fouling protection in sea water is the use of anti-fouling coatings with so-called biocides, which are mainly copper compounds. The intensive use of coatings containing copper biocides and a significant increase in their amount has led to the fact that, according to experts, more than 5 tons of heavy metal compounds are released into the aquatic environment annually. In ports, with a significant accumulation of ships painted with anti-fouling paints, their toxic components released from coatings accumulate in quantities that exceed existing standards.
Modern environmental requirements have led to tighter control in the field of the introduction and operation of antifouling coatings and biocidal compounds, and the interest of researchers has focused on identifying the mechanisms of biological protection against fouling that exist in nature and the search for natural products with antifouling properties.
Scientists from two institutes of the Far Eastern Branch of the Russian Academy of Sciences, the Institute of Chemistry and the Zhirmunsky National Scientific Center for Marine Biology, joined forces in an attempt to create an anti-fouling coating using products microbial biosynthesis.
«The search and synthesis of non-toxic and environmentally friendly anti-fouling substances of natural origin, which will serve as an effective replacement for toxic components of coatings, has been carried out since the 1990s. Natural compounds with anti-fouling activity have been isolated from seaweed, sponges, ascidians, corals. However, it is microorganisms represent a valuable and easily renewable source of natural antifouling compounds, since their use makes it possible to obtain a sufficient amount of active compounds, including on an industrial scale, without depleting natural resources,” explained one of the main developers of the coating, researcher at the Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, Uliana Kharchenko .
Scientists isolated a strain of one of the species of marine bacteria showed high antimicrobial and antifouling activity. Biological substances produced by this strain have been used as a natural biocide for the development of antifouling. The main biocidal component of the new coating is an encapsulated bacterial extract that is effective against microbes and algae.
Experiments carried out in natural marine conditions have shown that the developed coating effectively copes with biofouling. These experiments took place at the Tropical Center in the South China Sea (Vietnam).