Cyanobacteria Prochlorococcus, which produce about ten percent of oxygen, vulnerable to the effects of plastic pollution. According to a study published in the journal Biology Communications, polyethylene and polyvinyl chloride leached substances that inhibit the growth of populations of these organisms, reduce their productivity and hinder the process of photosynthesis.
As a rule, the main threat from plastic waste to marine life considered the possibility of entanglement in, or ingestion. Significantly less attention researchers pay to the chemicals which can be released from plastic when exposed to sea water, because most plastic polymers are considered stable and chemically inert. In fact, it is not so — to achieve improved performance, increased functionality and anti-aging to plastic in the production of add a number of chemical compounds. Most often it is curing the solvents, residues of chemical catalysts, plasticizers, metals, dyes, flame retardants, UV stabilizers, antioxidants and antimicrobial substances. All of these compounds can be leached from plastics and into the sea water.
Scientists led by Sasha Theta (Sasha G. Tetu) from Macquarie University in Sydney in vitro and studied the effect of substances videochiamata of plastic on the cyanobacterium Prochlorococcus marinus. These microorganisms play a critical role in the carbon cycle of the planet, forming 10 percent of the oxygen breathed by living organisms on Earth.
For research were selected two strains of Prochlorococcus — MIT9312 (HLII Clade) and NATL2A (LLI Clade), which are representative of the ecotypes for the World ocean in tropical and subtropical latitudes. As plastic debris, exposing the toxic effects of these cyanobacteria was selected product of the two most common polymers packages from HDPE (low pressure polyethylene, also called high-density polyethylene) and mattresses of PVC (polyvinyl chloride).
Leaching of plastics occurred in sterile sea water (environment AMP1), while strains of Prochlorococcus marinus cultured in media with the dilution of leached substances: 50, 25, 12,5, 6,25 and 3,125% for polyethylene; 10, 2, 1, 0.5 and 0.25% for PVC. Breeding for PVC is stronger, because preliminary tests showed that its leaching has a much greater effect than leaching of polyethylene at equivalent concentrations. In addition to media with dilute concentrations of toxic secretions, Prochlorococcus marinus were placed in a clean environment AMP1 as a control.