Degradation of polyhydroxyalkanoate films in brackish Lake Shira

Abstract

The degradation of polyhydroxyalkanoate films was firstly studied in brackish Lake Shira at different depths, 3, 9, 13 and 20 meters, those corresponded to the layers of stratification. It is found that poly (3-hydroxybutyrate) and copolymer poly (3-hydroxybutyrate-co-3-hydroxyvalerate) with less crystallinity are destroyed with varying intensity. The maximum mass loss of polymer films and decrease in polymer molecular weight were registered at 3 m, in oxygenic epilimnion where temperature is the highest. The phenomenon of polymer films destruction were also found in the chemocline and anoxic low-temperature monimolimnion, at 20 m depth.

Keywords

• Lake Shira
• stratification
• polyhydroxyalkanoates
• degradation
• molecular mass