Microbial degradation of polyhydroxyalkanoates in tropical soils

Bacterial polyhydroxyalkanoates-eco-friendly next generation plastic: Production, biocompatibility, biodegradation, physical properties and applications

“…It has been reported that poly(3-hydroxybutyrate-co-4-hydroxybutyrate) had a much faster degradation rate than homopolymer PHB (178). While according to the current investigation of Boyandin et al, the homopolymer of 3-hydroxybutyric acid is degraded at higher rates than the P(HB-HV) (176). Similarly, the average rates of mass loss were 0.04-0.33% per day for films and 0.02-0.18% for compact pellets, suggesting preferential degradation of the amorphous phase over pellet.…”

“…The main advantage of PHAs over other types of biodegradable plastic is that they do not require special environmental conditions and can degrade in either aerobic or anaerobic environments through thermal degradation or enzymatic hydrolysis (176,177). Biodegradation of PHAs is performed by microorganisms, which inhabit a specific natural environment (176).…”

“…The main advantage of PHAs over other types of biodegradable plastic is that they do not require special environmental conditions and can degrade in either aerobic or anaerobic environments through thermal degradation or enzymatic hydrolysis (176,177). Biodegradation of PHAs is performed by microorganisms, which inhabit a specific natural environment (176). But in the absence of biological agents (bacteria, algae and fungi) PHAs are practically not subject to mass lost under normal conditions (178) and they are degraded in biological media to form products innocuous to the environment.…”

“…PHA degradability is influenced by many factors, including the specificity and activity of extracellular depolymerases, physical and chemical properties of the polymer (stereo-configuration of its molecules, composition, shape of specimen, crystallinity and molecular weight, polydispersity), surface area, microbial activity of the disposal environment, the pressure of other nutrient materials, physicochemical conditions (pH, temperature, oxygen availability, moisture, salinity, acidity of the environment, etc. ), the shape and size of PHA-based devices, and weather and climate in different regions (28,176,180,189). It has been reported that poly(3-hydroxybutyrate-co-4-hydroxybutyrate) had a much faster degradation rate than homopolymer PHB (178).…”

“…Similarly, the average rates of mass loss were 0.04-0.33% per day for films and 0.02-0.18% for compact pellets, suggesting preferential degradation of the amorphous phase over pellet. The differences in degree of degradation are due to differences in the kinetics and mechanism of PHA biodegradation is caused by qualitative and quantitative dissimilarities between microbial communities of different habitats and other environmental and specimen-related factors (176). In microbially active environments, PHAs are initially viewed by microorganisms as energy sources and then start to degrade (107,190).…”