Micro-organisms
Micro-organisms that feed on dead biological material like biodegradable polymers are called saprophytes[5]. Some specific types of saprophytes that are present in the temperate forest biome (which is the class of British Columbia's environment), and that are liable to break down compostable plastic include bacteria and fungi[5]. These are the microorganisms that will be expected to decompose the samples involved with this study. If this study were longer in duration, earth worms would also be expected to contribute to the decomposition of the experimental groups, but they only become involved in process at the advanced stages of decomposition[10], and these stages will not be reached in this experiment.
Oxo-biodegradable plastics
Oxo-biodegradable plastic is composed of polymers such as polyethylene, polypropylene, and polystyrene. Pro-oxidants are added to oxidize the plastic and render it metabolizable by saprophytes. Saprophytes need oxygen for respiration[6], i.e. aerobic degradation. Aerobic degradation is the primary method that saprophytes use for metabolization of biological material[6], so oxygen is a necessity for successful degradation. The pro-oxidant is activated when exposed to sunlight or oxygen.
Starch-based biodegradable plastic
Not all starch-based or vegetable based plastic is biodegradable[8], but there are many brands that do produce biodegradable plastic. Biobag’s products meet the International Standards for biodegradation[7]. All of Biobag’s products are starch-based[7].
Biodegradable bioplastic undergoes biological anaerobic degradation to produce CO2, H2O, methane, biomass, and mineral salts, depending on the environmental conditions of the process[7].
In the following pages starch-based biodegradable plastic will be referred to simply as bioplastic.
Micro-organisms that feed on dead biological material like biodegradable polymers are called saprophytes[5]. Some specific types of saprophytes that are present in the temperate forest biome (which is the class of British Columbia's environment), and that are liable to break down compostable plastic include bacteria and fungi[5]. These are the microorganisms that will be expected to decompose the samples involved with this study. If this study were longer in duration, earth worms would also be expected to contribute to the decomposition of the experimental groups, but they only become involved in process at the advanced stages of decomposition[10], and these stages will not be reached in this experiment.
Oxo-biodegradable plastics
Oxo-biodegradable plastic is composed of polymers such as polyethylene, polypropylene, and polystyrene. Pro-oxidants are added to oxidize the plastic and render it metabolizable by saprophytes. Saprophytes need oxygen for respiration[6], i.e. aerobic degradation. Aerobic degradation is the primary method that saprophytes use for metabolization of biological material[6], so oxygen is a necessity for successful degradation. The pro-oxidant is activated when exposed to sunlight or oxygen.
Starch-based biodegradable plastic
Not all starch-based or vegetable based plastic is biodegradable[8], but there are many brands that do produce biodegradable plastic. Biobag’s products meet the International Standards for biodegradation[7]. All of Biobag’s products are starch-based[7].
Biodegradable bioplastic undergoes biological anaerobic degradation to produce CO2, H2O, methane, biomass, and mineral salts, depending on the environmental conditions of the process[7].
In the following pages starch-based biodegradable plastic will be referred to simply as bioplastic.