Bioplastic - The Future is Degradable Plastics. Investigating Biodegradation of Polyhydroxybutyrate Bioplastic by 紐西蘭 Soil Microorganisms
The rate and production of conventional petroleum based plastics is unsustainable and not eco-friendly. Plastics often end up in marine environments and can take hundreds of years to decompose in landfills. According to Statistica, in 2015 alone, global plastic production was approximately 322 million metric tonnes and is projected to increase in the future. PHB bioplastic or Polyhydroxybutyrate is both biologically produced and biodegradable and can serve as a viable alternative to conventional plastics. But can it be broken down by soil microbes within a reasonable time frame? I have set out to answer this question. My aim was to isolate and analyse microorganisms from the Rotorua area that are capable of degrading Polyhydroxybutyrate (PHB) bioplastic . I isolated PHB degrading microorganisms from Rotorua soils by culturing on an agar based mineral salt media supplemented with PHB powder (MSM PHB agar). Samples were taken from Mount Ngongotaha and Te Puia geothermal soils as well as Okareka, termite frass and termite guts. One isolate from the Te Puia sample (labelled G2) was found to successfully degrade PHB powder. After isolation and purification of the G2 isolate, it was cultured on a range of media types to examine properties exhibited under differing nutrient conditions. Multiple organisms were found to be involved in the degradation of PHB bioplastic and work together symbiotically, this included bacteria and fungi which was identified as penicillium. The sample isolated from Te Puia soils (site 2 – G2Clear) in the Rotorua environment was found capable of competently degrading PHB, clearing 8% of PHB after 26 days. The G2Clear isolate is a mixture of bacteria and fungi working in an endosymbiotic relationship to degrade PHB and are unable to successfully degrade PHB individually. It is through the secretion of an extracellular PHB depolymerase enzyme that PHB is degraded, conforming with my hypothesis. This proves that PHB bioplastic is a viable alternative to conventional petroleum based plastics as PHB can be relatively quickly broken down by soil microorganisms.
Extracting Water from Humid Air Using Solar Energy in Humid Areas
The study aims to evaluate the technique of extracting water from humid air using solar energy through greenhouses in local areas. This technique is believed to provide limited amount of water in areas where potable water is not accessible or abundant. To solve this problem a pyramid-shaped device was designed, it is made of glass panels ad equipped with glass doors, fans operated by solar energy, and multiple shelves covered with fabric to act as Absorbent Calcium Chloride (CaCl2) with a 30% concentration. The doors are open during the night for absorption and closed during the day for energy-generating. Humidity, temperature, and atmospheric pressure are measured every two hours. The amount of water extracted in this area in one full day was around 3.0 liters a day for every square meter. Perhaps the limited amount of water is due to low level of humidity in the area: an average of 50% and temperature of F10 Celsius at night. However, the device itself is independent, does not need power sources, water sources, or infrastructure, can be installed in various places depending on humidity level as well as having the possibility of increasing number or size of device. This makes the device a promising, alternative and environmental friendly solution to produce water. Cost-effective and lighter material can be used to make the device, which will produce an easy-to-use and affordable devices. It is an area in need for further research to improve and further develop it.