Bioremediation and waste management
Microbial Management Systems provides innovative environmental solutions to restore and build microbial communities that are required for soil health and which can be utilized for organic waste management.
Case study: rehabilitation of mine sites
Developing a soil structure, increasing organic matter content and turnover, and increased nutrient cycling are key to establishing a stable post-mining soil for the re-establishment of a self-sustaining vegetative cover. Microorganisms are vital to these processes occurring. The monitoring and management of soil microbes during soil removal, storage and replacement can minimize microbial community changes to ensure that soil substrates are optimised for re-use in rehabilitation activities.
Soil organic matter stores and buffers nutrient concentrations, influences water storage in the soil and is a major factor in determining soil structure and erosivity. It is also a store of energy in the soil that drives many of the soil-based processes. The soil biomass is predominantly of microbial origin and the size and composition of microbial communities in soils is primarily controlled by the quality, quantity, and distribution of organic matter.
The addition of composted organic waste to rehabilitating mine soils has been shown to hasten the soil profile and microbial community development on these sites through a number of processes shown in the model above.
Case study: microbial production of extracellular polymeric substances (EPS) utilizing waste organic matter
The production of EPS is a common property of many soil microbes. The natural functions of the EPS include surface adhesion, self-adhesion of cells into biofilms, formation of protective barriers, water retention and nutrient accumulation around roots. EPS are important in soil aggregate formation and stabilization and play a role in increasing soil water retention capacity and reducing soil moisture loss. MMS is developing microbial polymer applications which can be produced at low cost utilizing local organic waste stocks and which are an eco-friendly solution for soil stabilization and erosion reduction during the crucial period before vegetation cover is established on rehabilitating sites.
Case study: the oyster mushroom and woody waste
Large quantities of organic wastes are generated through the activities of the agricultural, forest and food processing industries. A significant proportion of these wastes are not reutilized, resulting in negative economic and ecological impacts. However, appropriate bioremediation can convert these wastes into valuable economic and environmental resources which can be of further value, especially in soil restoration activities.
For small-scale horticultural businesses, the generation and disposal of waste streams may impact upon profits and have serious ecological implications within the local environment.
A project undertaken for Horticulture Australia Ltd identified the oyster mushroom, Pleurotus ostreatus, as a suitable microbial bioremediation agent for woody horticultural waste streams in the Hawkesbury region neighbouring the Greater Blue Mountains World Heritage Area and demonstrated conversion of these wastes from potential environmental and economic liabilities into economic and environmental benefits.
The photos below depict the steps from woody waste to mulch to mushrooms.
