Mushrooms are an important food source in the Australian diet, supplying protein, vitamins and micronutrients. Growing nutrient-rich mushrooms requires a specialized compost, which is produced in a microbial process from wheat straw and poultry manure. The project will study microbial nitrogen cycling during composting and mushroom cropping, and how changes in microbial activity affect the nutritional content of the mushroom crop.
The button mushrooms available in Australian supermarkets are grown commercially on a specialized mushroom compost produced from two main ingredients: wheat straw, which provides carbon for mushroom growth, and poultry manure, which provides nitrogen. However, bacterial activity during the high-temperature composting process often releases much of the nitrogen as ammonia or nitrous oxide gases, and supplementary nitrogen sources usually need to be added late in the process to replace the losses. Our recent work has characterized the active microbes (bacteria and fungi) that are responsible for converting the wheat straw into productive compost, and many of these are also highly active in catalyzing these reactions of nitrogen-containing compounds during composting. In order to reduce nitrogen losses and increase the nutrient yield in the final mushroom crop, we need to understand how the nitrogen levels in the compost are controlled by the compost microbes. The project will use modern analytical and molecular genetic methods to investigate the overall balance of nitrogen inputs and outputs during composting, and will explore how gene expression in the key compost microbes controls this process. Changes in nitrogen supplementation will be related to microbial activity and to overall crop yield and nutritional value. The project will make use of the University’s Marsh-Lawson Mushroom Research Unit, and will integrate laboratory and model studies with full scale experiments in close collaboration with industrial mushroom composters and mushroom producers in the Sydney basin.
This project would suit a student with a strong interest in soil microbiology/microbial ecology, and some background in biochemistry and molecular genetics. Mushroom cultivation is done in our controlled environment facility dedicated to mushroom research, located on the Darlington campus. The composting experiments will be carried out in full scale composting tunnels, in collaboration with a commercial composting facility. Potential applicants may be interested in reading the following:
Kertesz, M. A. and M. Thai (2018). "Compost bacteria and fungi that influence growth and development of Agaricus bisporus and other commercial mushrooms." Applied Microbiology and Biotechnology 102: 1639-1650.
Carrasco, J., et al. (2018). "Supplementation in mushroom crops and its impact on yield and quality." AMB Express 8: 9.
HDR Inherent Requirements
In addition to the academic requirements set out in the Science Postgraduate Handbook, you may be required to satisfy a number of inherent requirements to complete this degree. Example of inherent requirement may include:
- Confidential disclosure and registration of a disability that may hinder your performance in your degree;
- Confidential disclosure of a pre-existing or current medical condition that may hinder your performance in your degree (e.g. heart disease, pace-maker, significant immune suppression, diabetes, vertigo, etc.);
- Ability to perform independently and/or with minimal supervision;
- Ability to undertake certain physical tasks (e.g. heavy lifting);
- Ability to undertake observatory, sensory and communication tasks;
- Ability to spend time at remote sites (e.g. One Tree Island, Narrabri and Camden);
- Ability to work in confined spaces or at heights;
- Ability to operate heavy machinery (e.g. farming equipment);
- Hold or acquire an Australian driver’s licence;
- Hold a current scuba diving license;
- Hold a current Working with Children Check;
- Meet initial and ongoing immunisation requirements (e.g. Q-Fever, Vaccinia virus, Hepatitis, etc.)
You must consult with your nominated supervisor regarding any identified inherent requirements before completing your application.
The opportunity ID for this research opportunity is 2541