Microbial activity in the subsurface
[Music plays softly and a split circle appears on screen, flicking between photographs of different CSIRO activities in either side of the circle before resolving as the CSIRO logo]
[Image changes to show the title text: “Microbial activity in the subsurface”]
[Image changes to a scientist leaning over and looking through a microscope]
Microbes are tiny organisms, which means you need a microscope to see them.
[Image shows a view through the microscope that reveals a group of microbes in a Petri dish. Different types of microbes appear. Text appears: “Bacteria” and “Single-celled organisms”.]
They include bacteria and other single-celled organisms.
[Image changes to a nature scene with a shining sun. Picture bubbles appear showing that microbes are present in different environments including trees, water and soil. The scene travels down below ground level revealing a subsurface environment.]
There are many types of microbes, and they occur in almost every environment, including below the Earth’s surface.
[Image changes to show a public forum of six people conversing with two CSIRO researchers. A projection screen shows the word “Microbes” followed by “in water bores and gas wells”.]
Public concerns have been raised about the potential for microbial activities to corrode metals, and damage cements in water bores and gas wells.
[Text changes to “Microbially Influenced Corrosion” with “M”, “I” and “C” in bold]
These activities are broadly referred to as Microbially Influenced Corrosion, or M I C,
[Image moves up to reveal a farm scene with cows, birds, irrigation systems and green rolling hills. A view into the subsurface level is shown at the bottom of the screen.]
and communities are concerned it could lead to contamination of groundwater and emissions.
[Image changes to a view through the microscope revealing a group of microbes in a Petri dish]
M I C is mostly caused by bacteria that can produce acids or directly interact with metals.
[Text appears alongside the microbes image: “Acid Producing Bacteria” and “Sulphate Reducing Bacteria”]
They include acid producing bacteria and sulphate reducing bacteria.
[Image changes to a close up of microbes forming a biofilm and adhering to a surface. “Biofilm” text appears on screen identifying the biofilm. The biofilm increases to show more microbes.]
Some of these microbes attach to surfaces by forming biofilms that provide optimal conditions for microbial activity.
[Image changes to a CSIRO scientist wearing a high-visibility vest, safety glasses and a hat, and holding a checklist on a clipboard. It’s titled “Microbially Influenced Corrosion (M I C)” and contains the following check boxes: Right types of microbes are present; Nutrients for microbial growth; Environment with appropriate forms of sulphur. A map of Australia is out of focus in the background.]
We know for M I C to occur, the right type of microbes must be present. There needs to be nutrients for microbial growth and, in the case of sulphate reducing bacteria, an environment with particular forms of sulphur.
[The image of the checklist and scientist moves out of frame, and the focus shifts to the map, highlighting a blue patch identified by text as the “Surat Basin”]
In Queensland’s Surat Basin, nutrients and sulphate
[Image reveals a scene of the Surat Basin, with grass, trees, rolling hills and cows under a shining sun. The scientist reappears, and “nutrients” and “environment with appropriate forms of sulphur” fade on the clipboard.]
are mostly lacking in the subsurface, and this would likely limit M I C.
But we need to know a lot more about M I C.
[Image changes to the scientist writing on sample bottle labels in the field. Other samples are resting on a portable cooler.]
That’s why C S I R O is undertaking studies on microbes and microbial activity in the subsurface to address knowledge gaps and community concerns.
[Image pans across to reveal a gas well surrounded by grass in the shining sun]
These studies will help us understand the diversity of microbes in groundwater and how microbial biofilms interact with cements and steels in wells.
[Image transitions to the CSIRO logo with the following text on screen: “GISERA Gas Industry, Social and Environmental Research Alliance gisera.cisro.au”.]
For more information, visit our website.
Microbial activity in the subsurface – GISERA video