microbiology

New genus of bugs discovered at WA alumina refinery

Previously unknown species of naturally-occurring bacteria have the potential to save the alumina and aluminium industries millions of dollars while helping to reduce their impact on the environment, microbiologist Naomi McSweeney has found in a collaborative project between Alcoa of Australia, CSIRO and the University of Western Australia. [click to continue…]

p8070118‘Fool’s gold’ has tricked many amateur gold miners, but Queensland researchers have discovered it can reveal much about the early evolution of life on Earth.

Three billion years ago the Earth couldn’t support life as we know it – the atmosphere was deadly to oxygen-breathing plants and animals.
But two and half billion years ago life changed the Earth’s atmosphere creating the oxygen-rich air we rely on today. [click to continue…]

Bore hole through ice. Credit: Mike Craven Australian Antarctic Division (AAD)Researchers at Geoscience Australia have unravelled the development of a unique seafloor community thriving in complete darkness below the giant ice sheets of Antarctica.

The community beneath the Amery Ice Shelf in Antarctica is 100 km from open water and hidden from view by ice half a kilometre thick. This ecosystem has developed very slowly over the past 9000 years, since the end of the last glaciation.

Today it is home to animals such as sponges and bryozoans fed by plankton carried in on the current. [click to continue…]

Little ripples, big swirl

16 August 2007

in 2007

How mini-earthquakes and tornados could one day be saving lives

Monash University engineer Leslie Yeo is using tiny earthquakes and tornados to assist the detection of biohazards and germ warfare. He and collaborator James Friend at the Micro/Nanophysics Research Laboratory hope to integrate their technology into an inexpensive, credit-card-sized sensor within five to ten years.

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Warfare between bacteria could provide an environmentally friendly solution to biofouling, according to Dhana Rao and her colleagues at the University of NSW.

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Fish make omega-3 from noxious weed

Australian scientists have found that fish fed oil extracted from one of Australia’s most damaging noxious weeds, Patterson’s curse, produce health-giving omega-3 oils for human consumption. [click to continue…]

Billion year old bacteria in NT rocks and bugs from outer space

Researchers from the CSIRO, Sydney University and Colorado State University have developed a means of detecting signs of ancient microbes which may have lived on Earth or come from outer space.

The group already has picked up signs of bacteria more than a billion years old inside rocks from the Northern Territory.

The technique centres around analysing tiny oil droplets-sealed inside rocks as they formed-for traces of chemical compounds known only to be produced by particular types of organisms. The results provide unequivocal evidence of their presence.

“Oil forms from decayed organisms, and therefore contains fatty tracers or biomarkers for the organism from which they came-like the footprint of a dinosaur, but at a molecular level,” says Herbert Volk from CSIRO Petroleum, a member of the research team.

“It’s important that we understand these early organisms, as they were the building blocks for the evolution of the more complex life forms which play an important part in today’s ecosystems.”

The team has managed to extract such biomarkers from oil droplets sealed in Precambrian rocks from the Northern Territory for more than a billion years.

The chemical analysis of the oil indicates that it is derived from single-celled cyanobacteria, the aquatic and photosynthetic bacteria responsible for increasing oxygen levels in the atmosphere. There is also evidence of the presence of more complex strains of life.

“Microscopic evidence of fossilised microbes is very rare in rocks of this age, and if present are often fiercely debated,” Volk says. “Biomarkers have been extracted from rocks of similar age before, but these were not from oil droplets sealed in crystals, so they may have been contaminated by more recent life forms. The new results are free of such doubt.

“And should oil inclusions be found in extraterrestrial rocks such as meteorites or Martian rocks, the molecular signature would be perfectly protected from traces of terrestrial life that could otherwise compromise the information.”

Herbert is one of 13 Fresh Scientists presenting their research to the public for the first time thanks to Fresh Science, a national program hosted by the State Library of Victoria. One of the Fresh Scientists will win a trip to the UK courtesy of the British Council to present his or her work to the Royal Institution.

To view larger image, click on image:  
Remote arid landscape near the drill site in the Roper Superbasin in the Northern Territory, near the Gulf of Carpentaria.
Photo: Dr David Rawlings
The Roper Superbasin is one of the oldest basins known to contain petroleum which is where the researchers look for life.
 This is a thin slice of rock viewed through a microscope with UV light. The oil inclusions are seen fluorescing in bright blue. What the researchers look for are biomarkers of life. Some of the chemical structures they look for are hopanes, derived mainly from hopanols which are fatty alcohols in the cell walls of bacteria.
This is the chemical structure of a hopane molecule.
Herbert Volk (right) and colleague Simon George (left), analysing the oil droplets using a mass spectrometer.

Hitchhiking pests uncovered

31 August 2004

in 2004

A test for  toxic algae could help save our coastal waters from attack by invading pests

Coastal waters around the world are threatened by invaders lurking in the ballast water of cargo ships.

A new global agreement will require ships to meet strict regulations to ensure they do not harbour any unwanted invaders. New technologies are therefore needed for treating ballast water on board. But which treatments will work? Some of the most dangerous algae can play dead.

CSIRO researcher Monique Binet has developed a new method for determining which ballast water treatment works, and which doesn’t. Her test will do in one day what previously took up to six months.

 ”Ballast water is essential to balance the ship’s cargo,” says Monique, one of the Fresh Science winners for 2004. “But some 15,000 species are hitchhiking lifts around the world with the water each week.”

“A particularly notorious type of algae are the toxic dinoflagellates which are capable of poisoning shellfish. These poisoned shellfish can be lethal if eaten by humans. Several international organisations have suggested that these algae should be one of the benchmarks used to assess new treatment technologies.”

“The trouble is that these are tough critters. The dinoflagellates form dormant cysts which can survive for years in the ballast tanks. So testing the different treatment technologies relies on the ability to distinguish between live and dead cysts.”

Until now this has meant painstaking hours of microscopic examination, followed by a wait for up to 26 weeks to see if the cysts germinate into live, swimming algae.

And that’s where the new method developed by Monique and her colleagues at CSIRO’s Centre for Environmental Contaminants Research (CECR) comes in.

“Using a technique called flow cytometry, we can now analyse each and every cyst for its size, structure and fluorescence. Based on these characteristics and the use of a DNA stain, we can tell which cysts will germinate into live cells in a matter of minutes” says Monique.

“The trick was first washing the cysts for 24 hours to remove their mucous coatings, and selecting the right staining conditions, so we can now determine cyst viability within 1 day, instead of the conventional 3-26 weeks.”

The research has attracted interest from around the world with Monique presenting at conferences in Germany and New Zealand.

Monique now plans to apply this method to other species of toxic dinoflagellates as well as other micro-organisms that hitch a ride in the ballast water tanks. Enabling the rapid assessment of ballast water will help prevent these pests from spreading any further.

 
As found in the sediment of ballast water tanks – the dinoflagellate Alexandrium catenella in its resting cyst form with surrounding mucous.  The dinoflagellate after a wash. The surrounding mucous has been removed allowing it to be analysed with flow cytometry   
   
The dinoflagellate in its motile form, a cell chain. This can bloom into red tides

Yoghurt won’t stop thrush

31 August 2004

in 2004

Probiotics not always the right approach

Millions of women around the world have probably used yoghurt as a folk remedy to prevent thrush while taking antibiotics. A Melbourne GP and PhD student has proven that Lactobacillus acidophilus, a key bacterium in yoghurt, was not effective in the prevention of thrush (‘vulvovaginitis’) after antibiotics.

Her findings were published today in the eminent British Medical Journal (BMJ). “It’s a reminder that all medicines, even natural ones need to be tested,” says Dr Marie Pirotta.

235 Melbourne women took probiotic (containing lactobacillus bacteria) or placebo
preparations orally or vaginally until four days after completion of their antibiotic course. They recorded any symptoms and provided vaginal swabs for analysis. The results were so clear cut that the trial was cut short on ethical grounds.

Dr Pirotta was surprised by her results, given that the folk remedy was so popular with women, including her own patients. “But at least now women can be better informed and can choose to use effective treatments instead,” she said. “Currently, there are no recommended medicines to prevent thrush, so women should discuss their options with their health care providers.”

Around 50% of women will suffer a bout of thrush after antibiotics at least once in their lifetime. Although thrush usually does not kill people, it does have a big impact on women’s physical and emotional wellbeing, as well as on their relationships. In 1995 the costs associated with diagnosing and treating thrush in the United States were $US1.8 billion (1).

The clinical trial was instigated after Dr Pirotta’s earlier research that found that around 40% of women had used yoghurt or Lactobacillus to try to prevent or treat thrush after antibiotics. These women also reported that they were concerned about getting thrush after antibiotics, and for a small number, the concern was so great that they would choose not to take the antibiotics (2).

She also found that more than two thirds of GPs and pharmacists that she surveyed thought that oral yoghurt or Lactobacillus could be effective to prevent thrush after antibiotics and they had recommended this therapy to women when prescribing or dispensing antibiotics.

Dr Pirotta said that “complementary therapies probably have a lot to offer in health care. It was disappointing to find that this type of Lactobacillus was not effective in this case. But this is a reminder that all medicines, even ‘natural’ ones, need to be tested, and wherever possible, treatments should be based on evidence.”

“This simple and relatively inexpensive study will change how GPs advise women about thrush prevention,” says Professor Michael Kidd, President of the Royal Australian College of General Practitioners.  “It demonstrates that research in general practice can help GPs deliver the best, most cost effective and evidence based care. We need to invest more in this kind of targeted medical research.”

Dr Pirotta was one of 15 early career scientists selected to take part in the 2004 Fresh Science Awards held recently in Melbourne. The one who most meets the program requirements will win a study tour of the UK courtesy of the British Council Australia.

Four thousand families around Sydney may be placing their young children at risk by spraying partially treated sewage from their onsite aerated sewage systems on lawns where children play.

The sewage may contain disease causing microorganisms such as viruses and Cryptosporidium which can cause gastroenteritis in children who play in areas sprayed with sewage.

Katrina Charles, a PhD student in the School of Civil and Environmental Engineering at the University of New South Wales and the Cooperative Research Centre for Water Quality and Treatment, says the domestic wastewater is safe to use provided the householder is aware of the risks and takes sensible precautions.

“Don’t spray the wastewater on lawn areas where kids play and don’t spray it on vegetable gardens” Ms Charles said.

“The best way to reuse this wastewater is through an underground irrigation system where the microorganisms become trapped and die in the soil but the water and nutrients are still available for the garden.”

Ms Charles has recently completed a study into the effectiveness of sewage treatment systems used in unsewered areas around Sydney.

She found that the disinfection used in these aerated treatment systems are not as effective as disinfection in larger sewage treatment plants and only remove a small number of disease causing microorganisms.

“Our results indicate that a safer way to reuse the wastewater is through an underground irrigation system.”

“These treatment and irrigation systems start from about $11,000 for an average block. But the value of water as a resource has never been plainer than in this drought. And underground irrigation systems not only dispose of sewage safely but provide water and nutrients for gardens.”

When there is an infected person in the house, sewage may contain a high number of disease causing microorganisms, including viruses, Cryptosporidium or bacteria. For example rotavirus which can be transmitted by sewage is the most common cause of severe gastroenteritis in young children worldwide.

Katrina was one of 15 early-career scientists who are presenting their work to the public and media as part of Fresh Science 2004. Fresh Science is a national competition aimed at getting the work of young scientists into public attention.

Irrigation on a football field Large sewage sprinkler near a dam
Environmental damage from over watering with sewage      
Sewage being used to water lawn  Watering the mail with sewage  Sprinklers near the vegie patch 
Katrina in the lab   Laying irrigation pipe 

 

Sampling for nutrients    
  Experimental site Goulburn boreholes

Plants can listen in on bacterial communication and can even mimic this communication, possibly in an attempt to stop any attacks, according to a breakthrough in scientific understanding announced today in Melbourne. [click to continue…]

Melbourne scientists plan to harness the strange appetite of newly discovered Australian bacteria to help purify arsenic-contaminated water. [click to continue…]

Pure clean water

A young Sydney researcher and surfer is using laser technology to revolutionise the detection of dangerous bugs like cryptosporidium in water. [click to continue…]

 Bacteria “talk” using chemical signals to prepare their attack on humans, animals and plants. Could a chemical from seaweed disrupt their conversation and stop the invasion? [click to continue…]