American Society for Microbiology meeting

American Society for Microbiology, New Orleans, May 21–24, 2011

Foiling cheaters
It can take an entire community to keep cheaters from prospering. New experiments with bacteria show that populations containing different types of bacteria behave very differently than groups composed of only one species. A cheating strain of Salmonella bacteria can make other types of Salmonella and E. coli die out by stealing food and not giving anything back, Christopher Marx of Harvard reported May 22. But mixing Salmonella and E. coli somehow thwarts the cheaters, Marx and his colleagues discovered in a preliminary study. Figuring out how bacteria team up to freeze out cheaters could help researchers better understand how microbial populations behave in the wild. —Tina Hesman Saey

 

Greenhouse gas changes soil microbes
Rising levels of carbon dioxide in the air may have profound effects on underground microbes. Researchers led by Zhili He of the University of Oklahoma examined soil microbe communities that formed under current atmospheric conditions or under elevated levels of carbon dioxide like those predicted for 2050. Fewer bacteria and less diverse microbe mixtures were present under high carbon dioxide conditions, He reported May 23. Some of the differences in bacterial mixes could be attributed to carbon dioxide directly, but the gas can also change microbe communities indirectly by altering plant physiology and soil conditions. —Tina Hesman Saey

Feather-eating bacteria
Feather-devouring bacteria use amino acids to home in on places where feathers are damaged, a new study shows. Bacillus bacteria can completely digest a feather in a test tube within 48 hours by attacking its protein skeleton. But it hasn’t been clear whether the bacteria just munch on feathers locally or if the microbes can move toward places where other bacteria are already chowing down. To find out, Chloe Hamrick of Ohio Wesleyan University in Delaware, Ohio, tested bacteria’s attraction to certain amino acids, the chemical building blocks of proteins. Some amino acids, such as those that might be shaken free when plumage gets damaged, attract feather-eating bacteria, while other amino acids repel the microbes, Hamrick reported May 23. —Tina Hesman Saey

Antimicrobial cell phones
Weak magnetic fields generated by electronic equipment, such as cell phones and microwaves, may alter the growth of friendly microbes in the body. Exposure to weak magnetic fields caused E. coli bacteria to thrive, but impaired growth of a common skin bacterium called Staphylococcus epidermidis and a pathogenic bacteria called Pseudomonas aeruginosa, Sanghoon Kang, a microbiologist at the University of Houston-Clear Lake reported May 24. “I don’t have a good answer to why,” Kang says. It’s also not clear whether bacteria in the body would be affected in the same way as those grown in the lab. —Tina Hesman Saey