Metal Eaters Propel The Demise Of The Titanic

Shipwreck porthole.

Oceanographer Robert Ballard’s literary showpiece The Discovery Of The Titanic today sits on a shelf in my bedroom collecting dust.  Gone are the days when it was heavily leafed through by relatives and close friends mesmerized as they were by the glossy pictures and personal accounts of disaster contained within its covers.  I had dismissed from mind images of the Titanic’s Captain Edward Smith and Marconi wireless operators Jack Phillips and Harold Bride that accompany the chilling story of the fateful night.  I had forgotten about Ballard’s detailed chronicling of the turbulent expeditions that led to the eventual finding of the Titanic more than 70 years later.  And I had put aside my fascination for the flagship submersible Argo that in 1985 had scoured the Atlantic at 13,000 feet below sea level until it finally met up with the eerie wreck of the luxury liner.   But my interest in the book has recently been revived by the molecular characterization of a fastidious strain of bacteria that is “speeding up the decay of the historic wreck” (1).

When Ballard wrote his book over 25 years ago, biologists had already advanced the idea that micro-organisms were breaking down the iron cladding of the Titanic.  His description of some of the first shuddersome glimpses of the ship’s contours give us an inkling of what was known at the time:

“As we rose in slow motion up the ghostly wall of the port bow, our running lights reflected off the still-unbroken glass of portholes in a way that made me think of cats’ eyes gleaming in the dark.  In places, the rust about them formed eyelashes, sometimes tears.  As though the Titanic were weeping over her fate.  Near the upper railing- still largely intact- reddish –brown stalactites of rust hung down as much as several feet, looking like long needle-like icicles.  This phenomenon, the result of iron-eating bacteria, was well known, but never had they been seen on such a massive scale.  I subsequently dubbed them “rusticles”-  a name which seems to have stuck” (2).

Now a joint effort from scientists in Spain and Canada has uncovered the DNA signature of one of a handful of bacterial agents that lie at the heart of the rusticle phenomenon. By removing stalactite pieces from the hull of the Titanic and performing a battery of elucidative phenotypic and chemotaxonomic tests, Christina Sanchez-Porro and others have homed in on the true identity of one salt-loving microbial wreck heister called Halomonas titanicae (3).

H.titanicae, dubbed BH1, is part of a larger family of bacteria that until now had never been observed so deep below the ocean surface.  It uses iron as an inorganic source of energy, oxidizing it and leaving rust behind as a waste product.  For many of the 27 bacterial strains now known to live in the rusticles, the deep sea conditions are not sufficiently acidic for growth (2).  They get around this by manufacturing a more favorable dwelling of “highly viscous slime” that encapsulates them away from seawater and gives them an acidic habitat in which to flourish (2).   But bacteria are not the only organisms feasting on the spoils of this particular maritime tragedy.  Wood-borers have all but decimated much of the exquisite woodwork in the ship’s interior although the high density teak wood found in many of the railings, staircases and roof trims has proven to be remarkably unyielding to these voracious assailants (2).      

Opinions differ over whether the havoc that bacteria such as BH1 are wreaking should be left to continue unabated (1)   Ontario Science Center biologist Bhavleen Kaur believes that the bacterial goings-on aboard the Titanic could be used to help us better understand and halt the breakdown of other manmade sea structures such as offshore oil rigs and gas pipelines (1,4,5).  Microbial ‘iron munching’ might even find application in recycling and disposal workflows (5).  Some heritage devotees are less than happy about such proposals preferring instead to promote efforts to halt H.titanicae in its tracks and preserve the wreck for posterity.

Bollard Titanic Book

While perhaps desirable, going head-to-head with nature’s forces seems impracticable given the sheer speed at which the wreck is succumbing to bacterial breakdown.  Canadian civil engineer Henrietta Mann posited that twenty years from now there may be little more than a “rust stain on the bottom of the Atlantic” marking the location where the Titanic’s shadowy grave once lay (4,5).  It is a sobering thought that such a fate should befall what was once a 50,000 ton steel leviathan of a ship (5).  Extensive video footage and photographs may soon become the only means we have by which to remember the Titanic’s “very human story” (4,5).

Further Reading

  1. Rachel Kaufman (2010) New Bacteria Found On Titanic; Eats Metal, National Geographic News, December 10th, 2010, See http://news.nationalgeographic.com/news/2010/12/101210-new-species-bacteria-metal-titanic-wreck-science/
  2. Robert Ballard (1984) The Discovery Of The Titanic: Exploring The Greatest Of All Lost Ships, Madison Press Books, Toronto, ON, p.116, p.208
  3. Sánchez-Porro C, Kaur B, Mann H, & Ventosa A (2010). Halomonas titanicae sp. nov., a halophilic bacterium isolated from the RMS Titanic. International journal of systematic and evolutionary microbiology, 60 (Pt 12), 2768-74 PMID: 20061494
  4. Graham Smith (2011) First it was an iceberg, now it’s bacteria: Rust-eating species ‘will destroy wreck of Titanic within 20 years’, Daily Mail, 12th January, 2011, See http://www.dailymail.co.uk/sciencetech/article-1346446/Titanic-wreck-completely-destroyed-20-years-new-rust-eating-bacteria.html
  5. Rosella Lorenzi (2010) Titanic Being Eaten By Destructive Bacteria, Discovery News, 7th December, 2010, See 

What Caused the Black Death?


I was confident I knew a few things about the bubonic plague: It was caused by the bacterium Yersinia pestis, which was transmitted to humans by fleas hitching a ride on the back of traveling rats. It spread rapidly and devastated populations around the globe, and because cats, a natural predator of scurrying rodents, had been killed, rats proliferated along with their deadly, infectious cargo. However, until I read a recent PLoS ONE article, I did not realize there was still debate about whether Yersinia pestis was the infectious agent for Black Death, the disease that ravaged 14th century Europe and killed one third of its population.

Yersinia pestis proposed infectious agent of the black death
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Human Microbiome Project

coliform bacteria

Did you know that the microorganisms living in and on the human body (most on the skin, in the gut, and in the mouth) outnumber all our human cells by a factor of ten? But read on before you grab the hand sanitizer and schedule a colonic, these “germs” may be an integral part of what makes you… well “you”. Indeed, the profile of microorganisms happily living in and on your body may be as unique a signature as your DNA profile or your fingerprints—perhaps more so.

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Finding the Next Generation of Antibiotics: Closthioamide

Closthioamide

Mention the word penicillin and it conjures up images of mold growing on bacterial culture plates and Dr. Alexander Fleming observing that the mold had killed the surrounding bacteria, ushering in the age of antibiotics. Bacterial infections could easily be treated with penicillin or any one of the bewildering array of new antibiotics continually being discovered. The result of using these antimicrobial drugs: numerous lives were saved and human health improved. However, bacteria are clever organisms and as quickly as humans developed an antibiotic to treat infection, the microbes would find a way around the bacteriostatic or bacteriocidal compound. It is a scary world where antibiotics are rendered impotent and fewer and fewer weapons are left in the arsenal to treat multidrug-resistant Staphylococcus aureus (MRSA) and hospital-acquired drug-resistant Gram-negative bacteria (e.g., Acinetobacter baumannii).

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Quorum Sensing in Bacteria: How a Picture can be Worth a Thousand Words

Increasingly, multimedia and video are being used in addition to traditional delivery methods to communicate scientific findings. Journals such as PLoS ONE, Cell, Nature and others often use video to either showcase particular articles, or offer authors the opportunity to include multimedia elements as part of their article. Some subjects lend themselves better to video delivery than others. Every so often a video report comes along that perfectly complements the content of the associated paper, illustrating the power of video to enhance communication of research findings.

In my opinion, the effective use of video to highlight results is beautifully illustrated by the report below, highlighting the publication “A synchronized quorum of genetic clocks” by Danino et al, which was published in Nature this week.

[youtube=http://www.youtube.com/watch?v=pnjdAr4EjI0]
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What’s in the H1N1 Vaccine Anyway?

I’m a microbiologist. I wash my hands often, I don’t eat canned green beans or any home-canned food (due to a horrible botulism example given in a bacteriology class), I don’t ask for antibiotics if I just have a cold, and I believe in vaccination programs.

Recently, due to the various controversies surrounding the H1N1 vaccine, and because I just gave permission for my children to be vaccinated at school, I have been thinking about vaccination rather a lot. Even though I believe absolutely in the benefits of vaccination, I also have the usual concerns when considering whether to accept a new vaccine for my children. So, when I read or hear sensational press coverage over emphasizing vaccination risks, I worry, and I want to hear a balanced viewpoint.

So I thought I would share what I have learned about the H1N1 vaccine.

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