Author and colleague Sara Klink recently wrote about the ever-visible changes that usher in the arrival of Autumn for many of us in the northern hemisphere (1). The beckoningly bright colors of the foliage on our trees and the seasonal appearance of pumpkins that adorn our porches and abound in the fields around our cities serve as reminders of a festive transition. Throw the occasional honking of migrating Canadian geese into the mix and it is easy to see why many of us cannot help but momentarily stop in awe. The geese in particular are my gaze-catchers. Craning my neck as I look straight up I have become obsessed with capturing the ‘V’ formation that characterizes the flight of these birds on camera.
But there is more that interests me about Canadian geese than simply their migratory ‘order of business’. Unknown to many a bird watcher, Canadian geese are one of several ‘gold mine’ species that harbor a strain of bacteria called Bacillus licheniformis in the tufts of their plumage (2). These feather-degrading bugs are prevalent in all manner of ground-foraging birds and occur in greatest numbers during the late autumn and winter months. Because of their tough keratin-rich microfibril composition, feathers are extraordinarily resistant to biodegradation (2). But not so tough that keratinolytic bacteria such as B. licheniformis cannot break them down (2). And biotechnologists are exploiting this ability to the full.
B. licheniformis has spawned much excitement in the agricultural world (3). Bird feathers are routinely used in animal feed. But until the early 1990’s steaming was the only means by which they could be made more digestible (3). Scientific acumen and ingenuity changed all that. By putting B.licheniformis to work on a feathery meal, an inter-disciplinary group from North Carolina State University generated “appreciable degradation products” of digestible protein (3). In so doing they opened the door for a commercially-viable process that improves on the nutritional value of traditional steaming methods.
And the agricultural relevance of B.licheniformis has not stopped there. These multi-purpose bacteria are also finding application in pest control as a “pre-harvest” treatment for eradicating diseases that attack fruit (4). Mangos, which today constitute “one of the most important fruit crops grown in tropical and subtropical regions” have been targeted for trials against bacterial blackspot (Xanthomonas campestris), anthracnose and soft rot (4). Chemical treatments such as Copper Oxychloride have been heavily legislated against because of their detrimental effects on soils (4). B.licheniformis has proven to be an effective antagonist against these diseases and is therefore gaining traction as the way of the future for pest control.
These same bacteria have also taken our homes by storm. In a good way, that is. Enzymes are commonly deployed in laundry products where they function as potent digesters of dried-on grime. And those of B.licheniformis are best-in-class when it comes to getting the job done. Look down the ingredients list of most brands of washing powder and you are likely to find two components-α-amylase and Subtilisin-A- that respectively perform the job of breaking down starch and proteins (5). Thankfully detergents do not adversely affect the ability of these enzymes to get to work on food splurges (6). Microbially-derived proteases form more than half of the industrial enzyme market (6). And those of alkaline-dwelling organisms such as B.licheniformis are particularly attractive given the high pH of laundry detergents (9.0-12.0) (6).
B.licheniformis has also joined a fast growing club of microorganisms able to synthesize gold nanoparticles which are used in the development of gold-based pharmaceuticals (7). Microorganisms such as B.licheniformis carry periplasmic proteins on their outer surface that bind and reduce Aureum Chloride and in the process generate 10-100nm sized nanoparticles that can be isolated from the bacterial fraction as a dried powder (7). The microorganismic approach to gold nanoparticle production has the unique advantage of being more ecologically sound than current procedures that use harmful reducing agents (7).
From our houses to our farms and onwards into the pharmaceutical development lab B.licheniformis is fast becoming an indispensable workhorse. Its many secrets are being exploited in ways that are revolutionizing how we live. And its novel attributes continue to amaze. Higher eukaryotes sport elaborate olfaction mechanisms to detect gas molecules (8). Up until earlier this year there had been no reports of similar mechanisms in bacteria (8). All that changed with the news that a couple of European biotechnologists had incontrovertibly demonstrated olfaction in B.licheniformis cultures (8). By putting B.licheniformis adjacent to inducer strains of B.subtilis, M.luteus and E.coli, Reindert Nijland and J. Grant Burgess observed notable color changes and a tendency for formation of dense pellicles (known in the trade as biofilms) (8,9). Some simple experiments gave Niijland and Burgess the clues they needed to home in on the molecular exchange that lay at the heart of this response- a rise in concentrations of gaseous ammonia (8,9).
Whether the ‘smelling’ aptitude of B.licheniformis can be translated into a useful application that aids in the “betterment of human life” (in accordance with the biotechnologists’ mantra, 10) remains to be seen. Yet the story of this robust microorganism seems far from over. And as the geese continue to pass overhead during this year’s autumnal leaf-fall I cannot help but see B.licheniformis in a new light- a bacterial ‘high-flyer’ that has taken center stage in the biotechnology arena.
- Sara Klink (2010) A Time For Harvest, Promega Connections, September, 24th, 2010, See http://promega.wordpress.com/2010/09/24/a-time-for-harvest/
- Edward Burtt, Jann Ichida (1999) Occurrence of feather-degrading bacilli in the plumage of birds, The Auk, See http://findarticles.com/p/articles/mi_qa3793/is_199904/ai_n8834646/
- C.M.Williams , C.S Richter, J.M. MacKenzie Jr, Jason C.H. Shih (1990) Isolation, Identification and Characterization of a Feather-Degrading Bacterium, Applied And Environmental Microbiology, Volume 56 (6), pp. 1509-1515
- Evaluation of pre-harvest Bacillus licheniformis sprays to control mango fruit diseases, Crop Protection, Volume 26, pp. 1474-1481
- Measurement of endo-Protease and α-Amylase in Biological Washing Powders & Liquids using AZO CASEIN and AMYLAZYME TABLETS www.megazyme.com/GetAttachment.aspx?id=17e0f84c-9ba1
- Nedra El Hadj-Ali, Rym Agrebi, Basma Ghorbel-Frikha, Alya Sellami-Kamoun, Safia Kanoun and Moncef Nasri (2007) Biochemical and molecular characterization of a detergent stable alkaline serine-protease from a newly isolated Bacillus licheniformis NH1, Enzyme and Microbial Technology, Volume 40, pp. 515-523
- Kalimuthu Kalishwaralal, Venkataraman Deepak, Sureshbabu Ram Kumar Pandian, Sangiliyandi Gurunathan (2009) Biological Synthesis Of Gold Nanocubes From Bacillus Licheniformis, Bioresource Technology, Volume 100, pp. 5356-5358
- Reindert Nijland and J. Grant Burgess (2010) Bacterial Olfaction, Biotechnology Journal, DOI 10.1002/biot.201000174
- Janelle Weaver (2010) Bacteria sniff out their food, Nature 16 August 2010, See http://www.nature.com/news/2010/100816/full/news.2010.411.html
- Abdelali Haoudi (2003) New Forum for Innovative Research in Biomedicine and Biotechnology, J Biomed Biotechnol. 2003, Issue 3, p.161