Original Article Published in

And giving them a place in our everyday products

 

 

We each kill bacteria by the billions each day – and that's a good thing.  Germs can cause maladies from simple infections to serious illness such as Septicemia.  Americans purchased more than half a trillion dollars worth of antibacterial soaps, hand-cleaners and detergents last year.  Antimicrobial body wash and shampoo, Triclosan soap, Micro-ban imbedded toothbrushes – and this doesn't even include a wide range of prescribed antibiotics.  But there is a downside to this widespread use of antimicrobials.

 

A study published by the CDC (Center for Disease Control) suggests that longer term use of antibacterial soaps and antibacterial-coated products may contribute to increases of antibiotic resistance in our society.  It is possible that these products could encourage bacteria to mutate in ways that make them resistant to antibacterial products, including antibiotics.  

 

While locked in this battle against bacteria it's easy to overlook that some of those bacteria aren't so bad; some are even beneficial when employed to do our work.  In fact, some are providing lucrative profits for industry by rolling up their sleeves and putting on hard hats.  

 

 

Micro Miners and Oil Dispatchers

​

Microorganisms have been introduced to the mining industry for the purpose of extracting metals from low-grade ores and bioleaching of ores and concentrates.  Some genetically engineered strains can stand up to high temperature processes and heavy metals such as arsenic, mercury or cadmium.  Such biomining has become one of the premier new mining innovations. One energy related application is to use microbes to clean high-sulfur coal, producing more environmentally friendly fuels for power plants.  In the future, reductions in sulfur-laden acid rain may well be attributed to microbes.

 

Cleaning up oil spills is a messy business.  After blocking and absorbing the spill with physical booms, sponges and skimmers, clean-up crews employ biological agents to break down the remaining oil through bioremediation.  Bioremediation employs microbiota to degrade polycyclic aromatic compounds found in crude oil.  The chemicals are consumed and output as carbon dioxide and water.  Some studies have shown that shoreline sites of prior spills have over time evolved biota populations that grow and degrade crude oil.  For areas new to spills a fluid mix of oil-eating bacteria and nutrients may have to be added to the environment to promote cleanup.

 

Microbes have also been used to coat concrete surfaces contaminated by nuclear waste.  The bacteria produce sulfuric acid which etches the contaminated concrete surface.  Lowing the humidity kills the microbes which are then vacuumed off the walls and floor as dust.  Clearly, bacteria are putting in some long hours working to clean up our messes.

 

 

Product Mutualism

​

Throughout history cultures have advanced through successive manipulation of biological resources.  Wild grains are bred into domestic wheat, wild oxen are domesticated into more productive breeds of cattle, bees are domesticated for honey production and now we have selective breeding and genetic manipulation of microbes.  In the farming industry taking care of animals to benefit society is called husbandry.  The breeds (or strains) selected benefit by having their genes selectively propagated over those of other organisms.  Society benefits from the goods (bread, milk, honey) produced.

 

Though both animals and people benefit from husbandry, it is somewhat different from the biological term mutualism, a type of symbiosis.  Mutualism is more “personal” than husbandry.  It is the mutually beneficial interdependence of two dissimilar organisms.  For example, clownfish that protect and are protected by sea anemones, or, the bacteria in the human gut which aid us in digestion.  These organisms evolved to take mutual advantage of each other for what they could not do alone.

 

There are also examples of beneficial situations between an organism and a designed product.  Such relationships between organisms and products could be described as product mutualism.  Better beer and wine production comes from vats designed to ferment select strains of yeast.  Similarly engineered environments produce higher yields of vitamins, pharmaceuticals, and soy sauce.  And without the correct strains of mold seeded into properly designed and monitored cheese vats and caseales (kitchens) we would never know the joy of Roquefort cheese.

 

Properly designed products supporting living bacteria let them do what either comes naturally or what they were bioengineered to do.  The products designed for these microbes are essentially micro-habitats.  And that's how the bacteria in the human gut would think of us (if they could think) – as a nice warm habitat in which to live and grow.  

 

 

Products as Microbe Habitats

​

We enjoy the by-products of mold and yeast, we just don't want them growing on our bathroom walls.  Free-range mold is not a good idea.  But with the advent of specifically designed micro-habitats for them, we can utilize microorganisms on a more personal product scale.

 

Not all bacteria are so macho as the previously mentioned biomining variety.  Some lead a relatively easy life as living components in products.  This month Kartik Madiraju, a 16-year old high school student, won $4,000 and the First Place Grand Award in Environmental Science for his project focused on using bacteria to generate electricity.  Madiraju discovered how to employ naturally occurring magnetic bacteria to generate electricity.  Current and power generated by the bacteria were sustained at 25 microamps and 5.5 microwatts, about half the voltage of an AA battery.  It opens possibilities for the bacterial powering of cell phones and laptops.

 

Another energy producer, an electrically-assisted microbial fuel cell design developed by Penn State and Ion Power, Inc., coaxes bacteria to produce four times as much hydrogen directly out of biomass than can be generated typically by fermentation alone.  That means more efficient fuel cells for electrical production.  It also accomplishes this while cleaning waste water. 

 

What else can you power with bacteria?  Ask the "gastrobot", the world's first robot that eats and digests to generate its own power.  Dubbed "Gastronome", it is powered by a microbial fuel cell filled with E. coli bacteria.  It breaks down glucose, releasing electrons which are captured to charge a battery.  Inventor Stuart Wilkinson, an associate professor of mechanical engineering, says one eventual commercial use could be “a robotic lawn mower that eats the clippings for power."

 

 

Smart Bacteria

​

Bacteria are even into computers, or rather, they are computers.  A report from Princeton and the National Academy of Sciences showed the feasibility of inserting engineered segments of DNA into cell nuclei to make them behave in the same manner as digital circuits. "The cells, for example, could be made to perform basic mathematical logic and produce crisp, reliable readouts that are more commonly associated with silicon chips than biological organisms." 

 

Researcher Ron Weiss from Princeton University and his collaborators have programmed bacteria to emit fluorescent light of one color when a higher concentration of a select chemical is detected, and another color when a lower concentration was sensed.  The bacteria communicate with each other and produce color-coded patterns.  They can be used to detect harmful chemicals and organisms in the environment. 

 

When living organisms become part of our personal lifestyles by powering our laptop fuel cells, running our lawnmowers and providing urban sensors that detect the presence of anthrax ... how should we relate to them?  Luckily there is a model of such a mutual relationship that has existed for thousands of years.  It's the practice of husbandry.  Only now its focus is upon a smaller animal – the bacteria.

 

 

4H for Bacteria

​

Properly designed product-microbe habitats can provide suitable environments for bacteria to perform specific functions such as produce power, do computations and act as environmental sensors.  We also know that bacteria can be slimy, smelly and taste badly.  But if you can bioengineer desired qualities you may be able to enhance personal products by making them fragrant, acidic, alkaline, fruity and, when appropriate, – sticky, slick or oily.

 

For example, a baseball bat grip designed of foamed plastic has millions of tiny foam cells open to the air.  Develop a resin-producing bacteria activated to produce a sticky residue in the presence of human sweat.  Imbed the foam cells with a bacteria infused nutrient promoting their growth while killing other bacteria.  The bat gradually generates resin when grasped with sweaty palms.  The more sweat, the more resin is produced giving a more secure grip.  The batter's grip is improved and the bacteria thrive.  Storing the bat at the end of the season in a hallway closet allows the bacteria to go dormant and resin production ceases until spring training begins.

 

In addition to resin for tool grips, other possibilities include variations on what bacteria do naturally.  Bioengineered bacteria that produce mucous (yuck!) to reduce drag on the surface of racing yacht hulls and water skis.  Or bacterial strains that sense chemicals associated with undesirable odors and respond by generating fragrant chemicals.  

 

By employing biological agents as part of a product's function a direct connection is made through the product back to nature.  That connection is as alive as the biological agent, which is somewhat fragile and needs care and attention to function properly.  In some ways care for your product is the bioengineering equivalent of the lessons of responsibility and animal husbandry taught worldwide through “4H” agriculture and farming clubs for children.  

 

Designing such product-microbe systems is the antithesis of designing "indestructible" products.  Indestructible products teach us nothing of caring for our possessions.  Knowing that the microbes require some minimal care and attention for proper functioning requires us to care for our possessions with the same responsibility as we do for our plants or pets.  And caring for products instills lessons that can apply to caring for the environment and caring for each other.