Not everything is bad about fungi and bacteria

By JoWI Carteciano
MediaCore, NRCP

Some life forms, so tiny they can only be seen through the aid of microscope, survive in the most complex environment.  Some of these microbial life forms are bacteria and fungi.  Both microbes are single-celled and plant-like microorganisms. A lot of them are parasitic.

Many bacteria live in or on other organisms to survive.  This is because they do not have the ability to metabolize or convert food into molecular energy. 

They totally depend on host organisms that metabolize food into energy.  Such micromonsters grow and produce poisonous or toxic substances, which ravages the biological system of host organisms--including humans.  They may also grow and produce toxin in foods that are improperly sterilized (boiled/cooked) and packed (cans/jars). 

Ingestion of toxin contaminated food leads to a poisoning called botulism.  This means toxin interferes with the normal muscle activity and death can follow as a result of respiratory failure.

Meanwhile, fungi grow in just about anything that has organic component like dead plants and animals, groceries, films, leather shoes, clothing, paper products, and even on jet fuel clogging fuel lines.

Fungi that live on organic materials are called saprobes, while parasitic fungi subsist directly in living host.  Parasitic fungi ignite some of the most common itchy skin infections like athlete's foot, ringworm, and jock itch.

In spite the notoriety, not everything is bad in bacteria and fungi, says Dr. Florinia E. Merca, a chemist-member of the National Research Council of the Philippines. 

Dr. Merca during a three-year research discovered carbohydrates binding protein or heat and energy compound called lectin from three species of fungi and a species of bacteria that may yield medical and economic benefits.  

The fungi species are Penicillium cyclopium, Aspergillus niger, and Lenzites while the bacterium is Bacillus thuringiensis.  Dr. Merca's pioneering research project spanned 1996 to 1999 with a P500,000 NRCP fund.  The "importance of lectin in medical research" along with its prohibitive cost locally spurred her research interest.

Previously, lectin is considered a poisonous compound commonly found in many plants and in seeds, especially beans, although it is not yet clear how the toxin benefits the seeds. 

Human body has natural detoxification system that can cope with small amount of most lectins.  In deadly doses, some lectins induce blood clotting and interfere with the immune system. 

If ingested, the first body part to be affected is the intestinal wall, which gets inflamed.  When lectins were absorbed in the bloodstream (capillaries and veins), cancerous cell would develop.  The most poisonous kind of lectin is known as ricin, which is found in castor beans.

Dr. Merca's research data, however, show that lectin activities such as mutagenic, mitogenic, and agglutination are present in the fungi and bacteria cited.

When lectins from tiny life forms are purified, they can be used by medical researchers to investigate the morphology or the structure and form of human cell surfaces undergoing mutation (lectin's mutagenic activity).  With this, development and changes in cancerous cell may be easily identified and studied for immediate medical remediation and cure.

Purified lectins are also used in detecting the presence of heavy metals like lead and mercury in the human blood--another form of poisoning.  Lead and mercury may cause kidney malfunction.

The same research data also show that other forms of lectins found from these tiny life forms exhibit mitogenic activity, or simply, the lectins induce cell division or reproduction of lymphocytes (white blood cell).   This kind of lectin provides a ready and simple means of evaluating the strength and capability of the immune system of a patient.

Other forms of lectins, especially those found in the species of bacteria exhibited agglutination capability, or the capability to attach to human red blood cells.  With this lectin character, the study of chemical nature of human blood groups, identification, diagnosis, and type classification would be easier.

Dr. Merca tested the bioactivities of lectin using slightly outdated human blood of different types provided by the National Red Cross in Sta. Cruz, Laguna, in recognition of scientific research ethics that prohibits human as specimen.

With the multi-bioactivities of lectin, Dr. Merca stresses lectin's great potential as prime ingredient in developing customized drugs because lectin could take the drug to the exact site of disease or infection.

The only blot in the brilliant work is it "needs a series of pre-clinical trials to transform this discovery into marketable lectin-based medical products", she said.

To date, the Philippines' pharmaceutical industry has yet to develop a local lectin product.  The country chiefly imports purified lectins that come at high cost. 

 Dr. Merca is recipient of the 2004 Commission on Higher Education Republic Award for scientific research.  She is currently based at UP Los Baños Institute of Chemistry and among the 2,889 member scientists of NRCP, the oldest basic research and scientific advisory arm of the government.

The NRCP will feature Dr. Merca's achievement during the 2004 National Science and Technology Week that will be held at Casablanca Hotel July 23-26 in Legaspi City.