Friday, November 4, 2011


Honey has been used since time immemorial for many therapeutic use and the exact mechanism as to how this natural plant derived product can achieve all the properties it is claimed to have is still not very clear. The fact that it has high sugar content especially the low molecular types, glucose and fructose, gives a clue that the "osmotic pressure" of the product might be responsible for the antibacterial activity attributed to it. However there are other unusual properties associated with Honey which makes it a unique natural nutraceutical. Its low water activity of about 0.6, low pH in the range of 3.2 to 4.5, ability to chelate free iron, slow release of Hydrogen Peroxide, presence of Methylglyoxal, all combine together to make honey a super food that can preserve itself and protect humans from bacterial pathogens. Presence of many antioxidants like chrysin, pinobanksin, vitamin C, catalase enzyme, pinocembrin further makes honey a formidable health promoting food. If honey was known to humans for the last 10000 years why is that it has recently captured attention of scientists in the US which is one of the top 3 honey producing countries in the world? In their relentless efforts to get a deeper insight into honey of different varieties, these scientists were able to stumble upon a new Bacteriocin, the newly emerging protein based antibiotics, with vast potential for use by agro-food industry. Here is a take on this latest development in the honey front.

"Randy Worobo, associate professor of food microbiology at the New York State Agricultural Experiment Station in Geneva, and his lab members tested more than 2,000 strains of bacteria from eight types of honey from the United States and New Zealand. One of them stood out. "In sunflower honey from South Dakota, we identified a strain of Bacillus thuringiensis the biological control known to organic gardeners as 'Bt' — which was effective against common food-borne pathogens including Listeria monocytogenes, the bacteria behind the recent deadly cantaloupe outbreak," said Worobo. "This Bt strain was intriguing, because it had both strong antibacterial and strong antifungal activity." In analyzing the compounds produced by the bacteria, they found one with strong antibacterial activity that they designated as thurincin H. They recognized it as a bacteriocin, a common class of antimicrobials that bacteria produce to compete against other microbes. But compared with the some 40 known bacteriocins, it is unique: It is coded in the bacterial DNA as a unit containing three identical copies of the same bacteriocin gene".

Bacillus thuringensis has been in the news recently for all wrong reasons as its genes were commercially exploited by the Genetic Engineering scientists to make transgenic cotton and a number of other plant crops to make the latter resistant to field pests. However this humble organism, especially its spores has served the organic food industry admirably well for use in place of chemical pesticides. There are many strains of a particular microorganism with minor variations in their properties and B.thuringensis isolated by the US scientists was found to contain a natural peptide based antibiotic that is active against both bacterial pathogens like Listeria and virulent forms of E.coli. There are at present over 30 bacteriocins derived from different sources and there is hope that these natural peptide containing antibiotics will eventually replace other dual purpose antibiotics now being used in food industry saving the world from the dangers posed by the new strains of antibiotic resistant pathogens.


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