NOVELTY - Method (M1) for enhancing fermentation efficiency of microorganism, involves contacting a medium containing microorganism capable of fermenting, with methylsulfonylmethane (MSM), where MSN has concentration of 0.5-5 wt.% with respect to the medium or moisture content of the medium.    USE - The method (M1) is useful for enhancing fermentation efficiency of microorganism, preferably yeast and algae for producing beer, biofuel, cider, bread and dairy products. The method (M2) is useful for enhancing growth of one or more probiotic microorganisms in probiotic-containing product including milk, yogurt, rice yogurt, frozen yogurt, chocolate, beer, wine, vinegar, cheese, sauerkraut or their combinations. The method (M4) is useful for inhibiting microbial activity (all claimed) for inhibiting formation and/or release of microbial toxic metabolites and preventing and/or treating infections caused by bacteria, virus, yeast and fungi and reducing skin irritation, and healing wound. The virus includes astrovirus, lasso virus, human coronavirus, influenza virus and human papilloma virus. The yeast includes Saccharomyces cerevisiae and Candida albicans. The infectious disease includes leishmaniasis, keratitis, measles, meningitis, plague and pelvic inflammatory disease. The method is further useful for inhibiting growth of microorganisms in cosmetics, health products, pharmaceutical products or equipment susceptible to contamination, optical products, oral products and daily use products. The cosmetics include lipstick, foundation, blush, blonzer, mascara, nail polish and sunscreen. The medicinal products include eye drops, inhalants, lotions and ointments for treating allergy and athlete's foot. The equipments include nebulizers, catheters, syringes, incubation tubes, bedding, and diagnostic equipments. The optical products include contact lens. The oral products include toothpaste, toothbrush and tooth gel.    ADVANTAGE - The MSM is added to the food products during processing and packaging materials, and hence shelf life of the products is increased. The MSM improves rate and frequency of the probiotic proliferation, and hence production of probiotic products is increased. The MSM increases the fermentation efficiency of the microorganism as compared to the fermentation efficiency in the absence of MSM, hence production of fermentation products is increased by 50% and inhibits microbial activity by reducing growth rate of H1N1 influenza virus by at least 50% as compared to the growth rate of H1N1 influenza virus in absence of MSM.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) in vitro method (M2) for enhancing growth of one or more probiotic microorganisms, involves (a) contacting one or more probiotic microorganisms with a medium capable of supporting growth of one or more probiotic microorganisms, and (b) providing MSM (0.4-5 wt.%) to the medium for enhancing growth of microorganisms in vitro compared to growth of the microorganisms in vitro in absence of MSM;    (2) method (M3) for enhancing growth of microorganism in a test sample, involves contacting the diagnostic test sample comprising one or more microorganisms with a medium, and performing step (b) of (M1); and    (3) method (M4) for inhibiting microbial activity, involves selecting a medium susceptible to H1N1 influenza contamination, and contacting the medium with MSM (10-16 wt.%).