Sunday, July 24, 2011
Grand Ballroom, 5th fl (Sheraton New Orleans)
Lipases (EC 3.1.1.3) are hydrolytic enzymes capable of catalysing the production of fatty acid methyl esters (biodiesel). In contrast to esterases, lipases are activated only when adsorbed to an oil-water interface. Commercially useful lipases are usually obtained from microorganisms that produce a wide variety of extracellular lipases. In the last two decades, lipases have gained interest because of their potential use in the food, detergent, leather and biodiesel industries. To date, however, reports on lipolytic microorganisms isolated from the Yellowstone National Park (YNP) are scant. The objective of this work was to isolate and screen for thermophlic lypolytic bacteria with unique properties and capabilities for transesterification of waste oils to biodiesel. Soil samples were collected from mushroom, bath and octopus springs in YNP and separately enriched at 650C in a basal medium (pH 7) supplemented with 1% (v/v) of tributyrine oil, tributyrine oil emulsion, soybean oil or waste cooking oil. The primary screening for lipase production was carried out using olive oil emulsion agar and rhodamine B agar plate techniques. Selected cultures were studied for extracellulase lipase production in liquid fermentations under various nutritional and environmental conditions. The most promising lipolytic bacterial isolates, shown to produce highly thermostable extracellular lipases, were selected for further optimization studies.