title: Strategy for improving extracellular lipolytic activities by a novel thermotolerant Staphylococcus sp. strain.
abstract: BACKGROUND
  Extracellular bacterial lipases received much attention for their substrate specificity and their ability to function under extreme environments (pH, temperature...). Many staphylococci produced lipases which were released into the culture medium. Reports of extracellular thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described.
  
  
  RESULTS
  This study focused on novel strategies to increase extracellular lipolytic enzyme production by a novel Staphylococcus sp. strain ESW. The microorganism needed neutral or alkaline pH values between 7.0 and 12.0 for growth. For pH values outside this range, cell growth seemed to be significantly inhibited. Staphylococcus sp. culture was able to grow within a wide temperature range (from 30 to 55°C). The presence of oils in the culture medium leaded to improvements in cells growth and lipolytic enzyme activity. On the other hand, although chemical surfactants leaded to an almost complete inhibition of growth and lipolytic enzyme production, their addition along the culture could affect the location of the enzyme. In addition, our results showed that this novel Staphylococcus sp. strain produced biosurfactants simultaneously with lipolytic activity, when soapstock (The main co-product of the vegetable oil refining industry), was used as the sole carbon source.
  
  
  CONCLUSIONS
  A simultaneous biosurfactant and extracellular lipolytic enzymes produced bacterial strain with potential application in soap stock treatment.
authors.affiliation: Laboratoire des Bioprocédés Environnementaux, Pôle d'Excellence Régional (PER, AUF), Centre de Biotechnologie de Sfax, Université de Sfax, Tunisia. slimcherif_enis@yahoo.fr
authors.forename: Slim
authors.initials: S
authors.lastname: Cherif
authors.forename: Sami
authors.initials: S
authors.lastname: Mnif
authors.forename: Fatma
authors.initials: F
authors.lastname: Hadrich
authors.forename: Slim
authors.initials: S
authors.lastname: Abdelkafi
authors.forename: Sami
authors.initials: S
authors.lastname: Sayadi
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism*; D002210:Caprylates / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D057075:Enzyme Assays; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000096:biosynthesis / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D013210:Staphylococcus / Q000201:enzymology*; D013501:Surface-Active Agents / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D002210:Caprylates; D003470:Culture Media; D008055:Lipids; D010938:Plant Oils; D013501:Surface-Active Agents; D014280:Triglycerides; C003637:tricaprylin; D008049:Lipase
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