Olive-mill wastewaters: a promising substrate for microbial lipase production

Area of Science:

• Biotechnology
• Environmental Science
• Enzyme Technology

Background:

• Olive-mill wastewater (OMW) is a significant industrial byproduct with environmental concerns.
• Valorization of OMW through microbial processes offers a sustainable solution.
• Lipases are versatile enzymes with broad industrial applications.

Purpose of the Study:

• To investigate the potential of OMW as a cost-effective medium for microbial lipase production.
• To screen various microbial strains for their ability to produce extracellular lipase using OMW.
• To optimize lipase production by identifying suitable nitrogen sources and inducers.

Main Methods:

• Screening of multiple fungal and yeast strains (Geotrichum candidum, Rhizopus, Aspergillus, Candida cylindracea, Penicillium citrinum) for lipase production on undiluted OMW.
• Cultivation of selected strains on OMW with variations in nitrogen sources (e.g., NH(4)Cl).
• Induction of lipase production using olive oil as a supplement.

Main Results:

• All screened microbial strains successfully grew on undiluted OMW and exhibited extracellular lipase activity.
• Candida cylindracea NRRL Y-17506 demonstrated the highest lipase activity across different OMW types.
• Optimal lipase production (9.23 IU ml(-1)) by C. cylindracea was achieved with OMW supplemented with 2.4 g/L NH(4)Cl and 3.0 g/L olive oil.

Conclusions:

• OMW is a viable and effective substrate for the microbial production of extracellular lipase.
• Candida cylindracea NRRL Y-17506 is a promising candidate for industrial lipase synthesis using OMW.
• Optimized conditions involving specific nitrogen sources and olive oil enhance lipase yield from OMW.