Pretreatment of olive mill wastewater for citric acid production by Yarrowia lipolytica

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Küçük Resim

Tarih

2016

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier Science Bv

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

Olive mill wastewater (OMW) is known as one of the most polluted wastes difficult to treat because of its high content in phenolic compounds. In this study, OMW was treated in order to decrease its phenolic compound content and to be used as a fer-mentation medium in citric acid production. Detoxification process included coarse filtration, overliming and pH adjustment followed by centrifugation and finally activated charcoal treatment. OMW was exposed to activated charcoal at 3% and 5% (w/v) concentra-tions at 45 ◦C and 100 strokes/min shaking rate for two hours. Both of the OMW were used in fermentation experiments without any dilution and after fortification with glucose (10%). Growth and cit-ric acid production of Yarrowia lipolytica 57 and a mutant strain Y. lipolytica K-168 were investigated in pretreated and fortified OMW. It was found that amount of total phenolic compounds decreased by 50% and 70% after overliming combined with 3% and 5% acti- vated charcoal, respectively. Cell counts of the yeasts increased by approximately 2 logarithmic units in both media. Citric acid pro-duction of Y. lipolytica 57 was recorded as 8.18 g/L and 5.54 g/L for 3% and 5% activated charcoal, respectively. Y. lipolytica K-168 produced 8.23 g/L citric acid in the medium exposed to 3% acti- vated charcoal and 7.60 g/L citric acid was obtained for 5% activated charcoal. Although detoxified and fortified OMW supported yeast.growth and citric acid production, it was suggested that optimiza- tion of detoxification steps would be appropriate for increasing citric acid yield.

Açıklama

Anahtar Kelimeler

Citric Acid Production, Yarrowia Lipolytica, Olive Mill Waste

Kaynak

New Biotechnology

WoS Q Değeri

Q1

Scopus Q Değeri

Cilt

33

Sayı

Künye