Impact of pH changes on neutral lipid production of the microalga Dunaliella tertiolecta isolated from Meke Crater Lake (Konya/Turkey)

Year 2018, Volume: 14 Issue: 3, 220 - 231, 01.09.2018

Zeynep Elibol Çakmak

https://doi.org/10.22392/egirdir.397153

Cited By: 1

Abstract

In
this study, the impact of a change in pH
of the growth medium on the production of
triacylglycerol (used as a biodiesel feedstock) and related parameters were evaluated in a green halophilic microalga Dunaliella tertiolecta. Microalgae were cultured
in Johnson's nutrient medium with different initial pH values (pH = 4, 6,
8, 10)  under suitable conditions for 25
days and growth was followed,
triacylglycerol production and related parameters were analyzed. There was an
increase in the growth rate, total chlorophyll and
carotenoid contents, net oxygen production and
consumption ratio did not show a significant change as accompanied by a remarkable increase of neutral lipid and
triacylglycerol content of microalgae in proportion to a decrease in initial
pH. On the other side, there was a decrease
in the total chlorophyll and carotenoid content accompanied by a decrease in
both oxygen production and consumption ration while there was no significant
change in growth rate, neutral lipid, and triacylglycerol production of
microalgae when the medium pH is adjusted as 10. Results show that lowering the
initial pH of the growth medium might be used as a practical approach for
induction of biodiesel feedstock production by Dunaliella tertiolecta.

Keywords

Biodiesel, Dunaliella tertiolecta, pH

Meke Krater Gölü’nden (Konya/Türkiye) İzole Edilen Dunaliella tertiolecta Mikroalginin Nötral Lipid İçeriğine pH Değişimlerinin Etkisi

Abstract

Bu çalışmada, halofil bir yeşil mikroalg
olan Dunaliella tertiolecta’nın
büyüme ortamındaki pH değişikliğinin biyodizel hammaddesi olarak kullanılan
triaçilgliserol üretimi ve ilgili parametrelerde meydana gelen değişimi üzerine
etkisi değerlendirilmiştir. Mikroalgler Johnson’s besin ortamında farklı
pH’larda (pH=4, 6, 8, 10) 25 gün boyunca uygun şartlarda kültüre alınmış ve
büyümeleri takip edilmiş, triaçilgliserol üretimleri ve ilgili parametreler analiz
edilmiştir. Mikroalglerin büyüme ortamının başlangıç pH’sındaki düşüşle doğru
orantılı olarak büyüme hızı, toplam klorofil ve karotenoid miktarlarında artış,
net oksijen üretim ve tüketim hızında önemli bir değişim belirlenmezken nötral
lipid ve triaçilgliserol üretiminde de artma olmuştur. Diğer taraftan ortam
pH’sı 10 olarak ayarlandığında ise mikroalglerin çoğalma hızında önemli bir
değişim belirlenmezken,  toplam klorofil
ve karotenoid miktarlarında düşüş, net oksijen üretim ve tüketim hızlarında
azalma olmuş, nötral lipid ve triaçilgliserol üretiminde dikkate değer bir
değişim gözlenmemiştir. Elde edilen sonuçlar D.tertiolecta’dan biyodizel hammaddesi üretimi için ortam pH’sını düşürmenin
etkili bir sonuç alınabilecek pratik bir yöntem olduğunu göstermiştir. 

Keywords

Biyodizel, Dunaliella tertiolecta, pH, Triaçilgliserol

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