INVESTIGATION OF THE MALIC ACID CONCENTRATION ON EXTREMOPHILIC RED MICROALGA GALDIERIA SULPHURARIA

Neslihan Demirci, Çiğdem Demirkaya, Zeliha Demirel, Esra İmamoğlu, Meltem Conk Dalay
2016 Deu Muhendislik Fakultesi Fen ve Muhendislik  
Malic acid is a dicarboxylic acid which is made by living organisms and the salts of malic acid are known as malates. Malates are used in pruvate/malate cycle that merges carbohydrate, fat and protein metabolism. Based on this cycle, the prediction was that malic acid could change carbohydrates ratio in G.sulphuraria. In this study, the effects of malic acid concentrations were investigated on growth (maximum specific growth rate and doubling time) of extremophilic, red alga Galdieria
more » ... Galdieria sulphuraria (SAG 108.79). By increasing malic acid concentration, specific growth rate and biomass concentration were also increased, however the highest concentration of protein (153.81±0.673 mg/L) was obtained in 5 mM. The total amount of carbohydrates was increased about 8.35%. ÖZ Malik asit yaşayan organizmaların ürettiği ve malatlar gibi malik asit tuzları olduğu bilinen bir dikarboksilik asittir. Karbohidrat, yağ ve protein metabolizmasını birleştiren pürivat/malat döngüsünü içinde malatlar kullanılır. Bu döngü temelinde, malik asit Galderia sulphuraria nın karbonhidrat oranını değiştirebildiğini tahmin ediyoruz. Ayrıca bu konudaki benzer çalışmalara rastlanamamıştır. Bu çalışmada, malik asit konsantrasyonlarının ekstremofilik kırmızı alg G. Sulphuraria (SAG 108.79) büyümesi (maksimum spesifik büyüme oranı ve ikileneme süresi) üzerine etkisi incelenmiştir. Artan malik asit konsantrasyonunda spesifik büyüme oranı ve biykütle konsantrasyonu artarken, 5 mM konsantrasyonda proteinin en yüksek konsantrasyonu (153,81 ± 0,673 mg / L) belirlenmiştir. Sonuçlarımız karbonhidrat miktarında yaklaşık % 8,35 artış olduğunu göstermektedir. Culture Conditions 250 ml cultures were prepared with the same cell concentration (Figure 1 ). Malic acid concentrations were 0, 2, 5 and 10 mM and culture conditions were under 24 0 C at the agitation rate of 100 rpm under continuous light intensity of 20 μmol photons m -2 s -1 for 15 days. The culture growth was monitored by using spectrophotometer (Ultrospec 1100 pro, Amersham Biosciences) at 750 nm and cell growth (cells mL −1 ) was estimated daily using a Neubauer counting chamber under an inverted microscope (Olympus CH40, Japan). The specific growth rate (µ) of the cells was calculated from the exponential (straight line) phase, as µ = (ln N 2ln N 1 )/d (t 2 -t 1 ) , where N 2 is the final cell concentration, N 1 is the initial cell concentration and dt is the time required for the increase in concentration from N 1 to N 2 . Doubling time (DT) was also calculated as DT = ln 2/µ, according to Wood et al. 2005 [11].
doi:10.21205/deufmd.20165217550 fatcat:uj73bmsgqrhvnlvly6xx2cs76e