Rhizopus arrhizus ile Atık Yemeklik Yağdan Biyodizel Üretiminin Kesikli Sistemde İncelenmesi ve Optimizasyonu

In this thesis study, the production of biodiesel by transesterification reaction from waste cooking oil and methanol was investigated in a batch system using dried R. arrhizus fungus, cultivated in different conditions, containing intracellular lipase enzyme directly as a catalyst. Also the parameters affecting the reaction were researched. In the first stage of study, R. arrhizus cultivated in the growth medium prepared from the waste orange peel at 30 oC and 120 rpm was determined having the maximum intracellular lipase activity compared to the intracellular lipase activities obtained from R. arrhizus grown in the nutrient media prepared from the glucose and the molasses. The effect of the initial concentration of total reducing sugar (TRS) of waste orange peel in the range of 9-21 g/L on microbial growth rate, yield and intracellular and extracellular lipase hydrolysis activities were investigated. While the maximum microbial growth was found as 3,83 g dried m.o./L in the growth medium prepared from 70 g/L waste orange peel containing 21,0 g/L TRS, the maximum intracellular lipase hydrolysis activity was obtained as 0,40 U/mg in the growth medium prepared from 50 g/L waste orange peel containing 15,0 g/L TRS. Olive oil or waste cooking oil (WCO) was added in the range of 5-40 g/L to the growth medium prepared from 50 g/L waste orange peel as an inducer to increase the intracellular lipase hydrolysis activity of the microorganism. The effects of additive oil concentrations on the microbial growth and intracellular lipase hydrolysis activity were examined. It was observed that the addition of WCO much more increased both microbial growth and intracellular lipase hydrolysis activity compared to olive oil addition. When 10 g/L WCO was added to the growth medium, intracellular lipase hydrolysis activity reached to 0,52 U/mg, increasing 30% compared to the activity obtained in the growth medium containing no WCO. The growth medium prepared from 50 g/L waste orange peel with 10 g/L WCO was used to grow the R. ...