Portakal Hidrolizatı ve Melas İçerikli Besiyeri Ortamında Sitrik Asit Üretimine Başlangıç Toplam Şeker Derişiminin Etkisi

Özet

In this study hydrolyzate which was obtained from orange peel and pretreated molasses were used. Aspergillus niger which was commonly in use for citric acid production was used. With this study orange peel which has a waste value was evaluated. In citric acid production various parameters has to be optimized. In this study effect of substrate concentration on citric acid was evaluated. In the study initial pH 6.0, methanol ratio 4%, incubation temperature 30oC, agitation rate 150 rpm. Incubation temperature 30oC, working volume 100 ml, microorganism ratio 1%,corn extract oil 2%, K4Fe(CN)6concentration 200 mg/l were adjusted constant. At 100 g/l total sugar concentration media, pH 3.01, citric acid 31.8g/l, used total sugar concentration 79 g/l and dried mycelia weight 24.3 g/l were observed at 6 th day incubation. At 140 g/l total sugar concentration media, pH 2.36, citric acid 35.6 g/l, used total sugar concentration 108 g/l and dried mycelia weight 28.7 g/l were observed. At 180 g/l sugar concentration media, pH 3.84, citric acid 18.8 g/l, used total sugar concentration132 g/l and dried mycelia weight 42.7 g/l were observed.Optimum sugar concentration chanced with used microorganism and fermentation material. Every researcher using different molasses type and fermentation material for this reason sugar optimum concentration is changeable. Citric acid can not be produced under 50 g/l sugar concentrations.At literature studies conducted at 100 and 140 g/l sugar concentrations that’s why in this study sugar concentration started with 100, and ended with 180 g/l. It has been thought that the reason for decreasing citric acid production with increasing sugar concentration might be substrate inhibition.