Variasi Ph Pada Media Tumbuh Dan Suhu Fermentasi Dalam Memproduksi Etanol Oleh Isolat BU3.111E1

Abstract

The aim of this research was to determine the growth phase curve of BU3.111E1 and to determine the effect of various pH and temperatures on BU3.111E1 isolate growth media to produce ethanol. These experiment was carried out in stages, namely culture stock rejuvenation, culture grow and adjustment, measuring the effects of various pH and temperature in media upon fermentation followed by distillation. This study used two variations of pH (4.0 and 5.0) and three variations of temperature (18, 24 and 30°C) and two repetitions. The growth curve of BU3.111E1 isolate showed that the isolate grew in 33 hours, starting from the exponential phase, stationary phase to the death phase. The fermentation results showed that, pH 4.0 at 30°C produced the highest ethanol which was 15.05 mL with a total dissolved solids of 2.50 (?% brix). pH 5.0 at 18°C ??was produced the lowest ethanol, which was 3.47 mL with a total dissolved solids of 0.65 (?% brix). The results indicate that pH and temperature affect bacteria during fermentation to produce ethanol.

Pengaruh Konsentrasi Crude Enzim Bacillus subtilis terhadap Kadar Gula dan Bioetanol Hasil Fermentasi Kulit Singkong Menggunakan Zymomonas mobilis

“…Terjadinya penurunan pH setelah fermentasi disebabkan Zymomonas mobilis selain memproduksi etanol juga terdapat CO2 dan asam-asam organik (Fadilah et al, 2018). pH yang terukur sudah sesuai dengan teori Malau et al (2022) Hasil uji ANOVA diperoleh signifikansi sebesar 0,000 artinya nilai 0,000 < 0,05 sehingga ditolak dan HI diterima. Hal ini dinyatakan bahwa terdapat beda nyata antara rerata gula reduksi terhadap gula reduksi pada setiap perlakuan.…”