Production of Ascorbic Acid by Acetobacter Species Isolated from Soil in Keffi, Nigeria

Abstract

This investigation aimed at Production of Ascorbic acid by Acetobacter spp Isolated from soil in Keffi, was carried out using standard microbiological methods and identified standard techniques. The ability of the various isolates to produce Ascorbic acid were determined using starch solution Test and iodine crystal potassium iodide method while the quantitative determination of Ascorbic acid produced by each isolate was carried out and estimated using Gas Chromatography and Mass Spectrometry (GC & MS). The results obtained showed that the different species of Acetobacter isolated from the study area included Acetobacter orientalis and Acetobacter orleanensis. The investigation further revealed that  Acetobacter orientalis produced the highest Ascorbic acid at temperature of 28oC with 12.34 mg/l and least at 39oC with 5.12 mg/l, while Acetobacter orleanensis also produced highest at  28oC with 8.04 mg/l and least at 39oC with 2.75 mg/l. Acetobacter orientalis yielded highest at 20% substrate concentration  with 19.51 mg/l and least at 5% substrate concentration  4.19 mg/l, while Acetobacter orleanensis  yield highest at substrate concentration of 25% with 10.98 mg/l and least at 5% substrate concentration 1.75 mg/l. Acetobacter orientalis produced highest ascorbic acid after 96 hours with 16.22 mg/l and lowest after 144 hours with 2.5 mg/l. Acetobacter orleanensis  also produced highest Ascorbic acid after 96hours with 10.11 mg/l and least after 144 hours with 1.02 mg/l. Highest ascorbic acid was produced at pH5.0 by Acetobacter orientalis with 16.68 mg/l and the least was at pH 4.0 with 3.21 mg/l while Acetobacter orleanensis  produced highest at pH 5.5 with 9.12mg/l, the lowest at pH4.0 with 3.12 mg/l. This study shows that Acetobacter species isolated from the soil in Keffi metropolis has the ability to produce Ascorbic acid.