Production, Purification and Characterization of Cellulose from Local Isolate of Pantoea spp

Abstract

Soil samples from fields cultivated with barley and wheat in addition to samples
from spoiled orange and apple fruits and carrot roots were collected with the aim to
isolate cellulase producing bacterial strains. Bacterial isolates obtained from these
samples were grown on a selective medium containing carboxymethyl cellulose
(CMC) as a sole source for carbon and energy. Results showed that nine isolates out
of fifty were able to produce cellulase.The specific activity of cellulase in culture
filtrate of the most efficient isolate was 1.601 u/mg protein.This isolate was
identified according to its morphological characteristics and biochemical tests, and
then by using Api 20-E and VITEK-II identification systems and was identified as
Pantoea dispersa. Cellulase produced by P. dispersa was purified throughout four
purification steps including ammonium sulfate precipitation, dialysis followed by
purification with ion exchange chromatography using DEAE-cellulose, and then gel
filtration throughout sephadex-G200. Purification results showed that the specific
activity of the purified enzyme was 1181.8 u/mg protein with a purification fold and
yield 115.2 and 26.6% respectively. Purified cellulase from Pantoea dispersa was
well characterized by studying some enzyme characteristics. The molecular weight
of cellulase was 15148 dalton, and pH 7.0 was the optimum for enzyme activity and
stability, while 30 ºC was the optimum for enzyme activity and stability