Cellulose production by Gluconacetobacter kakiaceti GM5 in two batch process using vinasse as culture media

Abstract

The present study was conducted to evaluate the cellulose production by Gluconacetobacter kakiaceti GM5 by means of two aerobic treatments: the static discontinuous fermentation process (treatment 1) and the discontinuous fermentation process in a rotary shaker (treatment 2). All these experiments were carried out using vinasse as experimental culture media (VM) and were compared with standard media containing glucose at 2% (standard medium (SM)). A sample of each treatment was extracted every 24 h over a period of 168 h. The maximum rates of cellulose produced in treatment 1 using SM added up to 3.63 ± 0.18 g l−1, and to 4.15 ± 0.16 g l−1 when VM was used. The amount of cellulose produced in treatment 2 using SM was 2.95 ± 0.09 g l−1 (which suggests an increase of 37%), and added up to 1.84 ± 0.07 g l−1 when using VM. A better global yield of both treatments in terms of sugar consumption after 168 h was obtained when using VM: 32% in treatment 1, whereas in treatment 2 it was 9%. A 20% decrease on vinasse COD (Chemical Oxygen Demand) values was found to be yet another important advantage of working with this strain.