Statistical Optimization of Medium Composition for Bacterial Cellulose Production by Gluconacetobacter hansenii UAC09 Using Coffee Cherry Husk Extract – an Agro-Industry Waste.

During the production of grape wine, the formation of
thick leathery pellicle/bacterial cellulose (BC) at the airliquid
interface was due to the bacterium, which was
isolated and identified as Gluconacetobacter hansenii UAC09.
Cultural conditions for bacterial cellulose production from
G. hansenii UAC09 were optimized by central composite
rotatable experimental design. To economize the BC
production, coffee cherry husk (CCH) extract and corn
steep liquor (CSL) were used as less expensive sources of
carbon and nitrogen, respectively. CCH and CSL are byproducts
from the coffee processing and starch processing
industry, respectively. The interactions between pH (4.5-
8.5), CSL (2-10%), alcohol (0.5-2%), acetic acid (0.5-
2%), and water dilution rate to CCH ratio (1:1 to 1:5)
were studied using response surface methodology. The
optimum conditions for maximum BC production were
pH (6.64), CSL (10%), alcohol (0.5%), acetic acid (1.13%),
and water to CCH ratio (1:1). After 2 weeks of fermentation,
the amount of BC produced was 6.24 g/l. This yield was
comparable to the predicted value of 6.09 g/l. This is the
first report on the optimization of the fermentation medium
by RSM using CCH extract as the carbon source for BC
production by G. hansenii UAC09.