Bacterial cellulose production by Acetobacter xylinum and Saccharomyces cerevisiae in green tea leaves and fruits juice medium.

Abstract

The biomembrane (bacterial cellulose) was developed by Gluconacetobacter xylinus ATTC 23769, associated to Saccharomyces cerevisiae, for 7-10 days cultivation, from residual fruit-vegetable juices added to green tea broth, was studied and hydroalcoholic Calendula officinalis extract (1:1) was incorporated into biomembrane. Cultures were grown 1200 mLflasks with 80% v/v broth (Green Tea, Orange, Papaya, Wine, Collagen and Beet broths) and 20% v/v inoculum, incubated for 7-10 days at 28±2°C under static conditions, pH initial 3.5 4.0. The biomembrane thickness, diameter and weight were measured. The DSC, FTIR, BET analyses were performed 
and Water and Marigold absorption capacity were calculated.The highest bacterial cellulose yield (6.1±0.5 g cellulose/day) was obtained in green tea medium with 40% v/v papaya juice and also 10% v/v orange juice. Moreover, the addition of 1.2% w/v collagen to the green tea medium increased by 1.5 times the biomembrane weight. The developed biomembrane is composed by cellulose (confirmed by infrared -1 spectroscopy (FTIR) at λ = 1644 cm ), with a total surface of max 22.07 m /g, an average porous size of 158 Å (BET), strength and elasticity between 0.09-0.5 MPa, (similar to Young's model for indentation) and thermal stability up to 137 °C (DSC). The biomembrane absorption capacity for water and hydroalcoholic Calendula officinalis extract (1:1), was six and five times higher than its dry weight, respectively. The Marigold extract was incorporated into the biomembrane due to its suitable topical properties, such as antioxidant, anti-inflammatory and 
wound healing.