Abstract
The low biodegradability and environmental impact of petrochemical polymers have motivated the development of sustainable polymeric materials within the circular economy. Bacterial cellulose (BC) is a biodegradable, high-value biopolymer whose production from agro-industrial by-products, such as cheese whey, offers a low-cost and sustainable alternative. This study evaluated the effects of light availability and pH on BC production by a Symbiotic Culture of Bacteria and Yeast (SCOBY) cultivated in a dairy-based medium. Four conditions were investigated: light/pH 5, light/pH 7, absence of light/pH 5, and absence of light/pH 7, under static cultivation at 30 °C for 12 days. BC yield and water retention capacity (WCR) were determined after purification and drying. The highest yields were obtained under light at pH 5 (7.80 ± 0.68 g.L-1) and in the absence of light at pH 7 (7,02 ± 1,57 g.L-1), indicating a complementary interaction between pH and light conditions. All samples exhibited WCR values above 95% (E1 = 98,36 ± 0,25; E2 = 95,13 ± 1,07; E3 = 96,62 ± 0,15; and E4 = 97,56 ± 0,36), confirming high hydrophilicity and structural integrity. These results demonstrate that pH and light significantly influence BC biosynthesis and highlight the metabolic flexibility of the microbial consortium, contributing to the development of sustainable biotechnological processes for dairy by-product valorization.
