Valorisation of bamboo stems for the production of fermentable carbohydrates

Fermentable carbohydrates serve as the primary raw material for the majority of bio-based commodity chemicals and biofuels. The demand for this raw material is projected to rise significantly in the coming decades. The anticipated rise in demand for fermentable carbohydrates (FC), also known as fermentable sugars (FS), is indicated by the numerous biochemical pathways being developed for the production of bio-based commodity chemicals through sugar fermentation. The high cellulose and hemicellulose content in bamboo stems makes them a promising source for producing fermentable sugars, which is the aim of this project, to valorise bamboo stems for the production of fermentable sugars.  A small amount of the bamboo stem sample (20 mg) was dried (55 °C, 10 mbar, 2 h) using a rotational vacuum concentrator (Christ Rvc 2-33IR), the dried substance was dissolved in 1000 µL of pyridine and placed in an ultrasonic bath for 5 min. In addition, the sample was mixed well by vortex for 20 s. The sample was centrifuged (12,000× g, 10 min, 20 °C) to remove any insoluble materials. Part of the supernatant, 800 µL, was taken for the oximation-silylation step. Pretereatment was by enzymatic hydrolysis and a gas chromatography-mass spectrometry (GC-MS) analysis was carried out, several carbohydrates were identified, including D-Galacturonic acid, D-Glucuronic acid, D-Fructose, L-Rhamnose, D-Glucose, D-Galactose, D-Mannose, L-Arabinose, D-Fucose, D-Xylose, D-Glucosamine hydrochloride, D-Galactosamine hydrochloride, D-Mannosamine hydrochloride, and Meso-Erythritol. The fermentation was carried out for 28 days and measurements were taken every 7 days. The fermentation process demonstrated a progressive increase in sugar concentrations, with D-Glucose and D-Xylose reaching their highest concentrations on Day 28, with peak areas of 23.41 and 31.77 respectively. The results confirm that bamboo stems are a viable and cost-effective lignocellulosic biomass contributing to effective waste management, renewable energy development and climate change mitigation efforts.