Novel xylanase activity and biofuel production in Lacrimispora xylanolytica isolated from termite guts symbionts.

Xylanase is crucial for converting lignocellulosic biomass into fermentable sugars, yet challenges such as thermostability, narrow pH activity ranges, and high production costs hindered recent advancements. The strain Ter3, isolated from termite guts and confirmed in both termite guts and nest soil via polymerase chain reaction-denaturing gradient gel electrophoresis, shares 99 % sequence similarity with Lacrimispora xylanolytica sy1. Ter3 produces 37-kilodalton extracellular endo-1,4-β-xylanase with an activity of 951.2 ± 25.9 U/mg at pH 6.5 and 50℃. Additionally, it generates 2,987.9 ± 31.1 mg/mL of ethanol, 37.6 ± 2.0 mg/L of butanol, and 41.5 ± 2.3 % hydrogen of total gas. Using molasses wastewater as a carbon source enhanced butanol production. Heterologous expression in Escherichia coli further increased specific activity of xylanase, reaching 8,960.1 ± 65.5 U/mg post-purification, surpassing that of the native enzyme. Ter3's robust xylanolytic, ethanologenic, and hydrogen-producing capabilities highlight its potential for biofuel production.