Characterization of agarolytic enzymes of Arthrobacter spp. AG-1 for the whole cell conversion of agar into 3,6-anhydro-a-l-galactose in one pot

3,6-anhydro-α-l-galactose (l-AHG) is a commercially unavailable monosaccharide with high therapeutic value, in particular, anti-viral. l-AHG is a selective inhibitor of HIV reverse transcriptase. Till date, the synthesis of l-AHG remains an intricate process and there is a need for a simpler approach producing l-AHG industrially. Herein, we report an agar-hydrolyzing Arthrobacter spp. AG-1 isolated from Gulf of Mannar, Tamil Nadu which completely converts agar to l-AHG with their extracellular agarase in one pot. The optimal temperature and pH for the maximal activity of Arthrobacter spp. strain AG-1 were 45 °C and pH 7 respectively. We purified and characterized the 44 kDa agarase involved in the glycoside hydrolysis. The Vmax, Km, and Kcat value of the agarase were determined as 1.7848 × 10−2 U/mg, 0.01825 ± 0.001 M and 0.1748 ± 0.006 S−1 respectively. Presence of l-AHG was confirmed by TLC. Detailed ESI–MS revealed the presence of a relatively higher abundance of l-AHG and chemical fingerprinting analysis by FT-IR, GC–MS and CD confirmed that the end product as l-AHG. Additionally, l-AHG exhibited notable anti-inflammatory and antibacterial activity. The whole cell biocatalytic system is predicted as a starting point for a more detailed study on Arthrobacter spp. extracellular agarase.