Enzymatic Saccharification of Dilute Acid Pretreated Saline Microalgae, Nannochloropsis Oculata

Published in: Global Partnerships for Development and Engineering Education: Proceedings of the 15th LACCEI International Multi-Conference for Engineering, Education and Technology
Date of Conference: July 19-21, 2017
Location of Conference: Boca Raton, FL, United States
Authors: Samriddhi Buxy, PhD. (University of Florida, US)
Robert Diltz, PhD. (United States Air Force, US)
Pratap Pullammanappallil, PhD. (University of Florida, US)
Full Paper: #467

Abstract:

Present study evaluated saccharification potential of marine microalgae N. oculata by employing conventional techniques of hydrolysis and subsequent saccharification often used for lignocellulosic biomass. N.oculata was first hydrolyzed using dilute acid such as, 5% (v/v) sulfuric acid, and 5% (v/v) and 2% (v/v) phosphoric acid at 160C before subjecting to enzymatic saccharification by two commercial cellulases, EI and EII. Neither dilute acid hydrolysis nor enzymatic saccharification alone released any sugars. However, hydrolysates after acid hydrolysis were readily saccharified on addition of enzymes EI or EII. The extent of saccharification ranged between 8 and 100% in all experiments. Sulfuric acid hydrolysis produced furfurals whereas no side products were detected after phosphoric acid hydrolysis. Maximum sugar yield using EI was 345 g sugars/kg ash free dry matter (afdm) within 4 hours whereas EII yielded 360 g sugars/kg afdm within 12 hours. Twice of the nominal enzyme loading facilitated 35% more sugar release and half the nominal enzyme loading yielded 64% less sugars. It was concluded that conventional dilute phosphoric acid hydrolysis followed by enzymatic saccharification using commercially available enzymes could be efficient for saccharification of marine microalgae.