Chemical Pretreatment and Enzymatic Saccharification of Seaweed Solid Wastes
Abstract: The technical
feasibility of seaweed waste utilization as a resource of renewable energy was
investigated in this paper. The production of fermentable sugars from seaweed
waste was studied by dilute sulfuric acid and sodium hydroxide pretreatment and
further enzymatic hydrolysis. Pretreatment was conducted by using 1.0 and 2.0%
dilute sulfuric acid w/v and 4 and 5% sodium hydroxide w/v for 30 min at 121
oC. Pretreated seaweed wastes were analyzed by XRay Diffraction (XRD) to
examine the crystallinity index of the cellulose and observed using Scanning
Electron Microscopy (SEM) to examine the changes in structure of cellulose
fiber. Saccharification of pretreated seaweed waste was carried out using crude
cellulase enzyme provided by Pulp and Paper Research Center in Bandung.
Saccharification was done in shake flask with 20% of substrate in citrate
phosphate buffer at 30 oC and 50 oC, agitation of 150 rpm in shaking incubator
for 48 h. Samples were collected at 2, 6, 12, 24 and 48 h for further analysis.
Enzyme concentrations were varied between 1050 U/g dry samples. The results
showed that dilute acid and base pretreatment of seaweed solid waste can be
used to improve the digestibility of seaweed waste. It successfully acted by
reducing the lignin content and degrading the structure of cellulose from
crystalline into amorphous form which is more susceptible to the enzyme
action.The optimum pretreatment condition was shown by 4% NaOH at 121 oC for 30
min, producing the most fermentable sugar concentration. Sugar concentration
produced by saccharification was optimum at 50 oC, enzyme concentration of 50
U/g sample for 24 h base pretreatment. The results of the experiment were
expected to contribute in the process development of bioconversion of
lignocellulosic materials into renewable energy sources.
Keywords: acid hydrolysis, base hidrolysis, crude cellulase, solid
seaweed waste
Author: Pujoyuwono
Martosuyono, Andi Hakim, Yusro Nuri Fawzya
Journal Code: jpperikanangg150035
