Malaysian Journal of Analytical Sciences Vol 19 No 4
(2015): 808 - 814
OPTIMIZATION ON
PRETREATMENT CONDITIONS OF SEAWEED LIQUID WASTE FOR BIOETHANOL PRODUCTION
(Pengoptimuman Kondisi Pra-Rawatan Sisa Cecair
Rumpai Laut untuk Penghasilan Bioetanol)
Nur Zatul
-‘Iffah Zakaria1, Dachyar Arbain1*, Mohd Noor Ahmad2,
Mohd. Irfan Hatim Mohamed Dzahir1
1School of
Bioprocess Engineering,
Universiti Malaysia Perlis, Kompleks
Pusat Pengajian Jejawi 3, 02600 Arau, Perlis Malaysia
2Centre of Excellence for Advanced Sensor Technology
(CEASTech),
Universiti
Malaysia Perlis, Pusat Pengajian Jejawi II, Taman Muhibah, 02600 Arau, Perlis,
Malaysia
*Corresponding author: dachyar@unimap.edu.my
Received:
23 November 2014; Accepted: 27 June 2015
Abstract
Seaweed
liquid waste (SLW) from a non-conventional seaweed (Gracilaria sp.)
drying process where the seaweed is ruptured and filter-squeezed has been
investigated. The liquid contains proteins and minerals which potentially
pollute the environment if it is not been properly treated. For that reason,
this paper deals with study on the feasibility of SLW utilization as a
feedstock for bioethanol production. The fermentation of bioethanol production
was carried out by Saccharomyces cerevisiae in which ethanol produced
was measured by gas chromatography. In order to increase its fermentable sugar
content, the SLW was treated with dilute acid. Center composite design of
response surface methodology (RSM) had been used to optimize the sugar content
by varying the parameters involved in the dilute acid pretreatment conditions.
These are sulphuric acid concentration (M), temperature (oC) and
seaweed waste concentration (g/ml). It
was obtained that the R2 value reached 0.97 indicating that the
model is acceptable. The three parameters showed p-value less than 0.05
suggesting their significance interactions. The optimization resulted 25 times
improvement of reducing sugar concentration. The reducing sugar resulting from
the optimized pretreatment was later used as fermentation medium to produce
ethanol up to 123.197mg/l.
Keywords: bioethanol,
dilute acid pretreatment, Gracilaria sp., Saccharomyces cerevisiae,
seaweed liquid waste
Abstrak
Sisa cecair rumpai laut (SLW)
hasil daripada proses pengeringan konvensional rumpai laut ( Gracilaria sp.)
di mana rumpai laut dipecah dan diperah-tapis telah di kaji. Cecair ini
mengandungi protein dan mineral-mineral yang berpotensi mencemarkan alam
sekitar sekiranya tidak dirawat dengan betul. Oleh hal yang demikian, kertas
kerja ini berkaitan dengan kajian mengenai kemungkinan penggunaan SLW sebagai
bahan mentah untuk penghasilan bioetanol. Penapaian
penghasilan bioetanol dilakukan oleh Saccharomyces cerevisiae di mana
etanol yang dihasilkan diukur dengan kromatografi gas. Dalam usaha untuk
meningkatkan kandungan gula fermentasi, maka SLW dirawat dengan asid cair. Reka
bentuk komposit berpusat dalam metodologi permukaan sambutan (RSM) digunakan
untuk mengoptimumkan kandungan gula dengan mengubah parameter yang terlibat
dalam keadaan pra-rawatan asid cair. Parameter tersebut adalah kepekatan asid
sulfurik (M), suhu (oC) dan kepekatan sisa rumpai laut (g/ml).
Didapati bahawa nilai R2 mencapai 0.97 yang menunjukkan bahawa model
ini boleh diterima. Tiga parameter menunjukkan nilai-p kurang daripada 0.05
menunjukkan kepentingan interaksi. Pengoptimuman ini memberikan peningkatan 25
kali kepekatan gula penurun. Gula penurun hasil daripada pra-rawatan yang
dioptimumkan kemudiannya digunakan sebagai medium fermentasi untuk menghasilkan
etanol sehingga 123.197mg / l.
Kata kunci: bioetanol, pra-rawatan acid cair, Gracilaria sp.,
Saccharomyces cerevisiae, sisa cecair rumpai laut
References
1.
Mansa R. F., Mansuit
H., Fong K. F. and Sipaut C. S. (2013). Review:
Pre-treatments and Fermentation of Seaweed for Bioethanol Production. Developments in Sustainable Chemical and
Bioprocess Technology: 129–136.
2.
Kim H. Ra C. H., and Kim S.K. (2013). Ethanol production
from seaweed (Undaria pinnatifida) using yeast acclimated to specific sugars. Biotechnology
and Bioprocess Engineering 18 (3): 533–537.
3.
Hom S. J. Aasen I. M. and Østgaard K. (2000). Ethanol production
from seaweed extract. Journal of
Industrial Microbiology and Biotechnology 25 (5): 249–254.
4.
Wang X. Liu X. and Wang G. (2011). Two-stage
hydrolysis of invasive algal feedstock for ethanol fermentation. Journal of Integrative Plant Biology
53 (3): 246–52.
5.
Kawa-rygielska J. and Pietrzak W. (2013). Ethanol
fermentation of very high gravity ( VHG ) maize mashes by Saccharomyces
cerevisiae with spent brewer’s yeast supplementation. Biomass and Bioenergy:
1–8.
6.
Goh C. S. and Lee K. T. (2010). A visionary and conceptual
macroalgae-based third-generation bioethanol (TGB) biorefinery in Sabah,
Malaysia as an underlay for renewable and sustainable development. Renewable and Sustainable Energy Reviews
14 (2): 842–848.
7.
Park J., Hong J., Chul H., Geun S., Kim S., Yoon J. and Jin
Y. (2012). Use of Gelidium amansii as a promising resource for bioethanol : A
practical approach for continuous dilute-acid hydrolysis and fermentation. Bioresource Technology 108: 83-88.
8.
Karunakaran S. and Gurusamy R. (2011). Bioethanol Production
as Renewable Biofuel from Rhodopyhtes Feedstock. International Journal of
Biological Technology 2 (2): 94–99.
9.
Jang J.-S., Cho Y., Jeong G.-T. and Kim S.-K. (2012).
Optimization of saccharification and ethanol production by simultaneous
saccharification and fermentation (SSF) from seaweed, Saccharina japonica. Bioprocess and Biosystems Engineering
35 (1–2): 11–8.
10.
Saqib A. A. N. and Whitney P. J. (2011). Differential
behaviour of the dinitrosalicylic acid (DNS) reagent towards mono- and
di-saccharide sugars. Biomass and Bioenergy 35 (11):4748–4750.
11.
Wyman C. E., Decker S. R., Himmel M. E., Brady J. W. and Skopec
C. E. (2005). Hydrolysis of Cellulose and Hemicellulose. Polysaccharides:
Structural Diversity and Functional Versatility: 1–39.
12.
Schmidt I. A. J., Orth R. J. and Franz J. A. (2004). Hydrolysis of Biomass
Material US 6 - 578 - 692,
13.
Zheng Y., Pan Z., and Zhang R. (2009). Overview of biomass
pretreatment for cellulosic ethanol production.
International of Journal Agricultural & Biological Engineering
2 (3): 51–68.