http://www.iisc.ernet.in/
Energy and Food Security from Macroalgae
 http://wgbis.ces.iisc.ernet.in/energy/
Deepthi Hebbale1, 2    M. D. Subash Chandran1    N. V. Joshi 1   T. V. Ramachandra 1,2,*  
1Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, Karnataka, India
2Centre for Sustainable Technologies, Indian Institute of Science, Bangalore 560 012, Karnataka, India
* Corresponding author: emram.ces@courses.iisc.ac.in (T.V. Ramachandra)

Results and Discussion

Table 4 gives biofuel production from different types of seaweeds based on literature review (Yanagisawa et al. 2013 Trivedi et al. 2015; Ramachandra and Deepthi 2016; Troell et al. 2006). Cellulosic rich seaweeds are easily hydrolysed by both acid and enzyme treatment resulting in higher yields of ethanol. Not all the sugars that are present in seaweeds are fermentable, Sugar alcohols like mannitol, sulphated polysaccharides like carrageenan, ulvan and alginate needs to be broken down into simpler sugars to achieve higher ethanol yield. Thus, the production of high concentrations of ethanol from seaweeds requires the conversion of all major carbohydrates into ethanol (Ramachandra and Deepthi 2016; Yanagisawa et al. 2013)

Seaweeds Ethanol yield g/l References
Ulva pertusa 7. 2 Yanagisawa et al. 2011
Ulva fasciata 0.45g/g RS Trivedi et al. 2013
Ulva reticulate 90 L/t Yoza and Masutani 2013
Undaria pinnatifida 9. 423
12.98 		Cho et al. 201
Kim et al. 2008
Saccharina japonica 6. 65 Cho et al. 201
Laminaria japonica 2. 9
0. 41 		Lee et al. 2013
Kim et al. 2008<
Saccharina latissimi 0.45% Cho et al. 201
Alaria crassifolia 0.244 Yanagisawa et al. 2013
Kappaphycus alvarezi 64.3
0.147 L per kg granules
0.369 g/g RS		 Hargreaves et al. 2013imi
Khambhaty et al. 2012
Gelidium elegans 5 5 Yanagisawa et al. 2011
Gracillaria verrucosa 0.43 g/g RS Kumar et al. 2013
Saccharina japonica 0.41 g/g RS Wargacki et al. 2012
Sargassum sagamianum 0.386 g/g RS Yeon et al. 2011
Laminaria hyperborean 0.43 g/g RS Horn et al. 2000

Table 4: Bioethanol f rom seaweeds

Suitability of Macroalgae as Feedstock for Biofuel Production

Microalgae as feedstock for biofuel production is appropriate due to
(i) Higher productivity - mass productivity of Macroalgae is 13.1 kg dry weight m  over a seven-month growth period, compared to terrestrial plants (0.5–4.4 kg dry weight m per year)
(ii) entire cell mass is utilized for biofuel production compared to terrestrial biomass feedstock, wherein only a part is economically useful for biofuel production
(iii) cultivating macroalgae in waste water, brackish water, and saline water do not pose threat to food security.

 

 
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