Macro algae as Carbon source in biopolymer production
Apurv Mhatre, Reena Pandit
Research Fellow, Institute of chemical Technology, Nathalal parekh marg, Matunga (East), 400019.
apurv15mhatre@gmail.com
1.
Introduction:
Marine alga biomass is a potential resource for biopolymer production because algae can exhibit high
productivity. Compared with terrestrial plants, macroalgae (i.e. seaweeds) have a high water content
of approximately 70–90%, a relatively low protein content of approximately 10%, and contain varying
levels of carbohydrates[1].Microalgae are comprised of 28–63% protein, 4–57% carbohydrates, and 2–
40% lipids/oils by weight. Conversion of biomass from marine algae into Biopolymer could be
economically feasible since some algae hydrolyzates can contain more total carbohydrate and
hexose sugars than some terrestrial, lignocellulosic biomass feedstock [2]
2.
Material and Methods:
2.1. Sources of algae and determination of their composition
Algae were cultured in lab in salt water media at temperature range of 28-300C. Algae were sun Dried
and partially Oven dried and stored at 40C for further use.
Carbohydrate and of algae was determined using analytical methods established by the National
Renewable Energy Laboratory (NREL) and Moisture content was determined by moisture content
analyser.
To determine the composition of algae, dried algal biomass was finely ground with a blender and was
collected for further use. Ash content was determined by weighing samples before and after heating
in a muffle furnace at 5560C for 12 h. Protein content was measured with the CHNS analyser using a
factor of N = 6.25. Lipid content was determined with the Phospho vaniline method.
2.2. Preparation of algal hydrolysates
Algae were blended with Mixer blender and fine powder was obtained. For chemical hydrolysis, 1 g of
crushed algae (dry base) was heated at 1210C for 15 min in the presence of 10 ml of 0.05, 0.1, 0.15,
0.2, or 0.3 N Ca(OH)2, HCl, or H2SO4. For enzymatic hydrolysis, acid generated hydrolysates were
adjusted to pH 5.5 with 0.05 M citrate buffer. Cellulase was added at a level of 0.01 g per g of original
dried biomass. The saccharification reaction was performed at 500C on a rotary shaker at 150 rpm in
the absence of antibacterial agents. Aliquots of 1 mL were taken periodically and analyzed for the
degree of enzymatic saccharification. After 24 h, the glucose, xylose, galactose, arabinose, mannose,
and mannitol profiles and concentrations of the enzymatic hydrolysates were analyzed using HPLC.
2.3. Biopolymer fermentation
In the culture medium , which contains (%, w/v): carbon source 1.0, peptone 0.5, yeast extract 0.5,
disodium phosphate 0.27, and citric acid 0.115. The prepared 30 ml culture medium in 100 ml flasks
were sterilized by autoclaving and were inoculated from the solid agar culture of A. Xylinus. The
inoculated media were incubated at 28C for 7 days using 90mm petridishes. After incubation, the
pellicles produced on the surface of each media were harvested and washed with water, 1% NaOH at
90C for 15 min., neutralized with 1% acetic acid and washed with distilled water, successively. It was
then dried on a Steel plate.
2.4. Sugar analysis
Soluble sugars were analyzed using HPLC with a refractive index detector. Chemically and
enzymatically treated samples and fermentation samples were loaded onto an Aminex HPX-87H
column (Bio-Rad). The temperature was 500C and 5 mM of H2SO4 (99.999%; Sigma–Aldrich, Inc.,
St. Louis, MO, USA) was used as an eluent at a flow rate of 0.6 mL/min (Lee et al., 2010). Acid
hydrolysates were analyzed using an Aminex HPX-87P column (Bio-Rad Laboratories, Inc., Hercules,
CA, USA). The temperature was set at 80 _C, and water deionized with Milli-Q (Millipore, USA) was
used as mobile phase at a flow rate of 0.5 mL/min. Sugars were quantified by comparing their peak
areas with those of standard sugars of known concentrations. Galactose, xylose, and arabinose were
not separated on the Aminex HPX-87P column, and therefore a mixture of those sugars was
quantified by comparing the mean peak areas.
3. Significant Results and Discussion
The Biopolymer productivity is expected to be close to standard process as glucose is used as C source though
its source is macro algae.
4. Conclusions:
At the end of process it can be concluded that macro algae can be considered potential source of
monosacchrides for bacterial media and can help in reducing the cost of production of biopolymers.
References
[1]Park, J.-I., Woo, H.-C., Lee, J.-H., 2008. Production of bio-energy from marine algae: status and perspectives. Korean
Chem. Eng. Res. 46 (5), 833–844.
[2]John, R.P., Anisha, G.S., Nampoothiri, K.M., Pandey, A., 2011. Micro and macroalgal biomass: a renewable source for
bioethanol. Bioresour. Technol. 102 (1), 186–193.