MICROALGA SPIRULINA

International Conference and Exhibition on

Sustainable Energy and Advanced Materials (ICE SEAM 2011)

Solo-Indonesia. October 3-4, 2011.

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Optimizing the Selection of Potential Species of Oil-Producing Microalgae

to Support Economic Feasibility of Biodiesel Production

Mujizat Kawaroe1,*)

, Ayi Rachmat2)

, and Abdul Days3)

SBRC- IPB, IPB Baranangsiang Campus, Jln. Raya Pajajaran No. 1, Bogor 16144 Indonesia 2)

Department of Marine Science and Fisheries, Faculty of Fisheries and Marine Science, Jl Agatis No. 1

Bogor Agricultural University Dramaga, Bogor 16680 Indonesia 3)

Process KPRT PPPTMGB “Lemigas” Building Jl Ciledug Raya, Cipulir, Kebayoran Lama, Jakarta 12230

Indonesia

* Corresponding author. Tel: +62 8121103313,

E-mail: [email protected]

Abstract

Marine microalgae are an alternative renewable energy source with huge potential. Microalgae can grow rapidly

and can be harvested in a short time, which is 7-10 days. In addition to producing oil from the fat content,

microalgae also contains starch that can be fermented into ethanol. Identification of microalgae species was

conducted to determine the type to be produced in microalgae culture. Calculation of microalgae density is

counted using Sedgewich Rafter. The method of analysis used to characterize the lipid content is extraction using

hexane and analyzed using gas chromatography detector Mass Spectrometry (GC-MS) Hewlett Packard. Based

on these results, the most potential species of microalgae used for cultivation is Spirulina platensis which has

specific growth value 0.35 / day and during the cultivation the growth always increases. Characterization of

carbohydrate and protein content is analyzed using spectrophotometric and titrimetric methods which are

conducted at Laboratory of Integrated Chemical IPB. The highest fat content was detected on Tetraselmis sp.

with high levels of vinyl laurite fatty acid compound of 46.7%. The highest protein content was obtained on

Scenedesmus sp. (35.48% w/w), and the highest carbohydrate content was found in Thalasiossira sp. with a

concentration of 5.36% w/w. The implication of this research is the potential acquisition of microalgae as a raw

material for producing biofuels.

Keywords: microalgae, lipid, carbohydrate, protein, biofuel.

1. Introduction

Scarcity of fuel oil that occurred recently has given a very broad impact on various sectors of life. The most

affected is the fast transport sector. Fluctuations in supply and oil prices should make us realize that the number

of existing oil is running low. Since petroleum is a fuel that cannot be renewed then we have to start thinking

about the replacement material. Actually, in Indonesia there are a lot of renewable energy sources, such as bio-

diesel from Jatropha, palm oil and soybeans. Methanol and ethanol from biomass, sugarcane, corn, etc. also

could be used as a substitute for gasoline. Besides that, the burning of fossil fuels has a negative impact on the

environment. Air quality which is decreasing due to the burning of petroleum fumes is one of the effects that we

can see clearly. Then the greenhouse effect that caused by CO2 from burning fossil fuels. As we all know the

burning of fossil fuels that is not perfect will produce CO2 gas, which will accumulate in the atmosphere.

Therefore the use of a renewable fuel that is safer for the environment is an absolute thing. One that has potential

as feedstock for fuel is microalgae.

Microalgae are the most primitive organisms‟ sized mobile plant commonly known as phytoplankton

(Schulz, 2006). Aquatic life habitat is the region around the world. This organism is capable of aquatic primary

producers such as higher plants photosynthesize (NREL, 1998). Although microalgae are plants that have the

most primitive level, but the photosynthesis mechanism and its ability to convert solar energy is more efficient

than higher plants because the cellular structure is much simpler. That makes microalgae can produce 30 times

more oil than biodiesel derived from other plants within the same unit of land area. Microalgae contain proteins,

fats, unsaturated fatty acids, pigments, and vitamins. The content of fat (lipid) inside microalgae is the source of




45 | I C E S E A M 2 0 1 1

energy. The content is generated from the process of photosynthesis which is a hydrocarbon (Prince and Haroon,

2005), and could be expected to produce energy that has not been explored and exploited.

The development of biofuels (biodiesel and bioethanol) as a substitute fuel has an advantage that it produces

some emissions are more environmentally friendly because the content of oxygen can improve combustion

efficiency. Biofuels are also able to increase octane and reduce the use of leaded additives are harmful to the

environment. The research activities included in developing research in the field of alternative fuels, especially

biofuels (BBN) and to support government programs to improve the production of biofuels. The purpose of this

study is to improve the efficiency of production of biofuels made from raw microalgae that can be achieved on

the economic feasibility of small-scale production. The specific objective is obtaining potential microalgae in

producing fat and starch.

2. Methodology

For the first step of research activities, the research methods are as follows:

1. Sampling of microalgae in the waters

The sampling was repeated 2 times per location which is Batam and the Thousand Islands. The tool used to

filter microalgae from seawater is the size of 35μm and 90μm plankton. Procedures for the microalgae sample

filter is first of all, the sea water is taken by using a bucket sized 1 liter. After that, sea water poured into

planktonet so microalgae can be filtered into the film bottle at the bottom of planktonet. This process is repeated

to 60 times so that microalgae samples dense enough to be identified. After filtered adequately, microalgae

sample was transferred into a sample bottle and labeled to be brought to the laboratory and identified under

microscope. Salinity measurements are also conducted in situ using refractometer. The procedure is first,

performed calibration using aquadest that dripped onto the glass using a pipette drops refractometer. After that,

by one eye closed the value can be seen in the refractometer.

2. Identification of sampling results

Identifying microalgae species is performed to determine the type to be cultivated in laboratory. Microalgae

are classified as plants because they contain chlorophyll and have a network of cells resembling higher plants.

Through this approach to classification scheme, microalgae species can be defined in morphological and

biochemical similarities. The procedure: first, samples were taken with a pipette of microalgae then put on the

object glass and covered with a glass object. After that, the glass object is put under the microscope.

Magnification lenses which is best for use in the identification of microalgae is 40 x 16 mm. When the

organisms has founded under the microscope vision, it can be matched with images of species that exist in the

identification book Yamaji (1968).

3. Isolation of species of microalgae from the sampling results

To obtain a species that will be cultivated, it would be insulating mono species microalgae. The method

used for the isolation of microalgae species this is the method of micromanipulation. In this method microalgae

isolated in agar (solid). The procedure is done: first, the media in order to be made by dissolving into the water to

a boil and stir, then add to the nutrient solution so that after the temperature reaches ± 60 ° C. Solution in order

to then pour into sterile petri dish, allow to thicken so that it can form a gel that half. After the agar formed,

heated capillary pipette tip with a small flame on a Bunsen burner, then pull the pipette tip by clamping the

pipette tip with tweezers. Narrow pipette tip should be two times larger than the diameter of the cell, in order to

be micromanipulated. After that, the micropipette sterilized by boiling in distilled water until boiling. Then the

sterile medium dropwise to 1.5% slab gel in a petri dish so that with a sterile Pasteur pipette and for alternative,

dropped three drops in a glass object. Distilled water suction and remove the hot water. It can sterilize

micropipette. Then algal cells that had been enriched to be isolated is placed in a glass object while observed, the

cell is in want pipetted into a micro pipette. Then the cells were transferred into sterile medium or on a plate or

glass objects in order. After that, sterilize micropipette. This process can be repeated to "wash" the cells. The

more frequently washed the cells less likely contaminated. However, the risk of cell damage increases with the

frequency of a cell is handled. The maximum amount of washing will depend on the type of algae.

4. Analysis of the abundance of microalgae

Microalgae abundance computed using instrument Sedgewich Rafter. Sedgewich Rafter is a rather thick

glass preparations which form the indentation in the center of the long terms. The indentation size varies with the

height 0.1 mm, due to get microalgae density, it must be known too long and wide. On the curve of the sample is




46 | I C E S E A M 2 0 1 1

placed microalgae want observed. The density of microalgae is calculated using almost the same Sedgewich

haemacytometer Rafter. Before using Sedgewich Rafter, clean it using 70% alcohol and dry it with paper towels.

Then put the glass lid with a slightly oblique position. Installation of cover with oblique position is intended to

be part of a gap there to shed microalgae sample which will be observed. Then the glass cover slides slowly to

avoid bubbles to cover the entire rectangular grooves. Further preparations were examined under a microscope

with a magnification of 100-400 x 10 field of view. To determine the density of microalgae used the following

formula:

K = N x (Jsk/Jbp) x 10000 (1)

where:

K = Density microalgae (ind / L)

N = Number of indvidu

JBP = Number of field of view

JSK = number of bulkhead sedgewich Rafter

5. Microalgae Biology Index

Shannon-Wiener index is used to calculate the index of diversity (diversity index) type, uniformity index,

and the dominance index was calculated according to Odum (1998) with the following formula:

a) Shannon-Wiener diversity index:

s

H’ = - (ni/N) ln (ni/N)i (2)

i=1

Value Shannon-Wiener diversity index has categories based on the specified range are as follows:

H '<2.3026: the diversity of small and low community stability

2.3026 6.9078 <H'>: diversity and stability of the community are being

H '> 6.9078: high diversity and high community stability

b) Uniformity index:

E = H’/Hmax (3)

Hmax = ln S (4)

Uniformity index ranged from 0-1. When the uniformity index close to 0 (zero), then the ecosystem has a

tendency dominated by a specific type and when close to 1 (one) then the ecosystem is relatively stable.

c) Dominance Index:

Dominance index values range from 0-1. When the dominance index close to 0, meaning no amount

indvidu an abundant species and is usually followed by high values of uniformity index. And when the

dominance index close to 1, meaning there are a bunch of certain numbers that the abundant species

(dominated) than other types and are usually followed by a low value of uniformity

s

D = ∑ [ ni/N ]2 (5)

i=1

where:

H '= Shannon-Wiener diversity index

E = uniformity index

D = dominance index simpson

ni = Number of individuals of genus i-th

N = total number of individuals of all genera

Hmax = maximum diversity index

(= Ln S, where S = number of species)




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6. Cultivation of microalgae

Laboratory-scale cultivation is conducted in laboratory of Microalgae Surfactant and Bioenergy Research

Center (SBRC) IPB for all the isolation and collection of species of microalgae that have been obtained. In

laboratory-scale cultivation, 1/3 part inoculants is inputted in sterile sea water which has been given in

accordance with the type of fertilizer that will be cultivated and then placed in microalgae culture vessel under

the light rack and aerated. The media being used were Guillard and Conway. Every day, the growth of

microalgae is always calculated to monitor the rate of cell growth. Then after 7 days of cultivation, microalgae

can be harvested to produce a powder that is dry.

7. Harvesting microalgae

Harvesting is conducted by flocculation using alum with a concentration of 120 ppm. After the deposition

process is done using a filtration or screening satin cloth for several hours. Once everything is accommodated in

the satin, the crop can be dried using the sun or oven if the weather is not hot enough. The result is a powder,

then further analysis will include the weighing of microalgae biomass.

8. Extraction microalgae

Extraction which will produce oil from the microalgae is conducted using the chemical hexane solution

(Bligh and Dyer, 1959). Hexane solution can be used directly to extract oil or combined with a pressing tool. The

way it works is: the harvested microalgae dry powder inputted to the filter paper that had been formed like

sohxlet tube with cotton placed at the top and bottom. Then the filter paper that contained the dry powder of

microalgae inserted into the sohxlet tube and diluted with hexane until the microalgae original color fading.

After that the hexane is evaporated until the only remaining in the process is microalgae crude oil. This process

is executed for at least 5-6 hours to obtain maximum results from microalgae. Extraction was carried out to

obtain microalgae oil and analyzed for hydrocarbon and lipids content in microalgae that have been cultured. Oil

content of microalgae were identified by inject it into the gas chromatography instrument with mass

spectrophotometer detector. The result is a chromatogram can be analyzed levels of a compound that is detected.

9. Analysis of crude protein (method semimikro kjeldhal)

Principle:

Nitrogen compounds converted to ammonium sulfate by concentrated H2SO4. Ammonium sulfate that is formed

is described with NaOH. Ammonia is liberated tied with boric acid and dititar with acid standard solution.

Protein content = (V1 - V2) x Nx x 0.014 x f.k fp (6)

w

Where:

w = weight of footage

V1 = volume of 0.01 N HCl used penitaran example

V2 = volume of HCl used penitaran blank

N = normality FICI

fk = conversion factor for protein and food in general: 6.25 Milk & processed products: peanut butter 638:

5.46

fp = dilution factor

10. Carbohydrate Analysis

Principle:

Hydrolysis of carbohydrates into monosaccdaydes that can reduce Cu2 + to Cu1 +. Excess Cu2 + can be

iodometric titrated.

Glucose = w1 x fp x 100% (7)

w

Where:

Carbohydrate content = 0.90 x glucose

w1 = weight of footage, in mg

w = glucose contained to ml tio used, in mg, of list

fp = dilution factor




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11. Test chemical content of microalgae with GC

Hydrocarbon extracts purified by using column chromatography in silica gel. Examples of hydrocarbons

were analyzed on SPB-1 column (30m x 0:32 mm ID x 0:25 μm film thickness) using GC with FID equipment

(Fig. 12) and identified by comparing fragmentation patterns with standards (Sigma) and also with NIST library

(Dayananda et al ., 2005). Fats (Lipids) was extracted using chloroform-methanol (2:1), chloroform and 1%

NaCl fluid was added to adjust the ratio between methanol, chloroform and water to be 2:2:1 and quantified

gravimetrically. All the chloroform layers that have been taken 3 times evaporated, dried in a desiccator, and

weighed as total lipid. Fatty acid methyl esters (FAME) prepared in accordance with the procedures Christie

(1982). FAME analyzed by GC-MS equipment (PerkinElmer, Turbomass Gold, Mass spectrometer) with FID

and using a capillary column SPB-1 (poly (dimetysiloxane)) (mx 30 mm ID x 0:25 0:32 μm film thickness) with

temperature programmed at 1300C up to 2800C at 20C/min average. FAME were identified by comparing the

fragmentation pattern of microalgae with a standard (Sigma) and the NIST library (Dayananda et al. 2006). This

process is quite done only with the chemical methanol and fat content yatu detector Gas Chromatography with

Flame Ionization detector (GC-FID).

3. Results and Discussion

3.1. The rate of growth of laboratory-scale cultivation of microalgae

Some microalgae collected by microalgae laboratory SBRC-IPB has been cultivated for 7 days to be seen

and calculated the rate of growth every day (Table 1). From the results of these calculations, it can be known

species of microalgae of the most rapid and stable growth. The best growth of microalgae can be seen from the

high value of specific growth rate. From the fifteenth species which had been analyzed it is known which species

has the most stable growth rate and the specific growth rate of the fastest per day. Porphyridium cruentum is a

microalgae that has the highest specific growth rate that is worth 0.3655 / day, Spirulina platensis also have a

specific growth rate that is quite high value of 0,3536 / day. Microalgae with the lowest specific growth rate are

Tetraselmis chuii worth 0.0502 / day. Resilience of microalgae to the environment can be seen from the

adaptation of new media, where the growth of microalgae is always increased until the end of cultivation day.

Microalgae that have a high adaptation to the environment among other types are Spirulina platensis, Chlorella

sp., and Isohcrysis sp. Based on these results, the best type of microalgae used for cultivation is Spirulina

platensis with the value of specific growth 0.3536 / day and growth during the cultivation that always increasing.




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Table 1. Growth rate of 15 microalgae species

Nannocloropsis sp Chlorella sp Dunaliella sp Tetraselmis chuii Spirulina platensis Porphyridium

cruentum

Scenedesmus sp Nitzschia sp

Day ke-

Solidity (ind/mL)

k (/day)

Solidity (ind/mL)

k (/day)

Solidity (ind/mL)

k (/day) Solidity (ind/mL)


k (/day)

Solidity (ind/mL)



k (/day)

0 6,500,000 - 2,250,000 - 19,916,667 - 1,750,000 - 2,583,333 - 2,166,667 - 5,583,333 - 1,833,333 -

1 15,083,333 1.1772 2,500,000 0.1473 23,083,333 0.2063 3,166,667 0.8294 3,166,667 0.2847 3,416,667 0.6369 8,583,333 0.6014 3,083,333 0.727

2 20,333,333 0.4177 3,166,667 0.3306 31,500,000 0.4347 3,333,333 0.0717 6,500,000 1.0056 5,250,000 0.6007 7,333,333 -0.2201 4,416,667 0.5026

3 21,166,667 0.0562 5,250,000 0.707 34,166,667 0.1136 3,750,000 0.1647 6,916,667 0.0869 5,750,000 0.1272 6,166,667 -0.2423 2,500,000 -0.7958

4 26,750,000 0.3274 5,583,333 0.0861 40,750,000 0.2464 3,333,333 -0.1647 7,666,667 0.144 8,583,333 0.5602 8,083,333 0.3785 3,000,000 0.255

5 18,916,667 -0.4845 6,416,667 0.1945 35,666,667 -0.1863 2,083,333 -0.6573 8,166,667 0.0884 12,500,000 0.5257 8,666,667 0.0974 2,250,000 -0.4023

6 20,833,333 0.135 7,083,333 0.1382 33,333,333 -0.0946 2,250,000 0.1076 11,833,333 0.5186 11,833,333 -0.0766 8,916,667 0.0398 4,500,000 0.9693

7 23,000,000 0.1384 8,583,333 0.2686 42,166,667 0.3287 2,250,000 0 15,166,667 0.3471 13,500,000 0.1843 9,250,000 0.0513 4,583,333 0.0257

Chaetoceros

gracilis

Chaetoceros ceratosporum Skeletonema costatum Chaetoceros calcitran Chaetoceros simplex Thalassiosira sp. Isochrysis sp.

Solidity

(ind/mL)

k (/day) Solidity

(ind/mL)

k (/day) Solidity

(ind/mL)

k (/day) Solidity (ind/mL) k (/day) Solidity

(ind/mL)

k (/day) Solidity

(ind/mL)

k (/day) Solidity

(ind/mL)

k (/day)

1,083,333 - 583,333 - 1,083,333 - 916,667 - 666,667 - 1,083,333 - 1,000,000 -

1,333,333 0.2904 750,000 0.3514 1,000,000 -0.1119 1,666,667 0.836 1,000,000 0.567 1,000,000 -0.1119 1,083,333 0.1119

1,583,333 0.2403 1,083,333 0.5142 1,250,000 0.3121 2,166,667 0.3669 1,583,333 0.6426 1,416,667 0.4871 1,250,000 0.2001

1,250,000 -0.3306 1,333,333 0.2904 1,500,000 0.255 1,583,333 -0.4386 1,333,333 -0.2403 1,666,667 0.2273 1,583,333 0.3306

1,500,000 0.255 916,667 -0.524 1,583,333 0.0756 2,416,667 0.5913 2,166,667 0.6789 2,083,333 0.3121 1,666,667 0.0717

1,666,667 0.1473 833,333 -0.1333 1,500,000 -0.0756 2,500,000 0.0474 2,333,333 0.1036 2,500,000 0.255 2,083,333 0.3121

1,250,000 -0.4023 1,250,000 0.567 1,750,000 0.2156 2,666,667 0.0903 2,416,667 0.0491 2,750,000 0.1333 2,250,000 0.1076

2,083,333 0.7144 1,416,667 0.175 1,916,667 0.1272 2,750,000 0.043 2,500,000 0.0474 3,083,333 0.16 2,416,667 0.0999




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3.2. Characterization of the fatty acid content of microalgae

For the levels of fatty acid compounds, each species has characteristic that is different. Fatty acid analysis

results are presented in Table 2. In Scenedesmus sp. fatty acid compounds is contained in the range of fatty acid

compounds between 0,07 to 35,52% with the highest concentrations are owned by the vinyl laurate and the

amount of fatty acid compounds that are detected as many as 6 compounds such as methyl capriate, methyl

laurate, methyl myristate, methyl stearate, glycerol trilaurat and vinyl laurate. While for Chlorella sp., the

dominant fatty acid compounds is methyl valerate at 10,06% with other fatty acid compounds detected such as

methyl palmitate and methyl valerate. For Nannochloropsis sp., the content of the dominant fatty acid compound

is methyl palmitate by fatty acid concentration range between 0,78 to 3,26% with the amount of fatty acid

compounds that are detected as many as 3 compounds of the methyl palmitate, methyl laurate and methyl

myristate. As for Dunaliella sp., there are none levels of fatty acid compounds once injected into a Gas

Chromatograph. In Isochrysis sp., the dominant fatty acid compounds is methyl oleate with a range of fatty acid

compound concentration between 0.33 to 1.25%. Fatty acids that detected in Isochrysis sp. are methyl myristate,

methyl palmitate, methyl margaric, methyl oleate and methyl dihydrochaulmoograte. While in Nitszchia sp., the

dominant fatty acid compounds is methyl palmitate with concentration range between 0.05 to 11.52%. Fatty acid

compounds that detected in Nitszchia sp. is Methyl margarate, Methyl laurate, methyl myristate, methyl

palmitoleate, methyl palmitolineat, methyl palmitate, methyl linoleic acid, methyl oleate and methyl stearate.

In Tetraselmis sp., the dominant fatty acid compounds contained in the vinyl laurate with fatty acid

compound concentration range between 0,12 to 46,7%. This type of fatty acid compounds detected is Methyl

stearate, methyl laurate, methyl myristate, methyl palmitate, methyl linoleic acid, methyl oleate, Glycerol

trilaurat and vinyl laurate. While in Spirulina platensis, The dominant fatty acid compounds contained in the

methyl oleate with a fatty acid compound concentration range between 0,07 to 22,58%. Types of fatty acids

detected is Methyl stearate, methyl laurate, methyl myristate, methyl palmitoleate, methyl caprate, methyl

palmitate, Methyl Methyl linoleic and oleic. In Chaetoceros gracilis, the dominant fatty acid compounds

contained in the methyl oleate with a range of concentrations of fatty acid compounds between 0,27 to 24,95%.

Types of fatty acids detected is Methyl stearate, methyl laurate, methyl myristat, palmitoleat Methyl, Methyl

palmitate, Methyl 8-Methyl oktadekanoat and oleic. As for Chaetoceros calcitrans, the dominant fatty acid

compounds contained methyl palmitate is a fatty acid compound concentration range between 0,1 to 8,48%.

Types of fatty acids detected are methyl stearate, methyl laurate, methyl myristate, Methyl palmitoleate, Methyl

caprate, methyl palmitate, methyl linoleic, cis-9-Methyl octadecanoate and Methyl oleate.

Ten (10) species have been analyzed using gas chromatography and mass spectrophotometry detector Flame

Ionization. In this study, among the ten species it can be seen that the species has the highest fatty acid

concentration is Tetraselmis sp. with high levels of vinyl lauric fatty acid compounds for 46,7% followed by

Scenedesmus sp. with high levels of vinyl lauric fatty acid compound of 35,52% and Chaetoceros gracilis with

high levels of methyl oleic fatty acid compound of 24.95% while the lowest is owned by Dunaliella sp.

(Undetectable). This type of fatty acid compounds most commonly found is the type of SFA (Saturated Fatty

Acid) that is kind of an unusual fatty acid found in food that can be consumed and digested easily or what is

known as saturated fatty acids. There are several types of unsaturated fatty acids MUFA (mono unsaturated fatty

acid) and PUFA (poly unsaturated fatty acid) as detected on several species of microalgae Chaetoceros gracilis,

Chaetoceros calcitrans, Isochrysis sp., Nitzschia sp., Tetraselmis sp. and Spirulina platensis. There are three

species such as Spirulina platensis, Tetraselmis sp. and Nitzschia sp. compounds containing unsaturated fatty

acids (PUFAs), namely linoleic acid compound or one of the essential fatty acids are commonly known as

Omega-6.

3.3. Characterization of the protein content of microalgae

Microalgae commonly used as ingredients of medicines and supplements the body because they contain

high levels of protein and good for humans. Of the several collections of SBRC IPB Microalgae Laboratory, has

conducted analysis of protein content to see the value of the quantity of protein present in microalgae using

titrimetric method (Kjehldahl). From the analytical results obtained, several species of microalgae have a high

protein content such as on the type of Scenedesmus sp. (35.48% w / w), Chaetoceros gracilis (19.03% w / w),

Thalasiossira sp. (21.61% w / w) and Skeletonema sp. (17.92% w / w). While in Dunaliella sp.,

Chlorella sp., Tetraselmis sp. and Porphyridium cruentum, protein content was detected very low between 1.58

to 4.10% w / w. The results of protein analysis are presented in Table 3.




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Tabel 2. Fatty acid composition in nine microalgae species

Compound

Microalgae species

Scenedesmus

sp.

Chlorella

sp.

Nannochloropsis

sp.

Isochrysis

sp.

Nitzschia

sp.

Tetraselmis

sp.

Spirulina

sp.

Chaetocero

s gracilis

Chaetoceros

calcitrans

Porphyridium

cruentum

Skeletonema Thalassiosira

Methyl capriate 0.07 - 0.30 - - - 0.07 - 0.1 -

Methyl Laurate 0.22 0.02 0.99 - 2.04 0.18 3.08 2.07 1.91 0.49 0.10

Methyl myristate 0.34 - 7.06 0.33 1.3 0.12 2 1.03 1.02 0.23 8.15

Methyl stearate 13.85 29.50 - 20.21 2.29 0.21 3.5 3.29 1.52 -

Methyl palmitate 20.29 8.09 23.07 0.93 11.52 1.05 17.28 12.23 8.48 1.01 0.18

Methyl oleate - 2.41 12.25 37.63 14.8 1.4 22.58 24.95 3.02 0.64 0.36 0.15

Methyl valerate - 10.06 - - - - - - - -

Methyl margaric - - - 0.77 0.05 - - - - - 0.25

Methyl palmitoleate 9.78 2.15 42.32 34.25 0.07 - 0.24 0.27 0.13 -

Methyl palmitolenate - - - - 0.16 - - - - -

Methyl linoleate 25.16 45.07 2.47 2.06 6.37 0.57 9.93 - - -

Methyl linolenate 16.16 11.49 - - - - - - - -

Gliserol trilaurate 3.73 - - - 46.5 - - - - -

Vinyl laurate 35.52 - - - 46.7 - - - - -




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The world of health, some species of microalgae such as Spirulina platensis and Chlorella sp. is known to

relieve diabetes, controlling cholesterol, vitamin A supplement, overcoming malnutrition, helping cancer patients

in chemotherapy, the formulation with other natural products as health supplements, able to repair liver damage,

treatment of burns, skin grafting, controlling obesity, and lactation for breastfeeding mothers. While the world's

fisheries, is used for special feeding ornamental fish because it can enrich the color of goldfish and koi, feed

formulation with the existing to add vitamins, high protein feed for fish consumption (fresh water), as well as

special feed for shrimp farms. Type of microalgae that is often used for fish feed is Nannochloropsis sp. and

Spirulina sp.

3.4. Characterization of carbohydrate content of microalgae

Carbohydrate content in microalgae performed using phenol-sulfuric method and means of

spectrophotometry. From the analysis, obtained several species of microalgae have a high carbohydrate content

that is kind Thalasiossira sp. with a concentration of 5.36% w / w followed by Skeletonema sp. with a

concentration of 3.77% w / w and Chaetoceros gracilis with a concentration of 3.69% w / w. As for the other

species of microalgae, carbohydrate content obtained is very small; between 0.34 to 1.13% w / w. The results of

carbohydrate analysis are presented in Table 3.

Carbohydrates in microalgae could be another alternative as a source of bio-fuels. Carbohydrates that there

could be transformed into a form of sugar or molasses to be used as fuel ethanol through enzymatic processes,

fermentation and heating. The higher the carbohydrate levels in a species of microalgae, the higher is likely to

produce bioethanol. Bioethanol is already widely produced in the world comes from corn, wheat and sugar cane.

With the microalgae, bioethanol can be produced in the sea or fresh water without having to spend a terrestrial

land which has been shrinking lately.

Table 3. Carbohydrate and protein content in 8 microalgae species

No Spesies Kadar (%)

Karbohidrat Protein

1 Dunaliella sp. 1.13 2.60

2 Skeletonema sp. 3.77 17.92

3 Thalasiossira sp, 5.36 21.61

4 Chaetoceros gracilis 3.69 19.03

5 Chlorella sp. 0.48 3.01

6 Tetraselmis sp. 0.41 4.10

7 Scenedesmus sp. 0.34 35.48

8 Porphyridium cruentum 1.06 1.58

4. Conclusions

For the specific growth rate of the fastest and most stable growth rate is a type of Spirulina platensis.

Porphyridium cruentum has the highest number of specific growth rate with the number 0.3655 / day, but the

graph suggests that these types do not have a stable growth rate on a particular day where a decrease in the

number of individuals per milliliter. While that has a specific growth rate is the slowest type of Tetraselmis chuii

with numbers 0.0502 / day.




53 | I C E S E A M 2 0 1 1

Ten (10) species of microalgae have been analyzed using gas chromatography and mass spectrophotometry

detector Flame Ionization. Among the ten species can be seen that the species has the highest concentration is

Tetraselmis sp. with high levels of vinyl lauric fatty acid compounds for 46.7% while the lowest is owned by

Dunaliella sp. (undetectable). For the analysis of proteins obtained, several species of microalgae have a high

protein content such as on the type of Scenedesmus sp. (35.48% w/w) whereas in the type of Dunaliella sp.,

Chlorella sp., Tetraselmis sp. and Porphyridium cruentum, protein content was detected very low between 1.58

to 4.10% w / w. For the analysis of carbohydrates, there are several species of microalgae that have a high

carbohydrate content such as Thalasiossira sp. with a concentration of 5.36% w/w while for other species such

as Scenedesmus sp., carbohydrate content obtained is very small, only 0.34% w/w.

5. Acknowledgement

This research is being acknowledged by Ministry of Research And Technology in Incentive Program

for Improvement of Production System Capacity in Science & Technology and also partnering with PT Diatoms

Cell Bioenergy

References

Bligh, E.G. and Dyer, W.J. (1959) „A Rapid Method of Total Lipid Extraction and Purification‟, Canadian

Journal of Biochemistry and Physiology, Vol.37, No. 8, pp.911-917.

NREL.(1998) A Look Back at the U.S Department of Energy's Aquatic Spesies Program: Biodiesel from Algae,

US National Energy Department. USA.

Odum, E.P. (1998) Dasar-dasar Ekologi : Terjemahan dari Fundamentals of Ecology, Alih Bahasa Samingan,

T. Edisi Ketiga. Universitas Gadjah Mada Press.

Prince, R.C. and Haroon, S.K. (2005) „The Photobiological Production of Hydrogen: Potential efficiency and

Effectiveness as a Renewable Fuel‟, Critical Review in Microbiology. Vol. 31, pp. 19-31.

Yamaji, I. (1968) The Plankton of Japanese Coastal Waters, Osaka, Hoikusha, p.238.

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