METHOD OF BIOSYNTHETICALLY PRODUCING HYDROCARBONS

FROM ALGAE

FIELD

The current invention pertains to methods for producing hydrocarbons.

BACKGROUND

At present, oil refineries are key to obtaining hydrocarbons; crude oil is processed through several stages to form desirable hydrocarbons, used in fuel and other commercial products. The environmental, economical and social costs of this method of production are well known and becoming more and more undesirable.

Algae are non vascular photosynthetic plants. They grow in a wide variety of aquatic environments from sweet to brackish to marine.

The literature records attempts at using algae as a source of hydrocarbons. For example, in U.S. 5476787 to Murakami Nobuo et al. a method is disclosed for extracting hydrocarbons from minute algae belonging to Bortryococcus. One of the drawbacks of this method is that the cells have to be lysed and hydrocarbon product is liberated from the algae by heating the water under high pressure, a high energy consuming process.

In JP 08168389A2 of Suzuki Taro et al, a method of obtaining organic matter is proposed. The obtained organic matter is however acetic acid and alcohol, and requires special conditions such as darkness and anaerobic incubation.

It has also been known that there are algae and bacteria that are able to digest oil and use it as an energy source and that there are algae and bacteria which live in high salt conditions. It has been suggested that plankton and algae in the seas and oceans synthesise materials that sink in the water and are compressed by the tremendous pressures, ultimately turning into oil and hydrocarbons.

A long felt need would therefore be satisfied by providing a method to obtain exogenously secreted hydrocarbons from algae.

SUMMARY

It is an object of the invention to provide a process for producing exogenously excreted hydrocarbons from algae. The process comprises steps of:

providing a mixed algal culture medium, containing a mixture of algae, wherein the algae are selected from the group consisting of members of the genera Ulva,

Enteromorpha, Chlorophora Rhizoclonium Rhodophycophyta, Porphyra contacting the mixed culture medium with extraneously added carbon dioxide incubating the mixed culture medium under suitable conditions to produce hydrocarbons and recovering said hydrocarbons.

It is a further object of the invention to provide the aforementioned process wherein the algal culture medium contains minerals and salts.

It is a further object of the invention to provide the aforementioned process wherein the medium comprises seawater.

It is a further object of the invention to provide the aforementioned process wherein the medium comprises artificial seawater

It is a further object of the invention to provide the aforementioned process wherein the medium comprises the constituents of seawater at a concentration of about 75% or

Dead sea water of a concentration of about 75%

It is a further object of the invention to provide the aforementioned process wherein the seawater is Dead Sea Water and is phosphate free

It is a further object of the invention to provide the aforementioned process wherein the medium includes sufficient EDTA or other chelating agent to prevent precipitation of magnesium carbonate.

It is a further object of the invention to provide the aforementioned process wherein the suitable conditions include excluding visible light by means of a red filter.

It is a further object of the invention to provide the aforementioned process wherein the suitable conditions include excluding visible light by steps of forming a salt layer on the surface of the algal growth medium using infrared lamps and/or filters.

It is a further object of the invention to provide the aforementioned process wherein the suitable conditions include addition of biologically available Silicon dioxide in the form of silicic acid to the growth medium

It is a further object of the invention to provide the aforementioned process wherein the suitable conditions include a step of adding biologically available Silicon dioxide in the form of silicic acid in light transmissible colloidal form and/or true suspension to the growth medium

It is a further object of the invention to provide the aforementioned process wherein the biologically available Silicon dioxide is provided to the algae in the form of an

algal culture growth promoting solution (ACGP), and the ACGP solution is prepared by steps of adding 0.9 gm Silicic acid to 200 mis of 5% Na2CO3, further addingl5 granules of NaOH to said solution boiling said solution for 6 hours or more until granules are dissolved adding a small or catalytic amount of Potassium Iodide removing 1.0 mililitre of an acidic solution of said silicic acid solution ,slowly adding

0.3 ml. cone. HCl to slight opacity, immediately adding one aliquot of 0.5 ml of cone.

HCl allowing the exothermic reaction to boil ,cooling said ACGP solution and adjusting said ACGP solution to pH 8.5. The aforementioned solution, when added dropwise in aliquots of 1.5-0.5 ml. to the algal culture medium provides Iy available

Silicon dioxide to the algae.

It is a further object of the invention to provide the aforementioned process wherein the produced hydrocarbons comprise at least one hydrocarbon selected from the group consisting of alkanes, alkenes, alkynes and arenes

It is a further object of the invention to provide the aforementioned process wherein the produced hydrocarbons comprise at least one selected from a group consisting of linear alkanes, linear alkenes, branched alkanes, branched alkenes, linear alkynes, branched alkynes.

It is a further object of the invention to provide the aforementioned process wherein the produced hydrocarbons comprise at least one cyclo - alkane.

It is a further object of the invention to provide the aforementioned process wherein at least a portion of the produced hydrocarbons are in gas, liquid, wax, low melting point solid or polymer form.

It is a further object of the invention to provide the aforementioned process wherein the hydrocarbon recovery is by steps of removing algal growth media from the upper and/or sub surface salt layer, replenishing the algal growth media with Dead Sea

Water or 75% Dead Sea Water or high saline seawater and isolating the hydrocarbons therefrom.

It is a further object of the invention to provide the aforementioned process wherein the hydrocarbon recovery is by a batch process.

It is a further object of the invention to provide the aforementioned process wherein at least one of the algae is non transgenic.

It is a further object of the invention to provide the aforementioned process wherein at least one of the algae is transgenic.

It is a further object of the invention to provide a mixed culture of algal strains useful for providing exogenously excreted hydrocarbons, the mixed culture adapted to produce exogenously excreted hydrocarbons.

It is a further object of the invention to provide the aforementioned mixed culture of algal strains wherein the mixed culture contains algae selected from the group consisting of members of the genera Ulva, Enteromorpha, Chlorophora Rhizoclonium

Rhodophycophyta, Porphyra. The aforementioned mixed culture is characterized by the ability to produce exogenously excreted hydrocarbons when contacted with extraneously added carbon dioxide and incubated under suitable conditions.

It is a further object of the invention to provide the aforementioned algal strains wherein the algal strains are characterized by a genetic trait of exogenously excreting the hydrocarbons under suitable conditions.

Moreover, it is a further object of the invention to provide the aforementioned algal strains wherein at least one algal strain is non transgenic

Furthermore, it is a further object of the invention to provide the aforementioned

Algal strains wherein at least one algal strain is transgenic.

Lastly, it is a further object of the invention to provide the aforementioned algal strains wherein all the strains are non transgenic.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 schematically illustrates steps of the method.

Figure IA inoculation of the culture.

Figure IB Growth of the algae.

Figure 1C Harvesting of the hydrocarbon product and replenishment of the seawater medium.

In the following description, various aspects of the invention will be described. For the purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the invention. However, it will be also apparent to one skilled in the art that the invention may be practiced without specific details presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the invention.

The classifications for hydrocarbons herein are as defined by IUPAC nomenclature of organic chemistry as follows:

Saturated hydrocarbons (alkanes) are the most simple of the hydrocarbon species and are composed entirely of single bonds and are saturated with hydrogen; they are the basis of petroleum fuels and are either found as linear or branched species of unlimited number. The general formula for saturated hydrocarbons is CnH2n + 2 (assuming non-cyclic structures).

Unsaturated hydrocarbons have one or more double or triple bonds between carbon atoms. Those with one double bond are called alkenes, with the formula CnH2n (assuming non-cyclic structures). Those containing triple bonds are called alkynes. Cycloalkanes are hydrocarbons containing one or more carbon rings to which hydrogen atoms are attached. The general formula for a saturated hydrocarbon containing one ring is CnH2n

Aromatic hydrocarbons, also known as arenes which have at least one aromatic ring Hydrocarbons can be gases (e.g. methane and propane), liquids (e.g. hexane and benzene), waxes or low melting solids (e.g. paraffin wax and naphthalene) or polymers (e.g. polyethylene, polypropylene and polystyrene).

DETAILED DESCRIPTION

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. With relation to chemical terminology, aromatic hydrocarbons or arenes, alkanes, alkenes and alkyne-based compounds composed entirely of carbon or hydrogen are referred to as "Pure" hydrocarbons, whereas other hydrocarbons with bonded compounds or impurities of sulphur or nitrogen, are referred to as "impure", and remain somewhat erroneously referred to as hydrocarbons. Hydrocarbons are referred to as consisting of a "backbone" or "skeleton" composed entirely of carbon and hydrogen and other bonded compounds, and lack a functional group that generally facilitates combustion without adverse effects. The majority of hydrocarbons found naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded can catenate to form seemingly limitless chains.

Algae and bacteria exist which thrive in various conditions of salinity. The core of the invention is to provide a method and means to reverse the degradation of hydrocarbons (catabolysis) by algae to hydrocarbon synthesis which is carried out (it is thought ) by green and possibly red algae on media of salt concentration similar to the Dead sea (30%) wt/vol or down to 22.5% wt/vol. The principle does not apply to

surface floating algae such as Dunaliella, but to sea water algae or even sweet water algae which are transferred to unusual and stressful conditions such that the desired metabolic changes occur. Observations have shown that if these algae, after growth in agal growth media described below, are transferred to salt water with constituents which include phosphates, the algae die. If phosphates are removed beforehand from the salt water media, the algae survive, and oxygen bubbles are observed. Furthermore, and surprisingly, the absence of phosphate prevents generation of sugars, and together with other factors, which will be discussed later, diverts algal metabolism in the direction of hydrocarbon generation, synthesized from CO2 and water, with oxygen release.

From an evolutionary standpoint, there is a lessening of synthesis of organic compounds needed for life, towards an increase in synthesis of simpler compounds. We disclose a method whereby the use of red filters, which exclude other visible light optimizes the hydrocarbon synthesis and algae survival at high salinity (such as is found in the Dead Sea) and at high temperatures (up to 50 degrees Centigrade). The method provides exogenously excreted hydrocarbons from algae. Algae are first grown in algal growth media, and then shifted to high saline growth media to promote hydrocarbon generation.

EXAMPLES

Reference is made to FIG. 1 schematically illustrating a method for producing hydrocarbons from algae.

The first stage (IA) comprises inoculating algae into Algal growth media and allowing the algae to grow until the surface is covered with algae, or the algae have formed a mat on the bottom of the chamber.

The second stage (IB) comprises drawing off the algal growth medium and replacing it with either Dead Sea Water, 75% Dead Sea Water, or High Saline Water, allowing the culture to stand for a period of about two to eight weeks, and allowing hydrocarbon production to occur.

The hydrocarbons are then harvested.

Algae which utilize red light are selected from a group comprising genera Ulva,

Enteromorpha, Chlorophora, Rhizoclonium Rhodophycophyta, Porphyra and undergo the selection and adaptation process of growth in seawater at a pH of 6 -8 at a temperature of 25 to 30 degrees Centigrade containing phosphate (lgm per litre).

GROWTH SYSTEM

Inoculum made up of genera Ulva, Enteromorpha, Chlorophora, Rhizoclonium

Rhodophycophyta, Porphyra or alternatively 10 ml of untreated seawater (containing algae naturally found therein) are inoculated into 1 litre of algal Growth Media.

The culture is grown in appropriate open chambers (30 X 40 cms X 4cms.).

In order to ensure routine and plentiful supply of CO2, Na2CO3 or NaHCCβ is added at a pH of between pH about 10 and 8.5.

The growth chambers may be outdoors exposed to sunlight, or under controlled red light conditions which filter out visible light. The growth chambers are allowed to stand until the upper liquid layer is covered with floating algae, or a substantial algal mat forms on the bottom of the chamber in the case of non floating algae.

When the aforementioned stage has been reached, the algal Growth Medium is drawn off and is replaced by Dead Sea Water Medium or High Salinity Water Medium. The

Dead Sea Water Medium can be diluted to about 75%.

Visible light is filtered to the surface of the chamber by red filters (maximum transmittance about 600nm dark red - about 597 nm for bright red) such that red light, reaches the surface of the growth chamber and the upper layer. Alternatively, a layer of salt can be allowed to form on the surface, which is also effective in blocking out visible light and allowing infra red light to pass through the salt layer to the water surface below.

Light from about 600nm to about 760 nm can be used, since optimal absorbance of chlorophyll a is about 650nm.

Magnesium is found at the centre of the HEME group of chlorophyll, and it is necessary to ensure a sufficient quantity of magnesium ions in the growth media solution. Without wishing to be bound by theory, it is likely that in order to maximise higher production of chlorophyll per unit of algae, it is necessary to ensure higher magnesium in the medium, in a surplus greater than the ratio of magnesium ions to chlorophyll molecules. In a concentrated medium such as Dead Sea Water there is probably a higher concentration of magnesium in the cells, and perhaps a more complex and efficient chloroplastic structure is formed.

Precipitation of magnesium carbonate is prevented by adding EDTA or another chelating agent before addition of carbonate to the Dead Sea Water medium.

Under these conditions, the algae will use the dissolved CO2 whether the origin is carbonate or atmospheric, and, due to the alkalinity of the medium, more CO2 will

enter the solution from the atmosphere. The pH will not drop because the CO2 will be incorporated in the hydrocarbons.

Addition of sufficient EDTA (Ethylene diamine Tetra Acetic acid), required to avoid magnesium carbonate precipitation is based on the method of LG. Car (Methods in

Enzymology XXXIII) as follows:

To 60 mis. of the above described growth media 0.5 mg. of EDTA (by transferring

0.01 ml. of a solution of 1 gm. EDTA dissolved in 20 ml. of water) are added; and only afterwards, 6.0 mis of the solution of 6.0 gms. Na2CO3 dissolved in lOOmls of water are added to the solution.

To 100 mis of the above mentioned algae growth media 1.0 mg. of EDTA per 0.36 gm. Na2CO3 and 0.02 gm MgSO4 7H2O.

For 1 litre approx lOmg of EDTA is added as above and for 1000 litre 1.0 gm is added.

For a solution of Dead Sea water which contains at least 6.0 gm of Mg. 0.3gm EDTA will be needed

Removal of phosphate from Algal Growth Medium and Dead Sea Water is by:

In practice the concentrations are not necessarily linear, and it is necessary to titrate lower and higher concentrations around these orders of magnitude.

RECOVERY OF HYDROCARBONS

If the hydrocarbons produced are light they will float on the surface of the water and disturb the passage of atmospheric carbon dioxide into solution. For recovery of these low density hydrocarbons, a continuous process is used. New sea water should be added in a manner which will not disturb the salt layer. The upper layer of low density hydrocarbons and water just below the salt is slowly and continuously drawn off.

For removal of heavy high density hydrocarbons, a batch recovery system is employed for removal of hydrocarbons at a depth below the surface.

METHOD FOR PROVIDING LY AVAILABLE SILICIC ACID

Silicic acid solution is made up as follows:

0.9 gm Silicic acid is added to 200 mis of 5% Na2CO3. 15 granules of NaOH are added, and the vessel containing the solution is heated to boiling for 6 hours or more until granules are dissolved. A small amount of Potassium Iodide is added (3-4 grains of commercial grade or equivalent). Sand of the silicate type, cooked with bicarbonate

until dissolution can be used. It is possible to clean the sands with water rinsing, followed by concentrated HCl and then Na OH before reacting with the Na2CO3.

In order to prepare silicic acid, to ImI of SiO2 of the above solution, is slowly added

0.3 ml. cone. HCl to light opacity, and then one aliquot of 0.5 ml of cone. HCl is added at once . Care should be taken since the reaction is exothermic. The cooled solution results in an acidic silicic acid (SiO2) solution which can be brought to pH

8.5 in small steps of 1.5-0.5 ml. this solution can be added to the algal growth medium.

It has been observed that the water from the Dead Sea preserves algae, so such a system can be preserved for a long time, even several months.

In order to grow these algae, a temperature of 23-25 degrees Centigrade is needed, but the temperature of the concentrated solutions can reach higher temperatures due to direct infra red radiation from the sun without yellowing of the algae due to chlorophyll destruction if light is red.

EXAMPLE 1

Preparation of Algal Growth Media adapted from (Stainer et al. the Microbial World).

Algal growth media is made up as follows:

MgSO4.7H2O 0.2 gr.

K2HPO4 0.1 gr.

FeSO4.7H2O 0.01 gr.

CaC12 0.02 gr.

,NaC12,4H2O gr.

NaMO4.2H20 gr.

NaCl gr. dissolve in 1 litre H20

The medium is exposed to atmospheric CO2 or CO2 is bubbled through it. The pH is adjusted to 6-8.

Carbonate is added in the form of Na2 CO3 or NHCO3 or both together for buffering. Addition of carbonate seems to increase the Iy available CO2 even from the atmosphere, thereby boosting ultimate yield of photosynthetic units. For the same reason, Magnesium salts, especially chlorides are added, and EDTA at 0.3 gm per litre is used to prevent precipitation of magnesium carbonate. Optionally, other

magnesium salts may be added. The rationale for all of the above is to possibly increase the number and quality of photosynthetic units (chlorophylls and chloroplasts).

The algae need Iy available SiO2. Hydrocarbon production is enhanced by adding add large quantities of silicon at the growth stage and/or to the Dead Sea water. The silicon can be added in the form of Silicic acid, silicon crystals or silica gel. Silicic acid, in solution with sodium bicarbonate with the pH varying from acidic to basic.

EXAMPLE 2

Algal growth media include the following ingredients:

MgSO4.7H2O 2 gr.

K2HPO4 10 gr.

FeSO4.7H2O 0.l gr.

CaC12 0.2 gr.

MnC12,4H2O 0.02 gr.

NaMO4.2H20 0.01 gr.

NaCl 5 gr.

NH4C1 10 gr.

KI 2-4 grains

SiO2 20 ml

Optionally, a small sized clump of pitch or tar of the type often found on the surface of the sea.

For hydrocarbons production the following ingredients are added:

EDTA 5 gr.

Dead Sea salts 3.75 gr. (for example purchased by AHAVA) dissolved in 10 liter H20

Optionally, 1 cm wax phase Paraffin

Algal growth protocol:

All the above detailed growth medium ingredients are added into a chamber or aquarium covered by red glass from all sides. For buffering, 50 ml Na2 CO3 and NHCO3 solution (NaHCO3 1.6 gr. + Na2CO3 2.6 gr. dissolved in 200 ml H2O) is added. The pH is adjusted to 6-8.

50 ml of seawater are than added to the algae growth medium. The medium is bubbled by atmospheric CO2.

Optionally, a small sized pitch or tar clump, obtained from the sea, is added to the algae growth medium.

The algae are grown in the above mentioned media for about two months.

For hydrocarbon production, EDTA and Dead Sea salts are added. The Dead Sea salts are added gradually, 3.75 gr. in each second day. Optionally, 1 cm paraffin wax phase is added. The aforementioned step is aimed to increasing the desirable hydrocarbon production possibly by generating elevated CO2 concentrations in the medium.

As used herein the term 'Dead Sea salts' refers to the Dead Sea's mineral composition. The aforementioned composition differs from that of ocean water, varying with season, rainfall, depth, and temperature. In particular, the salt in most oceans is approximately 97% sodium chloride while Dead Sea salt is only 12-18% sodium chloride and has vastly greater concentrations of other salts. An analysis of major ion concentrations in the water of the Dead Sea gave the following results:

As was found The Dead Sea's overall salt concentration is 340 g/I/

It should be emphasized that the algae are photosynthetically active and are green colored through the entire process and growth conditions.

The hydrocarbon recovery is assessed after two months.

It is a core purpose of the invention to disclose a process for producing exogenously excreted hydrocarbons from algae. The process comprises steps of: providing a mixed algal culture medium, containing a mixture of algae. The mixed algal culture medium comprises algae selected from the group consisting of members

of the genera Ulva, Enteromorpha, Chlorophora Rhizoclonium Rhodophycophyta,

Porphyra.

The method further comprises contacting the mixed culture medium with extraneously added carbon dioxide, which can be added as carbonate, or is atmospheric in origin.

The method further comprises of incubating the mixed culture medium under suitable conditions to produce hydrocarbons and recovering the hydrocarbons. Another aspect of the invention comprises the process as defined above, wherein the medium comprises seawater. Another aspect of the invention comprises the process as defined above wherein the medium comprises artificial seawater

Reference is now made to an embodiment of the invention being a mixed algal culture medium, containing a mixture of algae adapted for producing exogenously excreted hydrocarbons, said hydrocarbons excreted by after a process comprising the steps of:

(a) contacting said mixed culture medium with extraneously added carbon dioxide

(b) incubating said mixed culture medium under suitable conditions to produce hydrocarbons and

(c) recovering said hydrocarbons. wherein said algae are selected from the group consisting of members of the genera Ulva, Enteromorpha, Chlorophora Rhizoclonium Rhodophycophyta, Porphyra.

A yet further aspect of the invention comprises the process as defined above wherein the medium comprises the constituents of seawater at a concentration of about 75% A yet further aspect of the invention comprises the process as defined above, wherein the aforementioned seawater is Dead seawater and is phosphate free or the constituents of about 75% Dead seawater.

A further aspect of the invention comprises the process as described above wherein the aforementioned medium includes sufficient EDTA or other chelating agent to prevent precipitation of magnesium carbonate.

A further aspect of the invention comprises the process as described above wherein the aforementioned suitable conditions include excluding visible light by means of a red filter.

A further aspect of the invention comprises the process as described above wherein the suitable conditions include excluding visible light by steps of forming a salt layer on the surface of the algal growth medium

A further aspect of the invention comprises the process as described above wherein achieving the aforementioned suitable conditions includes addition of Iy available

Silicon dioxide in the form of silicic acid to the growth medium.

A further aspect of the invention comprises the process as described above wherein the aforementioned suitable conditions include a step of adding Iy available Silicon dioxide in the form of silicic acid in light transmissible colloidal form and/or true suspension to the growth medium and/or the Dead Sea Water medium.

A yet further aspect of the invention comprises the process as described above wherein the Iy available Silicon dioxide is provided to the algae in the form of an algal culture growth promoting solution (ACGP). The ACGP solution is prepared by steps of adding 0.9 gm Silicic acid to 200 mis of 5% Na2CO3, further addingl5 granules of NaOH to the solution boiling the solution for 6 hours or more until granules are dissolved and adding a small amount of about 20 mg. Potassium Iodide, removing 1.0 mililitre of an acidic solution of the silicic acid solution ,slowly adding

0.3 ml. cone. HCl to slight opacity, immediately adding one aliquot of 0.5 ml of cone.

HCl allowing the exothermic reaction to boil, cooling the ACGP solution and adjusting the ACGP solution to pH 8.5. Adding dropwise 1.5-0.5 ml. to the algal culture medium provides Iy available Silicon dioxide to the algae.

A yet further aspect of the invention comprises the process as described above wherein the produced hydrocarbons comprise at least one selected from the group consisting of alkanes, alkynes,alkenes and arenes

A yet further aspect of the invention comprises the process as described above wherein the produced hydrocarbons comprise at least one selected from a group consisting of linear alkanes, linear alkenes, branched alkanes, branched alkenes, linear alkynes, branched alkynes.

A yet further aspect of the invention comprises the process as described above wherein the produced hydrocarbons comprise at least one cyclo - alkane.

A yet further aspect of the invention comprises the process as described above wherein at least a portion of the produced hydrocarbons are in gas, liquid , wax, low melting point solid or polymer form.

A yet further aspect of the invention comprises the process as described wherein said hydrocarbon recovery is by steps of removing algal growth media from the upper and/or sub surface salt layer replenishing the algal growth media with Dead Sea

Water or about 75% Dead Sea Water or high saline seawater and isolating said hydrocarbons therefrom .

A yet further aspect of the invention comprises the process as described above wherein the hydrocarbon recovery is by a batch process.

A yet further aspect of the invention comprises the process as described above wherein at least one of said algae is non transgenic.

A yet further aspect of the invention comprises the process as described above wherein at least one of said algae is transgenic.

A yet further suprising aspect of the invention comprises providing a mixed culture of algal strains useful for providing exogenously excreted hydrocarbons, the aforementioned mixed culture adapted to produce exogenously excreted hydrocarbons.

A yet further aspect of the invention comprises providing a mixed culture of algal strains as described above, wherein the mixed culture contains algae selected from the group consisting of members of the genera Ulva, Enteromorpha, Chlorophora

Rhizoclonium Rhodophycophyta, Porphyra, themixed culture characterized by the ability to produce exogenously excreted hydrocarbons when contacted with extraneously added carbon dioxide and incubated under suitable conditions

A yet further aspect of the invention comprises providing algal strains as described above, wherein the algal strains are characterized by a genetic trait of exogenously excreting said hydrocarbons under suitable conditions.

A yet further aspect of the invention comprises providing algal strains as described above wherein at least one of the algal strain is non transgenic

A still further aspect of the invention comprises providing algal strains as described above wherein at least one algal strain is transgenic.

Lastly, a still further aspect of the invention comprises providing algal strains as described above wherein all the strains are non transgenic.

It is acknowledged that the word "about" indicates a possible variation of 25% of the measure, concentration or value referred to. It is further acknowledged that all measures, concentrations and values may vary by up to 25%.

While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claim as and claims hereafter introduced be interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.