WO2015123522A1

WO2015123522A1 - Process for phototrophic production of phas and h2 gas from wide range of organic waste

Info

Publication number: WO2015123522A1
Application number: PCT/US2015/015822
Authority: WO
Inventors: Roger Frank PEARSON; Gregory Scott Patterson
Original assignee: Willow Industries, Llc
Priority date: 2014-02-14
Filing date: 2015-02-13
Publication date: 2015-08-20

Abstract

A universally deployable process for the phototrophic production of commercially saleable polyhydroxyalkanoates and hydrogen gas in which an organic acid enriched feedstock is inoculated with a synergistic bacterial consortium, followed by light and dark phase fermentation and harvest of the polyhydroxyalkanoates.

Description

PROCESS FOR PROTOTROPHIC PRODUCTION OF PHAS AND H₂ GAS FROM WIDE RANGE OF ORGANIC WASTE

FIELD OF INVENTION

[0001] The invention relates to methods of converting organic waste into products of commercial value.

BACKGROUND

[0002] Environmentally sound conversion of organic waste, particularly agricultural waste, into a saleable revenue generating commodity has long been a desired but elusive goal throughout the world.

[0003] One of the complications involved in achieving such conversion is that bacteria commonly used in such processes perform well only under highly specific growth conditions and the composition of organic waste feedstreams tend to vary over time.

[0004] Accordingly, a need exists for an environmentally sound system and method for converting a wide-range of compositionally variable organic wastes into a saleable revenue generating commodity.

SUMMARY OF THE INVENTION

[0005] The invention is directed to a process for the phototrophic production of commercially saleable polyhydroxyalkanoates (PHAs) and hydrogen gas (¾) suitable for use with a wide range of organic wastes.

[0006] One embodiment of the process includes the steps of (-) anaerobically digesting, preferably involving acetogenesis, the organic waste for a digestion period to generate an organic acid enriched feedstock (digestion), (-) inoculating the organic acid enriched feedstock with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce an inoculated organic acid enriched liquor (inoculation), (-) fermenting the inoculated organic acid enriched liquor through at least one light phase period and one dark phase period to generate a polyhydroxyalkanoate enriched biomass (fermentation), and (-) harvesting the polyhydroxyalkanoates from the polyhydroxyalkanoate enriched biomass (harvest).

[0007] A second embodiment of the process includes the steps of (-) anaerobically digesting, preferably involving acetogenesis, the organic waste for a digestion period to generate an organic acid enriched feedstock (digestion), (-) inoculating the organic acid enriched feedstock with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce an inoculated organic acid enriched liquor (inoculation), (-) fermenting the inoculated organic acid enriched liquor with exposure to radiant energy for a light phase fermentation period to generate a glycogen enriched biomass (light phase fermentation), (-) fermenting the glycogen enriched biomass in the absence of radiant energy for a dark phase fermentation period to generate a polyhydroxyalkanoate enriched biomass (dark phase fermentation), and (-) harvesting the polyhydroxyalkanoates from the polyhydroxyalkanoate enriched biomass (harvest).

[0008] A third embodiment of the process includes the steps of (-) anaerobically digesting, preferably involving acetogenesis, the organic waste for a digestion period to generate an organic acid enriched feedstock (digestion), (-) fractionating the organic acid enriched feedstock by chemical composition of the organic acid into at least two acid fractions, (-) inoculating each of the acid fractions with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce inoculated homogeneous organic acid enriched liquors (inoculation), (-) fermenting each of the inoculated homogeneous organic acid enriched liquors with exposure to radiant energy for a light phase fermentation period to generate homogeneous glycogen enriched biomasses (light phase fermentation), (-) fermenting each of the homogeneous glycogen enriched biomasses in the absence of radiant energy for a dark phase fermentation period to generate homogeneous polyhydroxyalkanoate enriched biomasses (dark phase fermentation), and (-) harvesting homogeneous

polyhydroxyalkanoates from each of the homogeneous polyhydroxyalkanoate enriched biomasses (harvest).

[0009] The process preferably further comprising the step of inoculating the organic waste with photosynthetic sulfide oxidizing bacteria prior to or during digestion, with a preference for inoculation of the organic waste with the bacterial consortium employed in the inoculation step.

[0010] In a preferred embodiment the process further comprises the step of separating total suspended solids from the organic acid enriched feedstock to form a suspended solids enriched fraction and a suspended solids depleted organic acid enriched liquor, and inoculating the suspended solids depleted organic acid enriched liquor in the inoculation step.

[0011] In a further preferred embodiment the process further comprises the steps of (a) dividing the organic acid enriched feedstock into a first portion and a second portion, (b) employing the first portion in the inoculation step, (c) subjecting the second fraction to nitrification to produce a nitrate and/or nitrite enriched second portion, and (d) adding at least a proportion of the nitrate and/or nitrite enriched second portion to the organic acid enriched liquor prior to or during the inoculation step.

[0012] The process preferably includes the steps of withdrawing and collecting hydrogen gas generated during fermentation, including one or both of the light phase fermentation and the dark phase fermentation.

[0013] A portion of the polyhydroxyalkanoate enriched biomass may be diverted prior to harvest and added to the organic acid enriched liquor prior to or during fermentation, preferably prior to light phase fermentation.

[0014] The polyhydroxyalkanoates may be harvested from the polyhydroxyalkanoate enriched biomass by any of the well known harvesting techniques, including cryogenic and solvent based separation techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1, separated into Figures 1A, IB and 1C to facilitate depiction upon pages of restricted size, is a process flow diagram of one embodiment of the invention.

[0016] Figure 1A depicts the anaerobic digestion stage of the one embodiment of the invention wherein organic waste is converted to a supply of mixed organic acids (A) and a supply of total separated suspend solids (B).

[0017] Figure IB depicts the polyhydroxyalkanoate (PHA) type selection stage of the one embodiment of the invention wherein the mixed organic acids in the supply of organic acids (A) may be separated as desired to supply feedstocks of blended or segregated organic acids (Cn) for use in producing blended or segregated PHAs. A supply of ammonia, convertable to nitrites and nitrates (D) for use in the process, is also produced. The specific types of organic acids referenced in Figure IB are exemplary only. Other types of organic acids may be separated from the supply of mixed organic acids (A) as desired.

[0018] Figure 1 C depicts the production stage of the one embodiment of the invention wherein each feedstock of blended or segregated organic acids (Cn) is separately converted to commercially valuable PHA(s) and hydrogen gas.

[0019] Figure 2A is a graph of instantaneous dissolved hydrogen gas readings over time for the inoculated mixture of Example 1 during the bacterial growth period.

[0020] Figure 2B is a graph of conservatively estimated cumulative hydrogen gas generation over time for the inoculated mixture of Example 1 during the bacterial growth period.

[0021] Figure 3 is a gas chromatograph mass spectroscopy graph of abundance verses time for the polyhydroxyalkanoate enriched biomass produced in Example 2 with the isopropyl hydroxybutyrate peak occurring at approximately 7.01 labeled for convenience.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0022] As utilized herein, including the claims, fermentation refers to any of a group of chemical reactions induced by microorganisms or enzymes that split complex organic compounds into relatively simple substances.

[0023] As utilized herein, including the claims, family refers to a family of bacteria and any subset thereof having specifically defined characteristics.

[0024] Referring generally to Figures 1A, IB and 1C, the invention is directed to a process for the phototrophic production of commercially saleable polyhydroxyalkanoates and hydrogen gas, from a wide range of organic wastes.

[0025] One embodiment of the process includes the steps of (-) anaerobically digesting, preferably involving acetogenesis, the organic waste for a digestion period to generate an organic acid enriched feedstock, (-) inoculating the organic acid enriched feedstock with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce an inoculated organic acid enriched liquor, (-) fermenting the inoculated organic acid enriched liquor through at least one light phase period and one dark phase period to generate a polyhydroxyalkanoate enriched biomass, and (-) harvesting the polyhydroxyalkanoates from the polyhydroxyalkanoate enriched biomass.

[0026] The further detail, the fermentation step can include the steps of (-) fermenting the inoculated organic acid enriched liquor with exposure to radiant energy for a light phase fermentation period to generate a glycogen enriched biomass, and (-) fermenting the glycogen enriched biomass in the absence of radiant energy for a dark phase fermentation period to generate the polyhydroxyalkanoate enriched biomass.

[0027] Anaerobic digestion of the organic waste to generate an organic acid enriched feedstock in the digestion step preferably employs a hydraulic retention time of 1 to 3 days and includes inoculation of the organic waste with acetogens. Selection of acetogens suitable for effecting acetogenesis during the digestion period is well within the knowledge and skill of those of possessing routine skill in the art.

[0028] Referring to Figure 1C, the light phase fermentation period preferably has a hydraulic retention time of 6 to 16 hours, while the dark phase fermentation period has a hydraulic retention time of 2 to 12 hours. The process preferably involves a single cycle through the light and dark phases, but multiple cycles can be employed. It is also possible to reverse the sequence and employ the dark cycle first followed by the light cycle.

[0029] Referring to Figure 1 A, the organic waste can be inoculated with photosynthetic sulfide oxidizing bacteria, such as the bacterial consortium referenced in the inoculation step prior to or during the digestion step.

[0030] Referring still to Figure 1A, in a preferred embodiment the process further comprises the step of separating total suspended solids from the organic acid enriched feedstock to form a suspended solids enriched fraction and a suspended solids depleted organic acid enriched liquor, and inoculating the suspended solids depleted organic acid enriched liquor in the inoculation step. Selection of a suitable technique for separating total suspended solids from the organic acid enriched feedstock is well within the knowledge and skill of those of possessing routine skill in the art. One suitable technique is decantation employing a 10-500 μιη screen.

[0031] Referring to Figure IB, the process can include the steps of (a) dividing the organic acid enriched feedstock into a first portion and a second portion, (b) employing the first portion in the inoculation step, (c) subjecting the second fraction to nitrification to produce a nitrate and/or nitrite enriched second portion, and (d) adding at least a proportion of the nitrate and/or nitrite enriched second portion to the organic acid enriched liquor prior to or during fermentation. Nitrification of an organic acid enriched feedstock is a well known and understood process.

[0032] Referring to Figure 1C, a portion of the polyhydroxyalkanoate enriched biomass may be diverted prior to harvest and added to the organic acid enriched liquor prior to or during fermentation, preferably prior to or during light phase fermentation.

[0033] Referring still to Figure 3C, hydrogen gas may be withdrawn and collected during fermentation, including one or both of the light phase fermentation and the dark phase fermentation. Techniques for the withdrawal and collection of hydrogen gas from a hydrogen gas generating liquid are well known and understood.

[0034] Referring to Figures IB and 1C, the process can be adjusted to produce homogeneous polyhydroxyalkanoate enriched biomasses, by fractionating the organic acid enriched feedstock into at least two acid fractions by chemical composition of the organic acid, followed by (-) inoculating each of the acid fractions with the previously referenced synergistic bacterial consortium to produce inoculated homogeneous organic acid enriched liquors, fermenting each of the inoculated homogeneous organic acid enriched liquors with exposure to radiant energy for a light phase fermentation period to generate homogeneous glycogen enriched biomasses, fermenting each of the homogeneous glycogen enriched biomasses in the absence of radiant energy for a dark phase fermentation period to generate homogeneous polyhydroxyalkanoate enriched biomasses, and harvesting of homogeneous polyhydroxyalkanoates from each of the homogeneous polyhydroxyalkanoate enriched biomasses.

[0035] TABLE ONE provides preferred operational parameters and testing protocol for each of the Anaerobic Digestion Phase, Glycogen Phase and PHA Phase of the invention as depicted in Figure 1.

TABLE ONE

PARAMETERS PHASE GLYCOGEN

PHA PHASE PHASE

Temperature °C 10-80 °C Probe 10-35 °C 10-35 °C pH 6.0-8.0 Probe 6.0-8.0 6.0-8.0

Oxidation

Reduction Accumet Probe (100 to -300) (100 to -300) Potential

Dissolved

0-.5mg/l Probe 0-.5mg/l 0-.5mg/l Oxygen

Sulfides,

l-50mg/l 5-50mg/l .l-20mg/l dissolved

Total Solids A%-\0% SM 2540G .01%-5%

Volatile solids

as % of total 20 -80 SM 2540G 1.0%-80%

solids

Total Suspended 500mg/l-

SM 2540D 250mg/l

Solids 50000mg/l

lOOOmg/1- SM

Ammonia NH₄ 100-350mg/l 100-350mg/l

100,000mg/l 4500NH3BE

Total 50mg/l-

SW 846 6010 50-250mg/l 50-250mg/l

Phosphorus 50,000mg/l

Nitrate ASTM D3867 1-5000 mg/1 1-5000 mg/1

ORGANIC ACIDS

Acetic 8015B lmg/l-5000mg/l

Propionic 8015B lmg/l-5000mg/l

Butyric 8015B lmg/l-5000mg/l

Other(s) 8015B lmg/l-5000mg/l

LIGHT SOURCE FOR PHA CYCLE

(-600 to -

Infrared

950nm)

Total Luxs 1,000-15,000

[0036] TABLE TWO provides a listing of preferred bacteria species for use in the Glycogen Phase and PHA Phase of the invention as depicted in Figure 1. PURPLE FILAMENTOUS COLORLESS

PURPLE NON- GREEN SULFUR

BACTERIA GREEN SULFUR SULFUR BACTERIA BACTERIA CHROMATIUM BACTERIA BACTERIA

Chromatium Rhodspirrillum Chlorobium Chloroflexus Beggiatoaceae

Thiocyctis Rhodobacter Prosthecochloris Chloronema Achromatium

Thiospirillum Rhodopseudomonas Pelodictyon Oscillochloris Thiobacterium

Thiocapsa Rhodomicrobium Ancalochloris Macromonma

Lamprocystis Rhodopila Chloroherpeton Thiospira

Lamprobacter Thiovulum

Thiopedia Bilophocucus

Thiobacillus

Thiomicrospira

Thiodendron

Thiosphaera

Acidiphilium

Thermothrix

Sulfolobus

Acidianus

PERSNICKETY brand 713™ consortium of bacteria available from Syneco Systems Inc. of Chanhassen, Minnesota

EXAMPLES

Example 1

Hydrogen Gas Production through a Controlled

Anaerobic Process in a Bioreactor

[0037] A 2.5 gallon bucket (bioreactor) equipped with a thermostatically controlled heating element was filled with approximately 2.25 gallons of potable water and the thermostat set at 28 °C. Approximately 454 grams of crushed dry cat food was added to the potable water in the bioreactor and allowed to acclimate for 24 hours to allow for any free chlorine to gas off and the temperature of the mixture in the bioreactor to achieve a temperature of approximately 27 °C. [0038] An ORP (oxidation-reduction potential) probe, a dissolved oxygen probe, a pH probe, a temperature probe and a dissolved hydrogen gas probe were placed into sensing communication with the acclimated mixture in the bioreactor and baseline measurements taken as reported in TABLE THREE below.

[0039] The acclimated mixture in the bioreactor was inoculated with 500 ml of PERSNICKETY brand 713™ liquid consortium of photosynthetic sulfide-utilizing bacteria purchased from Syneco Systems Inc. of Chanhassen, Minnesota, and bacterial growth allowed through a forty four hour bacterial growth period.

[0040] Temperature and concentration of dissolved hydrogen gas readings were taken every 3-4 seconds throughout the bacterial growth period. Instantaneous dissolved hydrogen gas readings and conservatively estimated cumulative hydrogen gas generation are reported in FIGURES 2A and 2B respectively.

[0041] An infrared light (850 nm @ 9000 lux) was placed approximately 9 inches above the bioreactor and ambient light blocked by a black polypropylene sheet draped over the light and the open top of the bioreactor. The infrared light was turned off for an initial 10 hour period (dark phase), and then turned on for a 16 hour period (light phase) after inoculation. The infrared light was turned off thereafter.

[0042] Final readings of the inoculated mixture were taken at the end of the bacterial growth period as reported in TABLE THREE below.

[0043] Accelerated hydrogen production was achieved during the sixteen hour light phase growth following the initial ten hour dark phase growth. Superior hydrogen production continued at a decelerating pace throughout the secondary dark phase growth period.

Hydrogen product continued to decelerate into the secondary dark phase.

TABLE THREE

Example 2

Polyhyroxyalkanoate Production through a Controlled

Anaerobic Process in a Bioreactor

[0044] A 5 gallon bucket (bioreactor) equipped with a thermostatically controlled heating element was filled with approximately 4.25 gallons of potable water and the thermostat set at 28 °C. The water was allowed to acclimate for 24 hours to allow for any free chlorine to gas off and the temperature of the mixture in the bioreactor to achieve a temperature of approximately 25 °C.

[0045] Approximately 500 ml grams of liquid swine waste collected from a local swine production facility was added to the potable water in the bioreactor. Chemical analysis of the swine waste employing the testing methodology set forth in TABLE FOUR found the swine waste to contain the listed constituents in the concentrations set forth in TABLE FOUR.

TABLE FOUR

[0046] An ORP (oxidation-reduction potential) probe, a dissolved oxygen probe, a pH probe and a temperature probe and were placed into sensing communication with the mixture in the bioreactor and baseline measurements taken as reported in TABLE FIVE below. [0047] The mixture in the bioreactor was inoculated with 500 ml of PERSNICKETY brand 713™ liquid consortium of photosynthetic sulfide-utilizing bacteria purchased from Syneco Systems Inc. of Chanhassen, Minnesota, and bacterial growth allowed through a forty eight hour bacterial growth period.

[0048] An infrared light (850 nm @ 9000 lux) was placed approximately 9 inches above the bioreactor and ambient light blocked by a black polypropylene sheet draped over the light and the open top of the bioreactor. The infrared light was turned off for an initial 8 hour period (dark phase), and then turned on for an initial 12 hour period (light phase) after inoculation, followed by a secondary dark phase of 8 hours, a secondary light phase of 12 hours and a final dark phase of 8 hours.

[0049] Final readings of the inoculated mixture were taken at the end of the bacterial growth period as reported in TABLE FIVE below.

TABLE FIVE

[0050] A 250 ml composite sample of the final liquid mixture was taken from the bioreactor and centrifuged for 20 minutes. The liquid fraction from the centrifuged vial was discarded, leaving behind a solid biomass at the bottom of the vial. The solid biomass was removed and preserved in dichloromethane. The sample was subjected to hydrolysis and derivitization to form the isopropyl esters of the PHA inclusion incorporated in the recovered biomass. The derivitized extract was analyzed by GC/MS to identify and quantify the total PHA content. The results of the GC/MS analysis is set forth in FIGURE 3. Quantitation of the isopropyl hydroxybutyric acid in the sample indicated a concentration of about 0.56% of poly-3-hydroxybutyric acid in the sample by weight.

Claims

We claim:

A process for phototrophic production of polyhydroxyalkanoates from organic waste, comprising the steps of:

(a) anaerobically digesting the organic waste for a digestion period to generate an organic acid enriched feedstock,

(b) inoculating the organic acid enriched feedstock with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce an inoculated organic acid enriched liquor,

(c) fermenting the inoculated organic acid enriched liquor through at least one light phase period and one dark phase period to generate a

polyhydroxyalkanoate enriched biomass, and

(d) harvesting the polyhydroxyalkanoates from the polyhydroxyalkanoate

enriched biomass.

(c) fermenting the inoculated organic acid enriched liquor with exposure to

radiant energy for a light phase fermentation period to generate a glycogen enriched biomass,

(d) fermenting the glycogen enriched biomass in the absence of radiant energy for a dark phase fermentation period to generate a polyhydroxyalkanoate enriched biomass, and (e) harvesting the polyhydroxyalkanoates from the polyhydroxyalkanoate enriched biomass.

3. The process of claim 2 further comprising the step of inoculating the organic waste with photosynthetic sulfide oxidizing bacteria prior to or during step (a).

4. The process of claim 3 wherein the step of inoculating the organic waste with

photosynthetic sulfide oxidizing bacteria prior to or during step (a) comprises inoculating the organic waste with the bacterial consortium employed in step (b).

5. The process of claim 2 further comprising the step of separating total suspended solids from the organic acid enriched feedstock to form a suspended solids enriched fraction and a suspended solids depleted organic acid enriched liquor, and inoculating the suspended solids depleted organic acid enriched liquor in step (b).

6. The process of claim 2 further comprising the steps of: (i) dividing the organic acid enriched feedstock into a first portion and a second portion, (ii) employing the first portion in step (b), (iii) subjecting the second fraction to nitrification to produce a nitrate and/or nitrite enriched second portion, and (iv) adding at least a proportion of the nitrate and/or nitrite enriched second portion to the organic acid enriched liquor prior to or during step (c).

7. The process of claim 2 wherein hydrogen gas is generated during step (c) and the process further comprises the step of withdrawing and collecting the hydrogen gas generated during step (c).

8. The process of claim 2 wherein hydrogen gas is generated during step (d) and the process further comprises the step of withdrawing and collecting the hydrogen gas generated during step (d).

9. The process of claim 7 wherein hydrogen gas is generated during step (d) and the process further comprises the step of withdrawing and collecting the hydrogen gas generated during step (d).

10. The process of claim 2 wherein a portion of the polyhydroxyalkanoate enriched biomass is diverted prior to harvest and added to the organic acid enriched liquor prior to or during step (c).

11. The process of claim 2 wherein anaerobic digestion of the organic waste in step (a) involves acetogenesis.

12. The process of claim 2 wherein (i) anaerobic digestion is conducted at a temperature of between 10 and 80 °C, (ii) fermentation of the inoculated organic acid enriched liquor is conducted at a temperature of between 10 and 35 °C, and (iii) fermentation of the glycogen enriched biomass is conducted at a temperature of between 10 and 35 °C.

13. The process of claim 2 wherein (i) anaerobic digestion is conducted at a basic pH of 6 to 8, (ii) fermentation of the inoculated organic acid enriched liquor is conducted at a at a basic pH of 6 to 8, and (iii) fermentation of the glycogen enriched biomass is conducted at a basic pH of 6 to 8.

14. The process of claim 2 wherein (i) anaerobic digestion is conducted at a dissolved oxygen concentration of 0 to 0.5 mg/1, (ii) fermentation of the inoculated organic acid enriched liquor is conducted at a dissolved oxygen concentration of 0 to 0.5 mg/1, and (iii) fermentation of the glycogen enriched biomass is conducted at a dissolved oxygen concentration of 0 to 0.5 mg/1.

15. The process of claim 2 wherein (i) anaerobic digestion is conducted at an ammonia concentration of 1,000 to 100,000 mg/1, (ii) fermentation of the inoculated organic acid enriched liquor is conducted at an ammonia concentration of 100 to 350 mg/1, and (iii) fermentation of the glycogen enriched biomass is conducted at an ammonia concentration of 100 to 350 mg/1.

16. The process of claim 6 wherein (i) anaerobic digestion is conducted at an ammonia concentration of 1,000 to 100,000 mg/1, (ii) fermentation of the inoculated organic acid enriched liquor is conducted at an ammonia concentration of 100 to 350 mg/1, and (iii) fermentation of the glycogen enriched biomass is conducted at an ammonia concentration of 100 to 350 mg/1.

17. The process of claim 2 wherein (i) fermentation of the inoculated organic acid

enriched liquor is conducted at a nitrate concentration of 1 to 5000 mg/1, and (ii) fermentation of the glycogen enriched biomass is conducted at a nitrate concentration of 1 to 5000 mg/1.

18. The process of claim 6 wherein (i) fermentation of the inoculated organic acid

19. The process of claim 2 wherein (i) total suspended solids in the organic waste

subjected to anaerobic digestion is between 500 and 50,000 mg/1, and (ii) total suspended solids in the organic acid enriched feedstock subjected to inoculation is approximately 250 mg/1.

20. The process of claim 2 wherein the inoculated organic acid enriched liquor is exposed to 600 to 950 nm radiant energy during the light phase fermentation period.

21. The process of claim 2 wherein the digestion period is a hydraulic retention time of 1- 3 days.

22. The process of claim 2 wherein the light phase fermentation period is a hydraulic retention time of 6 to 16 hours.

23. The process of claim 2 wherein the dark phase fermentation period is a hydraulic retention time of 2 to 12 hours.

24. The process of claim 2 wherein the organic acid enriched feedstock is inoculated with a bacterial consortium containing at least one species of bacteria from all five of the bacterial families. The process of claim 2 wherein:

(a) the species of bacteria in the bacterial family of purple bacteria chromatium from which a species may be selected for inclusion in the bacterial consortium includes at least Chromatium, Thiocyctis, Thiospirillum, Thiocapsa,

Lamprocystis, Lamprobacter and Thiopedia,

(b) the species of bacteria in the bacterial family of purple non-sulfur bacteria from which a species may be selected for inclusion in the bacterial consortium includes at least Rhodspirrillum, Rhodobacter, Rhodopseudomonas,

Rhodomicrobium, and Rhodopila,

(c) the species of bacteria in the bacterial family of green sulfur bacteria from which a species may be selected for inclusion in the bacterial consortium includes at least Chlorobium, Prosthecochloris, Pelodictyon, Ancalochloris and Chloroherpeton,

(d) the species of bacteria in the bacterial family of filamentious green bacteria from which a species may be selected for inclusion in the bacterial consortium includes at least Chloroflexus, Chloronema and Oscillochloris, and

(e) the species of bacteria in the bacterial family of colorless sulfur bacteria from which a species may be selected for inclusion in the bacterial consortium includes at least Beggiatoaceae, Achromatium, Thiobacterium, Macromonma, Thiospira, Thiovulum, Bilophocucus, Thiobacillus, Thiomicrospira,

Thiodendron, Thiosphaera, Acidiphilium, Thermothrix, Sulfolobus and Acidianus.

A process for phototrophic production of fractionated polyhydroxyalkanoates from organic waste, comprising the steps of:

(b) fractionating the organic acid enriched feedstock by chemical composition of the organic acid into at least two acid fractions.

(c) inoculating each of the acid fractions with a bacterial consortium containing at least one species of bacteria from at least four of the bacterial families selected from purple bacteria chromatium, purple non-sulfur bacteria, green sulfur bacteria, filamentious green bacteria and colorless sulfur bacteria, to produce inoculated homogeneous organic acid enriched liquors, (d) fermenting each of the inoculated homogeneous organic acid enriched liquors with exposure to radiant energy for a light phase fermentation period to generate homogeneous glycogen enriched biomasses,

(e) fermenting each of the homogeneous glycogen enriched biomasses in the absence of radiant energy for a dark phase fermentation period to generate homogeneous polyhydroxyalkanoate enriched biomasses, and

(f) harvesting homogeneous polyhydroxyalkanoates from each of the

homogeneous polyhydroxyalkanoate enriched biomasses.

The process of claim 26 wherein the organic acid enriched feedstock is fractionated into at least a propionic acid enriched fraction, an acetic enriched fraction and a butyric enriched fraction.