US3264196A - Purification of micro-organisms cultivated on hydrocarbon feedstock - Google Patents

Purification of micro-organisms cultivated on hydrocarbon feedstock Download PDF

Info

Publication number
US3264196A
US3264196A US330527A US33052763A US3264196A US 3264196 A US3264196 A US 3264196A US 330527 A US330527 A US 330527A US 33052763 A US33052763 A US 33052763A US 3264196 A US3264196 A US 3264196A
Authority
US
United States
Prior art keywords
micro
organism
hydrocarbon
growth
straight chain
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US330527A
Other languages
English (en)
Inventor
Filosa Jean Antoine
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BP PLC
Original Assignee
BP PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BP PLC filed Critical BP PLC
Application granted granted Critical
Publication of US3264196A publication Critical patent/US3264196A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
    • C12N1/26—Processes using, or culture media containing, hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P21/00—Preparation of peptides or proteins
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00—Chemistry: molecular biology and microbiology
    • Y10S435/8215—Microorganisms
    • Y10S435/911—Microorganisms using fungi
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00—Chemistry: molecular biology and microbiology
    • Y10S435/8215—Microorganisms
    • Y10S435/911—Microorganisms using fungi
    • Y10S435/921—Candida
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00—Chemistry: molecular biology and microbiology
    • Y10S435/8215—Microorganisms
    • Y10S435/911—Microorganisms using fungi
    • Y10S435/921—Candida
    • Y10S435/923—Candida lipolytica
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S435/00—Chemistry: molecular biology and microbiology
    • Y10S435/8215—Microorganisms
    • Y10S435/911—Microorganisms using fungi
    • Y10S435/944—Torulopsis

Definitions

  • micro-organism In a process in which a micro-organism is cultivated in the presence of a hydrocarbon it has now been found that the micro-organism may be contaminated by absorbed. hydrocarbons. Sometimes other materials formed in the fermentation process may be present, thus yeasts may be contaminated by lipids.
  • the purification stage may be employed to eliminate lipids, esters, ketones and/or free fatty acids, or to reduce their quantity in association with amicro-organism, for example, a yeast.
  • the hydrocarbon feedstock contains C or higher.
  • a hydrocarbon fraction derived from petroleum is preferred.
  • a process which comprises cultivating a micro-organism in the manner as hereinbefore described in the presence of a petroleum fraction consisting in part of straight chain hydrocarbons and having a mean molecular weight corresponding to at least 10 carbon atoms per molecule, and in the presence of an aqueous nutrient medium; and in the presence of a gas containing free oxygen and separating from the mixture, on the one hand, the micro-organism and, on the other hand, a petroleum fraction having a reduced proportion of straight chain hydrocarbons or which is free of said straight chain hydrocarbons.
  • the process of the invention is of particular value for the treatment of petroleum gas oil fractions which contain straight chain hydrocarbons in the form of waxes, since by the process of the invention, a gas oil of improved pour point is obtained while the waxes are converted to a valuable product.
  • straight-chain hydrocarbons will be present in the feedstocks according to the invention as parafiins; however, the straight chain hydrocarbons may be present as olefins; also there may be used a mixture containing straight chain paraffins and olefins.
  • the percentage conversion of straight chain hydrocarbons which is achieved can be maintained at a value approaching without necessitating a very disproportionate expenditure of contact time to achieve small improvements. Furthermore, in the continuous: process, this high percentage conversion can be achieved without resorting to the use of a long reaction path.
  • Micro-organisms which are cultivated as herein described may be yeasts, moulds or bacteria.
  • a yeast is employed this is of the family Cryptococcaceae and particularly of the subfamily Cryptococcoideae; however, if desired there may be used, for example, ascosporogeneous yeasts of the sub-family Saccharomycoideae.
  • Preferred genera of the Cryptococcoideae sub-family are Torulopsis (also known as Torula) and Candida.
  • Preferred strains of yeast are as follows. In particular it is preferred to use the specific stock of indicated reference; these reference numbers refer to CBS stock held by the Central Bureau vor Schimmelculture, Baarn, Holland, and to INRA stock 3 held by the Institut National de la Recherche Agrono- Inique, Paris, France.
  • Suitable moulds are of the family Aspergillaceae.
  • a suitable genus is Penicillium.
  • Penicilliam expansum Preferably there is used Penicilliam expansum.
  • Another suitable genus is Aspergillus.
  • cultivation is carried out in the presence of an aqueous nutrient medium.
  • an aqueous nutrient medium may be employed.
  • certain solid nutrient media may be employed.
  • Penicillium expansum is suitable for cultivation in an aqueous nutrient medium containing hydrocarbons.
  • Penicilliwm roqaeforti, Penicilliam notatum, Aspergillas fussiga tas and Aspergillus niger, Aspergillas versicolor may be used for cultivation on a solid agent containing hydrocarbons as feedstock.
  • the bacteria which are employed are of the family Bacillaceae and Pseudomonad-aceae.
  • Preferred species are Bacillus megateriam, Bacillus subtilis and Pseadomonas aeruginosa.
  • Other strains which may be employed include:
  • a typical nutrient medium for the growth of Nocardia a genus in the Actinomycetales order, has the following composition:
  • a suitable nutrient medium for yeast (and moulds) has the composition:
  • the growth of the micro-organism used is favoured by the addition to the culture medium of a very small proportion of extract of yeast (an industrial product rich in vitamins of group B obtained by the hydrolysis of a yeast) or more generally of vitamins of group B and/or biotin.
  • This quantity is preferably of the order of 25 parts per million with reference to the aqueous fermentation medium. It can be higher or lower according to the conditions chosen for the growth.
  • the growth of the micro-organism takes place at the expense of the feedstock fraction with the intermediate production of bodies having an acid function, principally fatty acids, in such manner that the pH of the aqueous mineral medium progressively diminishes. If one does not correct it the growth is fairly rapidly arrested and the concentration of the micro-organism in the medium, that is cellular density, no longer increases so that there is reached a so-called stationary phase.
  • the aqueous nutrient medium is maintained at a desired pH by the step-wise or continuous addition of an aqueous medium of high pH value.
  • an aqueous medium of high pH value usually, when using moulds or yeasts and in particular when using Candida lipolytica, the pH of the nutrient medium will be maintained in the range 36 and preferably in the range 4-5. (Bacteria require a higher pH, usually 6.5-8.)
  • Suitable alkaline materials for addition to the growth mixture include sodium hydroxide, potassium hydroxide, disodium hydrogen phosphate and ammonia, either free or in aqueous solution.
  • the optimum temperature of the growth mixture will vary according to the type of micro-organism employed and will usually lie in the range 25-35 C. When using vC'zagugda lipolytica the preferred temperature range is 28-.
  • the take-up of oxygen is essential for the growth of the micro-organism.
  • the oxygen will usually be provided as air.
  • the air used to provide oxygen, should be present in the form of fine bubbles under the action of stirring.
  • the air may be introduced through a sintered surface. However there may be used the system of intimate aeration known as vortex aeration.
  • the micro-organism will usually grow initially at a low rate of increase in cellular density. (This period of growth is referred to as the lag phase),
  • the rate of growth will increase to a higher rate of growth; the period at the higher rate of growth is referred to as the exponential phase and subsequently again the cellular density will become constant (the stationary phase).
  • a supply of the micro-organism for starting the next batch will preferably be removed before the termination of the exponential phase.
  • the growth operation will usually be discontinued before the stationary phase.
  • micro-organism will usually be separated from the bulk of the un-used feedstock fraction.
  • the major part of the continuous aqueous phase is first separated; preferably this is carried out by centrifuging, or decanting.
  • the separated aqueous phase will usually contain a greater concentration of non-nutritive ions than can be tolerated in the recycle stream and when this is so, only a proportion of the recovered aqueous phase can be recycled.
  • the recycle stream is supplied with make-up quantities of the necessary nutrients and is returned to the fermenter; if desired the make-up materials may 'be fed to the fermenter as a separate stream.
  • a micro-organism cream consisting of microorganism, having a quantity of oil fixed onto the cells, together with aqueous phase.
  • Fraction (iii) will then be mixed with an aqueous nutrient medium, which may be the same as or different from the aqueous nutrient medium employed in the growth stage, and is maintained in admixture with a gas containing free oxygen whereby the hydrocarbon contaminating the micro-organism is reduced in quantity or is eliminated.
  • an aqueous nutrient medium which may be the same as or different from the aqueous nutrient medium employed in the growth stage, and is maintained in admixture with a gas containing free oxygen whereby the hydrocarbon contaminating the micro-organism is reduced in quantity or is eliminated.
  • the major part of the continuous aqueous phase is separated with recycle of a proportion of the recovered aqueous phase, as hereinbefore described; recycle may be to either the growth stage or purification stage as desired.
  • this cream may be further treated for the removal of traces of oil which may be held to the cells.
  • the micro-organism cream may be washed with an aqueous solution of a surfactant and thereafter with water.
  • yeast may be dried under conditions suitable for its subsequent use as a foodstuff.
  • the product obtained at the end of the growth stage may be maintained without the addition of feedstock but with continued mixing (in a purification stage) with a gas containing free oxygen, whereby contaminants in the micro-organism are reduced in quantity or are eliminated.
  • the micro-organism may be recovered after the purification stage as hereinbefore described.
  • the process may be operated continuously or batchwise.
  • stages of the process may be carried out entirely batchwise. However, if desired, any one or more stages herein described may be carried out in continuous manner.
  • cellular density is expressed as dry Weight of yeast per litre of culture.
  • Example 1 4-0 litres of an aqueous mineral nutrient medium having the composition given below were introduced in a stainless steel fermenter having an effective capacity of 60 litres.
  • the aqueous nutrient medium had the composition:
  • the temperature of the culture was kept at 30:1" (1., pH at 4 and aeration and agitation giving 3 millimoles of 0 per litre of medium per minute. 10 N ammonia was admitted by an automatic pH controller.
  • the yeasts were recovered at 25 hours and at 40 hours by centrifuging and washing at +5 C. They were then dried by lyophilisation and analysed. Their total lipid content (fraction soluble in hexane) was 18% when recovered after 25 hours and 3% when. recovered after 40 hours.
  • Example 2 A similar experiment was carried out to that described in Example 1 except that the yeast was recovered from the culture liquor at 25 hours and then placed in 60 litres of fresh mineral medium, without hydrocarbon, in the same fermenter. The mixture was then stirred 10 hours under the same culture conditions (temperature 30 C. pH aeration 3 millimoles 0 per litre per hour). The cellular density was of the order of 15 grams/litre at the start, and remained constant throughout the process. Even though the 'yeast contained dry 20% weight of total lipids at the moment of introduction into the new medium, after the starvation treatment it did not contain more than 8% by wt.
  • Example 3 A similar experiment to that described in Examples 1 and 2 was carried out on yeasts from continuous fermentation, but in this case it was necessary to work with washed yeasts in a fresh medium, as in the continuous process one cannot obtain a racking-01f liquor entirely free of assimilable carbon substrate.
  • the culture in the 60 litre fermenter was stabilised at 0.1 litre/hour of total mineral medium plus gas-oil per litre of culture in the fermenter.
  • the operating conditions having been fixed (in particular temperature at 30 C. and pH at 4), the yeast was removed from part of the culture by centrifugation at +5 C. After washing it was put into a 20 litre fermenter containing 15 litres of the mineral medium given in Example 1, to give a cellular density of 20 grams/ litre.
  • the pH was regulated automatically to 4, the temperature to 30 C. and the air fiow and agitation so as to give 3 millimoles of oxygen per litre of culture per minute.
  • the treatment was applied for hours.
  • the cellular density remained 20 grams/litre throughout the experiment.
  • the yeasts were analysed for their fat content at the beginning and end of the process. A marked fall in fat content was observed, from to 5% by wt. on dry matter.
  • a process which comprises, in a growth stage, cultivating a straight chain hydrocarbon consuming microorganism in the presence of a hydrocarbon feedstock comprising at least in part straight chain hydrocarbons; in the presence of an aqueous nutrient medium; and in p the presence of a gas containing free oxygen and subsequently recovering a micro-organism free of a substantial amount of hydrocarbon but containing a small amount of hydrocarbon as contaminant, and thereafter in a puri- 'fication stage are carried out in separate fermentation zones.
  • a processing according to claim 1 in which the micro-organism which is cultivated is a yeast.
  • yeast is Candida lipolytica.
  • microorganism is a "bacteria.
  • a process according to claim 1 wherein in the process of recovering the micro-organism free of a substantial amount of hydrocarbon it is necessary to separate the micro-organism from the bulk of unconsurned hydrocarbon.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Zoology (AREA)
  • Wood Science & Technology (AREA)
  • Genetics & Genomics (AREA)
  • Biotechnology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Microbiology (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Medicinal Chemistry (AREA)
  • Biomedical Technology (AREA)
  • Tropical Medicine & Parasitology (AREA)
  • Virology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Molecular Biology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Micro-Organisms Or Cultivation Processes Thereof (AREA)
US330527A 1962-12-31 1963-12-16 Purification of micro-organisms cultivated on hydrocarbon feedstock Expired - Lifetime US3264196A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB49057/62A GB1059886A (en) 1962-12-31 1962-12-31 Improvements in or relating to the production of micro-organisms

Publications (1)

Publication Number Publication Date
US3264196A true US3264196A (en) 1966-08-02

Family

ID=10450956

Family Applications (1)

Application Number Title Priority Date Filing Date
US330527A Expired - Lifetime US3264196A (en) 1962-12-31 1963-12-16 Purification of micro-organisms cultivated on hydrocarbon feedstock

Country Status (11)

Country Link
US (1) US3264196A (en)van)
AT (1) AT262201B (en)van)
BR (1) BR6355791D0 (en)van)
CS (1) CS155140B2 (en)van)
CY (1) CY425A (en)van)
DK (1) DK108492C (en)van)
FI (1) FI43302C (en)van)
GB (1) GB1059886A (en)van)
MY (1) MY6800065A (en)van)
NO (1) NO127540B (en)van)
SE (1) SE324344B (en)van)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3427223A (en) * 1964-06-10 1969-02-11 Exxon Research Engineering Co Coagulating microbial cells to enhance their separation
US3489648A (en) * 1966-12-22 1970-01-13 Phillips Petroleum Co Microbial hydrocarbon consumption
US3508927A (en) * 1965-09-15 1970-04-28 Exxon Research Engineering Co Use of unsaturated organic acids as bacterial growth promoters
US3520777A (en) * 1966-05-13 1970-07-14 British Petroleum Co Cultivation and separation of hydrocarbon consuming micro-organisms
US3522147A (en) * 1966-05-13 1970-07-28 British Petroleum Co Growth and separation of hydrocarbon consuming microorganisms
US3620927A (en) * 1969-06-26 1971-11-16 Gulf Research Development Co Cultivation of micro-organisms on hydrocarbons
US3622465A (en) * 1967-03-10 1971-11-23 Allied Chem Protein from normal hydrocarbons
US3642575A (en) * 1966-01-26 1972-02-15 Kyowa Hakko Kogyo Kk Process for producing sugars by fermentation
US3904476A (en) * 1973-05-29 1975-09-09 Mobil Oil Corp Treatment of cells of a hydrocarbon-consuming microorganism

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2697061A (en) * 1950-08-17 1954-12-14 Texaco Development Corp Processing of hydrocarbons
US2697062A (en) * 1951-03-30 1954-12-14 Texaco Development Corp Processing of hydrocarbons
US2742398A (en) * 1951-06-09 1956-04-17 Texaco Development Corp Method of removing deposits of wax and like materials
US2982692A (en) * 1957-06-26 1961-05-02 Hardin B Mcdill Dewaxing of oils
US3069325A (en) * 1959-12-21 1962-12-18 Phillips Petroleum Co Treatment of hydrocarbons

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2697061A (en) * 1950-08-17 1954-12-14 Texaco Development Corp Processing of hydrocarbons
US2697062A (en) * 1951-03-30 1954-12-14 Texaco Development Corp Processing of hydrocarbons
US2742398A (en) * 1951-06-09 1956-04-17 Texaco Development Corp Method of removing deposits of wax and like materials
US2982692A (en) * 1957-06-26 1961-05-02 Hardin B Mcdill Dewaxing of oils
US3069325A (en) * 1959-12-21 1962-12-18 Phillips Petroleum Co Treatment of hydrocarbons

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3427223A (en) * 1964-06-10 1969-02-11 Exxon Research Engineering Co Coagulating microbial cells to enhance their separation
US3508927A (en) * 1965-09-15 1970-04-28 Exxon Research Engineering Co Use of unsaturated organic acids as bacterial growth promoters
US3642575A (en) * 1966-01-26 1972-02-15 Kyowa Hakko Kogyo Kk Process for producing sugars by fermentation
US3520777A (en) * 1966-05-13 1970-07-14 British Petroleum Co Cultivation and separation of hydrocarbon consuming micro-organisms
US3522147A (en) * 1966-05-13 1970-07-28 British Petroleum Co Growth and separation of hydrocarbon consuming microorganisms
US3489648A (en) * 1966-12-22 1970-01-13 Phillips Petroleum Co Microbial hydrocarbon consumption
US3622465A (en) * 1967-03-10 1971-11-23 Allied Chem Protein from normal hydrocarbons
US3620927A (en) * 1969-06-26 1971-11-16 Gulf Research Development Co Cultivation of micro-organisms on hydrocarbons
US3904476A (en) * 1973-05-29 1975-09-09 Mobil Oil Corp Treatment of cells of a hydrocarbon-consuming microorganism

Also Published As

Publication number Publication date
FI43302C (fi) 1971-03-10
AT262201B (de) 1968-06-10
CS155140B2 (en)van) 1974-05-30
BR6355791D0 (pt) 1973-08-28
FI43302B (en)van) 1970-11-30
SE324344B (en)van) 1970-06-01
GB1059886A (en) 1967-02-22
DK108492C (da) 1967-12-27
NO127540B (en)van) 1973-07-09
MY6800065A (en) 1968-12-31
CY425A (en) 1968-01-08

Similar Documents

Publication Publication Date Title
EP0155420B1 (en) A method for the preparation of a fungal body and a lipid rich in gamma-linolenic acid therefrom
US3717552A (en) Apparatus for the cultivation and recovery of microorganisms
EP0005277B1 (en) Process for the microbiological production of oil
US3268412A (en) Process for rupturing micro-organism cells grown on hydrocarbon feedstock
US3268419A (en) Cultivation of micro-organisms on a feedstock consisting at least in part of a straight chain hydrocarbon
US3264196A (en) Purification of micro-organisms cultivated on hydrocarbon feedstock
US3271266A (en) Process for cultivating microorganisms on a hydrocarbon feedstock employing a carbohydrate pretreatment feedstock
US3193390A (en) Production of yeasts
US3822187A (en) Cultivation of micro-organismus
US3268414A (en) Process for cultivating micro-organisms on heavy distillate fraction containing straight-chain hydrocarbons
DE69019396T2 (de) Verfahren zur fermentativen Oxydation reduzierender Disaccharide.
US4220720A (en) Manufacture of fatty acids having straight and long carbon chains using a microorganism
US3510403A (en) Cultivation of hydrocarbon-consuming micro-organisms
US3259549A (en) Process for improving cloud point of petroleum gas oil by caustic washing thereof from hydrocarbon mixtures
US3520777A (en) Cultivation and separation of hydrocarbon consuming micro-organisms
US3258406A (en) Process for improving cloud point of petroleum gas oil by hydrogenation thereof from hydrocarbon mixtures
US3522147A (en) Growth and separation of hydrocarbon consuming microorganisms
US3698998A (en) Process for cultivating micro-organisms in the presence of hydrocarbons
US3560341A (en) Process for the removal of straight chain hydrocarbons from petroleum fractions
US3815331A (en) Apparatus for the recovery of micro-organisms cultivated on a hydrocarbon substrate
US3616209A (en) Solvent extraction process
US3752739A (en) Recovery of a cultivated micro organism and of residual substrate employed in the cultivation
US3709784A (en) Hydrocarbon fermentation
US2184637A (en) Fermentation process for treating crude ethereal oils
US3847739A (en) Cultivation of micro-organisms on a feedstock consisting at least in part of straight chain hydrocarbons