Continuous cultivation of hydrocarbon-consuming micro-organisms

Claim 2

A CULTURE MEDIUM CONSISTING OF AQUEOUS NUTRIENT MEDIUM, SURFACE ACTIVE AGENT AND HYDROCARBON IS SEEDED WITH A LOW CELL CONCENTRATION OF A HYDROCARBON-CONSUMING MICRO-ORGANISM.

Claim 3

AEROBIC CULTURING OF THE MICRO-ORGANISM IS INITIATED AND CONTINUED UNTIL ESSENTIALLY EQUILIBRIUM CONDITIONS ARE REACHED IN THE LOGARITHMIC GROWTH PHASE.

Claim 4

AEROBIC CULTURING OF THE MICRO-ORGANISM IS INITIATED AND CONTINUED UNTIL ESSENTIALLY EQUILIBRIUM CONDITIONS ARE REACHED IN THE LOGARITHMIC GROWTH PHASE.

Claim 5

The process of claim 1 wherein said micro-organism is a bacterium.

Claim 6

CONTINUOUS CULTURING IS INITIATED AND CONTINUED UNDER AEROBC CONDITIONS IN THE PRESENCE OF AQUEOUS NUTRIENT MEDIUM AND HYDROCARBON IN THE ABSENCE OF ADDED SURFACE ACTIVE AGENT.

Claim 7

CONTINUOUS CULTURING IS INITIATED AND CONTINUED UNDER AEROBC CONDITIONS IN THE PRESENCE OF AQUEOUS NUTRIENT MEDIUM AND HYDROCARBON IN THE ABSENCE OF ADDED SURFACE ACTIVE AGENT.

Claim 8

The process of claim 1 wherein said micro-organism is a yeast.

Claim 9

In a continuous process for cultivating a hydrocarbon-consuming micro-organism, the improvement which comprises initiating the propagation of the micro-organism by introducing a hydrocarbon-consuming micro-organism at an active fermentation temperature into a micro-organism growth-supporting mixture comprising an aqueous nutrient medium, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen, said mixture initially containing about 0.5 to about 3 grams of micro-organism per liter; cultivating the hydrocarbon-consuming micro-organism in said mixture until a maximum cell concentration of the micro-organism is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; and thereafter continuously cultivating the hydrocarbon-consuming micro-organism at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen in the absence of added surface active agent; continuously separating a micro-organism fraction from the fermentation mass; and recovering the micro-organism from said fraction.

Claim 10

In a continuous process for cultivating a hydrocarbon-consuming micro-organism, the improvement which comprises initiating the propagation of the micro-organism by introducing a hydrocarbon-consuming micro-organism at an active fermentation temperature into a micro-organism growth-supporting mixture comprising an aqueous nutrient medium, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen, said mixture initially containing about 0.5 to about 3 grams of micro-organism per liter; cultivating the hydrocarbon-consuming micro-organism in said mixture until a maximum cell concentration of the micro-organism is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; and thereafter continuously cultivating the hydrocarbon-consuming micro-organism at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen in the absence of added surface active agent; continuously separating a micro-organism fraction from the fermentation mass; and recovering the micro-organism from said fraction.

Claim 11

In a continuous process for cultivating a hydrocarbon-consuming yeast, the improvement which comprises initiating the propagation of the yeast by introducing a hydrocarbon-consuming yeast at an active fermentation temperature of about 25* to about 40* C. into a yeast growth-supporting mixture comprising an aqueous nutrient medium, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen, said mixture initially containing about 0.5 to about 3 grams of yeast per liter; cultivating the hydrocarbon-consuming yeast in said mixture until a maximum cell concentration of the yeast is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; thereafter continuously cultivating the hydrocarbon-consuming yeast at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen in the absence of added surface active agent; continuously separating a yeast-containing fraction from the fermentation mass; and recovering the yeast from said fraction.

Claim 12

In a continuous process for cultivating a hydrocarbon-consuming yeast, the improvement which comprises initiating the propagation of the yeast by introducing a hydrocarbon-consuming yeast at an active fermentation temperature of about 25* to about 40* C. into a yeast growth-supporting mixture comprising an aqueous nutrient medium, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen, said mixture initially containing about 0.5 to about 3 grams of yeast per liter; cultivating the hydrocarbon-consuming yeast in said mixture until a maximum cell concentration of the yeast is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; thereafter continuously cultivating the hydrocarbon-consuming yeast at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium, a hydrocarbon and a gas containing free oxygen in the absence of added surface active agent; continuously separating a yeast-containing fraction from the fermentation mass; and recovering the yeast from said fraction.

Claim 13

The process of claim 5 wherein the yeast is of the family Cryptoccaceae.

Claim 14

The process of claim 5 wherein the yeast is of the subfamily Cryptococcoideae.

Claim 15

The process of claim 5 wherein the yeast is of the genus Candida.

Claim 16

The process of claim 5 wherein the yeast is of the strain Candida tropicalis.

Claim 17

The process of claim 5 wherein the yeast is Candida tropicalis, CS-9-5.

Claim 18

The process of claim 5 wherein the hydrocarbon is a liquid petroleum fraction consisting essentially of a mixture of straight chain hydrocarbons.

Claim 19

The process of claim 11 wherein the liquid petroleum fraction is a mixture of C9 to C13 normal paraffins.

Claim 20

The process of claim 5 wherein the pH of the aqueous nutrient medium is within the range of about 1.5 to about 8.

Claim 21

The process of claim 5 wherein the oxygen-containing gas is air.

Claim 22

In a continuous process for cultivating a hydrocarbon-consuming yeast of the strain Candida tropicalis, the improvement which comprises initiating the propagation of the yeast by introducing Candida tropicalis at a temperature of about 28* to about 32* C. into a yeast growth-supporting mixture comprising an aqueous nutrient medium whose pH is maintained within the range of about 3 to about 5, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon feedstock comprising a mixture of C9 to C13 normal paraffins and air, said growth-supporting mixture initially containing about 0.5 to about 3 grams of yeast per liter; cultivating the Candida tropicalis in said growth-supporting mixture until a maximum cell concentration of the yeast is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; thereafter continuously cultivating the Candida tropicalis at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium whose pH is maintained within the range of about 3 to about 5, a hydrocarbon feedstock comprising a mixture of C9 to C13 normal paraffins and air in the absence of added surface active agent; continuously separating a Candida tropicalis fraction from the fermentation mass; and recovering Candida tropicalis from said fraction.

Claim 23

In a continuous process for cultivating a hydrocarbon-consuming yeast of the strain Candida tropicalis, the improvement which comprises initiating the propagation of the yeast by introducing Candida tropicalis at a temperature of about 28* to about 32* C. into a yeast growth-supporting mixture comprising an aqueous nutrient medium whose pH is maintained within the range of about 3 to about 5, a surface active agent which comprises about 0.005 to about 0.05 percent by weight of the aqueous nutrient medium, a hydrocarbon feedstock comprising a mixture of C9 to C13 normal paraffins and air, said growth-supporting mixture initially containing about 0.5 to about 3 grams of yeast per liter; cultivating the Candida tropicalis in said growth-supporting mixture until a maximum cell concentration of the yeast is obtained under logarithmic growth, said maximum cell concentration being about 15 to about 25 grams per liter; thereafter continuously cultivating the Candida tropicalis at a cell concentration of about 15 to about 25 grams per liter in the presence of an aqueous nutrient medium whose pH is maintained within the range of about 3 to about 5, a hydrocarbon feedstock comprising a mixture of C9 to C13 normal paraffins and air in the absence of added surface active agent; continuously separating a Candida tropicalis fraction from the fermentation mass; and recovering Candida tropicalis from said fraction.

Claim 24

The process of claim 15 wherein the surface active agent is a nonionic surface active agent.

Claim 25

The process of claim 15 wherein the surface active agent is polyoxyethylene sorbitan monooleate.