Process for production of B avermectins and cultures therefor

Claim 2

Streptomyces avermitilis lacking branched-­chain 2-oxo acid dehydrogenase activity and avermectin B O-methyltransferase activity.

Claim 3

Streptomyces avermitilis lacking branched-chain 2-oxo acid dehydrogenase activity and avermectin B O-methyltransferase activity characterized by the inability of permeabilized cells thereof to produce ¹⁴CO₂ from added [¹⁴C-1]-2-oxoisocaproic acid.

Claim 4

Streptomyces avermitilis lacking branched-chain 2-oxo acid dehydrogenase activity and avermectin B O-methyltransferase activity characterized by the inability of permeabilized cells thereof to produce ¹⁴CO₂ from added [¹⁴C-1]-2-oxoisocaproic acid.

Claim 5

Streptomyces avermitilis having the identifying characteristics of ATCC 53692.

Claim 6

Streptomyces avermitilis having the identifying characteristics of ATCC 53692.

Claim 7

Streptomyces avermitilis ATCC 53692.

Claim 8

Streptomyces avermitilis ATCC 53692.

Claim 9

A process for preparation of a B avermectin which comprises aerobically fermenting with a strain of Streptomyces avermitilis which lacks branched-chain 2-oxo acid dehydrogenase activity and avermectin 5-O-methyltransferase activity, an aqueous nutrient medium comprising an assimilable source of nitrogen, carbon and inorganic salts and a compound capable of utilization in the biosynthesis of an avermectin.

Claim 10

A process for preparation of a B avermectin which comprises aerobically fermenting with a strain of Streptomyces avermitilis which lacks branched-chain 2-oxo acid dehydrogenase activity and avermectin 5-O-methyltransferase activity, an aqueous nutrient medium comprising an assimilable source of nitrogen, carbon and inorganic salts and a compound capable of utilization in the biosynthesis of an avermectin.

Claim 11

A process according to claim 5 wherein the S . avermitilis has the identifying characteristics of ATCC 53692.

Claim 12

A process according to claim 5 wherein the compound is of the formula R-COOH wherein R is an alpha-branched-chain group, the carbon atom thereof to which is attached the -COOH group is also attached to at least two other atoms or groups other than hydrogen; or a compound convertible to said compound during the fermentation process.

Claim 13

A process according to claim 7 wherein R is an alpha-branched C₃-C₈ alkyl, alkenyl, alkynyl, alkoxy­alkyl or alkylthioalkyl group; a C₅-C₈ cycloalkylalkyl group wherein the alkyl group is an alpha-branched C₂-C₅ alkyl group; a C₃-C₈ cycloalkyl or C₅-C₈ cyclo­alkenyl group, either of which may optionally be substituted by methylene or one or more C₁-C₄ alkyl groups or halo atoms; or a 3 to 6 membered oxygen or sulfur containing heterocyclic ring which may be saturated, or fully or partially unsaturated and which may optionally be substituted by one or more C₁-C₄ alkyl groups or halo atoms, or a compound convertible to said compound during the fermentation process.

Claim 14

A process according to claim 7 wherein the compound convertible to substrate RCOOH is R-(CH₂) n -Z wherein R is as previously defined; n is 0, 2, 4 or 6; and Z is -CH₂OH, -CHO, -COOR⁴, -CH₂NH₂ or -CONHR⁵ wherein R⁴ is H or (C 1-6 )alkyl; R⁵ is hydrogen, (C 1-4 )alkyl, -CH(COOH)CH₂COOH, -CH(COOH) (CH₂)₂COOH or -CH(COOH) (CH₂)₂SCH₃.

Claim 15

A process according to claim 8 wherein R is cyclobutyl cyclopentyl cyclohexyl cycloheptyl 2-methylcyclopropyl 3-cyclohexenyl 1-cyclopentenyl 1-cyclohexenyl 3-methylcyclohexyl (cis/trans) 4-methylenecyclohexyl 3-methylcyclobutyl 3-methylenecyclobutyl 3-cyclopentenyl 1-cyclopropylethyl 3-fluorocyclobutyl 4,4-difluorocyclohexyl isopropyl sec-butyl 2-pentyl 2,3-dimethylpropyl 2-hexyl 2-pent-4-enyl 2-methylthioethyl S-2-pentyl R-2-pentyl 2-thienyl 3-thienyl 4-tetrahydropyranyl 3-furyl 2-chlorothienyl 3-tetrahydrothienyl 4-methylthio-2-butyl 4-tetrahydrothiopyranyl 4-methoxy-2-butyl or 4-methylthio-2-butyl.

Claim 16

A process according to claim 10 wherein R is derived from a carboxylic acid of formula R-COOH.

Claim 17

A process according to claim 11 wherein R is cyclopentyl, cyclohexyl or thienyl.

Claim 18

A process according to claim 10 wherein R is derived from a compound convertible to R-COOH during the fermentation, said compound being of the formula R-(CH₂ n -Z wherein R is a previously defined; n is 0, 2, 4 or 6; Z is -CH₂OH, -CH)-, -COOR⁴, -CH₂NH₂ or -CONHR⁵ wherein R⁴ is (C 1-6 )alkyl; R⁵ is hydrogen, (C 1-4 )alkyl, -CH(COOH)CH₂COOH, -CH(COOH) (CH₂)₂COOH or -CH(COOH) (CH₂)₂SCH₃.

Claim 19

A process according to claim 8 wherein when R is an alpha-branched C₃-C₈ alkyl group, it is not isopropyl or (S)-sec-butyl.

Claim 20

The process according to claim 8 wherein the strain of S . avermitilis is S . avermitilis ATCC 53692.

Claim 21

A novel strain belonging to the genus Streptomyces which produces substantially no C-076 avermetins when fermented in an aqueous nutrient medium comprising an assimilable source of carbon, nitrogen and inorganic salts under aerobic conditions, said medium being substantially free of an acid of the formula R-COOH , or a compound convertible to said acid by S . avermitilis , wherein R is isopropyl or (S)-sec-butyl, but being capable of producing substantially only B avermectins upon fermentation in said medium when said medium contains an acid of the formula RCOOH, or a compound convertible to said acid by S . avermitilis , wherein R is isopropyl or (S)-sec-butyl, wherein said strain is obtained by a process which comprises mutating Streptomyces avermitilis ATCC 53567.

Claim 22

A novel strain belonging to the genus Streptomyces which produces substantially no C-076 avermetins when fermented in an aqueous nutrient medium comprising an assimilable source of carbon, nitrogen and inorganic salts under aerobic conditions, said medium being substantially free of an acid of the formula R-COOH , or a compound convertible to said acid by S . avermitilis , wherein R is isopropyl or (S)-sec-butyl, but being capable of producing substantially only B avermectins upon fermentation in said medium when said medium contains an acid of the formula RCOOH, or a compound convertible to said acid by S . avermitilis , wherein R is isopropyl or (S)-sec-butyl, wherein said strain is obtained by a process which comprises mutating Streptomyces avermitilis ATCC 53567.