Synthesis of Glycols by Microbial Transformation of Some Monocyclic Terpenes

The transformation of three monocyclic terpenes by three soil microorganisms have been studied. The organisms were isolated on, and grew rapidly in, mineral salts medium containing the appropriate terpene substrates as sole carbon sources. These organisms belong to the class Fungi Imperfecti, and two of them have been tentatively identified as Cladosporium species. A Cladosporium species designated T₁ was isolated from terpene-soaked soil, using 1-menthene as the sole source of carbon. The major catabolic product isolated from the growth medium of this organism was found to be a cyclic 1,2-diol identified as trans-p-methane-1,2-diol. A similar but biochemically distinct Cladosporium sp. designated T₇ was isolated on D-limonene. After growth, the medium of this organism contained 1.5 g/liter of the analogous product, trans-limonene-1,2-diol. Minor quantities of the corresponding cis-1,2-diol were also isolated. The third organism, designated as laboratory culture T₈, was isolated on 3-menthene and yielded a diol identified as trans-p-menthane-3,4-diol. From these results it is concluded that the formation of diols is a common intermediate in the fungal metabolism of monocyclic terpenes.     

Microbiological Transformations 15. The Enantioselective Microbiological Baeyer-Villiger Oxidation of Alpha-Substituted Cyclopentanones

Two strains of Acinetobacteria have been studied in order to perform enantioselective Baeyer-Villiger-type oxidations of racemic alpha-substituted cyclopentanones. This allows a one-step synthesis of various delta-lactones showing optical purities up to 97%, using whole-cell procedures. Tetraethylpyrophosphate and 1,2-cyclohexanediol have been used in order to enhance the yields of the bioconversion. The obtained (S)-lactones are of high interest as readily accessible chirons as well as to the flavor industry.     

Microbiological Transformations 15. The Enantioselective Microbiological Baeyer-Villiger Oxidation of Alpha-Substituted Cyclopentanones

Two strains of Acinetobacteria have been studied in order to perform enantioselective Baeyer-Villiger-type oxidations of racemic alpha-substituted cyclopentanones. This allows a one-step synthesis of various delta-lactones showing optical purities up to 97%, using whole-cell procedures. Tetraethylpyrophosphate and 1,2-cyclohexanediol have been used in order to enhance the yields of the bioconversion. The obtained (S)-lactones are of high interest as readily accessible chirons as well as to the flavor industry.     

Continuous Microbiological Transformation of Steroids

Continuous fermentation trials on the bioconversions of pregnadiene to pregnatriene by Septomyxa affinis and progesterone to 11α-hydroxyprogesterone by Rhizopus nigricans were conducted successfully in an eight-stage pilot plant reactor. The first stage was used as the mycelial growth stage while the steroid solutions were added continuously to stage 2, thus using the remaining stages as conversion vessels. Recoveries of 50 to 60% oxidized steroid (based on total steroid supplied) were obtained in both cases upon a contact time of 5 hr between mycelium and steroid. Longer contact times resulted in a gradual net loss of steroid. It was concluded that two-stage reactors (one growth stage and one conversion stage) were adequate for efficient continuous operation of such processes. The reaction volumes of both stages have to be kept in proper balance to insure optimal holdup times for both the cell growth and conversion steps.     

Some Effects of Douglas Fir Terpenes on Certain Microorganisms

The Douglas fir terpene α-pinene was shown to inhibit the growth of a variety of bacteria and a yeast. Other terpenes of the Douglas fir, including limonene, camphene, and isobornyl acetate, were also inhibitory to Bacillus thuringiensis. All terpenes were inhibitory at concentrations normally present in the fir needle diet of Douglas fir tussock moth larvae. The presence of such terpenes in the diet of these insects was found to strongly influence the infectivity of B. thuringiensis spores for the Douglas fir tussock moth larvae. The terpene α-pinene destroyed the cellular integrity and modified mitochondrial activity in certain microorganisms.     

Studies on the Microbiological Transformation of Steroids

An attempt was made to clarify how Pellicularia filamentosa f. sp. microsclerotia IFO 6298 capable of hydroxylating C₂₁-steroids at the C-19 position converts C₁₉-steroids, especially monohydroxyderivatives of androst-4-ene-3, 17-dione. Such substrates as 11β-hydroxyandrost-4-ene-3,17-dione (I), androst-4-ene-3, 11, 17-trione (II), androsta-1,4-diene-3, 17-dione (III), 11β-hydroxyandrosta-1,4-diene-3,17-dione (IV), 14α-hydroxyandrost-4-ene-3, 17-dione (V), 15α-hydroxyandrost-4-ene-3, 17-dione (VI) and 9α-hydroxyandrost-4-ene-3, 17-dione (VII) were converted by the organism. All the main and several minor products were then isolated and identified. As a result it is concluded that this organism converts I and II into 14α-hydroxyandrost-4-ene-3,11,17-trione, III and IV into 14α-hydroxyandrosta-1,4-diene-3,1l,17-trione, V into 11α 14α dihydroxyandrost-4-ene-3, 17-dione (main) and 11β, 14α-dihydroxyandrost-4-ene-3, 17-dione (minor, a tentative structure), VI into 11β, 15α-dihydroxyandrost-4-ene-3,17-dione (main) and 15α-hydroxyandrost-4-ene-3,11,17-trione (minor, a tentative structure) and VII into 9α, 14α-dihydroxyandrost-4-ene-3, 17-dione (main) and 6β, 9α-dihydroxyandrost-4-ene-3,17-dione (minor).

In addition, the structural requirement of substrate for the 19-hydroxylation catalyzed by the organism and the influence of a hydroxyl group on steroid nucleus upon the 11β- and 14α-hydroxylations and the 11β-OH-dehydrogenation was discussed.     

Microbiological Transformations of Δ6a,10a-Tetrahydrocannabinol

A screening program was conducted to find microorganisms that catalyze transformation reactions with cannabinoids. Three hundred fifty-eight cultures, consisting of 97 bacteria, 175 actinomycetes, and 86 molds, were incubated in media containing 0.5 mg of Δ^6a,10a-tetrahydrocannabinol (Δ^6a,10a-THC) per ml. After 120 h of cultivation, ethyl acetate extracts of the cultures were examined by thin-layer chromatography (TLC) for transformation products. About 18% of the cultures modified Δ^6a,10a-THC. The ability to modify the substrate did not predominate among any particular group of microorganisms. After purification, the products from three cultures were analyzed by high-resolution mass spectrometry, 100-mHz proton magnetic resonance spectrometry, ultraviolet spectrometry, and infrared spectrometry. These spectral data indicated that a Mycobacterium sp. oxidized Δ^6a,10a-THC to cannabinol and a diastereomeric pair of 6a-hydroxy-Δ^10,10a-THC isomers; a Streptomyces sp. and a Bacillus sp. oxidized Δ^6a,10a-THC to 7-keto-Δ^6a,10a-THC and 4′-hydroxy-Δ^6a,10a-THC, respectively. The occurrence of these products and the presence of others that have not yet been isolated or identified indicate that microbial transformation may be a useful tool for the preparation of new cannabinoids that have desirable pharmacological properties.     

Studies on the Microbiological Transformation of Steroids

Some features of the NMR spectra of 19-hydroxy- and 19-acetoxy-steroids were presented and by making use of the features an unknown product of a microbiological transformation of 17α,20α,21-trihydroxypregn-4-en-3-one was easily characterized as a 19-acetoxysteroid.     

Studies on the Microbiological Transformation of Steroids

The microbiological reduction of the 20-carbonyl group of steroids has been investigated. Candida pulcherrima IFO 0964 and Sporotrichum gougeroti IFO 5982 converted the following substrates into the corresponding 20β-hydroxy derivatives (yields of the products are indicated in parentheses): Reichstein’s Compound S (60~70%) and 17α,21-dihydroxypregna-l,4-diene- 3,20-dione (40~80%). Rhodotorula glutinis IFO 0395 converted the following substrates into the corresponding 20α-hydroxy derivatives: Reichstein’s Compound S (65%), 17 α,21-dihydroxy- pregna-l,4-diene-3,20-dione (80%), llβ,l7α-dihydroxypregn-4-ene-3,20-dione (45%) and 17α, 19,21 -trihydroxypregn-4-ene-3,20-dione (10%).     

Some Microbiological Aspects of Staphylococcal Mastitis

(1) Mannitol fermentation is a reasonably reliable method for the detection of coagulase positive staphylococci in milk. This reliability can be improved if mannitol fermentation is carried out under anaerobic conditions.(2) Among hemolytic strains of staphylococci isolated from milk, beta hemolytic staphylococci predominate. Bovine and sheep blood agar plates give similar hemolytic patterns, but the hemolysis is more pronounced on sheep blood agar.(3) Gelatin liquefaction cannot be relied upon for the selection of coagulase positive staphylococci in milk.(4) Urease production is a feature of the majority of coagulase positive staphylococci isolated from milk.(5) Tellurite Glycine agar medium is not satisfactory for the selection of coagulase positive staphylococci in milk.     

Fungi of Delhi: III. Some interesting ascomycetes

Three coprophilous ascomycetes have been reported for the first time from India. They arePreussia isomera Cain,Gelasinospora tetraspora Dowding andPodospora absimilis Cain.     

Studies on Transformations of Hemophilus influenzae : III. The genotypes and phenotypic patterns of three streptomycin-resistant mutants

A general method of determining the nature of the genotypes in mutants of transformable bacteria with similar phenotypes is discussed. The method is used to identify the genotypic patterns of three mutants of Hemophilus influenzae which are resistant to different levels of streptomycin. A mutant resistant to 700 µg per ml of the antibiotic was found to be made up of two unlinked, independent loci—presumably on different molecules of transforming DNA. These loci, when in separate cells, render them resistant to maximum levels of 10 and 100 µg per ml streptomycin respectively and are therefore designated as Sm¹⁰ and Sm¹⁰⁰. When they enter the same cell they produce a resistance up to 700 µg per ml streptomycin, so the cells are noted as Sm⁷⁰⁰. This multiplicative action is more easily visualized as due to two independent processes of combating the antibiotic which enhance each other rather than two identical processes.