Vol. 7 No. 1,1993

Published by the Society for Actinomycetes, Japan

Code Number: AC93012
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ABSTRACTS OF PAPERS

EFFECT OF PENICILLIN ON BACTERIOPHAGE NJL ADSORPTION TO RHODOCOCCUS RHODOCHROUS

M.Sunairi, H.Murooka and M.Nakajima

Laboratory of Molecular Microbiology, College of Agriculture and Veterinary Medicine, Nihon University 1866 Kameino, Fujisawa, Kanagawa 252, Japan

Actinomycetologica, 7: 23-30, 1993

There was a remarkable decrease in the number of bacteriophage NJL adsorbed to the cells of Rhodococcus rhodochrous CF222 grown in the presence of penicillin G as compared with that to the cells grown in the absence of the drug. However, no differences in quantity and quality of the bacteriophage NJL receptor (NRS) were detected between the cells grown in the absence and presence of penicillin G. Its presence during cultivation increased phospholipid content of the cells and changed the ratios among phospholipids, i.e. phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. Phospholipase C treatment restored the bacteriophagebinding activity of the cells grown in the presence of penicillin G. Penicillin G might cause changes in the cell surface, not in NRS, that result in decreased bacteriophage adsorption. The increase in phospholipid of bacterial cells seemed to be a strong candidate for such changes .

Authors' Abstract

DNA HOMOLOGY BETWEEN CHROMOPROTEIN ANTIBIOTIC PRODUCERS

N.Sakata, T.Mase, S.Ikeno, M.Hori, T.Otani* and M.Hamada**

Showa College of Pharmaceutical Sciences, 3-3165 Higashi Tamagagawagakuen, Machida-shi, *Biological Research Laboratory, Taiho Pharmaceutical Co., Ltd., Kawauchi-cho, Tokushima 771-01, **Institute of Microbial Chemistry, 3-14-23, Kami-osaki, Shinagawa-ku, Tokyo 141, Japan

Actinomycetologica, 7: 31-36, 1993

We have cloned and sequenced apoprotein genes for chromoprotein antibiotics; neocarzinostatin, macromomycin, actinoxanthin and C-1027. Here we show the homology between these genes in comparison with that between genomes of the corresponding antibiotic producers, evaluate the classical taxonomy based on phenotypic features of producer strains, and discuss the origin of the apoprotein genes.

Authors' Abstract

Summaries of 6th and 7th SAJ Colloquia

6th SAJ Colloquia

Human Resources Development Center, Takeda Chem.Ind., Ltd.

Dec. 3, 1992

MICROORGANISMS COLLECTION IN THE JUNGLES OF PERU: II

Y.Kawamura

Shionogi Research Laboratories

Actinomycetologica, 7: S7, 1993

Memories of life in the jungles of Peru collecting microorganisms are presented. Collecting microorganisms in the jungle is not an easy task and it is necessary to be careful of the following points:

I) As there is no electricity in the jungle, it is necessary to improvise some sort of light source for microscopic observation such as candles or a flash light and solar battery charger.

2) Clean water for media can not be obtained in the jungle making a water filtration instrument a necessary item.

3) It is also necessary to take along a heat source, for example a simple portable kerosene range or solid fuel to boil and/or sterilize media.

4) Since there are many harmful insects, such as mosquitoes, bees, ants, etc. in the jungle, it is necessary to carry effective insect repellent and mosquito coil s .

5) It is also very important to hire a competent guide who knows not only jungle life but also the plants and animals found there.

6) Also as a general caution, it is very important to be attentive to your personal security and to keep an eye on your personal belongings as things are known to disappear if not watched carefully.

Also, recently there has been a greater emphasis on protecting natural environments and collection of plants, animals, and even microorganisms may require special permission in some countries. It is also important to make the proper arrangements for importing the collections into Japan prior to departure.

Author's Abstract

DEVELOPMENT AND UTILIZATION OF POTENTIAL SECONDARY-METABOLITE PRODUCTIVITY OF PLANTS

A.Kobayashi

Lab. Chem. & Biochem. Cell Culture Products, Faculty of Agriculture, Okayama University,,Japan

Actinomycetologica, 7: S7, 1993

Survey for useful compounds from the plant kingdom has been performed since the dawn of history. And now sophisticated biotechnology is available for natural product chemists to search for new bioactive compounds. The advanced techniques applicable for the following subjects was proposed.

1. Characterization of new biotic elicitors prepared from neutral polysaccharides was achieved. The elicitors activated the secondary metabolite production in Leguminoceae species and could be used for induction of secondary metabolites in other plants.

2. A massive cell-sorting and modification effort to improve the pigment production in safflower tissue culture system allowed us to isolate a novel rose-colored pigment (kinobeon A) and to elucidate the chemical structure. However, this pigment was not found in the mother plant.

3. Peroxidase, a key enzyme activated on pathogenic attack to plants, catalyzes polymerization of simple phenolic compounds to give oligomeric phenols with potent antimicrobial activities. This mechanism would play an important role in plant defence systems.

Author's Abstract

CHITINASE INHIBITORS OF ACTINOMYCETES

Y.Yamada

Department of Biotechnology, Faculty of Engineering, Osaka University, Japan

Actinomycetologica, 7: S7-8, 1993

A chitinase inhibitor, allosamidin, was isolated from Streptomyces sp. by one of our colleagues in The University of Tokyo. It has a unique pseudotrisaccharide structure and strongly inhibits the chitinase of insects.

The following topics were discussed.

1) Effects of demethylallosamidin on the chitinase and cell division of yeast.

2) Isolation and characterization of new allosamidins.

3) Biosynthesis of allosamidin.

4) Purification and characterization of chitinase from allosamidin-producing Streptomyces.

Author's Abstract

7th Colloquium

National Institute of Health, Tokyo

Feb. 26, 1993

CHARACTERIZATION OF A GENE INVOLVED IN MORPHOLOGICAL DEVELOPMENT OF STREPTOMYCES GRISEUS CAPABLE OF SPORULATION IN SUBMERGED CULTURES

S.Kawamoto

Dept. Appl. Bioscience, Faculty of Agriculture, Hokkaido Univ., Sapporo, Japan

Actinomycetologica, 7: S8, 1993

Streptomyces griseus NRRL B2682 sporulates with a degree of synchrony at a programmed time of 26-28h when grown in a semi-defined liquid medium. However, the organism grows profusely as branched mycelia, but does not sporulate when the medium is supplemented with 0.5-1.0% or more of casein hydrolysate and yeast extract. In order to clarify the underlying mechanism of this sporulation repression, we isolated mutants that sporulated under the above conditions. Since these mutants turned out to possess normal sporulation genes, they were regarded as the ones quite different from the sporulation defective mutants of Streptomyces studied so far by other research groups. When these mutants were transformed with a gene library of parental DNA constructed in a multicopy plasmid vector, 6 different DNA fragments proved to convert the mutant phenotype (sporulation) to the parental phenotype (no sporulation). Subsequent characterization of one of the fragments identified a gene designated ssgA that contained an ORF capable of encoding a polypeptide of 145 amino acids and repressed sporulation of the mutant cells growing in the rich medium. It should be noted that ssgA caused fragmentation of mycelial cells and suppressed sporulation of the parental S.griseus strain and S.lividans. It seemed thus likely that ssgA gene product could be involved in the regulatory mechanism of cell division and sporulation.

Sporulation of Streptomyces occurs only on agar surface cultures in most species (presumably in response to nutrient depletion signals) and is an intriguing and complicated process involving temporally as well as spatially regulated expression of genes. Furthermore, the sporulation of streptomycetes is far from synchronous so that the culture is always a mixture of young and senescent vegetative mycelia and hyphae at any stage of sporulation process. Such a background has limited the progress in studying sporulation mechanism. In this regard, S.griseus NRRL B2682 and its mutants as well as the cloned genes will be a good model to illuminate a different aspect of the regulatory mechanism of Streptomyces sporulation from ones so far studied by other research groups.

This work was carried out at Prof. J. C. Ensign's laboratory, University of Wisconsin .

Author's Abstract

BIPHENOMYCIN A PRODUCTION BY A MIXED CULTURE

M.Ezaki, M.Iwami, M.Yamashita, S.Hashimoto, T.Komori, K.Umehara, M.Kohsaka, H.Aoki and H.Imanaka

Exploratory Res. Labs., Fujisawa Pharmaceutical Co., Ltd., Japan

Actinomycetologica, 7: S8-9, 1993

Mixed culture of actinomycetes and bacteria was used as screening source for new antibiotics. Biphenomycin A was found in such a screening system. Biphenomycin A was produced in a mixed culture of Streptomyces griseorubiginosus No.43708 and Pseudomonas maltophylia No.1928. The former strain produced a precursor of biphenomycin A besides small amounts of biphenomycin A, and the latter converted the precursor to biphenomycin.

Authors' Abstract

USEFULNESS AND SIGNIFICANCE OF ACTINOMYCETES ISOLATED FROM MARINE ENVIRONMENTS AND AUSTRALIAN SOILS

T.Okazaki and R.Enokita

Tsukuba Res. Labs., Sankyo, Co., Ltd., Japan

Actinomycetologica, 7: S9, 1993

One may expect some differences in physiological and taxonomical properties among actinomycetes existing in different environments. In this presentation, our research experiences with actinomycetes isolated from two different natural environments (sea sediments around Japan and soils in Australia) were reported.

In relation with marine environment, we have expected that some terrestrial actinomycetes might be transported into sea and then adapted to their new environment, possibly involving some physiological changes including secondary metabolism. As expected, we were successful to obtain actinomycete isolates capable of producing novel antibiotics. The aplasmomycin-producing strain of Streptomyces griseus isolated from a sea sediment may represent the ones with expected properties. The isolate produced this antibiotic favorably in a nutritionally poor medium. Aplasmomycin is a polyether antibiotic which chelates Ag or Br in its molecule.

Australia has extremely different environments from Japan. Total 677 Australian soil samples we collected in 1980, 1985 and 1990 showed approximately neutral pH and their moisture and organic material contents were about 1/7 and 1/3, respectively, of those of soils collected in Japan. For isolation of actinomycetes, we established innovative isolation methods based on environmental conditions under which the collected soil samples existed. Consequently, we succeeded in isolating large numbers and wide varieties of microorganisms including various actinomycete genera. Characterization of their taxonomic and metabolic properties has revealed that there were numbers of actinomycete strains of taxonomic interest and/or industrial significance. Especially, it was our happy surprise that we encountered with an actinomycete strain capable of extremely-efficient hydroxylation of ML-236 B or milbemycins that are antiparasitic macrolide antibiotics.

Thus, we believe that the use of microbial sources from unique environments and innovative (or unique) isolation methods is critical for isolating actinomycetes with unique metabolic properties. We have been and will be studying with deep concern about what and/or how environmental factors (or stresses) influence actinomycete diversity.

Authors' Abstract

NEW EVALUATION SYSTEMS FOR INHIBITORS OF ONCOGENIC SIGNAL TRANSDUCTIONS

Y.Uehara

National Institute of Health, Japan

Actinomycetologica, 7: S9-10, 1993

Cell proliferation and differentiation are regulated by a variety of cellular elements which participate in signal transduction pathways. Many oncogenes have been found to encode oncoproteins corresponding to these elements. Abnormal expression or constitutive activation of oncoproteins will lead to unlimited cell growth and malignant cell transformation. But it is still largely unknown how these elements, many of which are protein kinases, regulate each other in signalling pathways and what kind of roles they play in transformation. Therefore, development of specific inhibitors against these abnormal signalling transducers should be useful in understanding mechanisms of signal transduction pathways and in developing new antitumor drugs. Interested in discovering such inhibitors from microbial secondary metabolites, we established two new assay methods for evaluating specific inhibitors of oncogenic signal transduction and protein kinases. One method which was developed to evaluate inhibitors of oncogenic signal transduction pathways was based on different growth abilities of normal and transformed cells in a defined serum-free medium. In this system, the specific cytoplasmic protein tyrosine kinase inhibitor herbimycin A more potently inhibited the growth of src or abl transformed cells in a serum-free medium than in a serum-containing medium. Herbimycin A did not show such an effect on ras transformed cells, and the treatment of src transformed cells with other protein kinase inhibitors or cytotoxic drugs showed little IC[50] shift between the two media. In the second method which was developed to evaluate protein kinase inhibitors, a post-nuclear supernatant of v-src transformed cells was incubated with activators of protein kinases and [g^-32P]ATP, and phosphorylated proteins were analyzed by SDS-PAGE and autoradiography. The method permitted simultaneous detection of activities of protein kinase A, protein kinase C, protein tyrosine kinase and calmodulin-dependent protein kinase III on a single gel. Examinations of specificities of known protein kinase inhibitors suggested its usefulness in evaluating and screening new protein kinase inhibitors. With the former system used for screening, we isolated a new substance, angelmicin, which selectively inhibited the growth of the src or abl but not the ras oncogene-transformed cells in the serum-free medium, and demonstrated that this compound inhibited tyrosine kinase activity without affecting protein kinase A or protein kinase C in the latter in vitro assay. Thus, our systems were found helpful in identifying specific inhibitors of oncogenic signal transduction pathways mediated by growth factors and certain oncogene products.

Author's Abstract

Copyright 1993 C.E.T.A.