Actinomycetes University of Udine, Mycology Department ISSN: 0732-0574 Vol. 1, Num. 3, 1990, pp. 83-88

ACTINOMYCETOLOGICA Vol. 4 No. 1 1990

Published by Society for Actinomycetes, Japan

Abstracts Of Papers

Code Number: AC90013
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Vertical Distribution Of Microorganisms In Soils

Takahashi, Y., Y.Seki, Y.Tanaka, R.Oiwa, Y.Iwai and S.Omura

The Kitasato Institute, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108, Japan

Actinomycetologica, 4: 1-6, 1990

Vertical distribution of microorganisms in soils was studied. The largest populations of bacteria (10^3/g of dried soil), actinomycetes (10^7/g) and fungi (10^5/g) were observed in soils from the top layer (0-30cm in depth) of black color loam. Reduced numbers of bacteria and actinomycetes, but few fungi, were detected in soils of the second upper layer (50cm- 5m) of black loam. Bacteria (10^5/g) were also found even in silty sand soils of 40m depth. Vertical distribution of actinomycetes was examined in detail in soils of 0-100cm depth taken at a 10cm interval. The actinomycete population was the largest in soils of the surface layer (0-10cm) and decreased gradually as the depth increased. A comparative survey of all the isolates showed that ca. 80 % of different kinds of actinomycete cultures were isolated from surface soils. It was demonstrated that actinomycetes peculiar to individual soil layers existed. Authors' Abstract

Characterization Of Adenine-thiamine Auxotrophic Mutant Of Streptomyces azureus ATCC 14921

Ogata, S. and S.Yamada

Microbial Genetics Division, Institute of Genetic Resources, Kyushu University, 46, Higashi-ku, Fukuoka 812, Japan

Actinomycetologica, 4: 7-10, 1990

An auxotrophic mutant of Streptomyces azureus, lacking thiostrepton production, was isolated by UV- radiation of spores. The mutant lacks 5'phosphoribosyl-5- amino-4-imidazole carboxamide (AICAR) formyl-transferase. Adenine and to a lesser degree hypoxanthine (but not guanine) appear to inhibit sporulation by stimulating abnormal accumulation of AICAR. AICA (5-amino-4-imidazole carboxamide), which stimulates both mycelial growth and thiostrepton production of S. azureus, prevents the inhibition of spore formation. It is supposed that the accumulation of AICAR or other intermediates in the purine synthetic pathway affects the formation of spores. Excess of adenine and hypoxanthine would intensify the accumulation of AICAR and other intermediates in the mutant. AICA may enhance the mycelial metabolism so that AICAR and other intermediates could be further metabolized. R.L.

Actinomycetes: Yesterday, Today And Tomorrow: Opening Remarks

Koyama, Y.

President of the Society for Actinomycetes

Actinomycetologica, 4: 12, 1990

This is the opening address to the Symposium on "Actinomycetes: Yesterday, Today and Tomorrow - Biology of Streptomyces griseus '90", held on January 19, 1990 at the Science Council of Japan. The following papers were all presented at that meeting. The symposium was sponsored by the "Society for Actinomycetes, Japan" and the "National Committee for Microbiology, Science Council of Japan" and cosponsored by the "Society for Applied Genetics of Actinomycetes" and the "Japan Antibiotics Research Association". The symposium, organized by Dr.A.Seino, consisted of three sessions, Metabolism and Products (Chaired by Y.Tanaka), Gene Expression (K.Hotta) and Species Concept (I.Kawamoto). R.L.

Metabolism And Products Of Actinomycetes - An Introduction

Tanaka, Y. and S.Omura

The Kitasato Institute, 5-9-1 Shirokane, Minato-ku, Tokyo 108, Japan

Actinomycetologica, 4: 13-14, 1990

The authors stress the role of actinomycetes as a source of bioactive metabolites (67%) as compared to other bacteria (13%) and fungi (20%). Nearly 200 metabolites are produced by Streptomyces griseus, which is also characterized by a high structural variety of products. The ability of S.griseus to produce a large number of different metabolites is mainly determined by its genetic characteristics. R.L.

Streptomycin Biosynthesis And Self-resistance Mechanism In Streptomycin Producing Streptomyces griseus

Sugiyama, M. and O.Nimi

Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Kasumi 1-2-3, Minarm-ku, Hiroshima 734 and Department of Fermentation Technology, Faculty of Engineering, Hiroshima University, Saijo-cho, Higashi-Hiroshima 724, Japan

Actinomycetologica, 4: 15-22, 1990

The principal findings of streptomycin biosynthesis by S. griseus were reviewed. In this context we found the correlation between streptomycin biosynthesis and D- glucosamine metabolism. Biochemical and genetic basis for streptomycin resistance of the organism was also reviewed. In addition to enzymic inactivation by streptomycin-6- phosphotransferase, we confirmed that the reduction of streptomycin uptake which develops with cell growth plays a role in self-resistance in streptomycin producing S.griseus HUT 6037. Authors' Abstract

Streptomyces griseus As An Excellent Object For Studying Microbial Differentiation

Ochi, K.

Exploratory Research Laboratories, Fujisawa Pharmaceutical Co., 5-2-3 Tokodai, Tsukuba, Ibaraki 300-26, Japan

Actinomycetologica, 4: 23-30, 1990

Differentiation and secondary metabolism of Streptomyces griseus are analysed. Morphological and physiological differentiation begin as responses to a decrease in nutrition. It is therefore reasonable to assume that cells possess a "sensory pathway" by which the initial nutritional stress is sensed and eventually transmuted into the gene expression for differentiation. Once key genes for differentiation are expressed, numerous differentiation- specific ones appear in a hierarchical regulatory cascade. In addition to signal molecules, differentiation requires endogenously produced factors (autoregulating factors). The membrane seems to be important in the initiation of differentiation. ADP-ribosylation of the membrane protein is an essential process in S.griseus differentiation, as shown by mutants with reduced ADP-ribosyltransferase and characterised by a highly reduced ability to differentiate.

The genetic approach involves the use of mutants with blocked or stimulated differentiation. In S.griseus the relC mutant loses the capability of accumulating ppGpp (a signal molecule) and thus is deficient in streptomycin production. Aerial mycelium production is also reduced. The introduction of the relC mutation into various Streptomyces spp. regularly results in a loss of antibiotic production, suggesting the role of ppGpp as a general regulatory molecule for triggering secondary metabolism in Streptomyces. In S.griseus a mutation (sup) suppresses the relC effect. The dependence of streptomycin and aerial mycelium production on the relC gene can be bypassed by the sup mutation rendering S.griseus relC cells capable of producing streptomycin and aerial mycelium without restoring their ppGpp-accumulating ability. In addition differences in the role of the A-factor on S.griseus and on S.coelicolor are discussed.R.L.

Gene Expression In Streptomyces griseus: Introduction

Hotta, K.

Department of Antibiotics, National Institute of Health of Japan, 2-10-35 Kamiosaki, Shinagawa-ku, Tokyo 141, Japan

Actinomycetologica, 4: 31-32, 1990

The introductory remarks to the "Gene Expression" session of the symposium illustrate the progress in the field with particular reference to S.griseus (A-factor, afs genes, etc.). Improvements in streptomycin production, interspecific protoplast fusions, resulting novel antibiotics (indolizomycin) and kanamycin resistance are also mentioned.

R.L.

Cryptic Kanamycin Resistance Gene In Streptomyces griseus

Ishikawa, J.

Department of Antibiotics, National Institute of Health of Japan, 2-10-35 Kamiosaki, Shinagawa-ku, Tokyo 141, Japan

Actinomycetologica, 4: 33-36, 1990

Cryptic kanamycin resistance gene (kan^o) and its functional forms (kan and kan') of Streptomyces griseus strains were genetically analyzed. Cloning of these genes cleared that resistance determinants (kan and kan') lied within 1.5 kb MluI fragments with no difference in restriction site and size compared to the corresponding fragment containing kan^o. Gene amplification of kan' in a KM-resistant strain caused a highly elevated expression of kan' due to gene dosage effect. Sequencing of the 1.5 kb MluI fragment containing kan revealed an ORF which could generate an about 30,000 Dalton protein regarded presumably as an AAC(3). Analysis of mRNA revealed that activation of kan^o was regulated at transcription level. Based on these results, we propose that the cryptic gene kan^o was activated by a mutation at the 5' region, providing a promoter activity. Author's Abstract

Regulation Of Secondary Metabolism And Morphogenesis In Streptomyces

Beppu, T.

Department of Agricultural Chemistry, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113, Japan

Actinomycetologica, 4: 37-38, 1990

Regulatory networks of secondary metabolism and morphogenesis in Streptomyces with reference to A- factor and afs genes are described. In particular the role of the A-factor-receptor protein, detectable in the cytoplasmic fraction, as a repressor-type regulator is discussed. Experiments suggest that the A-factor-dependent protein plays a role in repressing both streptomycin production and sporulation. In addition investigations on A- factor-dependent promoters in streptomycin biosynthesis indicate the presence of a regulatory system of secondary metabolism whose function is modulated by phosphorylation of the regulatory protein. R.L.

Species Concept

Kawamoto, I.

Tokyo Research Laboratory, Kyowa Hakko Kogyo Co., Ltd., 3-3-6, Asahimachi, Machidashi, Tokyo 194, Japan

Actinomycetologica, 4: 39-40, 1990

Introductory remarks by the chairman of the session "Species Concept" deal with the problematics of Streptomyces taxonomy (sensu Cowan, i.e. including classification, nomenclature and identification). The species concept is introduced with the statement that in Streptomyces it "should be based on the measurement of evolutionary divergence in the information- bearing molecules, and that phenetic characters correlated well with them should be used for identification". R.L.

A History Of Systematics And A Concept Of Species In Streptomycetes

Miyadoh, S.

Pharmaceutical Research Center, Meiji Seika Kaidha, Ltd., Morooka, Kohoku, Yokohama 222, Japan

Actinomycetologica, 4: 41-48, 1990

The paper deals with the historical development of streptomycete systematics with the aim of defining the species concept in the organisms. A summary of streptomycete systematics from 1875 (Cohffs Streptothrix foersteri) to 1989 (Bergey's Manual, vol.4) is presented followed by a discussion on changes of criteria used for streptomycetes systematics from Krainsky (1914) up to the latest edition of Bergey's Manual. The concept of species in streptomycetes is then discussed, stressing differences between actinomycetes and higher organisms, continuity of clusters in the former, problems presented by variability, etc. Supergeneric levels of classification are also discussed. Finally the author proposes the latest edition of Bergey's as a starting point for future taxonomic work. R.L.

Species Concept Of Streptomycetes - Approaches From Nucleic Acids

Japan Collection of Microorganisms, RIKEN, 21, Hirosawa, Wako, Saitama 351-01, Japan

Actinomycetologica, 4: 49-54, 1990

After an introduction on "traditional classification" the contribution of nucleic acid data to systematics is presented under the headings DNA base composition, DNA-DNA hybridization, 16S rRNA oligonucleotide cataloging and 16S rRNA sequencing. Informational macromolecules represented by DNA and rRNA have been shown to be excellent molecules for systematics reflecting genealogy. Therefore it is desirable to accumulate data with regard to genetic material and use it to support numerical phenetic data. Defining borders between categories by using DNA or rRNA sequence homology values may define organisms otherwise indistinguishable. Information obtained by the analysis of nucleic acids may be relevant not only for classification and identification purposes but also for providing an objective evaluation of taxonomic markers as defined by phenetic analyses.R.L.

Cellular Components Of Streptomyces griseus And Its Implication For The Species Concept

Itoh, T.

Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 01 Gensuke, Fujieda-shi, Shizuoka 426, Japan

Actinomycetologica, 4: 55-60, 1990

Chemotaxonomy contributions to S.griseus species concept are presented with reference to protein electrophoresis, serology, teichoic acid presence and phage sensitivity. The following considerations are discussed in regard to the use of chemical criteria in defining the species concept in streptomycetes: 1) Reproducibility or stability of chemical components 2) Selection of test strains so as to allow comparison and examination of enough strains for each taxon 3) Objective interpretation of analytical results 4) Comparison of data obtained with others based on different criteria 5) Development in accuracy and rapidity of analytical procedures 6) Understanding of biosynthetic, physiological and genetic information on cellular components. R.L.

Problems In Identification Of Streptomyces griseus

Okazaki, T.

Tsukuba Research Laboratories, Sankyo Co., Ltd., 33 Miyukigaoka, Tsukuba-shi, Ibaraki 305, Japan

Actinomycetologica, 4: 61-64, 1990

Problematics in the identification of Streptomyces griseus are discussed. Starting from ISP descriptions and considering in particular the role of physiological characteristics, the subjectivity of the investigator is stressed. Chemotaxonomy appears valuable but so far only at the generic level. In the author's opinion the species concept in actinomycetes is confused because there is no clear definition of the species. We lack an absolute measure for its recognition, such as sexual reproduction in eukaryotes. In addition taxonomic methods and criteria change according to technological progress. Therefore the species concept in actinomycetes is ambiguous. A final comment is devoted to the identification of new isolates. R.L.

Actinomycetes: Yesterday, Today And Tomorrow. General Discussion

Yagisawa, M.

Japan Antibiotics Research Association, 2-20-8, Kamiosaki, Shinagawa-ku, Tokyo 141, Japan

Actinomycetologica, 4: 65-67, 1990

The paper summarizes the general discussion on the three sessions of the symposium. "Species Concept" Session. Theoretically it would be possible to establish some 7.7 million different species of streptomycetes using cross combination of morphological, cultural and physiological characteristics. In addition proper identification and classification methodologies are suggested, keeping in mind the implications of genetics. With reference to "Gene Expression" limitations to full expression of introduced genes are stressed. Even when the complete set of information to produce a metabolite is introduced into a host, supply of energy and precursors, release from repression and inhibition, defence against the product, excretion and other metabolic functions might affect overall production of the metabolite. "Metabolism and Products". The wide range of metabolites of various chemical structures and differing in biological activity of S.griseus is undeniable. At the moment interest is focussed on the potential mechanisms regulating the flow of key intermediates. Two approaches are possible, i.e. research on intracellular regulatory factors (A*factor, ppGpp, etc.) and extracellular ones (C*, N-, P-sources, etc.). The conclusive discussion on "Future Trends" results in a proposal to establish a project for the analysis of the whole genome of S.griseus, similar to the human genome HUGO Project.R.L.

Copyright 1990 C.E.T.A., The International Centre for Theoretical and Applied Ecology, Gorizia