Actinomycetes University of Udine, Mycology Department ISSN: 0732-0574 Vol. 6, Num. 1, 1995

A New Genus of Actinomycetes: Streptoplanospora gen.nov.

H. Runmao and L. Junying

Sichuan Industrial Institute of Antibiotics, Sichuan, Chengdu, P.R. of China 610051

Code Number: AC95003
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ABSTRACT.

An actinomycete culture (strain NA 941733 = SIIA 941888), isolated from soil, produces chains of rod shaped sporangia containing zoospores, has cell wall chemotype I with galactose, glucose and madurose as whole cell sugars. On the basis of these characteristics the organism is regarded as belonging to a new genus of the actinomycetes, Streptoplanospora gen.nov. Streptoplanospora viridis sp. nov. is proposed as the type species of the genus.

During an investigation on the actinomycete population of soils from the southern part of P.R. China, strain NA 941733 was isolated from a sample collected in Ganzhu, Jiangxi province. The organism is characterised by unusual spore- bearing structures containing zoospores, chemotype I (LL- diaminopimelic acid) cell wall and by glucose, galactose and madurose as whole cell sugars. A description of the organism is reported.

MATERIALS and METHODS

Organism. Strain NA 941733T (T = type strain) was isolated from a soil sample collected in Ganzhu, Jiangxi province, on HV-agar (Hayakawa and Nonomura, 1987) after 9dd incubation at 28C, using a previously described isolation procedure (Runmao et al., 1994).

Cultural characterisation. Cultural characteristics were determined after 7, 14 and 21dd incubation at 28C. The following media were used: ISP (International Streptomyces Project) media 2 to 7 (Shirling and Gottlieb, 1966) and Czapek solution agar.

Morphological characteristics. These were examined by light and transmission electron microscopy (Runmao et al., 1993).

Physiological characterisation. Carbohydrate utilisation was determined according to Shirling and Gottlieb (1966).

Chemotaxonomic characterisation. Analyses were carried out according to the methods of Becker et al. (1965) and Lechevalier (1968).

RESULTS and DISCUSSION

Description of Streptoplanospora gen.nov. Streptoplanospora (Strep.to. pla'no.spo.ra. Gr.adj. streptes, pliant, bent; Gr.n. planos, wanderer; Gr.n. spora, a seed; M.L. fem.n. Streptoplanospora, an organism with pliant hyphae, bearing motile spores).

Gram-positive, non acid fast, non fragmenting substrate mycelium, well developed within the agar medium and forming a more or less compact layer at its surface. Aerial mycelium forming mainly rod shaped (0.4-0.6 x 1.0-2.5um) sporangia in chains.

Rod shaped sporangiospores of various length (0.43-0.63 x 1.0-2.3um). The envelope of the sporangia has a wrinkled surface (Plate I). Sporangiospores, in the presence of water, show subpolar flagella and motile zoospores (0.4-0.65 x 1.0- 2.3um).

Cell walls contain L-diaminopimelic acid and whole cell hydrolysates consist of glucose, galactose and madurose. Type species: Streptoplanospora viridis.

Plate I.Figs. 1-3: Morphology of Streptoplanospora viridis: aerial mycelium and sporangia. Fig. 4: A sporangiospore (zoospore) with a single subpolar flagellum. Magn.: figs. 1-2, 5,800x; figs. 3-4, 19,000x.

Description of Streptoplanospora viridis sp.nov. Streptoplanospora viridis (vi.ri'dis. L.adj. viridis, green, with reference to the colour of substrate mycelium).

Poor growth on ISP medium 6; on other media substrate mycelium colourless to light brownish or green. Aerial mycelium absent on ISP media 4 and 6, abundant and whitish on the other media. Soluble brownish violet pigment produced on ISP medium 7 (Table 1).

Well developed aerial hyphae (0.2-0.5um in diameter) bearing elongated tubular sporangia separated by septa. Rod shaped sporangiospores (0.4-0.6x1.0-2.5um), motile by a subpolar flagellum.

D-glucose, D-xylose, maltose, sucrose, D-galactose, ribose, salicin, L-rhamnose, lactose, L-arabinose, D-melibiose and inulin utilised; no growth with D-sorbitol, dulcitol, D- mannitol and melezitose as sole carbon sources.

Optimum temperature for growth around 28 C.

The species description is based on a single isolate and strain NA 941733 represents the type strain of Streptoplanospora viridis. The type culture has been deposited in the National Culture Centre of China, as SIIA 941888.

    
       -----------------------------------------------------------
       ---
       Medium   Vegetative mycelium   Aerial mycelium      Soluble
                Amount and colour    Amount and colour    pigment
       
       ISP 2   Good, light brownish  Abundant, white         -
       ISP 3   Good, green           Abundant, whitish       -
       ISP 4   Good, hyaline         Moderate                -
       ISP 5   Good, light brownish  Abundant, whitish       -
       ISP 6   Poor, hyaline         Poor                    - 
       ISP 7   Good, brownish violet Abundant, white      Brownish
                                                           violet
       Czapek  Good, hyaline         Moderate, white          -
       agar
       

-------------------------------------------------------------- On the basis of its wall chemotype I, whole cell hydrolysates containing glucose, galactose and madurose and formation of a well developed aerial mycelium with chains of sporangia containing zoospores, strain NA 941733 could be related to the genera Sporicththya (Lechevalier et al., 1989) and Planopolyspora (Petrolini et al., 1993).

Sporichthya forms a very short, sparse, sparingly branched aerial mycelium which divides into rod shaped to coccoid, motile spores. No sporangia are produced and no substrate mycelium is formed.

Planopolyspora is characterised by multispored sporangia containing a single row of numerous zoospores. The organisms are of chemotype III and whole-cell hydrolysates contain madurose (sugar pattern B).

In conclusion strain NA 941733 appears well differentiated from previously described genera and therefore a new genus, Streptoplanospora, is proposed to accommodate the culture. Streptoplanospora viridis sp.nov. represents the type species of the genus.

ACKNOWLEDGEMENTS.

The authors wish to thank Dr.Chen Weiqun of the Central Analysis Department of Sichuan University for electron microscopy, Mr.Zhuhui and Maliang for the collection of soil samples. and Prof.Cai Shunyang for assistance with the manuscript.

REFERENCES

Becker, B., M.P.Lechevalier & H.A.Lechevalier (1965). Chemical composition of cell-wall preparations from strains of various form genera of aerobic actinomycetes. Appl.Microbiol., 13: 236-243

Hayakawa, M. & H.Nonomura (1987). Humic acid-vitamin agar, a new medium for the selective isolation of soil actinomycetes. J.Ferment.Technol., 65: 501- 509

Lechevalier, M.P. (1968). Identification of aerobic actinomycetes of clinical importance. J.Lab. Clin.Med., 71: 943-944

Lechevalier, M.P., H.A.Lechevalier & P.E. Holbert (1989). Genus Sporichthya, Lechevalier, Lechevalier and Holbert. In: S.T.Williams, E. Sharpe & J.G.Holt (eds.) Bergey's Manual of Systematic Bacteriology. Williams & Wilkins, Baltimore, Vol.4, pp. 2507

Petrolini, B., S.Quaroni, M.Saracchi & P. Sardi (1993). A new genus of the maduromycetes: Planopolyspora gen. nov. Actinomycetes, 4: 8-16

Runmao, H., W.Guizhen & L.Junying (1993). A new genus of actinomycetes, Planotetraspora gen.nov. Int.J.Syst.Bacteriol., 43: 468-470

Runmao, H, M.Lianjun & W.Guizhen (1994). Distribution of soil actinomycetes in North-East China. Actinomycetes, 5: 12-13

Shirling, E.B. & D.Gottlieb (1966). Methods for characterization of Streptomyces species. Int.J. Syst.Bacteriol., 16: 313-340.

Copyright 1995 CECT

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