 |
| About Bioline | All Journals | Testimonials | Membership | News |
|
||||||
|
||||||
A New Genus of Actinomycetales: ASIOSPORANGIUM GEN.NOV. H. Runmao, L. Junying and M. Lianjun Sichuan Industrial Institute of Antibiotics, Sichuan, Chengdu, P.R. of China 610051
Code Number: AC95012
Sizes of Files:
Text: 9K
Graphics: Photos (jpg) 239K
ABSTRACT. A new aerobic mesophilic genus of
Actinomycetales, Asiosporangium gen.nov. is
proposed. Morphological characteristics differentiate it from
previously described genera. Cell walls contain meso-
diaminopimelic acid. Galactose, glucose, mannose, madurose and
ribose are the sugars present in whole-cell hydrolysates. MK-8
is the predominant menaquinone. A.albidum is proposed
as the type species of the genus and strain NA944235 (= SIIA
943018) is designated as the type strain.
During an investigation of actinomycete soil populations (Runmao et al., 1994a), an uncommon strain was isolated from a sample collected in Southern China. The present report deals with the description of the strain and the proposal to place it in a new genus of Actinomycetales.
MATERIALS and METHODS
Strain NA944235 (= SIIA943018) was isolated from a soil sample collected in the Jiangxi province, P.R. of China, by a previously described isolation procedure (Runmao et al., 1994b). Morphological, cultural and chemotaxonomic characteristics were determined according to Runmao et al. (1994b), Collins et al. (1977) and Tamoaka et al. (1983).
RESULTS and DISCUSSION
The non fragmenting substrate mycelium of strain NA944235 grows within the agar medium, forming a compact layer at its surface, and does not bear spores. The aerial mycelium is well developed forming lateral sessile warty sporangia (Figs. 1 and 2), containing single rod-shaped spores (Figs. 3 and 4). Sporangiospores (0.60-0.68x0.70-0.88um) are released after immersion of sporangia in water and show a polar flagellum embedded in a type of sheath (Fig. 5) which dissolves rapidly (Fig. 6). Cultural characteristics are summarised in Table 1. Meso-diaminopimelic acid is present in the cell wall and whole-cell hydrolysates contain galactose, glucose, mannose, madurose and ribose (chemotype III). MK-8 is the predominant menaquinone. On the basis of the morphological characteristic of sessile sporangia with single zoospores, strain NA944235 appears related to the oligozoosporic genera Planomonospora and Cathayosporangium (Runmao et al., 1995). However it is differentiated by morphological and chemotaxonomic features (Table 1) and therefore represents a new morphological type of motile actinomycete. Consequently it is proposed to allocate the organism to a new genus of Actinomycetales, Asiosporangium gen.nov., as the type species, Asiosporangium albidum sp.nov.
Description of Asiosporangium gen. nov. Asiosporangium (A.sio.spo.ran'gi. um. L.n. Asia, Asia; Gr.n. spore, a seed; Gr.n. angeion, a vessel; M.L.neut. n. Asiosporangium, Asian sporangium).
Figures 3 and 4. Ultrathin sections of sporangia (48,000x and 36,000x magnification respectively) Figures 5 and 6. Zoospores of with single polar flagella (10,000x and 19,000x magnification respectively)
--------------------------------------------------------------
Genus Sporangium Zoospore Whole-cell Menaquinone
arrangement type
--------------------------------------------------------------
Asiosporangium oval single B MK-8
Planotetraspora cylindrical four in a line A MK-9 (H2)
Streptoplanospora rod-shaped single B MK-9 (H4)
Cathayosporangium globose single B MK-9 (H4H6)
Planomonospora clavate single B MK-9 (H2)
--------------------------------------------------------------
Table 1. Comparison of Asiosporangium with
related genera of motile actinomycetes. All genera form aerial
mycelium and show cell wall type III.
--------------------------------------------------------------
Medium Vegetative mycelium Aerial mycelium Sporangium
Amount and colour Amount and colour formation
--------------------------------------------------------------
ISP 2 Good, light brown Abundant, yellowish white Good
ISP 3 Good, hyaline Abundant, white Good
ISP 4 Moderate, hyaline Poor, white Moderate
ISP 5 Good, light yellow Abundant, yellowish white Good
ISP 6 Poor, hyaline absent None
ISP 7 Good, light brown Abundant, yellowish white Good
Czapek-Dox Good, light brown Abundant, Good
--------------------------------------------------------------
Table 2. Cultural characteristics of Asiosporangium
albidum, strain NA944235. No soluble pigments are
produced.Aerobic, mesophilic, gram positive and non acid fast. Well developed, nonfragmenting, substrate mycelium. Sessile warty sporangia irregularly borne as side branches of aerial filaments containing rod shaped single sporangiospores (0.60-0.68x0.70-0.88æm), released when flooded with water, and swimming by means of a polar flagellum. Cell wall containing meso-diaminopimelic acid and whole-cell hydrolysates characterised by the presence of galactose, glucose, mannose, madurose and ribose (chemotype III). MK-8 is the predominant menaquinone. Type species: Asiosporangium albidum sp.nov.
Description of Asiosporangium albidum sp.nov. (al'bi.dum Lat. adj. albidus, white, whitish) Morphological characteristics as for the genus. Good growth, between 28 and 38 C, on ISP media (Shirling and Gottlieb, 1966) 2, 3, 4, 5 and 7 and on Czapek-Dox agar. Vegetative mycelium hyaline to light coloured, aerial mycelium white to creamy (Table 2). No soluble nor melanin-like pigments produced. No sugar utilisation on basal ISP medium 9. On Czapek-Dox agar, as basal medium, good growth with L- arabinose, D-galactose, D-glucose, inulin, maltose, D- mannitol, raffinose, L-rhamnose, salicin, sucrose and D- xylose, moderate with lactose and melibiose and none with dulcitol, melezitose, D-sorbitol or L-sorbose. Peptonisation of milk and hydrolysis of gelatine and starch. The species description is based on a single isolate and strain NA944235 represents the type strain of the species. The type strain has been deposited in the Culture Collection Centre of the Sichuan Industrial Institute of Antibiotics (SIIA) Chengdu, P.R. of China, as strain SIIA 943018.
Acknowledgements. The authors wish to thank Dr.Chen Weiqun and Dr.Zhen Giayu of the Central Analysis Department of Sichuan University for electron microscopy, Dr.Tuywen and Dr.Zhengling for collection of soil samples and Dr.Li for assistance in the preparation of the manuscript.
References
Collins, M.D., T.Pirouz, M.Goodfellow & D. E.Minnikin (1977). Distribution of menaquinones in actinomycetes and corynebacteria. J.gen. Microbiol., 100: 221- 230
Shirling, E.B. & D.Gottlieb (1966). Methods for characterization of Streptomyces species. Int.J. Syst.Bacteriol., 16: 313-340
Tamoaka, J., Y.Katayama-Fujimura & H. Kurnishi (1983). Analysis of bacterial menaquinone mixtures by high performance liquid chromatography. J.Appl.Bacteriol., 54: 34-36.
The following images related to this document are available:Photo images[ac95012c.jpg] [ac95012b.jpg] [ac95012a.jpg] |
| |||||||||
