By using baiting techniques and different purification methods, a high number of myxobacterial strains have been isolated as pure cultures from soil of different regions of China. Because myxobacterial cells do not disperse easily in liquid media, a medium containing an enzymatic hydrolysate of casein (CEH) medium have been used for purification and purity tests combined in a single step. The key method, in which isolates are reintroduced to sterile rabbit dung to induce fruiting bodies formation, facilitates purification of myxobacteria. Sterile rabbit dung pellets are used to mimic the natural growth substance of these organisms which has the advantage that characteristic fruiting bodies emerge, which is a key characteristics in the taxonomy of myxobacteria. In this study, the optimum program of isolation and purification of some myxobacteria strains has been established which will facilitate screening programs. Moreover, the development of fruiting body formation of strain BD20 (Chondromyces) and strain BD54 (Cystobacter) have been recorded in this study.

A catalase-negative actinomycete, strain YIM 21741T, was isolated from a soil sample collected from a primeval forest at Xishuangbanna, Yunnan Province, China. Analysis of 16S rDNA showed the strain to be related to members of the genus Agromyces, with which it also shares morphological characteristics, e.g. branching hyphae breaking into diphtheroid and rod-like, irregular, non-motile fragments and a peptidoglycan containing the diagnostic amino acid 2,4-diamino-n-butyric acid. Whole-cell hydrolysates of strain YIM 21741T contained rhamnose and small quantities of glucose, galactose and mannose. The major menaquinone was MK-12, while MK-13 and MK-12 were minor components. Diagnostic phospholipids were phosphatidylglycerol and diphosphatidylglycerol. The G+C content of the DNA was 72

A halophilic actinomycete, strain YIM 90003T, was isolated from a soil sample collected from Xinjiang Province, China, by using starch-casein agar with a salt concentration of 20% (w/v), pH 7·0. The strain grew well on most media tested. No diffusible pigment was produced. Aerial mycelium and substrate mycelium were well developed on most media. The aerial mycelium formed short spore chains, bearing non-motile, straight to flexuous spores with wrinkled surfaces. The cell walls of strain YIM 90003T contained meso-diaminopimelic acid as the diagnostic diamino acid. Cell-wall hydrolysates contained galactose and arabinose. Menaquinone composition varied with the medium used for cell cultivation; on glucose-yeast extract medium supplemented with 10% NaCl, the major menaquinone was MK-9(H4), while, on vitamin-enriched ISP 2 medium, the major menaquinones were MK-10(H2), MK-9(H8) and MK-10(H4). Phospholipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, diphosphatidyl glycerol, methylphosphatidylethanolamine, phosphatidylserine, phosphatidylcholine and an unidentified phospholipid. 16S rRNA gene sequence analysis showed Streptomonospora salina as the closest phylogenetic neighbour. On the basis of these analyses, strain YIM 90003T is a member of the genus Streptomonospora, though its properties do not match the generic description fully with respect to the menaquinone composition and peptidoglycan amino acid. Analyses of mechanically disrupted cell walls of the type species, Streptomonospora salina DSM 44593T, and strain YIM 90003T, purified by tryptic digestion and subsequent SDS treatment, revealed the exclusive presence of meso-diaminopimelic acid as the diagnostic diamino acid of peptidoglycan. Thus, the genus description of Streptomonospora, indicating the presence of several amino acids usually not found in the peptidoglycan moiety, is therefore emended. DNA–DNA hybridization and comparison of physiological and chemotaxonomic characteristics demonstrated strain YIM 90003T to be different from Streptomonospora salina. The name Streptomonospora alba sp. nov. is proposed, with strain YIM 90003T (=CCTCC AA001013T=DSM 44588T) as the type strain.

14 strains of Actinomycetes were isolated from soil samples collected in Yunnan, China Experiments showed that they had activity of herbicide. In this paper, the morphological and chemotaxonomic characters of these strains were studied and they were identified as three genera of Actinomycetales respecitively, such as Streptomyces. Nficromonospora and Nocardia.

通过对河北、云南、青藏高原不同地区的粘细菌进行生态多样性研究，从42 个样品中分离得到了10个属（A rchangium、Myxococcus、Cystobacter、Corallococcus、Melittangium、Sorangium、Polyangium、Chondromyces、Angiococcus、Stigmatella） 的150余株粘细菌，其中包括一些尚未有描述的菌株，有待鉴定。根据这些菌株的子实体结构、菌落形态、营养细胞、粘孢子形态等特征将它们初步鉴定到属。对这些特有自然生态环境的粘细菌按不同地点、植被、营养基质进行统计比较，结果表明粘细菌生态分布极为广泛，具有丰富的生态多样性。以上结果为粘细菌生物资源的有效开发利用奠定了基础。