A Gram-negative, motile, non-spore-forming and moderately halophilic ellipsoid-shaped marine coccobacillus, designated strain SS011B1-4T, was isolated from benthic sediment of the South China Sea. Optimum growth occurred at 30-37 6C, pH 7.5-8.0 and 4-8% (w/v) NaCl. Strain SS011B1-4T utilized a variety of organic substrates as sole carbon sources, but did not utilize toluene, n-tetradecane or crude oil. Strain SS011B1-4T had ubiquinone-9 as the major respiratory quinone and C18: 1v9c, C16: 0 and C12: 0.3-OH as the predominant fatty acids. The genomic DNA G+C content was 62.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SS011B1-4T belonged to the genus Marinobacter of the Gammaproteobacteria. The results of the phenotypic, phylogenetic and genomic analyses revealed that strain SS011B1-4T represents a novel species of the genus Marinobacter. The name Marinobacter segnicrescens sp. nov. is therefore proposed, with strain SS011B1-4T (5LMG 23928T5CGMCC 1.6489T) as the type strain.

A thermophilic, methylotrophic methanogen, strain ZC-1T, was isolated from the Shengli oilfield, China. Cells of strain ZC-1T were motile cocci, 0.7-1.0 mm in diameter and always occurred in clusters of two to four cells. Lysis-susceptibility experiments and analysis of transmission electron micrographs of strain ZC-1T suggested the presence of a proteinaceous cell wall. Strain ZC-1T used methanol, methylamine and trimethylamine as substrates for methanogenesis. Optimal growth, with a doubling time of around 5 h, occurred at pH 6.0-6.5, 65 6C, 0.3-0.5 M NaCl and 0.05-0.20 M MgCl2. The DNA G+C content of this organism was 56 mol%. Analysis of 16S rRNA gene sequence and the inferred amino acid sequence of the mcrA gene of strain ZC-1T indicated that it is related specifically to members of the family Methanosaetaceae (90.6 and 76.6% sequence similarity, respectively). However, strain ZC-1T failed to grow with acetate as substrate for methanogenesis, which is a special characteristic of the family Methanosaetaceae. Based on these phenotypic and phylogenic characteristics, strain ZC-1T is proposed to represent a novel genus and species, for which the name Methermicoccus shengliensis gen. nov., sp. nov. is proposed. The type strain is ZC-1T (5CGMCC 1.5056T5DSM 18856T). Methermicoccaceae fam. nov. is also proposed.

采用油井采出液培养基和加入无机盐成分的改良油井采出液培养基，对大庆油田萨北过渡带油井采出液中的细菌进行分离培养及初步鉴定，比较了两种情况下培养出的具有硝酸盐和/或亚硝酸盐还原，以及/或反硝化能力菌群结构的差异。利用采出液培养基培养出一组新的微生物菌株，并且分离的硝酸盐和/或亚硝酸盐还原菌，以及/或反硝化细菌（Nitrate/nitrite reducing bacteria, denitrifying bacteria, NRDB）比例明显高于无机盐- 采出液培养基；但培养基中无机盐成分的添加，提高了可培养NRDB的群落生物多样性。仅仅向油井采出液中直接投加硝酸盐作为电子受体，对其中硝酸盐还原、亚硝酸盐还原和反硝化微生物（NRDB）的激活作用以及产抑制硫化物产生的能力有限，而同时加入分离自采出液的NRDB和硝酸盐则对硫酸盐还原菌（SRB）的生长和产硫化物活性都产生了明显的抑制。但是NRDB与硝酸盐同时投加对不同SRB的抑制效果并不相同，导致了SRB群落结构的变化。

Two novel strains, SL014B61AT and SL014B11A, were isolated from an oil-polluted saline soil from Gudao in the coastal Shengli Oilfield, eastern China. Cells of strains SL014B61AT and SL014B11A were motile, Gram-negative and rod-shaped. Growth occurred at NaCl concentrations of between 0 and 15% and at temperatures of between 10 and 45 6C. Strain SL014B61AT had Q9 as the major respiratory quinone and C16: 0 (21.2%), C18: 1v9c (20.3%), C16: 1v7c (7.3%) and C16: 1v9c (6.4%) as predominant fatty acids. The G+C content of the DNA was 57.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SL014B61AT belonged to the genus Marinobacter in the class Gammaproteobacteria. Strain SL014B61AT showed the highest 16S rRNA gene sequence similarity with Marinobacter bryozoorum (97.9%) and showed 97.8% sequence similarity to Marinobacter lipolyticus. DNA–DNA relatedness to the reference strains Marinobacter bryozoorum and Marinobacter lipolyticus was 35.5% and 33.8%, respectively. On the basis of these data, it is proposed that strains SL014B61AT and SL014B11A represent a novel species, Marinobacter gudaonensis sp. nov. The type strain is strain SL014B61AT (=DSM 18066T=LMG 23509T=CGMCC 1.6294T).

目前自然界中只有极少部分微生物能够得到培养，严重阻碍了对微生物生命活动规律的研究和微生物资源的开发。改进传统培养方法，采用新型培养技术，提高微生物可培养性，大量培养自然界中存在的微生物，从而更全面、准确地了解微生物细胞的生命规律、获悉微生物群落中各种微生物之间的动态相互作用和相互协调的规律，对环境微生物工艺进行准确地设计、精细地调控和高效地利用。简要介绍了微生物不可培养的原因，系统总结了有关提高微生物可培养性方法的最新研究进展，提出研究中存在的问题，并阐述了模拟自然环境条件、强调微生物相互关系是提高微生物可培养性的关键。