Biology of a problematic marine fungus,dermocystidium sp.

Summary The life cycle of a nonfilamentous marine phycomycete, Dermocystidium sp., is described from its growth in axenic culture under controlled conditions. Reproduction occurs by vegetative means involving a process of cell enlargement and ecdysis modifiable by the methods of cultivation. Zoospores and sexuality were not observed. The results of inoculation studies with algae, phanerogam debris, and molluscs suggest that the fungus may be a free-living saprophyte in coastal waters.     

A freeze-etch study of the central myelin

The intramembranous organization of the interparanodal myelin lamellae in CNS was investigated by means of the freeze-etching technique. The density of the IMPs is about equal on both P- and E- fracture faces of every myelin sheath, but varies between the myelin sheaths. The morphology of the myelin tight junctions is also described. The nature of the IMPs and the functional significance of their mode of distribution are discussed.     

Amanita ibotengutake sp. nov., a poisonous fungus from Japan

On the basis of molecular phylogeny, it is clear that the fungi treated as Amanita pantherina in Japan are confused, i.e., A. pantherina and a misidentified species. As for morphology, the misidentified species differs from A. pantherina by having clamp connections on hyphae and basidia, a larger-sized fruitbody, ascending volval rings of stipe base and deciduous annulus. It is clear that the misidentified species is a poisonous fungus containing ibotenic acid and muscimol and causes the Pantherina syndrome. On these characters, it is concluded that the misidentified species is the unexplored Amanita species treated under the Japanese name ‘ibotengutake’ after which ibotenic acid was named. Here, we described it as a new species Amanita ibotengutake.     

Trichosporonoides nigrescens sp. nov., a new xerophilic yeast-like fungus

A new yeast-like fungus isolated from jam on two occasions is described as Trichosporonoides nigrescens. It is a true xerophile, able to grow at water activities at least as low as 0.75. For this reason, its carbon assimilation pattern was examined using both dilute (standard) and concentrated carbon sources: six to nine compounds not assimilated at the standard concentrations of 0.5% (0.001 to 0.1 mol/kg) were assimilated at 1.5 to 2.0 mol/kg. Cell wall and septal ultrastructure, DNA base ratios, and the nuclear cycle were examined to determine the generic and higher taxonomic affinities of this microorganism. All properties were consistent with its assignment to Trichosporonoides Haskins et Spencer. However, while ultrastructure indicated an affinity with the Basidiomycetes, the mitotic nuclear cycle and the xerophilic nature of this fungus suggested an Ascomycete affinity. The GC content (57%) is consistent with assignment to either. No teleomorphic state was found.     

Photoresponses of the marine protist Ulkenia sp. zoospores to ambient, artificial and bioluminescent light

Ulkenia sp. zoospores are attracted to 492 nm wavelength light produced by the marine bacterium Vibrio fischeri. Zoospores are positively photoresponsive to wavelengths of 440, 460 and 480 nm and contain a pigment that absorbs blue light. The average velocity of the zoospores is 0.47 m h(-1). Stimulatory intensities of these wavelengths ranged from 0.5 to 3.5 μEm(-2) s(-1) in both laboratory and field studies. The response of this protist to bioluminescence produced by Vibrio fischeri may direct zoospores to a nutrient rich environment colonized by these bacteria. In addition, the greatest responses were found at intensities associated with the light regime found near the bottom of naturally turbid estuaries or at greater depths of nonturbid, offshore waters. Positive phototaxis was not seen in zones of high light intensity either in field or laboratory studies, and there is some indication that zoospores may swim away from high light intensities.     

Ultrastructure of Thraustochytrium sp. zoospores

Summary Acid phosphatase distribution in the biflagellate zoospores of a marine fungus Thraustochytrium, resembling T. motivum Goldstein, was examined utilizing ultrastructural cytochemistry. Acid phosphatase activity was found in the Golgi saccules, Golgi vesicles, multivesicular bodies, endoplasmic reticulum, and autophagic vacuoles.Extensive autolysis of cellular structures occurs in the zoospores. Organelles or portions of the cytoplasm are segregated from the rest of the cytoplasm by acid phosphatase-positive vesicles and lamellae. These vesicles and lamellae coalesce around a portion of cytoplasm forming an enclosing double membraned sac. One of the membranes, probably the inner, is disrupted, releasing the hydrolytic enzymes which initiate digestion of the enclosed cytoplasm. These cytolysomes eventually fuse with larger cytolysomes where digestion is presumably completed. The final fate of the digestive residues and the large cytolysomes has not been determined.Contribution No. 501, Virginia Institute of Marine Science, Gloucester Point, Virginia 23062, U.S.A.Supported in part by the Oceanographic Section, National Science Foundation, Grant # GA-31014, to Dr. Frank O. Perkins.     

海洋真菌Arthrinium sp. UJNMF0008代谢产物的研究

为丰富海洋真菌的化学多样性,发现海洋真菌活性代谢产物,对海洋沉积物来源真菌Arthriniumsp.UJNMF0008的化学成分及其生物活性进行研究,采用硅胶柱色谱、凝胶柱色谱、反向柱色谱和高效液相色谱等方法从海洋沉积物来源真菌Arthriniumsp.UJNMF0008的发酵提取物中分离到5个化合物,通过核磁共振、质谱等方法,结合文献对照,鉴定了化合物的结构分别为arthoneF(1)、arthoneG(2)、sydoxanthoneC(3)、(3R,4R)-cis-4-hydroxymellein(4)和2-(2′S-hydroxypropyl)-5-methyl-7-hydroxychromone(5),其中化合物1和2是新化合物,化合物3首次从该属真菌中分离到。活性测试显示,化合物1~5在50μmoL/L的测试浓度下均没有表现出明显的抗氧自由基活性、抗菌活性以及NO释放抑制活性。     

Redoxcitrinin, a biogenetic precursor of citrinin from marine isolate of fungus Penicillium sp

A chemical analysis of the fermentation of the marine-derived fungus Penicillium sp. led to the isolation of a biogenetic precursor of citrinin, redoxcitrinin (1), together with polyketide mycotoxins, phenol A (2), citrinin H2 (3), 4-hydroxymellein (4), citrinin (5), and phenol A acid (6). The structures of compounds 1-6 were determined on the basis of physicochemical data analyses. Among them, compounds 1-3 exhibited a potent radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 values of 27.7, 23.4, and 27.2 microM, respectively.     

源自海洋裸孢壳属真菌Emericella sp. TJ414JZ-21的次级代谢产物

采用硅胶柱层析、中压反相柱层析、Sephadex LH-20凝胶柱层析以及半制备高效液相色谱等分离技术,从真菌Emericella sp.的大米发酵产物中分离得到了8个单体化合物,并利用波谱学方法结合文献数据对其结构进行了鉴定,分别为：asteltoxin (1)、asteltoxin B (2)、penicillide (3)、purpactin A (4)、tajixanthone hydrate (5)、mycophenolic acid (6)、trans-dehydrodiferulate dimethyl ester (7)、2,8-dihydroxy-1,3-dimethoxy-6-methylanthraquinone (8)。其中,化合物3和4均为首次从该属真菌中分离得到。     

Remispora spinibarbata sp. nov., a marine lignicolous ascomycete from Denmark

Remispora spinibarbata sp. nov. is described from driftwood found on the north coast of Sealand and compared with the type species of Remispora, Ceriosporopsis and Nimbospora .     

Halorubrum salinum sp. nov., isolated from a marine solar saltern

The halophilic archaeal strain GX71^T was isolated from the Gangxi marine solar saltern near the Weihai city of Shandong Province, China. Cells of the strain were pleomorphic and lysed in distilled water, stained Gram-negative and formed red-pigmented colonies. Strain GX71^T was able to grow at 25–45 °C (optimum 30 °C), in the presence of 1.7–4.8 M NaCl (optimum 2.6 M NaCl), with 0.005–0.7 M MgCl₂ (optimum 0.05 M MgCl₂) and at pH 5.5–9.5 (optimum pH 7.0–7.5). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 10 % (w/v). The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, one major glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-3) and an unidentified lipid was also detected. The 16S rRNA gene sequence of strain GX71^T showed 94.0–97.0 % similarity to members of the genus Halorubrum of the family Halobacteriaceae. The rpoB′ gene sequence of strain GX71^T was 87.3–93.4 % similarity to current members of the genus Halorubrum. The DNA G+C content of GX71^T was 67.1 mol%. Strain GX71^T showed low DNA–DNA relatedness with Halorubrum lipolyticum CGMCC 1.5332^T, Halorubrum saccharovorum CGMCC 1.2147^T, Halorubrum kocurii CGMCC 1.7018^T and Halorubrum arcis CGMCC 1.5343^T, the most closely related members of the genus Halorubrum. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain GX71^T represents a novel species of the genus Halorubrum, for which the name Halorubrum salinum sp. nov. is proposed. The type strain is GX71^T (= CGMCC 1.10458^T = JCM 17093^T).     

Haloarchaeobius litoreus sp. nov., isolated from a marine solar saltern

Two extremely halophilic archaeal strains GX1^T and GX60 were isolated from the Gangxi marine solar saltern, China. Cells from the two strains were observed to be rod-shaped and stained Gram-negative, with red-pigmented colonies. Strains GX1^T and GX60 were found to be able to grow at 25–50 °C (optimum 37 °C), at 1.4–4.8 M NaCl (optimum 2.6 M), at pH 5.5–9.5 (optimum pH 7.0) and neither strain required Mg²⁺ for growth. The cells lysed in distilled water and the minimal NaCl concentration to prevent cell-lysis was found to be 8 % (w/v). The major polar lipids of the two strains were identified as phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and three glycolipids chromatographically identical to those of Haloarchaeobius iranensis IBRC-M 10013^T. 16S rRNA gene analysis revealed that each strain had two dissimilar 16S rRNA genes and both strains were phylogenetically related to Hab. iranensis IBRC-M 10013^T (94.9–98.9 % nucleotide identity). The rpoB′ gene similarity between strains GX1^T and GX60, and between these strains and Hab. iranensis IBRC-M 10013^T were found to be 99.6, 96.0 and 95.8 %, respectively. The DNA G + C content of strain GX1^T and GX60 were determined to be 67.7 and 67.8 mol %, respectively. The DNA–DNA hybridization value of strains GX1^T and GX60 was 86 % and the two strains showed low DNA–DNA relatedness with Hab. iranensis IBRC-M 10013^T (38 and 32 %). It was concluded that strain GX1^T (= CGMCC 1.10390^T = JCM 17114^T) and strain GX60 (= CGMCC 1.10389 = JCM 17120) represent a new species of Haloarchaeobius, for which the name Haloarchaeobius litoreus sp. nov. is proposed.     

Kocuria sediminis sp. nov., isolated from a marine sediment sample

A Gram-positive, pinkish-orange pigmented, coccoid strain, FCS-11^T was isolated from a marine sediment sample taken from Kochi fort area, Kerala, India and subjected to polyphasic taxonomic study. The 16S rRNA gene sequence of the strain was determined and the results of 16S rRNA gene sequence analysis showed that the strain FCS-11^T should be assigned to the genus Kocuria. The chemotaxonomic data supported this taxonomic placement i.e. menaquinones MK-7(H₂), MK-8(H₂) and MK-9(H₂); major fatty acids anteiso C15:0 and iso-C15:0 and phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG) as major polar lipids. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed that the strain FCS-11^T belonged to the genus Kocuria and is closely related to Kocuria turfanensis MTCC 10790^T (99.4%) followed by Kocuria polaris MTCC 3702^T (98.2%), Kocuria rosea MTCC 2522^T (98.2%), Kocuria flava MTCC 10971^T (98.2%), Kocuria aegyptia MTCC 10791^T (98.0%), Kocuria himachalensis MTCC 7020^T (97.5%) and Kocuria atrinae MTCC 10972^T (97.1%). However, the DNA–DNA hybridisation values obtained between strain FCS-11^T and other related strains were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was 60.7 mol%. The phenotypic and genotypic data showed that the strain FCS-11^T merits the recognition as a representative of a novel species of the genus Kocuria. It is proposed that the isolate should be classified in the genus Kocuria as a novel species, Kocuria sediminis sp. nov. The type strain is FCS-11^T (= MTCC 10969^T = JCM 17929^T).