Reisolation and characterization of Haemophilus influenzae-murium.

Twenty-three Haemophilus influenzae-murium strains were isolated from the nasopharynx of healthy CFLP white mice. Microbiological characterization of the cultures confirmed the taxonomic position of the organisms which had become problematic due to the loss of the original isolates. The type strain proposed, EO1, is available from the Hungarian National Collection of Medical Bacteria, National Institute of Public Health, Budapest as 95001.     

On the regulation of D-ribose metabolism in E. coli B-r. I. Isolation and characterization of D-ribokinaseless and D-ribose permeaseless mutants

Summary A presumed single site mutation designated leu-500, affects both the basal expression and response to the leucine repression signal by the leucine operon of Salmonella typhimurium. The distantly located supX mutation suppresses the leucine auxotrophy imposed by the leu-500 mutation by raising the level of basal expression while maintaining the abnormal regulation. An additional type of suppressor mutation which is closely linked to the leu-500 locus restores essentially normal regulation but maintains the low repressed expression characteristic of the leu-500 strain. The leucine sufficiency of the leu-500 strain with the linked suppressor and the supX leu-500 strains is temperature conditional in that both types require leucine for growth at 42° but not at 37°. These results, which indicate that a single site mutation can simultaneously affect promoter-like and operator-like function, are discussed in terms of DNA superstructure.This investigation was supported by U.S. Public Health Service Research Grant GM-12551 from the National Institute of General Medical Sciences, and is a portion of the work submitted by Lloyd H. Graf in partial fulfillment of the requirements for the hP. D. degree from Duke University. Lloyd H. Graf was the recipient of a predoctoral fellowship award from the National Institute of General Medical Sciences. R. O. Burns is the recipient of a Research Career Development Award from the National Institutes of General Medical Sciences.     

Isolation and identification of newly isolated antagonistic Streptomyces sp. strain AP19-2 producing chromomycins

A new antagonistic strain of actinomycete, designated AP19-2, was isolated from the feces of giant pandas inhabiting the Foping National Nature Reserve in China. Cultural characteristic studies strongly suggested that this strain is a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene of strain AP19-2 evidenced profound similarity (97-99%) with other Streptomyces strains. Two pure active molecules were isolated from a fermentation broth of Streptomyces sp. strain AP19-2 via extraction, concentration, silica gel G column chromatography, and HPLC. The chemical structures of the two related compounds (referred to as chromomycin A2 and chromomycin A3) were established on the basis of their Infrared spectra (IR), High Resolution Electrospray Ionization Mass Spectrometry (HR-ESI-MS), and Nuclear Magnetic Resonance (NMR) data, and by comparison with published data.     

Studies on histoplasmosis I. Comparative virulence of variant and parent strain Histoplasma capsulatum in Hamsters

Summary 1. A variant strain ofHistoplasma capsulatum was isolated from a secondary colony in cultures of tissue from hamsters infected with the parent strain ofHistoplasma. The variant strain was found to differ from the parent strain in colonial morphology, stability of the yeast phase in subculture, and in growth rate.2. Results of virulence testing with these two strains showed the parent strain to be somewhat more virulent than the variant strain as measured by survival time and slope of the death rate curve over a 19 day period.3. Nevertheless, in view of the more rapid growth rate of the variant and its probable antigenic variation from the parent strain, the development of such a variant is viewed as an increased hazard to the host, particularly in a longer term infection.4. The repeated isolation of a variant strain ofHistoplasma suggests that strain variation may play a significant role in the outcome of naturally acquired infections.This work was initiated at the State University of New York, Downstate Medical Center, Brooklyn, N. Y., and supported in part by funds ((#12-1081) from the National Fund for Medical Education, grant # 12-1054.     

Campylobacter troglodytis sp. nov., isolated from feces of human-habituated wild chimpanzees (Pan troglodytes schweinfurthii) in Tanzania

The transmission of simian immunodeficiency and Ebola viruses to humans in recent years has heightened awareness of the public health significance of zoonotic diseases of primate origin, particularly from chimpanzees. In this study, we analyzed 71 fecal samples collected from 2 different wild chimpanzee (Pan troglodytes) populations with different histories in relation to their proximity to humans. Campylobacter spp. were detected by culture in 19/56 (34%) group 1 (human habituated for research and tourism purposes at Mahale Mountains National Park) and 0/15 (0%) group 2 (not human habituated but propagated from an introduced population released from captivity over 30 years ago at Rubondo Island National Park) chimpanzees, respectively. Using 16S rRNA gene sequencing, all isolates were virtually identical (at most a single base difference), and the chimpanzee isolates were most closely related to Campylobacter helveticus and Campylobacter upsaliensis (94.7% and 95.9% similarity, respectively). Whole-cell protein profiling, amplified fragment length polymorphism analysis of genomic DNA, hsp60 sequence analysis, and determination of the mol% G+C content revealed two subgroups among the chimpanzee isolates. DNA-DNA hybridization experiments confirmed that both subgroups represented distinct genomic species. In the absence of differential biochemical characteristics and morphology and identical 16S rRNA gene sequences, we propose to classify all isolates into a single novel nomenspecies, Campylobacter troglodytis, with strain MIT 05-9149 as the type strain; strain MIT 05-9157 is suggested as the reference strain for the second C. troglodytis genomovar. Further studies are required to determine whether the organism is pathogenic to chimpanzees and whether this novel Campylobacter colonizes humans and causes enteric disease.     

Phylogenetic assessment of culture collection strains of Thiobacillus thioparus, and definitive 16S rRNA gene sequences for T. thioparus, T. denitrificans, and Halothiobacillus neapolitanus

The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by different culture collections have been compared. A definitive sequence for the reference type strain (Starkey; ATCC 8158^T) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, confirming their sustained identity after passage through different laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539^T) was determined and used to confirm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitrificans indicated that the sequence for the type strain (NCIMB 9548^T) should always be used as the reference sequence for new and existing isolates.     

Bullera hoabinhensis sp. nov., a new ballistoconidiogenous yeast isolated from a plant leaf collected in Vietnam

VY-68, a ballistoconidiogenous yeast strain, isolated from a plant leaf at Cuc Phuong National Park of Ninh Binh Province, Vietnam, was assigned to the genus Bullera based on morphological and chemotaxonomical characteristics. Based on the sequence analyses of 18S rDNA, D1/D2 region of 26S rDNA, and internal transcribed spacer regions (ITS), VY-68 was phylogenetically closely related to Bullera pseudoalba and Cryptococcus cellulolyticus. DNA-DNA reassociation experiments among VY-68, B. pseudoalba and C. cellulolyticus revealed that strain VY-68 is a distinct species, and the latter two are conspecific. Bullera hoabinhensis is proposed for VY-68.     

Cryopreservation of a water-bloom forming cyanobacterium, Microcystis aeruginosa f. aeruginosa

A method for the Cryopreservation of Microcystis aeruginosa f. aeruginosa is described. For the five strains tested, dimethyl sulfoxide (DMSO) (3% v/v) was the only effective cryoprotectant for freezing to, and thawing from -196°C and allowed the successful recovery (>50%) of all the strains. The viability of frozen material was independent of the period of storage in liquid nitrogen. The strain NIES-44 (National Institute for Environmental Studies) had a recovery level of greater than 90% at 3–10% (v/v) DMSO in both two step and rapid cooling methods. The other three strains, NIES-87, 88 and 89 had greater than 60% of viability after freeze/thawing in presence of both 3% and 5% DMSO concentrations. On the other hand, the strain NIES-90 showed approximately 50% of viability in only 3% DMSO solution after two step cooling to and thawing from -196°C. This strain was damaged by greater than 4% DMSO and by rapid cooling to -196°C. It was found that cold shock injury and the cytotoxicity of DMSO were different at a strain level.     

Development and characterization of the IOR/Hab inbred mouse strain

The IOR/Hab inbred mouse strain, developed and maintained in the National Institute of Oncology and Radiobiology, is the first inbred strain to be developed in Cuba. It has a high fertility in this tropical climate. A number of physiological characteristics such as longevity, haematological characteristics, and growth are reported. Other experiments and results concerning spontaneous tumour frequency suggest that the strain is well adapted to standard environmental conditions, and could be useful for biomedical research.     

Four new species of Kockovaella isolated from plant leaves collected in Vietnam

Five ballistoconidiogenous yeast strains, isolated from plant leaves at Cuc Phuong National Forest of Ninh Binh, Vietnam, were assigned to the genus Kockovaella based on morphological and chemotaxonomical characteristics. They represent four new species based on analyses of 18S rDNA sequence, sequences of internal transcribed spacer regions, and DNA-DNA reassociation experiments. Four new species, Kockovaella calophylli (1 strain), Kockovaella cucphuongensis (2 strains), Kockovaella litseae (1 strain), and Kockovaella vietnamensis (1 strain) are proposed for these strains.     

Ring-like nucleoid does not play a key role in radioresistance of Deinococcus radiodurans

The conclusion based on transmission electron microscopy, “the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance”, has instigated lots of debates. In this study, according to the previous research of Pprl’s crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. radiodurans R1 strain, pprf function-deficient mutant (YR1), and pprl function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence microscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells exhibit the tightly packed ring-like morphology, while the pprl function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprl completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprl partly function-complementary strain YR1002’s nucleiods exhibit about 60% ring-like structure; (3) a Pprl C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensitive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance. Supported by the National Basic Research Program of China (Grant No. 2004CB19604), the National Natural Science Foundation of China (Grant No. 30330020), and the National Science fund for Distinguished Young Scholars (Grant No. 30425038)     

An alkaliphilic and xylanolytic strain of actinomycetes <Emphasis Type="Italic">Kocuria</Emphasis> sp. RM1 isolated from extremely alkaline bauxite residue sites

We have isolated and characterized a xylanolytic actinomycete strain (RM1) from the extremely alkaline bauxite residue obtained from National Aluminum Company Ltd., Damanjodi, India. The phenotypic features and complete sequence of 16S rRNA revealed that this strain belong the genus Kocuria and showed 98% sequence similarity with Kocuria aegyptia. The RM1 strain was able to grow at pH 10.5 in buffered and unbuffered media and utilize 40 different carbon substrates. The RM1 strain under optimal conditions produced extracellular xylanase at 311 U/ml. The xylanase produced by RM1 showed a wide range of temperature (30–85°C) and pH (4.5–9) tolerance by retaining 90% of its activity. This is the first report of isolation of actinomycetes, Kocuria sp., which produces high amount of xylanase, from bauxite residue and offers a new source of xylanase-producing strains.     

Vulcaniibacterium tengchongense gen. nov., sp. nov. isolated from a geothermally heated soil sample, and reclassification of Lysobacter thermophilus Wei et al. 2012 as Vulcaniibacterium thermophilum comb. nov.

A thermotolerant Gram-staining negative and aerobic bacterium, designated strain YIM 77520^T, was isolated from a geothermally heated soil sample collected at Rehai National Park, Tengchong, Yunnan Province, South-West China. Cells of the strain were found to be rod-shaped and colonies were light beige and circular. The strain was found to grow in the presence of 0–2 % (w/v) total salts (optimum, 0 %), at pH 6.0–8.0 (optimum, pH 7.0) and 25–55 °C (optimum, 45 °C). The only quinone detected was Q-8 and the genomic DNA G+C content was determined to be 66.9 mol%. The major fatty acids (>10 %) were identified as iso-C_16:0 and iso-C_15:0. The phospholipids were found to consist of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, five unknown phospholipids and three aminophospholipids. Based on the 16S rRNA gene sequence analysis, strain YIM 77520^T was found to form a cluster with Lysobacter thermophilus YIM 77875^T and showed the highest 16S rRNA gene sequence similarity to L. thermophilus YIM 77875^T (96.0 %). These two strains formed a distinct lineage of the family ‘Xanthomonadaceae’. On the basis of the morphological and chemotaxonomic characteristics, as well as genotypic data, a new genus, Vulcaniibacterium gen. nov. is proposed with Vulcaniibacterium tengchongense sp. nov. as the type species. The type strain of V. tengchongense sp. nov. is strain YIM 77520^T (=DSM 25623^T = CCTCC AB 2011152^T). Furthermore we propose that L. thermophilus Wei et al. 2012 is reclassified in the new genus as Vulcaniibacterium thermophilum comb. nov. (type strain YIM 77875^T = CCTCC AB 2012064^T = KCTC 32020^T) based on polyphasic data.     

Bacillus methanolicus sp. nov., a new species of thermotolerant, methanol-utilizing, endospore-forming bacteria.

The generic position of 14 strains of gram-positive bacteria able to use methanol as a growth substrate was determined. All are obligately aerobic, thermotolerant organisms that are able to grow at temperatures of 35 to 60 degrees C. Nine of the strains produce oval spores at a subterminal-to-central position in slightly swollen rod-shaped cells. DNA-DNA hybridization studies, 5S rRNA sequence analysis, and physiological characteristics revealed that all 14 strains cluster as a well-defined group and form a distinct new genospecies. Analysis of the 16S and 5S rRNA sequences indicated that this new species is distinct from Bacillus brevis but closely related to B. firmus and B. azotoformans. The name proposed for this new species is B. methanolicus. The type strain, PB1, has been deposited in the National Collection of Industrial and Marine Bacteria as NCIMB 13113.     

Mixed infection with type 2 poliomyelitis virus and Columbia SK group virus in man; an attempt to explain any relation of viruses of the Columbia SK group to human poliomyelitis

Summary Two virus strains isolated from stools of poliomyelitis patients were apparently a mixture of a type 2 strain of poliomyelitis virus, and of a strain of the Columbia SK group of viruses. Both components of the E.S. strain could be separated by neutralization of second passage cynomolgus monkey cord with either Lansing or Columbia SK hyperimmune serum. A similar technique with the 19th monkey passage of the A.K. strain failed to separate the components of this strain, which is suggested to be due to interference. Under experimental conditions, the murine A.K. strain was shown to interfere with the simian A.K. strain. Similarly, the original Columbia SK virus interfered with the Aycock strain of type 2 poliomyelitis virus. No interference was observed between the murine A.K. strain and types 1 and 3 poliomyelitis virus. Aided with a grant from the National Health Research Council T.N.O., The Hague, and from the Dr Simon Baruch Foundation, New York. W. H. O. Fellow, on leave of absence from the Université Libre de Bruxelles.     

Some ring-trap mutants of the fungusDactylella brochopaga drechsler

Mutagenesis with nitrosoguanidine yielded two classes of ring trap mutants in the predacious HyphomyceteDactylella brochopaga: strains which could make no traps and those with a proportion of giant, functional traps. A third strain, derived from a trapless strain made abnormally small functional traps. The giant traps are described, together with developmental abnormalities they sometimes display. The characteristics of the chief mutant strains are discussed.This research was supported by a grant from the National Research Council of Canada which is gratefully acknowledged     

马乳酒样乳杆菌马乳酒样亚种及其研究进展

马乳酒样乳杆菌(Lactobacillus kefiranofaciens)是一类革兰氏阳性乳杆菌,其来源广泛,功能多样,安全性好.2020年12月国家卫健委批准马乳酒样乳杆菌马乳酒样亚种作为我国新食品原料.本文主要综述国内外马乳酒样乳杆菌和马乳酒样乳杆菌马乳酒样亚种的菌种形态学和基因组特性、益生功能、主要价值和发展前...