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1.
Mykytczuk NC Trevors JT Foote SJ Leduc LG Ferroni GD Twine SM 《Antonie van Leeuwenhoek》2011,100(2):259-277
Cold tolerant strains of Acidithiobacillus ferrooxidans play a role in metal leaching and acid mine drainage (AMD) production in northern latitude/boreal mining environments. In
this study we used a proteomics and bioinformatics approach to decipher the proteome changes related to sustained growth at
low temperatures to increase our understanding of cold adaptation mechanisms in A. ferrooxidans strains. Changes in protein abundance in response to low temperatures (5 and 15°C) were monitored and protein analyses of
a psychrotrophic strain (D6) versus a mesophilic strain (F1) showed that both strains increased levels of 11 stress-related
and metabolic proteins including survival protein SurA, trigger factor Tig, and AhpC-Tsa antioxidant proteins. However, a
unique set of changes in the proteome of psychrotrophic strain D6 were observed. In particular, the importance of protein
fate, membrane transport and structure for psychrotrophic growth were evident with increases in numerous chaperone and transport
proteins including GroEL, SecB, ABC transporters and a capsule polysaccharide export protein. We also observed that low temperature
iron oxidation coincides with a relative increase in the key iron metabolism protein rusticyanin, which was more highly expressed
in strain D6 than in strain F1 at colder growth temperatures. We demonstrate that the psychrotrophic strain uses a global
stress response and cold-active metabolism which permit growth of A. ferrooxidans in the extreme AMD environment in colder climates. 相似文献
2.
Lee Chang KJ Dunstan GA Abell GC Clementson LA Blackburn SI Nichols PD Koutoulis A 《Applied microbiology and biotechnology》2012,93(5):2215-2231
Heterotrophic growth of thraustochytrids has potential in co-producing a feedstock for biodiesel and long-chain (LC, ≥C20) omega-3 oils. Biodiscovery of thraustochytrids from Tasmania (temperate) and Queensland (tropical), Australia, covered a
biogeographic range of habitats including fresh, brackish, and marine waters. A total of 36 thraustochytrid strains were isolated
and separated into eight chemotaxonomic groups (A–H) based on fatty acid (FA) and sterol composition which clustered closely
with four different genera obtained by 18S rDNA molecular identification. Differences in the relative proportions (%FA) of
long-chain C20, C22, omega-3, and omega-6 polyunsaturated fatty acids (PUFA), including docosahexaenoic acid (DHA), docosapentaenoic acid, arachidonic
acid, eicosapentaenoic acid (EPA), and saturated FA, as well as the presence of odd-chain PUFA (OC-PUFA) were the major factors
influencing the separation of these groups. OC-PUFA were detected in temperate strains of groups A, B, and C (Schizochytrium and Thraustochytrium). Group D (Ulkenia) had high omega-3 LC-PUFA (53% total fatty acids (TFA)) and EPA up to 11.2% TFA. Strains from groups E and F (Aurantiochytrium) contained DHA levels of 50–61% TFA after 7 days of growth in basal medium at 20 °C. Groups G and H (Aurantiochytrium) strains had high levels of 15:0 (20–30% TFA) and the sum of saturated FA was in the range of 32–51%. β,β-Carotene, canthaxanthin,
and astaxanthin were identified in selected strains. Phylogenetic and chemotaxonomic groupings demonstrated similar patterns
for the majority of strains. Our results demonstrate the potential of these new Australian thraustochytrids for the production
of biodiesel in addition to omega-3 LC-PUFA-rich oils. 相似文献
3.
Siristova L Luhovy R Sigler K Rezanka T 《Extremophiles : life under extreme conditions》2011,15(3):423-429
Two thermophilic strains belonging to Geobacillus stearothermophilus and Meiothermus ruber, which naturally do not synthesize ω-alicyclic fatty acids (ω-FAs) were cultivated with cyclopropyl, cyclobutyl, cyclopentyl
and cyclohexyl carboxylic acids. Gas chromatography–mass spectrometry analysis of fatty acid methyl and picolinyl esters showed
that both strains are able to synthesize ω-FAs when cultivated with the appropriate precursor. The incorporation of cyclic
acids influenced the whole FA composition as well as membrane fluidity. Membrane fluidity of intact cells was studied by measuring
the fluorescence polarisation of the probe l,6-diphenyl-1,3,5-hexatriene incorporated into membrane lipid bilayers. Cytoplasmic
membrane became more fluid with increasing content of ω-FAs. This is caused by considerable changes in lipid packing within
the membrane induced by the presence of ω-FAs not found in the natural environment of Geobacillus and Meiothermus strains. 相似文献
4.
Generalized membrane lipid composition determinants of fluidity have been widely investigated, including phospholipid/cholesterol
ratio and unsaturation index. Individual phospholipids differ in their physical characteristics, including their interaction
with cholesterol and level of unsaturation, emphasizing the importance of examining their individual influence on membrane
fluidity. Thus, the purpose of this study was to examine the dominant phospholipids of biological membranes (phosphatidylcholine,
PC; phosphatidylethanolamine, PE; sphingomyelin, SM) through a meta-analysis to assess the validity of an inclusive phospholipid
fluidity index (PFI = PC/(PE + SM)) as a determinant for membrane fluidity (expressed as polarization of fluorescent probe
1,6 diphenyl-1,3,5-hexatriene) in comparison to previous phospholipid ratios (PC/PE and PC/SM). The results demonstrate that
all indices significantly predicted membrane fluidity at 25°C (based on 10–13 data points). In contrast, only PFI approached
significance when predicting membrane fluidity at 37°C (P = 0.10 based on five points). As a result, PFI appears to be the only phospholipid index close to significantly predicting
membrane fluidity at mammalian physiological temperature. Because this meta-analysis only assessed studies using mammalian
membranes, future work should experimentally assess the validity of the PFI utilizing membranes from mammals and a variety
of other species and tissues at their respective physiological temperatures. 相似文献
5.
Qing-Zhong Peng Jun Chen Yu-Qin Zhang Qi-Hui Chen De-Jiao Peng Xiao-Long Cui Wen-Jun Li Yi-Guang Chen 《Antonie van Leeuwenhoek》2009,96(4):645-652
A Gram-positive, endospore-forming, catalase- and oxidase-positive, motile, rod-shaped, aerobic bacterium, designated strain
JSM 079157T, was isolated from surface seawater off the coastline of Naozhou Island in South China Sea. The organism was able to grow
with 1–15% (w/v) total salts (optimum, 4–7%), and at pH 6.0–10.0 (optimum, pH 7.5) and 10–45°C (optimum, 30°C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant menaquinone was MK-7, and the polar lipids
were diphosphatidylglycerol and phosphatidylglycerol. The major cellular fatty acids were anteiso-C15:0 (45.1%) and anteiso-C17:0 (16.2%), and the DNA G + C content was 39.5 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed
that strain JSM 079157T should be assigned to the genus Virgibacillus, being related most closely to the type strains of Virgibacillus litoralis (97.4% sequence similarity), Virgibacillus necropolis (97.3%) and Virgibacillus carmonensis (97.1%). These four strains formed a distinct subcluster in the phylogenetic tree. The levels of DNA–DNA relatedness between
the new isolate and the type strains of V. litoralis, V. necropolis and V. carmonensis were 30.4, 19.3 and 12.6%, respectively. The results of the phylogenetic analysis, combined with DNA–DNA relatedness data,
phenotypic characteristics and chemotaxonomic information, support the suggestion that strain JSM 079157T represents a new species of the genus Virgibacillus, for which the name Virgibacillus zhanjiangensis sp. nov. is proposed. The type strain is JSM 079157T (=DSM 21084T = KCTC 13227T). 相似文献
6.
A new monoamine oxidase type C-like dehydratase gene (MaoC) supplying (R)-3-hydroxyacyl-CoA from the fatty acid oxidation pathway to polyhydroxyalkanoates (PHAs) biosynthetic pathways was identified
from Phytophthora capsici. MaoC was over-expressed in Escherichia coli and the recombinant MaoC was purified. The purified tagged MaoC shows the enoyl-CoA hydratase activity of 58 U/mg towards
crotonyl-CoA. MaoC may not fold properly above 40°C which was revealed by circular dichroism analysis. Crystal of MaoC diffracts
to 2.9 ? in space group P212121, with unit-cell parameters a = 81.5 ?, b = 82.6 ?, c = 124.2 ?, α = β = γ = 90°. 相似文献
7.
Da-Chun Zhuang Yi-Guang Chen Yu-Qin Zhang Shu-Kun Tang Xiao-Lei Wu Zhou-Cai Tan Wen-Jun Li Xiao-Long Cui 《Antonie van Leeuwenhoek》2009,96(3):295-301
A novel Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped, aerobic bacterium, designated strain JSM
078120T, was isolated from sea water collected from a tidal flat of Naozhou Island, South China Sea. Growth occurred with 1–15% (w/v)
total salts (optimum, 2–4%), at pH 6.0–10.0 (optimum, pH 7.5) and at 4–35°C (optimum, 25–30°C). The major cellular fatty acids
were C18:1
ω9c, C16:0, C12:0 3-OH and C16:1
ω7c. The predominant respiratory quinone was ubiquinone Q-9, and the genomic DNA G + C content was 60.6 mol%. Phylogenetic analysis
based on 16S rRNA gene sequences indicated that strain JSM 078120T should be assigned to the genus Marinobacter, being related most closely to the type strains of Marinobacter segnicrescens (sequence similarity 98.2%), Marinobacter bryozoorum (97.9%) and Marinobacter gudaonensis (97.6%). The sequence similarities between the novel isolate and the type strains of other recognized Marinobacter species ranged from 96.7 (with Marinobacter salsuginis) to 93.3% (with Marinobacter litoralis). The levels of DNA–DNA relatedness between strain JSM 078120T and the type strains of M. segnicrescens, M. bryozoorum and M. gudaonensis were 25.3, 20.6 and 18.8%, respectively. The combination of phylogenetic analysis, DNA–DNA relatedness, phenotypic characteristics
and chemotaxonomic data supported the view that strain JSM 078120T represents a novel species of the genus Marinobacter, for which the name Marinobacter zhanjiangensis sp. nov. is proposed. The type strain is JSM 078120T (= CCTCC AB 208029T = DSM 21077T = KCTC 22280T).
The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JSM 078120T is FJ425903. 相似文献
8.
M. V. Zaicnikova Yu. Yu. Berestovskaya V. N. Akimov N. A. Kostrikina L. V. Vasilieva 《Microbiology》2011,80(1):101-107
Two novel strains of budding bacteria, Z-0071T and Z-0072, were isolated from dystrophic humified waters formed by xylotrophic fungi in the course of spruce wood degradation.
The cells of both strains are coccoid (0.95–1.80 μm), nonmotile, single or arranged in pairs. The cells have a complex system
of intracellular membranes and are covered with fimbriae and surrounded by a mucous capsule up to 0.3 μm thick. Both strains
are aerobic organoheterotrophic, mesophilic, and acid-tolerant microorganisms that are able to grow under microaerobic conditions.
They utilize N-acetyl-glucosamine, carbohydrates, and lactate as growth substrates. The strains grow in a pH range of 4.0–7.5
with an optimum at 6.0–6.5. The temperature range for growth is 4–30°C, with an optimum at 25–28°C. Strains Z-0071T and Z-0072, inhabitants of dystrophic low-mineral waters, are NaCl-sensitive: the NaCl content in the media above 0.5 g/l
inhibited growth. The main fatty acids of strains Z-0071T and Z-0072 are C16:0, C18:1ω9c, and C18:2ω9c, 12c. The DNA G + C base content is 51.2–51.7 mol %. The sequences of the 16S rRNA gene fragments (1310 bp) of strains Z-0071T and Z-0072 were found to be identical. The obtained sequences showed a 94.3% similarity with the sequences of the type strain
of the most closely related species Singulisphaera acidiphila MOB10≅T. The phenotypic and phylogenetic properties of strains Z-0071T and Z-0072 support classification of these strains within the genus Singulisphaera as a new species Singulisphaera mucilagenosa sp. nov., with the type strain Z-0071T (VKM B-2626). 相似文献
9.
The taxonomic position of strain DFH11T, which was isolated from coastal seawater off Qingdao, People’s Republic of China in 2007, was determined. Strain DFH11T comprised Gram-negative, motile, strictly aerobic spirilli that did not produce catalase. Comparative 16S rRNA gene sequence
analysis revealed that strain DFH11T shared ~97.2, 93.3, 91.8, 91.7 and 91.5% sequence similarities with Oleispira antarctica, Spongiispira norvegica, Bermanella marisrubri, Oceaniserpentilla haliotis and Reinekea aestuarii, respectively. DNA–DNA hybridization experiments indicated that the strain was distinct from its closest phylogenetic neighbour,
O. antarctica. The strain grew optimally in 2–3% (w/v) NaCl, at pH 5.0–10.0 (optimally at pH 7.0) and between 0 and 30°C (optimum growth
temperature 28°C). The strain exhibited a restricted substrate profile, with a preference for aliphatic hydrocarbons, that
is consistent with its closest phylogenetic neighbour O. antarctica. Growth of the isolate at different temperatures affected the cellular fatty acid profile. 28°C cultured cells contained
C16:1ω7c and/or iso-C15:0 2-OH (50.4%) and C16:0 (19.2%) as the major fatty acids. However, the major fatty acids of the cells cultured at 4°C were C16:1ω7c and/or C16:1ω6c (40.2%), C16:0 (17.2%) and C17:1ω8c (10.1%). The G+C content of the genomic DNA was 42.7 mol%. Phylogeny based on 16S rRNA gene sequences together with data
from DNA–DNA hybridization, phenotypic and chemotaxonomic characterization revealed that DFH11T should be classified as a novel species of the genus Oleispira, for which the name Oleispira
lenta sp. nov. is proposed, with the type strain DFH11T (=NCIMB 14529T = LMG 24829T). 相似文献
10.
Qing-Zhong Peng Qing-Jing Peng Yu-Qin Zhang Zhu-Xiang Liu Yong-Xia Wang Wen-Jun Li Xiao-Long Cui Yi-Guang Chen 《Antonie van Leeuwenhoek》2009,96(4):497-504
A moderately halophilic, Gram-positive, catalase- and oxidase-positive, rod-shaped, aerobic bacterium, designated strain JSM
071077T, was isolated from a subterranean brine sample collected from a salt mine in Hunan Province, China. Cells were motile by
means of peritrichous flagella and formed ellipsoidal endospores lying in subterminal swollen sporangia. Strain JSM 071077T was able to grow with 2–25% (w/v) total salts (optimum, 5–10%), at pH 6.0–10.0 (optimum, pH 7.5) and 10–40°C (optimum, 25–30°C).
meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant menaquinone was MK-7, and the major cellular
fatty acids were anteiso-C15:0, anteiso-C17:0 and iso-C15:0. The genomic DNA G+C content was 41.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequence comparisons revealed that
strain JSM 071077T should be assigned to the genus Halobacillus, being related most closely to the type strain of Halobacillus
naozhouensis (98.8% sequence similarity), and the two strains formed a distinct subline in the neighbor-joining, minimum-evolution and
maximum-parsimony phylogenetic trees. The sequence similarities between the novel isolate and the type strains of other recognized
Halobacillus species ranged from 97.6% (with Halobacillus
alkaliphilus) to 95.2% (with Halobacillus kuroshimensis). The results of the phylogenetic analyses, combined with DNA–DNA relatedness data, phenotypic characteristics and chemotaxonomic
information, support that strain JSM 071077T represents a new species of the genus Halobacillus, for which the name Halobacillus hunanensis sp. nov. is proposed. The type strain is JSM 071077T (=DSM 21184T = KCTC 13235T). 相似文献
11.
Heptanol-induced decrease in cardiac gap junctional conductance is mediated by a decrease in the fluidity of membranous cholesterol-rich domains 总被引:7,自引:0,他引:7
E. M. Lars Bastiaanse Habo J. Jongsma Arnoud van der Laarse Brenda R. Takens-Kwak 《The Journal of membrane biology》1993,136(2):135-145
To assess whether alterations in membrane fluidity of neonatal rat heart cells modulate gap junctional conductance (g
j
), we compared the effects of 2mm 1-heptanol and 20 μm 2-(methoxyethoxy)ethyl 8-(cis-2-n-octylcyclopropyl)-octanoate (A2C) in a combined fluorescence anisotropy and electrophysiological study. Both substances decreased fluorescence steady-state
anisotropy (rss), as assessed with the fluorescent probe 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) by 9.6±1.1% (mean
±sem,n=5) and 9.8±0.6% (n=5), respectively, i.e., both substances increased bulk membrane fluidity. Double whole-cell voltage-clamp experiments showed
that 2mm heptanol uncoupled cell pairs completely (n=6), whereas 20 μm A2C, which increased bulk membrane fluidity to the same extent, did not affect coupling at all (n=5).
Since gap junction channels are embedded in relatively cholesterol-rich domains of the membrane, we specifically assessed
the fluidity of the cholesterol-rich domains with dehydroergosterol (DHE). Using DHE, heptanol increased rss by 14.9±3.0% (n=5), i.e., decreased cholesterol domain fluidity, whereas A2C had no effect on rss (−0.4±6.7%,n=5).
Following an increase of cellular “cholesterol” content (by loading the cells with DHE), 2mm heptanol did not uncouple cell pairs completely:g
j
decreased by 80±20% (range 41–95%,n=5). The decrease ing
j
was most probably due to a decrease in the open probability of the gap junction channels, because the unitary conductances
of the channels were not changed nor was the number of channels comprising the gap junction. The sensitivity of non-junctional
membrane channels to heptanol was unaltered in cholesterol-enriched myocytes.
These results indicate that the fluidity of cholesterol-rich domains is of importance to gap junctional coupling, and that
heptanol decreasesg
j
by decreasing the fluidity of cholesterol-rich domains, rather than by increasing the bulk membrane fluidity. 相似文献
12.
Yi-Guang Chen Shu-Kun Tang Yu-Qin Zhang Zhu-Xiang Liu Qi-Hui Chen Jian-Wu He Xiao-Long Cui Wen-Jun Li 《Extremophiles : life under extreme conditions》2010,14(4):397-402
A novel moderately halophilic, alkaliphilic, non-motile, non-sporulating, catalase-positive, oxidase-negative, aerobic, coccus-shaped,
Gram-positive bacterium, designated strain JSM 071043T, was isolated from a subterranean brine sample collected from a salt mine in Hunan Province, China. Growth occurred with
0.5–20% (w/v) NaCl (optimum 5–10%) at pH 6.5–10.5 (optimum pH 8.5) and at 10–40°C (optimum 25–30°C). Good growth also occurred
in the presence of 0.5–20% (w/v) KCl (optimum 5–8%) or 0.5–25% (w/v) MgCl2·6H2O (optimum 5–10%). The peptidoglycan type was A4α (l-Lys–l-Ala–l-Glu) and major cell-wall sugars were tyvelose and mannose. The major cellular fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. Strain JSM 071043T contained MK-9 and MK-8 as the predominant menaquinones and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol
as the major polar lipids. The DNA G + C content was 67.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed
that strain JSM 071043T was a member of the suborder Micrococcineae, and was most closely related to Zhihengliuella halotolerans YIM 70185T (sequence similarity 98.9%) and Zhihengliuella alba YIM 90734T (98.2%), and the three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis,
DNA–DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 071043T represents a novel species of the genus Zhihengliuella, for which the name Z. salsuginis sp. nov. is proposed. The type strain is JSM 071043T (= DSM 21149T = KCTC 19466T). 相似文献
13.
A Gram-negative, facultatively anaerobic, motile by means of single polar flagellum, rod-shaped marine bacterium, designated
strain E414, was isolated from sea water collected from a farming pond rearing marine shrimp Litopenaeus vannamei in Zhanjiang, Guangdong province, PRC. The strain was able to grow in the presence of 0.5–6% (w/v) NaCl (optimally in 3–6%
(w/v) NaCl), between pH 6 and 9 (optimally at pH 7–8), between 15 and 37°C (optimally at 25–30°C). Phylogenetic analysis based
on 16S rRNA gene sequences locate strain E414 in the vicinity of the coralliilyticus clade within the genus Vibrio. DNA–DNA relatedness data and multigene phylogenetic analysis based on the concatenated sequences of four genes (16S rRNA,
rpoA, recA and pyrH) clearly differentiated strain E414 from its closest phylogenetic neighbours. Analysis of phenotypic features, including
enzyme activities and utilization and fermentation of various carbon sources, further revealed discrimination between strain
E414 and phylogenetically related Vibrio species. The major fatty acid components are C16:1ω6c and/or C16:1ω7c (27.4%), C18:1ω7c and/or C18:1ω6c (19.3%) and C16:0 (18.2%). The DNA G+C content of strain E414 was 38.7 mol%. Based on phenotypic, chemotaxonomic, phylogenetic and DNA–DNA
relatedness values, it can be concluded that E414 should be placed in the genus Vibrio as representing a novel species, for which the name Vibrio zhanjiangensis sp. nov. is proposed, with the type strain E414 (=CCTCC AB 2011110T = NBRC 108723T = DSM 24901). 相似文献
14.
Huang HY Chen YG Wang YX Liu JH Tang SK Peng Q Wen ML Yu H Cui XL 《Extremophiles : life under extreme conditions》2008,12(6):829-835
A novel Gram-negative, slightly halophilic, catalase- and oxidase-positive, obligately aerobic bacterium, strain YIM-C248T, was isolated from a sediment sample collected from a salt-lake in the Qaidam Basin in Qinghai, north-west China. Cells were
non-sporulating short rods, occurring singly or as doublets, motile with peritrichous flagella. Growth occurred with 1–15%
(w/v) NaCl [optimum 2–4% (w/v) NaCl], at pH 6.0–10.0 (optimum pH 7.5) and at 4–35°C (optimum 25–30°C). The major cellular
fatty acids were C18:1
ω7c, C12:0 3-OH, cyclo C19:0
ω8c, C16:0 and C16:1. The predominant respiratory quinone was Q-9 and the genomic DNA G + C content was 58.6 mol%. Phylogenetic analysis based
on 16S rRNA gene sequences indicated that strain YIM-C248T should be assigned to the genus Halomonas. The sequence similarities between the isolate and the type strains of members of the genus Halomonas were in the range of 92.5–97.5%. The combination of phylogenetic analysis, DNA–DNA hybridization data, phenotypic characteristics
and chemotaxonomic differences supported the view that strain YIM-C248T represents a new species of the genus Halomonas, for which the name Halomonas sediminis sp. nov. is proposed, with YIM-C248T (=CCTCC AA 207031 = KCTC 22167) as the type strain.
The GenBank/EMBL/DBBJ accession number for the 16S rRNA gene sequence of strain YIM-C248T is EU135707. 相似文献
15.
Mariane Schmidt Anders Priemé Anders Johansen Peter Stougaard 《Extremophiles : life under extreme conditions》2012,16(2):297-305
Three novel Gram-positive, endospore-forming bacteria were isolated from a cold and alkaline environment. Phylogenetic analysis
showed that the strains were almost identical, and that they were related to Natronobacillus azotifigens 24KS-1T (95.8% identity), Paraliobacillus quinghaiensis YIM-C158T (95.1%), Paraliobacillus ryukyuensis O15-7T (94.5%), and Halolactibacillus miurensis M23-1T (93.9%). The isolates produced amylase, α-galactosidase, β-galactosidase, and β-glucuronidase, and showed optimal growth
at pH 10, at 20°C, and at 2–8% (w/v) NaCl. Major fatty acids were C14:0 (10.6–11.6%), anteiso-C15:0 (25.7–32.7%), C16:1
ω11c (12.2–16.0%), and C16:0 (14.0–20.4%). The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol, and meso-diaminopimelic acid was found in the cell-wall peptidoglycan. The G+C content was 38.4%. DNA–DNA hybridization between strain
GCM68T and H. miurensis M23-1T was 32.4%, while hybridization to N. azotifigens 24KS-1T, Amphibacillus tropicus Z-7792T, and Paraliobacillus ryukyuensis O15-7T was below 30%. The phylogenetic analysis and G+C content place strain GCM68T in relation to species belonging to Bacillus rRNA group 1, but phylogenetic and physiologic data combined with chemotaxonomic analyses support our proposal for a new
genus, Alkalilactibacillus, gen. nov., with the novel species Alkalilactibacillus ikkensis, sp. nov. (type strain is GCM68T = DSM 19937 = LMG 24405). 相似文献
16.
C. Fuentes-Grünewald E. Garcés E. Alacid N. Sampedro S. Rossi J. Camp 《Journal of industrial microbiology & biotechnology》2012,39(1):207-216
Two different strains of microalgae, one raphidophyte and one dinoflagellate, were tested under different abiotic conditions
with the goal of enhancing lipid production. Whereas aeration was crucial for biomass production, nitrogen deficiency and
temperature were found to be the main abiotic parameters inducing the high-level cellular accumulation of neutral lipids.
Net neutral lipid production and especially triacylglycerol (TAG) per cell were higher in microalgae (>200% in Alexandrium minutum, and 30% in Heterosigma akashiwo) under treatment conditions (25°C; 330 μM NaNO3) than under control conditions (20°C; 880 μM NaNO3). For both algal species, oil production (free fatty acids plus TAG fraction) was also higher under treatment conditions
(57 mg L−1 in A. minutum and 323 mg L−1 in H. akashiwo). Despite the increased production and accumulation of lipids in microalgae, the different conditions did not significantly
change the fatty acids profiles of the species analyzed. These profiles consisted of saturated fatty acids (SAFA) and polyunsaturated
fatty acids (PUFA) in significant proportions. However, during the stationary phase, the concentrations per cell of some PUFAs,
especially arachidonic acid (C20:4n6), were higher in treated than in control algae. These results suggest that the adjustment
of abiotic parameters is a suitable and one of the cheapest alternatives to obtain sufficient quantities of microalgal biomass,
with high oil content and minimal changes in the fatty acid profile of the strains under consideration. 相似文献
17.
Qin S Yuan B Zhang YJ Bian GK Tamura T Sun BZ Li WJ Jiang JH 《Antonie van Leeuwenhoek》2012,102(2):353-360
A novel Gram-positive, aerobic, rod-shaped and mycelia-producing bacterial strain, designated KLBMP 1050T, was isolated from the stem of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Phylogenetic analysis based on the 16S rRNA gene sequence revealed
that the isolate KLBMP 1050T belonged to the genus Nocardioides, with the highest sequence similarity to Nocardioides albus KCTC 9186T (99.38 %) and Nocardioides luteus KCTC 9575T (99.03 %). However, the DNA–DNA relatedness of isolate KLBMP 1050T to these two type strains were 37.5 ± 3.5 and 33 ± 2.3 %, respectively. Strain KLBMP 1050T grew at the pH range 6–11, temperature range 10–32 °C and with 0–12 % NaCl. The physiological properties of strain KLBMP
1050T differ from those of N. albus KCTC 9186T and N. luteus KCTC 9575T. The cell-wall peptidoglycan contained ll-diaminopimelic acid and MK-8(H4) was the major respiratory quinone. The predominant cellular fatty acid of strain KLBMP 1050T was iso-C16:0 (23.3 %). The total DNA G+C content was 70.1 mol%. On the basis of the phenotypic, chemotaxonomic and phylogenetic data,
strain KLBMP 1050T represents a novel species of the genus Nocardioides, for which the name Nocardioides panzhihuaensis sp. nov. is proposed. The type strain is KLBMP 1050T (= KCTC 19888T = NBRC 108680T). 相似文献
18.
This study attempted to determine the optimal temperature and initial cultivation pH by conducting a series of batch tests
in stirred-tank bioreactor using fructose-producing wastewater as an organic substrate. The bioreactor temperature was controlled
at 35–55°C with an initial pH of 4–8. Hydrogen production efficiency was assessed using specific hydrogen production potential
(SHPP) and the maximum specific hydrogen production rate (SHPRm). Experimental results indicated that temperature and initial pH markedly affected SHPP and SHPRm, volatile fatty acids distribution as well as the ratio of butyrate/acetate (BHu/HAc). Two-fold higher SHPP and SHPRm were obtained at thermophilic condition (55°C) than those at mesophilic condition (35°C). The optimal initial pH was 6 for
hydrogen production with peak values of SHPP of 166.8 ml-H2/g-COD and SHPRm of 26.7 ml-H2/g-VSS-h for fructose-processing wastewater. Molasses-processing wastewater had a higher SHPP (187.0 ml-H2/g-COD) and SHPRm (42.7 ml-H2/gVSS-h) than fructose-processing wastewater at pH 6. The DGGE profiles indicated that molasses-processing wastewater is a
better substrate than fructose-processing wastewater for growth of hydrogen-producing bacteria due to the high staining intensity
of bands. 相似文献
19.
Yi-Guang Chen Jun Chen Qi-Hui Chen Shu-Kun Tang Yu-Qin Zhang Jian-Wu He Wen-Jun Li Yan-Qi Liu 《Antonie van Leeuwenhoek》2010,98(3):395-401
A novel Gram-stain-positive, slightly halophilic, facultatively alkaliphilic, non-motile, non-sporulating, catalase-positive,
oxidase-negative, aerobic bacterium, designated strain JSM 070026T, was isolated from non-saline forest soil in China. Growth occurred with 0–20% (w/v) NaCl (optimum, 2–4%) and at pH 6.0–10.5
(optimum, pH 8.0) and 5–40°C (optimum, 30°C). Good growth also occurred in the presence of 0–28% (w/v) KCl (optimum, 2–5%)
or 0–25% (w/v) MgCl2·6H2O (optimum, 1–4%). The peptidoglycan type was A4α (l-Lys–Gly–l-Glu). Cell-wall sugars contained mannose and xylose. The major cellular fatty acids were anteiso-C15:0 and iso-C15:0. Strain
JSM 070026T contained menaquinone 8 as the major respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol
as the major polar lipids. The DNA G + C content of strain JSM 070026T was 56.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JSM 070026T was a member of the suborder Micrococcineae and most closely related to Yaniella flava YIM 70178T (sequence similarity 99.4%) and Yaniella halotolerans YIM 70085T (97.9%). The three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis, DNA–DNA
relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 070026T represents a novel species of the genus Yaniella, for which the name Yaniella soli sp. nov. is proposed. The type strain is JSM 070026T (=DSM 22211T = KCTC 13527T). 相似文献
20.
To understand the influence of temperature on host–parasitoid interactions as a consequence of climatic change, we studied
development, survival, and fecundity of field and laboratory strains of the Helicoverpa armigera larval endoparasitoid, Campoletis chlorideae at five different temperatures under laboratory conditions. Post-embryonic development period and degree-days required for
completing the life cycle by both the strains decreased by 2.5 and 1.5 folds at 27°C compared to 18°C. Post embryonic development
period showed a negative (r = −0.99, P < 0.001) and the development rate a positive (r = 0.99, P < 0.001) association with an increase in temperature. However, no parasitoid larvae survived in H. armigera larvae reared at 12 and 35°C after parasitization, suggesting that temperatures ≥35°C as a result of global warming will
be lethal for development and survival of immature stages of C. chlorideae. Adult longevity was negatively associated (r = −0.91 to −0.96, P < 0.001) with temperatures between 12 and 35°C. The parasitoid adults stored at 12°C survived for longer period and exhibited
higher fecundity than those kept at 27°C, but the efficiency of parasitism and adult emergence were quite low. Sex ratio of
the progeny at 12°C was highly male-biased than the insects kept at 27°C. Laboratory strain of the parasitoid exhibited better
survival, and the adults lived longer than the field strain at 18°C than at 27°C. Therefore, C. chlorideae adults stored at 18°C could be used for parasitism, while the immature stages should be reared at 27°C for mass production
of the parasitoid for biological control of H. armigera. 相似文献