共查询到20条相似文献,搜索用时 24 毫秒
1.
Ha Na Seo Bo Young Jeon Hung Thuan Tran Dae Hee Ahn Doo Hyun Park 《Biotechnology and Bioprocess Engineering》2008,13(2):224-231
Saccharomyces sp. SK0704 (further defined as SK0704) isolated from long-term-ripening kimchi was identified by a biochemical method with
an API kit; its physiology was found to be very similar to that of S. cerevisiae ATCC 26603 (further defined as ATCC 26603), except in terms of starch utilization. SK0704 did not excrete extracellular glucoamylase,
but utilized starch as a sole carbon source under only aerobic conditions. Crude enzyme excreted from SK0704 catalyzed the
saccharification of starch to glucose, but ATCC 26603 did not. The PCR product obtained using the chromosomal DNA of SK0704
and the primers designed on the basis of the extracellular glucoamylase-coding gene of S. diastaticus was homologous with the intracellular sporulation-specific glucoamylase of S. cerevisiae. SDS-PAGE pattern of soluble protein extracted from yeast cells grown on glucose was greatly different from that on starch.
From these results, we proposed that the SK0704 may have a specific physiological function for starch catabolism such as membrane
transport system and intracellular sac-charification of starch. 相似文献
2.
Functional expression of lipase from Burkholderia sp. C20 (Lip) in various cellular compartments of Escherichia coli was explored. The poor expression in the cytoplasm of E. coli was improved by several strategies, including coexpression of the cytoplasmic chaperone GroEL/ES, using a mutant E. coli host strain with an oxidative cytoplasm, and protein fusion technology. Fusing Lip with the N-terminal peptide tags of T7PK,
DsbA, and DsbC was effective in enhancing the solubility and biological activity. Non-fused Lip or Lip fusions heterologously
expressed in the periplasm of E. coli formed insoluble aggregates with a minimum activity. Biologically active and intact Lip was obtained upon the secretion into
the extracellular medium using the native signal peptide and the expression performance was further improved by coexpression
of the periplasmic chaperon Skp. The extracellular expression was even more effective when Lip was secreted as a Lip–HlyA
fusion via the α-hemolysin transporter. Finally, Lip could be functionally displayed on the E. coli cell surface when fused with the carrier EstA. 相似文献
3.
Xin Li Hui-Ying Yu Yi-Feng Lin Hong-Mei Teng Lei Du Guo-Gang Ma 《Biotechnology letters》2010,32(10):1487-1495
The morphological effects of CF66I, an antifungal compound produced by Burkholderia cepacia, on growing hyphae of Fusarium oxysporum were studied by fluorescence microscopy (FM) and transmission electron microscopy (TEM). At 20 μg/ml, CF66I strongly inhibited
growth and induced significant changes of the hyphal morphology. These changes included swelling of hyphae with considerable
thickening cell wall and abnormal chitin deposition, which was indicative of the alterations in cell wall structure. Furthermore,
fluorescein diacetate (FDA) staining indicated the loss of intracellular esterase activity. CF66I probably inhibits fungal
growth by interfering with the cell metabolic pathways. At 120 μg/ml, CF66I killed F. oxysporum (accompanied by propidium iodide permeation, intracellular cytoplasm leakage and crushing of hyphal tips), probably by direct
damage to the cell membrane. Thus, there are two different antifungal mechanisms of CF66I, depending on its concentration,
and further studies on this compound might be useful for us to develop a new class of antifungal agents. 相似文献
4.
C. K. Deepa Syed G. Dastager Ashok Pandey 《World journal of microbiology & biotechnology》2010,26(12):2277-2283
A Gram-positive rod-shaped bacterium isolated on nutrient agar plates incubated at 28 ± 2°C. The identity of the bacterium
was confirmed by sequencing of the 16S rRNA gene and it reveals that it shares highest similarity with Bacillus thioparus CECT 7196T (99.08%). It was capable of growing at temperatures ranging from 4 to 40°C, but optimum growth was observed at 28 ± 2°C.
Strain NII-0902 is endowed with multiple plant growth promotion attributes such as phosphate solubilization, Indole acetic
acid (IAA), siderophore and HCN production, which were expressed differentially at sub-optimal temperatures (5–40°C). It was
able to solubilize phosphate (17.7 μg ml−1), and produce IAA (139.7 μg ml−1) at 28 ± 2°C. Qualitative detection of siderophore production and HCN were also observed. At 5°C it was found to express
all the plant growth promotion attributes except HCN production. The ability to colonize roots is a sine qua non condition
for a rhizobacteria to be considered a true plant growth-promoting rhizobacteria (PGPR). Bacillus sp. NII-0902 has a potential ability to colonize roots visualized by transparency, bacterial growth (turbid, milky and narrow
zone) along and around roots and truly supported by scanning electron micrograph. Hence, it is proposed that, Bacillus thioparus sp. NII-0902 could be deployed as an inoculant to attain the desired results of bacterization. 相似文献
5.
Moslem Papizadeh Mohammad Roayaei Ardakani Gholamhossein Ebrahimipour Hossein Motamedi 《World journal of microbiology & biotechnology》2010,26(7):1195-1200
Oil-polluted soils were sampled from National Iranian South Oil Company (NISOC) for isolation and screening of C–S and not
C–C targeted Dibenzothiophene (DBT) degrading microorganisms. Microbacterium sp. NISOC-06, a C–S targeted DBT degrading bacterium, was selected and its desulfurization ability was studied in aqueous phase and water-gasoline
biphasic systems. The 16srRNA gene was amplified using universal eubacteria-specific primers, PCR product was sequenced and
the sequence of nearly 1,500 bp 16srDNA was studied. Based on Gas Chromatography results Microbacterium sp. NISOC-06 utilized 94.8% of 1 mM DBT during the 2 weeks of incubation. UV Spectrophotometry and biomass production measurements showed
that the Microbacterium sp. NISOC-06 was not able to utilize DBT as a carbon source. There was no accumulation of phenolic compounds as Gibb’s assay showed. Biomass
production in a biphasic system for which DBT-enriched gasoline was used as the sulfur source indicated the capability of
Microbacterium sp. NISOC-06 to desulfurize gasoline. 相似文献
6.
The isolate from urine of a dog with cystitis was molecularly identified Candida tropicalis and its minimum inhibitory concentration (MIC) was determined by a microdilution method. The 25S ribosomal DNA sequence analysis
indicated that the clinical isolate was essentially identical to that of C. tropicalis and distinct from other Candida species. The MIC50 and the MIC90 of fluconazole (FLZ) for the clinical isolate of C. tropicalis was 6.25 and 25 μg/ml, respectively, indicating that susceptibility of the clinical isolate of C. tropicalis to FLZ was less than for other strains of C. tropicalis as well as C. albicans. The molecular analysis as presented in this study assisted the diagnosis of candidiasis by identifying the yeasts in urine
samples within 2 days. The patient dog, a 10-year-old male Shih Tzu dog (7.0 kg) referred for examination of cystitis was
successfully treated with itraconazole. 相似文献
7.
8.
Domínguez-Bocanegra AR Ponce-Noyola T Torres-Muñoz JA 《Applied microbiology and biotechnology》2007,75(4):783-791
Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) and Haematococcus pluvialis are known as the major prominent microorganisms able to synthesize astaxanthin natural pigment. Important research efforts
have been made to determine optimal conditions for astaxanthin synthesis. When the focus is on astaxanthin production, the
maximal reported value of 9.2 mg/g cell is obtained within H. pluvialis grown on BAR medium, under continuous illumination (345 μmol photon m−2 s−1) and without aeration. Whereas fermentation by mutated R1 yeast grown on coconut milk produced 1,850 μg/g yeast. However,
when looking at astaxanthin productivity, the picture is slightly different. The figures obtained with P. rhodozyma are rather similar to those of H. pluvialis. Maximal reported values are 170 μg/g yeast per day with a wild yeast strain and 370 μg/g yeast per day with mutated R1 yeast.
In the case of H. pluvialis, maximal values ranged from 290 to 428 μg/g cell per day depending on the media (BG-11 or BAR), light intensity (177 μmol
photon m−2 s−1), aeration, etc. The main aim of this work was to examine how astaxanthin synthesis, by P. rhodozyma and H. pluvialis, could be compared. The study is based on previous works by the authors where pigment productions have been reported. 相似文献
9.
A bacterium, which was observed in all cultivations of Microcystis sp., was isolated and designated as Rhodococcus sp. KWR2. The growth of bloom-forming cyanobacteria, including four strains of Microcystis aeruginosa and Anabaena variabilis, was suppressed by up to 75–88% by 2% (v/v) culture broth of KWR2 after 5 days. But KWR2 did not inhibit eukaryotic algae,
Chlorella vulgaris and Scenedesmus sp. An extracellular algicidal substance produced by KWR2 showed a cyanobactericidal activity of 94% and was water-soluble
with a molecular weight of lower than 8 kDa. 相似文献
10.
Autolysis is an important physiological process found in fungal cultivation. However, there is hitherto no report on the autolysis
of Pleurotus tuber-regium. We have investigated the enzymes secreted by temperature-induced (40°C as treatment versus 10°C as control) autolysis of
the mycelium of P. tuber-regium grown in submerged cultivation. A comparison between the intracellular proteins (inside the mycelium) and the extracellular
proteins (in the culture medium) of the treatment and control by proteomic analysis involving 2D PAGE and MALDI–TOF–MS was
made. Twenty-two up-regulated protein spots were detected and eight proteins were identified. They included proteasome which
participates in the ubiquitin–proteasome pathway; β-1,3-glucanosyltransferase and tubulin which are involved in the renewal
and repair of cell wall; protease and endoglucanase which promote the natural degradation of cell wall and cytoplasm; 14-3-3
protein which takes part in cell signal transduction; and two putative proteins presumably relate to the autolysis process.
These identified proteins suggest partially the metabolic processes of the autolysis in the P. tuber-regium mycelium. 相似文献
11.
Forty-six Rhizobium isolates from legume root and stem nodules were examined for their phosphate-solubilizing ability on Pikovskaya’s agar medium.
Rhizobium isolates from root nodules of Cassia absus, Vigna trilobata and three strains from Sesbania sesban showed zone of tricalcium phosphate (TCP) solubilization. The isolate from C. absus showed maximum solubilization (620 μg/ml) after 12 d of incubation, while the Rhizobium sp. strain 26 (from S. sesban) showed the least amount (150 μg/ml) of phosphate solubilization. Among the carbon sources tested for their ability to solubilize
TCP, maximum solubilization (620 μg/ml) was observed in glucose by Rhizobium isolate from C. absus. Phosphate solubilization increased with increase in glucose concentration steeply up to 2% and slowly
above this concentration in four isolates. Among the nitrogen sources tested, maximum solubilization (620 μg/ml) was observed
in ammonium sulphate by Rhizobium isolate from C. absus. 相似文献
12.
Balasubramanian Radhakrishnan Radha Prasanna Pranita Jaiswal Saswati Nayak Prem Dureja 《Biologia》2009,64(5):881-889
An investigation was undertaken to evaluate a set of cyanobacterial strains in terms of production of biocidal compounds exhibiting
allelochemical and fungicidal properties. Two cyanobacterial strains — Anabaena sp. and Calothrix sp. were selected for further investigation, on the basis of their larger inhibition zones on the lawn of Synechocystis and Synechococcus sp. and two phytopathogenic fungi — Rhizoctonia bataticola and Pythium debaryanum. The diameter of the inhibition zone was largest when extracellular filtrates of the two cultures incubated at high light
intensity (90–100 μmol photons m−2 s−1) and temperature (40 ± 2 °C) or grown in medium containing two-folds higher P (1.4 mg/L, as compared to 0.7 mg/L in BG 11
medium) were taken. A pH of 8 was the most optimal for both strains, in terms of growth and biocidal activity. Partial purification
of ethyl acetate extract using TLC, followed by GLC revealed a single peak. This study highlights the importance of environmental
factors in aggravating or reducing the toxic effects of these harmful cyanobacteria and their potential as a biocontrol agent. 相似文献
13.
Jin Zhou Ju Chu Yong-Hong Wang Si-Liang Zhang Ying-Ping Zhuang Zhong-Yi Yuan 《World journal of microbiology & biotechnology》2008,24(6):789-796
An intracellular S-adenosylmethionine synthetase (SAM-s) was purified from the fermentation broth of Pichia pastoris GS115 by a sequence chromatography column. It was purified to apparent homogeneity by (NH4)2SO4 fractionation (30–60%), anion exchange, hydrophobic interaction, anion exchange and gel filtration chromatography. HPLC showed
the purity of purified SAM-s was 91.2%. The enzyme was purified up to 49.5-fold with a final yield of 20.3%. The molecular
weight of the homogeneous enzyme was 43.6 KDa, as determined by electro-spray ionization mass spectrometry (ESI-MS). Its isoelectric
point was approximately 4.7, indicating an acidic character. The optimum pH and temperature for the enzyme reaction were 8.5
and 35 °C, respectively. The enzyme was stable at pH 7.0–9.0 and was easy to inactivate in acid solution (pH ≤ 5.0). The temperature
stability was up to 45 °C. Metal ions, such as, Mn2+ and K+ at the concentration of 5 mM had a slight activation effect on the enzyme activity and the Mg2+ activated the enzyme significantly. The enzyme activity was strongly inhibited by heavy metal ions (Cu2+ and Ag2+) and EDTA. The purified enzyme from the transformed Pichia pastoris synthesized S-adenosylmethionine (SAM) from ATP and l-methionine in vitro with a K
m of 120 and 330 μM and V
max of 8.1 and 23.2 μmol/mg/min for l-methionine and ATP, respectively. 相似文献
14.
Martin Bačkor Jozef Kováčik Alexander Dzubaj Miriam Bačkorová 《Plant Growth Regulation》2009,58(3):279-286
Peltigera rufescens (Weis) Humb. with a prokaryotic photobiont Nostoc sp. and Cladina arbuscula subsp. mitis (Sandst.) Ruoss with a eukaryotic photobiont Trebouxia sp. were studied to determine the copper sensitivity of lichens with different algal symbionts. Samples growing on historic
copper mine-spoil heaps at Ľubietová–Podlipa, Slovakia were assessed for physiological parameters, including total and intracellular
uptake of copper, assimilation pigmentation, activity of photosystem II, ergosterol levels, thiobarbituric acid reactive substances
and water-soluble protein content. Our results indicate that P. rufescens was more sensitive to copper exposure than C. arbuscula subsp. mitis. 相似文献
15.
Hartung de Capriles C Mata-Essayag S Pérez C Colella MT Roselló A Olaizola C Abate SM 《Mycopathologia》2005,160(3):227-234
Over the past decades there has been a significant increase in fungal infections caused by Candida species, and continues to be common in immunocompromised individuals infected with the human immunodeficiency virus (HIV).
Although Candida albicans remains the fungal species most frequently isolated as an opportunistic oral pathogen, other non-albicans are often identified in this cohort of patients, including C. dubliniensis. This yeast is closely related to and shares many phenotypic characteristics with C. albicans. Colonies of these two species appear morphologically identical when not grown on special media. The shared phenotypic characteristics
of C. dubliniensis and C. albicans suggest that many C. dubliniensis isolates may have been misidentified as C. albicans in the past. The present studies aim is to recover and identify C. dubliniensis, and presumptive clinical C. albicans, from the oral cavities of HIV-seropositive individuals, comparing conventional media to obtain a simple, low-cost and reliable
identification system for C. dubliniensis. A total of 16 isolates (3,98%) had been obtained from 402 HIV infected individuals with recurrent oropharyngitis and were
identified as C. dubliniensis. Out of these C. dubliniensis isolates 19% were resistant, with MICs above 64 μg/ml to fluconazole. This constitutes, to the authors knowledge the first
recovery of this organism in Venezuela. 相似文献
16.
With the growing interest in using surfactants to improve microbial cell performance for whole-cell biocatalysis and bioremediation,
understanding the interactions between surfactants and bacteria is of great importance. By using cyanine fluorescent protein
(CFP) and bacterial luciferase (LUX) as dual bioreporters, the effects of n-dodecyltrimethylammonium bromide (DTAB) on the whole cells and intracellular proteins in Pseudomonas putida cultures were quantitatively and systematically studied. The dual reporter system was shown to be a useful indicator to assess
the effect of DTAB treatment on whole-cell metabolic activity, membrane permeability, and cellular enzyme activity. CFP was
useful to assess the leakage of intracellular enzymes and the lysis of cells and was able to reflect the activities of most
cellular enzymes, while LUX reflected the permeability of cell membranes and cellular metabolic activity. The validity of
CFP–LUX dual bioreporters was further confirmed by detecting changes in extracellular proteins, membrane potential, oxygen
consumption rate (OUR), and intracellular catechol 2,3-dioxygenase (C23O) activity with the addition of DTAB. The dual LUX–CFP
bioreporter is a useful tool for analyzing the surfactant–bacterium interactions for biotechnological applications. 相似文献
17.
Abhishek Tripathi Neeta Sharma Vinay Sharma 《World journal of microbiology & biotechnology》2009,25(3):503-512
Hyptis
suaveolens L. (Poit.) essential oil was tested in vitro on the growth and morphogenesis of Fusarium oxysporum f.sp. gladioli (Massey) Snyder & Hansen, which causes Fusarium corm rot and yellows in various susceptible cultivars of gladiolus. The fungitoxicity of the oil was measured by percentage radial growth inhibition using the poisoned food technique (PF)
and volatile activity assay (VA). The mycelial growth of the test fungus was completely inhibited at 0.998 and 0.748 μg ml−1 concentration of oil in PF and VA, respectively. Essential oil was found to be fungicidal in nature at 1.247 and 0.998 μg ml−1 concentration of oil in PF and VA, respectively. Determination of conidial germination in the presence of oil was also carried
out and it was found that the oil exhibited 100% inhibition of conidial germination at 0.450 μg ml−1 concentration. The effect of essential oil on the yield of mycelial weight was observed and it was found that at 0.873 μg ml−1 concentration no mycelium was recorded and 100% inhibition was observed. The fungitoxicity of oil did not change even on
exposure to 100°C temperature or to autoclaving, and the oil also retained its fungicidal nature even after storage of 24 months.
The main changes observed under light microscopy after oil treatment were a decrease and loss of conidiation and anomalies
in the hyphae such as a decrease in the diameter of hyphae and granulation of cytoplasm. The treatment of the oil also showed
highly reduced cytoplasm in the hyphae, showing clear retraction of the cytoplasm from the hyphae and ultimately in some areas
hyphae without cytoplasm were also found. GC-MS studies of the essential oil revealed that the oil consisted of 24 compounds
with 1,8-cineole as major component accounting for 44.4% of the total constituents. 相似文献
18.
N. E. Suzina V. I. Duda T. Z. Esikova A. P. Shorokhova A. B. Gafarov R. R. Oleinikov V. N. Akimov T. N. Abashina V. N. Polivtseva A. M. Boronin 《Microbiology》2011,80(4):535-548
Two strains, NF4 and NF5, of a yellow-colored gram-negative bacterium were isolated from sediments of Lake Baikal and from
old oil sludge of the Nizhnekamsk oil-processing plant. The cells of the strains are ultrasmall coccoids or short rods, measuring
0.2–0.4 × 0.2–0.5 μm; the average cell volume ranges from 0.004 to 0.04 μm3. A considerable proportion (30–60%) of cells have nanometer dimensions (180–300 nm in diameter and 0.004–0.02 μm3 in volume). The new isolates are thus among the smallest representatives of presently known free-living ultramicrobacteria.
The two studied isolates are gram-negative nonmotile cells possessing a pronounced outer membrane. The cells do not have flagella
and are not capable of gliding motility. They divide by constriction, budding, and multiple septation. The multiplicity of
reproduction mechanisms results in a high degree of cell polymorphism. The isolates are chemoorganotrophic, aerobic, psychrotolerant,
oxidase- and catalase-positive. Their characteristic trait is the absence of extracellular hydrolytic enzymes, such as proteases,
lipases, pectinases, and cellulases. Menaquinone MK-6 is the main respiratory quinone; the flexirubin pigment was not detected.
The G + C contents of the DNA of strains NF4 and NF5 are 40.8 and 40.5 mol %, respectively. The DNA-DNA hybridization level
of strains NF4 and NF5 was close to 100%. Analysis of the 16S rRNA gene sequences and the fatty acid compositions showed that
the isolates are most closely related to certain representatives of the genus Chryseobacterium (C. solincola, C. antarcticum, and C. jeonii). However, the differences in the 16S rRNA gene sequences, as well as in the phenotypic properties, such as formation of
ultrasmall cells, the absence of extracellular hydrolases, oligotrophy, and the capacity for epibiosis on bacterial cells,
suggest that the studied strains belong to a new species of the genus Chryseobacterium. The capacity for epibiosis, i.e., the ability to exist in a tightly adhered state on the surfaces of host Bacillus subtilis cells, is a peculiar trait of the studied isolates. It is assumed that adhesion of the cells of strains NF4 and NF5 (members
of the phylum Bacteroidetes) occurs via by the same unique mechanism as the mechanism that we previously described for representatives of Alphaproteobacteria (Kaistia sp., NF1, and NF3), which use polysaccharide chains equipped with sticky granules as trapping and constricting cords. 相似文献
19.
Sisir Ghosh Pallab Ghosh Pradipta Saha Tushar Kanti Maiti 《Symbiosis (Philadelphia, Pa.)》2011,53(2):75-81
The symbiont isolated from root nodules of Phaseolus mungo L., a widely grown legume in India was identified as a Rhizobium sp. a Rhizobium sp. close to R. multihospitium based on a biochemical and 16S rRNA gene-based phylogenetic approach. This Rhizobium sp. was able to produce large amounts of extracellular polysaccharides (EPS) in a yeast extract mannitol (YEM) broth medium.
Both growth and EPS production started simultaneously though each had different stationary phases. EPS production increased
enormously with supplementation by the preferred carbon, nitrogen and vitamin sources. Attempts were made to optimize the
cultural requirements for maximum growth and maximum EPS production. The EPS produced by the symbiont contained large amount
of mannose together with small amounts of arabinose and xylose. The possible role of EPS production on the Rhizobium—root nodule symbiosis is briefly discussed. 相似文献
20.
Orlita A Sidwa-Gorycka M Malinski E Czerwicka M Kumirska J Golebiowski M Lojkowska E Stepnowski P 《Biotechnology letters》2008,30(3):541-545
Growth of Ruta graveolens shoots was induced when Bacillus sp. cell lysates were added to the culture medium. Elicitation of coumarin by this lysate was also very effective; the concentrations
of isopimpinelin, xanthotoxin and bergapten increased to 610, 2120 and 1460 μg g−1 dry wt, respectively. It also had a significant effect on the production of psoralen and rutamarin (680 and 380 μg g−1 dry wt) and induced the biosynthesis of chalepin, which was not detected in the control sample, up to 47 μg g−1 dry wt With lysates of the Pectobacterium
atrosepticum, their effect on growth was not so significant and had no effect on the induction of coumarin accumulation. But elicitation
with this lysate was much more effective for inducing the production of furoquinolone alkaloids; the concentrations of γ-fagarine,
skimmianine, dictamnine and kokusaginine rose to 99, 680, 172 and 480 μg g−1 dry wt, respectively. 相似文献