共查询到20条相似文献,搜索用时 10 毫秒
1.
N. Raaman B. Mahendran C. Jaganathan S. Sukumar V. Chandrasekaran 《World journal of microbiology & biotechnology》2010,26(6):1033-1039
The tannase production by Paecilomyces variotii was confirmed by high performance thin layer chromatography (HPTLC), and substrate specificity of the tannase was determined
by zymogram analysis in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS–PAGE). A clear band of activity observed
after electrophoresis of culture filtrate in non-denaturing gels indicated the production of extracellular tannase by P. varoitii. HPTLC analysis revealed that gallic acid was the enzymatic degradation product of tannic acid during the fermentation process.
The optimum condition for tannase production was at 72 h of incubation in shaking condition and addition of 1.5% tannic acid,
1% glucose and 0.2% sodium nitrate at temperature of 35°C and pH of 5–7. The production of extracellular tannase from Paecilomyces variotii was investigated under optimized conditions in solid-state fermentation (SSF), submerged fermentation (SmF) and liquid surface
fermentation (LSF) processes. The maximum extracellular tannase production was obtained within 60 h of incubation under SSF
followed by SmF and LSF. 相似文献
2.
A. P. Bellanger J. P. Cervoni J. F. Faucher D. Weil-Verhoeven M. Ginet E. Deconinck F. Grenouillet 《Mycopathologia》2017,182(7-8):761-765
Paecilomyces sp. are emerging pathogens in immunocompromised patients. We report here a case of Paecilomyces variotii fungemia, cured with amphotericin and anidulafungin, illustrating difficulties of early diagnosis and therapeutic choice in such rare fungal infection. 相似文献
3.
Nguyen VN Oh IJ Kim YJ Kim KY Kim YC Park RD 《Journal of industrial microbiology & biotechnology》2009,36(2):195-203
Two extracellular chitinases were purified from Paecilomyces variotii DG-3, a chitinase producer and a nematode egg-parasitic fungus, to homogeneity by DEAE Sephadex A-50 and Sephadex G-100 chromatography.
The purified enzymes were a monomer with an apparent molecular mass of 32 kDa (Chi32) and 46 kDa (Chi46), respectively, and
showed chitinase activity bands with 0.01% glycol chitin as a substrate after SDS-PAGE. The first 20 and 15 N-terminal amino
acid sequences of Chi32 and Chi46 were determined to be Asp-Pro-Typ-Gln-Thr-Asn-Val-Val-Tyr-Thr-Gly-Gln-Asp-Phe-Val-Ser-Pro-Asp-Leu-Phe
and Asp-Ala-X-X-Tyr-Arg-Ser-Val-Ala-Tyr-Phe-Val-Asn-Trp-Ala, respectively. Optimal temperature and pH of the Chi32 and Chi46
were found to be both 60°C, and 2.5 and 3.0, respectively. Chi32 was almost inhibited by metal ions Ag+ and Hg2+ while Chi46 by Hg2+ and Pb2+ at a 10 mM concentration but both enzymes were enhanced by 1 mM concentration of Co2+. On analyzing the hydrolyzates of chitin oligomers [(GlcNAc)
n
, n = 2–6)], it was considered that Chi32 degraded chitin oligomers as an exo-type chitinase while Chi46 as an endo-type chitinase. 相似文献
4.
KiBeom Lee 《World journal of microbiology & biotechnology》2007,23(9):1317-1320
Lactobacillus
delbrueckii subsp. lactis strains were developed having increased activity, by gradually acclimatizing the bacteria to acidic conditions over repeated
batch culture. Cells from one batch culture were used as the inoculum for the subsequent batch culture and thereby an adapted
strain of Lactobacillus was obtained showing improved lactic acid productivity, cell growth and total glucose utilization. Furthermore, the acclimatized
cells used significantly less nitrogen for a given level of lactic acid production, which is significant from an industrial
point of view. The developed procedure decreases fermentation time and nutrient use, leading to reduced operation costs, while
providing a lactic acid yield superior to previously reported methods. 相似文献
5.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
6.
Summary A heavy metal resistant bacterium, Bacillus circulans strain EB1 showed a high cadmium biosorption capacity coupled with a high tolerance to this metal when grown in its presence. Bacillus circulans EB1 cells grown in the presence of 28.1 mg cadmium/l were capable of removing cadmium with a specific biosorption capacity of 5.8 mg Cd/g dry wt biomass in the first 8 h. When the cells were pre-conditioned with low concentrations of cadmium in pre-grown medium, the uptake was increased to 6.7 mg Cd/g dry wt biomass. The maximum uptake of␣cadmium was during mid-logarithmic phase of growth. The resting cells (both wet and dry) of EB1 were also able to biosorb cadmium. Specific biosorption capacities of wet and dry biomass were 9.8 and 26.5 mg Cd/g dry wt biomass, respectively. Maximum cadmium removals by both wet and dry cells were at pH 7.0. The results showed that the cadmium removal capacity of resting cells was markedly higher than that of growing cells. Since both growing and resting cells had a high biosorption capacity for cadmium, EB1 cells could serve as an excellent biosorbent for removal of cadmium from natural environments. 相似文献
7.
Uricase is an important medical enzyme which can be used to determine urate in clinical analysis, to therapy gout, hyperuricemia, and tumor lysis syndrome. Uricase of Candida utilis was successfully expressed in Hansenula polymorpha under the control of methanol oxidase promoter using Saccharomyces cerevisiae alpha-factor signal peptide as the secretory sequence. Recombinant H. polymorpha MU200 with the highest extracellular uricase production was characterized with three copies of expression cassette and selected for process optimization for the production of recombinant enzyme. Among the parameters investigated in shaking flask cultures, the pH value of medium and inoculum size had great influence on the recombinant uricase production. The maximum extracellular uricase yield of 2.6 U/ml was obtained in shaking flask culture. The yield of recombinant uricase was significantly improved by the combined use of a high cell-density cultivation technique and a pH control strategy of switching culture pH from 5.5 to 6.5 in the induction phase. After induction for 58 h, the production of recombinant uricase reached 52.3 U/ml (about 2.1 g/l of protein) extracellularly and 60.3 U/ml (about 2.4 g/l) intracellularly in fed-batch fermentation, which are much higher than those expressed in other expression systems. To our knowledge, this is the first report about the heterologous expression of uricase in H. polymorpha. 相似文献
8.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner.
The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate
larvae Galleria
mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host. 相似文献
9.
Noel H. Holmgren 《Brittonia》2018,70(1):115-139
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations. 相似文献
10.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
11.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献
12.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
13.
14.
15.
Paecilomyces variotii IRI017 was isolated as a formaldehyde-resistant fungus from wastewater containing formaldehyde. The fungus grew in a medium
containing 0.5% formaldehyde and had consumed formaldehyde completely after 5 days. Alcohol oxidase was purified from the
fungus grown on methanol. A 20-fold purification was achieved with a yield of 44%. The molecular mass of the purified enzyme
was estimated to be 73 and 450 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography,
respectively, suggesting that the enzyme consists of six identical subunits. The N-terminal amino acid sequence of the subunit
was TIPDEVDIII. The enzyme showed an absorption spectrum typical of a flavoprotein and had a noncovalently bound flavin different
from FAD, FMN, and riboflavin. The pH optimum of the enzyme activity was pH 6–10. The enzyme was stable in the pH range of
pH 5–10. The enzyme retained full activity after incubation at 50°C for 30 min. The enzyme oxidized not only methanol but
also lower primary alcohols and formaldehyde. The K
m values for methanol, ethanol, and formaldehyde were 1.9, 3.8, and 4.9 mmol l−1, respectively. 相似文献
16.
The phytopathogenic fungus Sclerotium (Athelia) rolfsii CBS 191.62 is a very efficient producer of the hemoflavoprotein, cellobiose dehydrogenase (CDH), forming up to 225 mg l(-1) (15,000 units cytochrome c activity l(-1)) of this protein, which is of biotechnological interest for sensors, biocatalysis and bioremediation. Both cellulose as inducing substrate and the use of a rich medium containing increased concentrations of peptone from meat or suitable amino acids are important for attaining high CDH yields. CDH, containing a protease-sensitive linker region, can be cleaved by endogenous proteases into a catalytically active flavin fragment and an inactive heme domain. By using increased concentrations of peptone, or certain amino acids such as valine or leucine, or by adding exogenous protease inhibitors, this cleavage can be almost completely inhibited, so that more than 95% intact CDH is obtained under optimised culture conditions. When using non-inhibitory amino acids, e.g. glutamine or lysine, in the medium, more than 80% of the total cellobiose-oxidising activity can be attributed to the flavin fragment. 相似文献
17.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
18.
Lima FL de Carvalho MA Apolônio AC Bemquerer MP Santoro MM Oliveira JS Alviano CS Farias Lde M 《Journal of industrial microbiology & biotechnology》2008,35(2):103-110
Aggregatibacter (Actinobacillus) actinomycetemcomitans P7–20 strain isolated from a periodontally diseased patient has produced a bacteriocin (named as actinomycetemcomitin) that is
active against Peptostreptococcus anaerobius ATCC 27337. Actinomycetemcomitin was produced during exponential and stationary growth phases, and its amount decreased until
it disappeared during the decline growth phase. It was purified by ammonium sulphate precipitation (30–60% saturation), and
further by FPLC (mono-Q ionic exchange and Phenyl Superose hydrophobic interaction) and HPLC (C-18 reversed-phase). This bacteriocin
loses its activity after incubation at a pH below 7.0 or above 8.0, following heating for 30 min at 45°C, and after treatment
with proteolytic enzymes such as trypsin, α-chymotrypsin, and papain. Actinomycetemcomitin has a molecular mass of 20.3 KDa
and it represents a new bacteriocin from A. actinomycetemcomitans. 相似文献
19.
Ping Li Xuewu Guo Tingting Shi Zhihui Hu Yefu Chen Liping Du Dongguang Xiao 《Journal of industrial microbiology & biotechnology》2017,44(11):1541-1550
As a byproduct of yeast valine metabolism during fermentation, diacetyl can produce a buttery aroma in wine. However, high diacetyl concentrations generate an aromatic off-flavor and poor quality in wine. 2,3-Butanediol dehydrogenase encoded by BDH1 can catalyze the two reactions of acetoin from diacetyl and 2,3-butanediol from acetoin. BDH2 is a gene adjacent to BDH1, and these genes are regulated reciprocally. In this study, BDH1 and BDH2 were overexpressed in Saccharomyces uvarum to reduce the diacetyl production of wine either individually or in combination. Compared with those in the host strain WY1, the diacetyl concentrations in the recombinant strains WY1-1 with overexpressed BDH1, WY1-2 with overexpressed BDH2 alone, and WY1-12 with co-overexpressed BDH1 and BDH2 were decreased by 39.87, 33.42, and 46.71%, respectively. BDH2 was only responsible for converting diacetyl into acetoin, but not for the metabolic pathway of acetoin to 2,3-butanediol in S. uvarum. This study provided valuable insights into diacetyl reduction in wine. 相似文献
20.
The B subfamily of ATP-binding cassette (ABC) proteins (ABCB) plays a vital role in auxin efflux. However, no systematic study has been done in apple. In this study, we performed genomewide identification and expression analyses of the ABCB family in Malus domestica for the first time. We identified a total of 25 apple ABCBs that were divided into three clusters based on the phylogenetic analysis. Most ABCBs within the same cluster demonstrated a similar exon–intron organization. Additionally, the digital expression profiles of ABCB genes shed light on their functional divergence. ABCB1 and ABCB19 are two well-studied auxin efflux carrier genes, and we found that their expression levels are higher in young shoots of M106 than in young shoots of M9. Since young shoots are the main source of auxin synthesis and auxin efflux involves in tree height control. This suggests that ABCB1 and ABCB19 may also take a part in the auxin efflux and tree height control in apple. 相似文献