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1.
A marine bacterial strain, F72T, was isolated from a solitary scleractinian coral, collected in Yap seamounts in the Pacific Ocean. Strain F72T is a Gram-negative, light-yellow-pigmented, motile, rod-shaped bacterium. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain F72T is related to the genus Novosphingobium and has high 16S rRNA gene sequence similarities with the type strains of Novosphingobium pentaromativorans US6-1T (97.7 %), Novosphingobium panipatense SM16T (97.6 %), Novosphingobium mathurense SM117T (97.2 %) and Novosphingobium barchaimii LL02T (97.1 %). Ubiquinone Q-10 was detected as the dominant quinone. The predominant cellular fatty acids were C18:1ω7c and C17:1ω6c. The genomic DNA G+C content of strain F72T was 63.4 mol %. The polar lipids profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylcholine, sphingoglycolipid and one uncharacterized lipid. Strain F72T shared DNA relatedness of 25 % with N. pentaromativorans JCM 12182T, 31 % with N. panipatense DSM 22890T, 21 % with N. mathurense DSM 23374T and 26 % with N. barchaimii DSM 25411T. Combined data from phenotypic, phylogenetic and DNA–DNA relatedness studies demonstrated that the strain F72T is a representative of a novel species of the genus Novosphingobium, for which we propose the name Novosphingobium profundi sp. nov. (type strain F72T = KACC 18566T = CGMCC 1.15390T).  相似文献   

2.
We determined the prevalence rate and risk of infection of Trypanosoma cruzi and other trypanosomatids in Peruvian non-human primates (NHPs) in the wild (n = 126) and in different captive conditions (n = 183). Blood samples were collected on filter paper, FTA cards, or EDTA tubes and tested using a nested PCR protocol targeting the 24Sα rRNA gene. Main risk factors associated with trypanosomatid and T. cruzi infection were genus and the human–animal context (wild vs captive animals). Wild NHPs had higher prevalence of both trypanosomatids (64.3 vs 27.9%, P < 0.001) and T. cruzi (8.7 vs 3.3%, P = 0.057), compared to captive NHPs, suggesting that parasite transmission in NHPs occurs more actively in the sylvatic cycle. In terms of primate family, Pitheciidae had the highest trypanosomatid prevalence (20/22, 90.9%) and Cebidae had the highest T. cruzi prevalence (15/117, 12.8%). T. cruzi and trypanosomatids are common in Peruvian NHPs and could pose a health risk to human and animals that has not been properly studied.  相似文献   

3.
Availability of molecular methods, gene sequencing, and phylogenetic species recognition have led to rare fungi being recognized as opportunistic pathogens. Fungal keratitis and onychomycosis are fairly common mycoses in the tropics, especially among outdoor workers and enthusiasts. The frequently isolated etiological agents belong to genera Candida, Aspergillus, and Fusarium. Within the genus Fusarium, known to be recalcitrant to prolonged antifungal treatment and associated with poor outcome, members of the Fusarium solani species complex are reported to be most common, followed by members of the Fusarium oxysporum SC and the Fusarium fujikuroi SC (FFSC). Morphological differentiation among the various members is ineffective most times. In the present study, we describe different species of the FFSC isolated from clinical specimen in south India. All twelve isolates were characterized up to species level by nucleic acid sequencing and phylogenetic analysis. The molecular targets chosen were partial regions of the internal transcribed spacer rDNA region, the panfungal marker and translation elongation factor-1α gene, the marker of choice for Fusarium speciation. Phylogenetic analysis was executed using the Molecular Evolutionary Genetics Analysis software (MEGA7). In vitro susceptibility testing against amphotericin B, voriconazole, posaconazole, natamycin, and caspofungin diacetate was performed following the CLSI M38-A2 guidelines for broth microdilution method. The twelve isolates of the FFSC were F. verticillioides (n = 4), F. sacchari (n = 3), F. proliferatum (n = 2), F. thapsinum (n = 1), F. andiyazi (n = 1), and F. pseudocircinatum (n = 1). To the best of our knowledge, this is the first report of F. andiyazi from India and of F. pseudocircinatum as a human pathogen worldwide. Natamycin and voriconazole were found to be most active agents followed by amphotericin B. Elderly outdoor workers figured more among the patients and must be recommended protective eye wear.  相似文献   

4.
Species of Trichoderma are widely recognized for their biocontrol abilities, but seldom studied collectively, for their plant growth promotion, abiotic stress tolerance and bioremediation properties. Our study is a concentrated effort to establish the potential of native isolate Trichoderma harzianum KSNM (T103) to tolerate biotic (root pathogens) and abiotic stresses [high salt (100–1000 mM); heavy metal (chromium, nickel and zinc: 1–10 mM); pesticides: malathion (100–600 ppm), carbofuran (100–600 ppb)], along with its ability to support plant growth. In vitro growth promotion assays with T103 treated Vigna radiata, Vigna mungo and Hordeum vulgare confirmed ‘non-species specific’ growth promotion effects of T103. At lower metal concentration, T103 treatment was found to completely negate the impact of metal stress [60 % increase in radicle length (RL) with no significant decrease in %germination (%G)]. Even at 10 mM metal, T103 inoculation gave 80 % increase in %G and >50 % increase in RL. In vitro experiments confirmed high metal reduction capacity (47 %-Cr, 35 %-Ni and 42 %-Zn) of T103 at concentrations as high as 4 mM. At maximum residual concentrations of malathion (440 ppm) and carbofuran (100 ppb) reported in agricultural soils, T103 maintained 80 and 100 % survivability, respectively. T103 treatment has improved %G and RL in all three hosts challenged with pesticide. Isolate T103 was found to effectively suppress growth of three major root pathogens: Macrophomina phaseolina (65.83 %) followed by Sclerotium rolfsii (19.33 %) and Fusarium oxysporum (19.18 %). In the light of these observations, native T. harzianum (T103) seems to be a competent biocontrol agent for tropical agricultural soils contaminated with residual pesticides and heavy metals.  相似文献   

5.
In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups—non-severe and severe gastric pathologies—and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p < 0.0001; OR = 8.75; 95% CI 3.54–21.64). Conversely, cagA (p = 0.3507; OR = 1.62; 95% CI 0.59–4.45) and vacAi2 (p = 0.0114; OR = 3.09; 95% CI 1.26–7.60) genes were not associated with damage, while the dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09–0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.  相似文献   

6.
Laccase CotA from Bacillus subtilis 168 was successfully displayed on the membrane of Escherichia coli cells using poly-γ-glutamate synthetase A protein (PgsA) from B. subtilis as an anchoring matrix. Further analyses demonstrated that the fusion protein PgsA/CotA efficiently translocates to the cell surface of E. coli with an enzymatic activity of 65 U/108 cells. Surface-displayed CotA was shown to possess improved enzymatic properties compared with those of the wild-type CotA, including higher thermal stability (above 90% activity at 70 °C and nearly 40% activity at 90 °C after 5-h incubation) and stronger inhibitor tolerance (approximately 80 and 65% activity when incubated with 200 and 400 mM NaCl, respectively). Furthermore, the whole-cell system was demonstrated to have high enzymatic activity against anthraquinone dye, Acid Blue 62, triphenylmethane dye, Malachite Green, and azo dye, Methyl Orange with the decolorization percentages of 91, 45, and 75%, after 5-h incubation, respectively.  相似文献   

7.
The objective of this study was to determine the occurrence and distribution of antibiotic resistant (AR) lactic acid bacteria (LAB) in Indian poultry. LAB from poultry farm feces (n = 21) and samples from slaughter houses comprising chicken intestine (n = 46), raw meat (n = 23), and sanitary water (n = 4) were evaluated and compared with those from organic chicken (OC) collected from nearby villages. Screening studies showed 5–7 log units higher erythromycin (ER), tetracycline (TC) and vancomycin (VAN) resistant LAB from conventional poultry chicken (CC) compared to OC. Molecular characterization of isolated cultures (n = 32) with repetitive-PCR profiling and 16S rRNA gene sequencing revealed their taxonomical status as Enterococcus faecium (n = 16), Enterococcus durans (n = 2), Lactobacillus plantarum (n = 10), Lactobacillus pentosus (n = 1) and Lactobacillus salivarius (n = 3). The isolates were found to harbor erm(B), msr(C), msr(A/B), tet(M), tet(L) and tet(K) genes associated with Tn916 and Tn917 family transposons. Expression studies through real-time PCR revealed antibiotic-induced expression of the identified AR genes. In vitro and in vivo conjugational studies revealed transfer of ER and TC resistant (ERR and TCR) genes with transfer frequencies of 10?7 and 10?4 transconjugants recipient?1, respectively. Although no known VAN resistance (VANR) genes were detected, high phenotypic resistance was observed and was transferable to the recipient. From a public health point of view, this study reports Indian poultry as a major source of high levels of AR bacteria contaminating the food chain and the environment. Thus, urgent and determined strategies are needed to control the spread of multiple AR bacteria.  相似文献   

8.
The effect of five constant temperatures of 21, 24, 27, 30 and 33 °C on adult life span, reproduction, oviposition behavior and larval developmental time of a bitter gourd inhabited coleopteran insect Epilachna dodecastigma (Wied.) (Coccinellidae) was determined in laboratory conditions under 70 ± 5 % relative humidity and a photoperiod of 12 L : 12 D. Larval developmental time of E. dodecastigma decreased as temperature increased from 21 to 33 °C. Life table data revealed that overall mortality was lowest at 27 °C and highest at 21 °C. Females lived longer than males at all temperatures; but longevity decreased with increase in temperature. Pre-oviposition period decreased significantly with increase in temperature up to 27 °C and thereafter increased at a slower rate; whereas oviposition period decreased significantly with increase in temperature. Fecundity and egg viability increased significantly with an increase in temperature up to 27 °C and thereafter decreased at a slower rate. The intrinsic rate of increase (r m ) was 0.1703, 0.1984, 0.2235, 0.2227 and 0.2181 day?1 at 21, 24, 27, 30 and 33 °C, respectively. The net reproductive rate and finite rate of increase was highest at 27 °C (R o  = 112.05; λ = 1.4233) and lowest at 21 °C (R o  = 51.23; λ = 1.2581).  相似文献   

9.

Background

The solute carrier family 30 member 8 gene (SLC30A8) encodes a zinc transporter in the pancreatic beta cells and the major C-allele of a missense variant (rs13266634; C/T; R325W) in SLC30A8 is associated with an increased risk of type 2 diabetes (T2D). We hypothesized that the association between zinc intake and T2D may be modified by the SLC30A8 genotype.

Results

We carried out a prospective study among subjects with no history cardio-metabolic diseases in the Malmö Diet and Cancer Study cohort (N = 26,132, 38% men; 86% with genotype data). Zinc intake was assessed using a diet questionnaire and food record. During a median follow-up of 19 years, 3676 T2D cases occurred. A BMI-stratified Cox proportional hazards regression model with attained age as the time scale was used to model the association between total and dietary zinc intake, zinc supplement use, zinc to iron ratio, and risk of T2D adjusting for putative confounding factors.The median total zinc intake was 11.4 mg/day, and the median dietary zinc intake was 10.7 mg/day. Zinc supplement users (17%) had a median total zinc intake of 22.4 mg/day. Dietary zinc intake was associated with increased risk of T2D (P trend < 0.0001). In contrast, we observed a lower risk of T2D among zinc supplement users (HR = 0.79, 95% CI 0.70–0.89). The SLC30A8 CC genotype was associated with a higher risk of T2D (HR = 1.16, 95% CI 1.07–1.24), and the effect was stronger among subjects with higher BMI (P interaction = 0.007). We observed no significant modification of the zinc-T2D associations by SLC30A8 genotype. However, a three-way interaction between SLC30A8 genotype, BMI, and zinc to iron ratio was observed (P interaction = 0.007). A high zinc to iron ratio conferred a protective associated effect on T2D risk among obese subjects, and the effect was significantly more pronounced among T-allele carriers.

Conclusions

Zinc supplementation and a high zinc to iron intake ratio may lower the risk of T2D, but these associations could be modified by obesity and the SLC30A8 genotype. The findings implicate that when considering zinc supplementation for T2D prevention, both obesity status and SLC30A8 genotype may need to be accounted for.
  相似文献   

10.
Research focused on the occurrence of Fusarium spp. in atmospheric dust or rainwater is not common. Preliminary studies with four sampling dates in 2007 revealed that several species of Fusarium may also be conveyed by rainwater. In order to determine the regular presence of Fusarium spp. in rainfall water, samples were systematically collected for a year (from October 2009 to October 2010) in three points on the Mediterranean coast of the province of Granada (Spain) 10-km distance between them. Throughout the year of sampling, a total of 179 rainwater samples were collected during every significant rainfall event. Eight different Fusarium species were isolated from the rainwater samples: F. oxysporum (32 %), F. proliferatum (26 %) and F. equiseti (20 %) coincide with previous studies, while F. dimerum (3 %), F. semitectum (4.7 %), F. solani (8 %), F. avenaceum (0.5 %) and F. chlamydosporum (3.7 %) were isolated for the first time from rainwater. Results were consistent with previous surveys conducted 100 km away from the sampling sites. Inoculation of 39 different isolates from five different Fusarium species showed pathogenicity on plants. Disease severity differed depending on the inoculated plant species, which means that rain water can be an effective vector to transport new pathogens into new cultivated areas. This work reveals some epidemiological aspects of Fusarium genus in natural environments. Some of the isolated Fusarium spp. are potential mycotoxin producers, such as zearalenone, fumonisin, moniliformin or nivalenol.  相似文献   

11.
Triticum timopheevii (2n = 4x = 28, GGAtAt) is a tetraploid wheat formerly cultivated in western Georgia. The natural allopolyploid Triticum zhukovskyi is a hexaploid taxon originated from hybridization of T. timopheevii with cultivated einkorn T. monococcum (2n = 2x = 14, AmAm). Karyotypically T. timopheevii and T. zhukovskyi differ from other tetraploid and hexaploid wheats and were assigned to the section Timopheevii of the genus Triticum L. Triticum timopheevii and T. zhukovskyi are resistant to many fungal diseases and therefore could potentially be utilized for wheat improvement. We were aiming to precisely identify all T. timopheevii chromosomes and to trace the evolution of T. zhukovskyi. For this, we developed a set of molecular cytogenetic landmarks based on eleven DNA probes. Each chromosome can now be characterized by two to eight probes. The pTa-535 sequence allows the identification of all At-genome chromosomes, whereas G-genome and some At-genome chromosomes can be identified using (GAA/CTT) n and pSc119.2 probes. The probes pAesp_SAT86, pAs1, Spelt-1, Spelt-52 and 5S and 45S rDNA can be applied as additional markers to discriminate particular chromosomes or chromosomal regions. The distribution of (GAA/CTT) n , pTa-535 and pSc119.2 DNA probes on T. timopheevii chromosomes is distinct from other tetraploid wheats and can therefore be used to track individual chromosomes in introgression programs. Our study confirms the origin of T. zhukovskyi from hybridization of T. timopheevii with T. monococcum; however, we show that the emergence was accompanied by changes involving mostly At-genome chromosomes. This may be due to the presence of two closely related A-genomes in the T. zhukovskyi karyotype.  相似文献   

12.
Gastric cancer incidence varies considerably among populations, even those with comparable rates of Helicobacter pylori infection. To test the hypothesis that genetic variation plays a role in gastric disease, we assessed the relationship between genotypes and gastric histopathology in a Colombian study population, using a genotyping array of immune-related single nucleotide polymorphisms (SNPs). Two synonymous SNPs (rs6061243 and rs6587239) were associated with progression of premalignant gastric lesions in a dominant-effects model after correction for multiple comparisons (p = 2.63E?07 and p = 7.97E?07, respectively); effect sizes were β = ?0.863 and β = ?0.815, respectively, where β is an estimate of effect on histopathology scores, which ranged from 1 (normal) to 5 (dysplasia). In our replication cohort, a second Colombian population, both SNPs were associated with histopathology when additively modeled (β = ?0.256, 95 % CI = ?0.47, ?0.039; and β = ?0.239, 95 % CI = ?0.45, ?0.024), and rs6587239 was significantly associated in a dominant-effects model (β = ?0.330, 95 % CI = ?0.66, 0.00). Because promoter methylation of GATA5 has previously been associated with gastric cancer, we also tested for the association of methylation status with more advanced histopathology scores in our samples and found a significant relationship (p = 0.001). A multivariate regression model revealed that the effects of both the promoter methylation and the exonic SNPs in GATA5 were independent. A SNP-by-methylation interaction term was also significant. This interaction between GATA5 variants and GATA5 promoter methylation indicates that the association of either factor with gastric disease progression is modified by the other.  相似文献   

13.
The bioremediation of tetrachloroethene (perchloroethene; PCE) contaminated sites generally requires a supply of some fermentable organic substrates as an electron donor. On the other hand, organic substrates can induce the massive growth of microorganisms around the injection wells, which can foul the contaminated subsurface environment. In this study, PCE dechlorination to ethene was performed in a microbial electrochemical system (MES) using the electrode (a cathode polarized at ?500 mV vs. standard hydrogen electrode) as the electron donor. Denaturing gel gradient electrophoresis and pyrosequencing revealed a variety of non-Dehalococcoides bacteria dominant in MES, such as Acinetobacter sp. (25.7 % for AS1 in suspension of M3), Rhodopseudomonas sp. (10.5 % for AE1 and 10.1 % for AE2 in anodic biofilm of M3), Pseudomonas aeruginosa (22.4 % for BS1 in suspension of M4), and Enterobacter sp. (21.7 % for BE1 in anodic biofilm of M4) which are capable of electron transfer, hydrogen production and dechlorination. The Dehalococcoides group, however, was not detected in this system. Therefore, these results suggest that a range of bacterial species outside the Dehalococcoides can play an important role in the microbial electrochemical dechlorination process, which may lead to innovative bioremediation technology.  相似文献   

14.
The present study investigated the role of Xeroderma pigmentosum group A (XPA) polymorphism (A23G and G709A) with lung cancer risk and its association with overall survival in North Indians. 370 cases and 370 controls were investigated to evaluate association between XPA polymorphism (A23G and G709A) with lung cancer risk using logistic regression analysis. A follow-up study was also conducted for 291 lung cancer cases illustrating correlation between overall survival in lung cancer patients and XPA variants. GG genotype showed an increased lung cancer risk (p = 0.0007) for A23G polymorphism whereas G709A polymorphism was associated with significant protective effect in heterozygous (AG) subjects (p = 0.001). When stratified according to smoking status an increased risk for lung cancer was observed for GG genotype in A23G polymorphism (p = 0.0002). A poor survival in females carrying variant genotype (GG) was observed (p = 0.001; MST = 4.16 months) for A23G polymorphism. Adenocarcinoma patients with heterozygous genotype showed an increased hazard ratio (p = 0.02) for A23G polymorphism. G709A was associated with a reduced hazard ratio marking a better survival among mutant females (HR 0.17; p = 0.05; MST = 18.63 months). It can be concluded that A23G polymorphism might contribute to increased lung cancer risk in North Indian population emphasizing on poor survival among females. G709A polymorphism might result in protective effect in lung cancer subjects. The present study had a low sample size but it could act as reference for the large sample studies in future.  相似文献   

15.
The diamondback moth Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) is an herbivorous specialist on Brassicaceae species. Brassicas spp. plants developed a range of defenses (chemical, physical, and morphological) to prevent herbivores attack. In this study, we reported the antixenotic and antibiotic effects of outermost layer of two species of epicuticular wax of Brassicaceae, Brassica oleracea L. var. “Santo Antônio,” and Hybrid Kope F1 100MX, on larvae and adult of P. xylostella. In the choice experiment, P. xylostella adults showed an oviposition preference for collard cultivars Santo Antônio (control) and Hybrid Kope F1 100MX with wax removal. In the no-choice experiment, oviposition was 6.4 times higher in the Hybrid Kope F1 100MX with wax removal than without wax removal. There were significant differences among larvae feeding on leaf disks of Hybrid Kope F1 100MX in the treatments with (65.3 mg) and without wax removal (23.5 mg). The net reproduction rate (R 0 ), and intrinsic (rm) and finite rates of increase (λ) of P. xylostella in the cv. Santo Antônio were bigger in the treatment without wax removal (R 0  = 50.4, rm = 0.23 and λ = 1.26) than treatment with wax removal (R 0  = 28.5, rm = 0.20 and λ = 1.22). However, only the R 0 value was affected by mechanical wax removal in the Hybrid Kope F1 100MX (with wax removal R 0  = 43.3 and without wax removal R 0  = 30.8). In conclusion, the results indicate that collard’s wax is important to accessibility and development of P. xylostella, and its removal changes the resistance of collard’s varieties to P. xylostella.  相似文献   

16.
The primary aim of the research was to assess the level of trace elements and electrolytes in serum of postmenopausal diabetic women. Sixty-four postmenopausal women with type 2 diabetes mellitus (DM2) and 64 age- and body mass index-matched controls were examined. Serum trace elements were assessed using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS). Fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) levels were evaluated using Randox kits. The obtained data demonstrate that DM2 patients were characterized by 42 and 34 % higher FPG and HbA1c levels, respectively (p < 0.001). The level of Cu and Se in diabetic postmenopausal women was increased by 10 and 15 % in comparison to the respective control values (p = 0.002 and <0.001). Serum Mn, Zn, and Ni concentrations were lower than the control ones by 32 % (p = 0.003), 8 % (p = 0.003), and 23 % (p = 0.046), respectively. FPG and HbA1c levels directly correlated with serum Se (p < 0.001) and Cu (p = 0.014 and p = 0.028) concentrations and inversely related to Zn (p < 0.001) and Tl (p = 0.023 and p = 0.029) levels. Multiple regression analysis demonstrated a significant association between serum Zn and Se and FPG and HbA1c levels. It is proposed that Zn and Se play an important role in DM2 pathogenesis. Further studies are required to assess the intimate mechanisms of the observed differences.  相似文献   

17.

Objective

To study Candida albicans genotypes using RAPD and their susceptibility to fluconazole in healthy pregnant women and in vulvovaginal candidiasis (VVC) patients after topical treatment with clotrimazole.

Methods

Vaginal swabs were collected at t = 0 and t = 1 (1 month later) in pregnant women (control group, n = 33), and before (t = 0), at 1 month (t = 1) and at 2 months (t = 2) after clotrimazole treatment in pregnant women with VVC.

Results

Candida albicans was isolated in 30% of healthy pregnant women and 80% of patients with VVC. A high genetic heterogeneity was observed in C. albicans genotypes between individuals. In patients with VVC, topical antifungal treatment with clotrimazole was clinically effective, but only in a 62% C. albicans was eradicated. In patients in which C. albicans was not eradicated, this microorganism persisted for 1 or 2 months after the antifungal treatment. The persistent colonies were not associated with a specific genotype, but they were associated with higher MICs in comparison with colonies isolated from the control group.

Conclusions

Therapy with topical clotrimazole, despite a good clinical outcome, could not eradicate completely C. albicans allowing the persistence of genotypes, with higher MICs to fluconazole. More studies with higher number of patients are needed to validate this preliminary finding.
  相似文献   

18.
Fundulus grandis (Baird and Girard), the Gulf Killifish, is an abundant species throughout the marshes of the northern Gulf of Mexico. Its wide distribution and high site fidelity makes it an ideal indicator species for brackish and salt marshes, which experience a variety of anthropogenic disturbances. Despite the ecological, commercial, and scientific importance of F. grandis, age determination methods have not been validated and little is known of its growth pattern. By combining a tag-recapture study with a chemical marker to stain otoliths, we validated an ageing method for F. grandis adults (49–128 mm TL) using whole sagittal otoliths and determined growth rates of recaptured individuals in winter (n = 58) and summer (n = 36) in Louisiana. Mean somatic growth in length was significantly greater during the winter (0.085 mm d?1) than summer (0.054 mm d?1). In contrast, mean otolith growth was significantly greater in summer (1.37 μm d?1) than winter (0.826 μm d?1). The uncoupling of somatic and otolith growth may be primarily attributed to warm summer temperatures, which led to enhanced otolith growth while simultaneously reducing somatic growth. Fundulus grandis was aged to a maximum of 2.25 years. The parameters of the von Bertalanffy growth model were estimated as: L  = 87.27 mm, k = 2.43 year?1, and t 0 = ?0.022. These findings reveal essential age and growth information for F. grandis and provide a benchmark to evaluate responses to environmental disturbances.  相似文献   

19.
High fructose corn syrup (HFCS) is an alternative of liquid sweetener to sucrose that is isomerized by commercial glucose isomerase (GI). One-step production of 55 % HFCS by thermostable GI has been drawn more and more attentions. In this study, a new hyperthermophilic GI from Thermoanaerobacter ethanolicus CCSD1 (TEGI) was identified by genome mining, and then a 1317 bp fragment encoding the TEGI was synthesized and expressed in Escherichia coli BL21(DE3). To improve the activity of TEGI, two amino acid residues, Trp139 and Val186, around the active site and substrate-binding pocket based on the structural analysis and molecular docking were selected for site-directed mutagenesis. The specific activity of mutant TEGI-W139F/V186T was 2.3-fold and the value of k cat/K m was 1.86-fold as compared to the wild type TEGI, respectively. Thermostability of mutant TEGI-W139F/V186T at 90 °C for 24 h showed 1.21-fold extension than that of wild type TEGI. During the isomerization of glucose to fructose, the yield of fructose could maintain above 55.4 % by mutant TEGI-W139F/V186T as compared to 53.8 % by wild type TEGI at 90 °C. This study paved foundation for the production of 55 % HFCS using the thermostable TEGI.  相似文献   

20.
Dual metabolite, i.e., ginsenoside and anthocyanin, co-accumulating cell suspensions of Panax sikkimensis were subjected to elicitation with culture filtrates of Serratia marcescens (SD 21), Bacillus subtilis (FL11), Trichoderma atroviridae (TA), and T. harzianum (TH) at 1.25% and 2.5% v/v for 1- and 3-week duration. The fungal-derived elicitors (TA and TH) did not significantly affect biomass accumulation; however, bacterial elicitors (SD 21 and FL11), especially SD 21, led to comparable loss in biomass growth. In terms of ginsenoside content, differential responses were observed. A maximum of 3.2-fold increase (222.2 mg/L) in total ginsenoside content was observed with the use of 2.5% v/v TH culture filtrate for 1 week. Similar ginsenoside accumulation was observed with the use of 1-week treatment with 2.5% v/v SD 21 culture filtrate (189.3 mg/L) with a 10-fold increase in intracellular Rg2 biosynthesis (31 mg/L). Real-time PCR analysis of key ginsenoside biosynthesis genes, i.e., FPS, SQS, DDS, PPDS, and PPTS, revealed prominent upregulation of particularly PPTS expression (20–23-fold), accounting for the observed enhancement in protopanaxatriol ginsenosides. However, none of the elicitors led to successful enhancement in in vitro anthocyanin accumulation as compared to control values.  相似文献   

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