scholarly journals Influence of physiological factors on growth, sporulation and ochratoxin A/B production of the new Aspergillus ochraceus grouping

2009 ◽  
Vol 2 (4) ◽  
pp. 429-434 ◽  
Author(s):  
A. Abdel-Hadi ◽  
N. Magan
Keyword(s):  
Ochratoxin A ◽  
Maximum Growth ◽  
Spore Production ◽  
Aspergillus Ochraceus ◽  
Optimum Temperature ◽  
Physiological Factors ◽  
Large Numbers ◽  
Asexual Spore ◽  
The Impact ◽  
First Time

Recently, new species within the Aspergillus section Circumdati group responsible for ochratoxin production were reported. This study has examined the impact of interactions between water activity (aw, 0.99-0.90), temperature (20-35 °C) on growth, asexual spore production and ochratoxin A and B (OTA and OTB) on strains of each of the three species from this new grouping (A. ochraceus, A. steynii, and A. westerdijkiae) for the first time. The maximum growth occurred at 0.95 aw and 30 °C for both A. ochraceus and A. westerdijkiae, while it was at 0.99 aw and 30 °C for A. steynii. No conidial spore production occurred at 0.99 aw in cultures of A. ochraceus and A. steynii but large numbers of spores (2.3×107/cm2) were produced by A. westerdijkiae. Optimum temperature for spore production was 0.95 aw and 30 °C for A. westerdijkiae and A. ochraceus, and 0.95 aw and 35 °C for A. steynii. Quantification of OTA showed that optimum was produced at 0.99 aw, by A. steynii at 30 °C, for A. westerdijkiae at 25 °C and for A. ochraceus at 20 °C. As water stress was imposed (0.95 aw), the temperature for maximum OTA production changed. For example, for A. steynii and A. westerdijkiae this was at 35 °C, for A. ochraceus, 25 °C. Much less OTB was produced relative to OTA, but the production followed the same pattern at all aw levels and temperatures. This is the first detailed study to examine the similarities and differences in ecology of these related species in this important mycotoxigenic group.

Agrobacterium-mediated insertional mutagenesis of the ochratoxigenic fungus Aspergillus westerdijkiae

2007 ◽  
Vol 53 (1) ◽  
pp. 148-151 ◽  
Author(s):  
Marcia M Mata ◽  
Marta H Taniwaki ◽  
Beatriz T Iamanaka ◽  
Daniele Sartori ◽  
André L.M Oliveira ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Insertional Mutagenesis ◽  
Aspergillus Ochraceus ◽  
Agrobacterium Mediated Transformation ◽  
Morphological Variations ◽  
Carcinogenic Potential ◽  
Coffee Beans ◽  
Aspergillus Westerdijkiae ◽  
Polymerase Chain ◽  
First Time

Aspergillus westerdijkiae is a potent ochratoxin A (OTA) producer that has been found in coffee beans. OTA is known to have nephrotoxic effects and carcinogenic potential in animal species. Here we report for the first time the Agrobacterium-mediated transformation for Aspergillus westerdijkiae and the generation of ochratoxin-defective mutants. Conidia were transformed to hygromycin B resistance using strain AGL-1 of Agrobacterium tumefaciens. The obtained transformation frequency was up to 47 transformants per 106 target conidia. Among 600 transformants, approximately 5% showed morphological variations. Eight transformants with consistently reduced OTA production were obtained. Two of these transformants did not produce OTA (detection limit: 0.1 µg/kg); the other six mutants produced lower amounts of OTA (1%–32%) compared with the wild-type strain. By using thermal asymmetric interlaced polymerase chain reaction, we successfully identified a putative flavin adenine dinucleotide monooxygenase gene.Key words: Aspergillus ochraceus, Aspergillus westerdijkiae, Agrobacterium-mediated transformation, Agrobacterium-mediated insertional mutagenesis, ochratoxin A.

Ochratoxin A Production by Some Fungal Species in Relation to Water Activity and Temperature

1979 ◽  
Vol 42 (6) ◽  
pp. 485-490 ◽  
Author(s):  
M. D. NORTHOLT ◽  
H. P. VAN EGMOND ◽  
W. E. PAULSCH
Keyword(s):  
Ochratoxin A ◽  
Water Activity ◽  
Minimum Temperature ◽  
Fungal Species ◽  
Aspergillus Ochraceus ◽  
Optimum Temperature ◽  
Temperature Range ◽  
Penicillium Cyclopium ◽  
Agar Media ◽  
Penicillium Viridicatum

The effects of water activity (aw) and temperature on growth of and ochratoxin A (OA) production by strains of Aspergillus ochraceus, Penicillium cyclopium, and Penicillium viridicatum were investigated. On agar media in which the aw had been adjusted by addition of sucrose or glycerol, the minimum aw values for OA production by A. ochraceus, P. cyclopium and P. viridicatum lay between 0.83–0.87, 0.87–0.90, and 0.83–0.86, respectively. At 24 C, optimum aw values for OA production by A. ochraceus and P. cyclopium were 0.99 and 0.95–0.99, respectively, whereas that of P. viridicatum varied and was 0.95 and 0.99 for the two strains tested. At optimum aw, the temperature range for OA production by A. ochraceus was 12–37 C, whereas that of P. cyclopium and P. viridicatum was 4–31 C. Optimum temperature for OA production by A. ochraceus was 31 C, whereas that of P. cyclopium and P. viridicatum was 24 C. On Edam cheese of 0.95 aw the minimum temperature for OA production by P. cyclopium was 20 C. On barley meal, P. viridicatum produced maximal quantities of OA at 0.97 aw and could produce OA at temperatures as low as 12 C.

scholarly journals Fungal G-Protein-Coupled Receptors: A Promising Mediator of the Impact of Extracellular Signals on Biosynthesis of Ochratoxin A

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Gao ◽  
Xinge Xu ◽  
Kunlun Huang ◽  
Zhihong Liang
Keyword(s):  
G Protein ◽  
Ochratoxin A ◽  
G Protein Coupled Receptors ◽  
Aspergillus Ochraceus ◽  
Transmembrane Receptors ◽  
Environmental Signals ◽  
Extracellular Signals ◽  
Fungal Biology ◽  
The Impact ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to coordinate cell transport, metabolism, and growth to promote their survival, reproduction, and virulence. There are 14 classes of GPCRs in fungi involved in sensing various ligands. In this paper, the synthesis of mycotoxins that are GPCR-mediated is discussed with respect to ligands, environmental stimuli, and intra-/interspecific communication. Despite their apparent importance in fungal biology, very little is known about the role of ochratoxin A (OTA) biosynthesis by Aspergillus ochraceus and the ligands that are involved. Fortunately, increasing evidence shows that the GPCR that involves the AF/ST (sterigmatocystin) pathway in fungi belongs to the same genus. Therefore, we speculate that GPCRs play an important role in a variety of environmental signals and downstream pathways in OTA biosynthesis. The verification of this inference will result in a more controllable GPCR target for control of fungal contamination in the future.

scholarly journals The Impact of Coastal–Highland Interactions and Population Movements on the Development and Collapse of Complex Societies in Nasca, Peru (AD 500–1450)

2021 ◽  
Vol 32 (2) ◽  
pp. 405-421
Author(s):  
Christina A. Conlee
Keyword(s):  
Complex Societies ◽  
Middle Horizon ◽  
Population Movements ◽  
Social Instability ◽  
Intermediate Period ◽  
Large Numbers ◽  
Political Dominance ◽  
New Type ◽  
The Impact ◽  
First Time

Coastal–highland relationships were important in the development, expansion, and collapse of ancient societies in Nasca, Peru. Connections between the regions began with the earliest occupants and extended through Inca rule; they consisted of the exchange of goods, sharing of ideas, migration, and political dominance. By the end of the Early Intermediate period (Late Nasca, AD 500–650), highland relationships intensified, and during the Middle Horizon (AD 650–1000), Nasca for the first time came under highland control as the Wari Empire brought transformations to the region. By the end of the Middle Horizon, Wari had collapsed, and much of the Nasca drainage was abandoned. People emigrated from the region, probably because of drought coupled with political and social instability. When Nasca was repopulated (ca. AD 1200) in the Late Intermediate period, a new type of society developed that was likely the result of large numbers of highland immigrants.

Pedestrian Crowd Dynamics Observed at Merging Sections: Impact of Designs on Movement Efficiency

2017 ◽  
Vol 2622 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Zahra Shahhoseini ◽  
Majid Sarvi ◽  
Meead Saberi ◽  
Milad Haghani
Keyword(s):  
Collective Motion ◽  
Human Movement ◽  
Simulation Tools ◽  
Large Numbers ◽  
Movement Characteristics ◽  
The Difference ◽  
The Impact ◽  
First Time ◽  
Geometric Designs ◽  
Pedestrian Crowd

The need for reliable crowd simulation tools has necessitated an accurate understanding of human behavior and the rules that govern their movements under normal and emergency escapes. This paper investigates the dynamics of merging streams of pedestrians. In the merging sections, the interaction between pedestrians and geometric features of merging sections can significantly impede the collective motion and can increase the possibility of flow breakdown, particularly under emergency conditions. Therefore, to create safe and efficient designs, it is important to study human movement characteristics associated with these types of conflicting geometries. In this study, empirical data collected from large numbers of high-density experiments with people at different desired speed levels were used to explore the effect of different merging configurations (i.e., design and angle) on dynamics of merging crowds. For the first time, this study examined the impact of elevated speed regimes (as a behavioral proxy of emergency escapes) on the movement efficiency of crowds in merging sections with different geometric designs. In particular, this study investigated the impact of these conflicting geometric settings on the average waiting time in the system as a measure of movement efficiency. Results suggest that the experienced delay is dramatically greater in asymmetrical setups compared with the delay in symmetrical setups and that the difference is even more pronounced at elevated levels of pedestrians’ desired speed. These findings give significant insights into the implications of inefficient designs of merging sections for pedestrians’ safety, notably when quick movement of crowds is necessary (e.g., in emergencies).

Syrian Crisis and Migration

2015 ◽  
Vol 12 (3) ◽  
pp. 181-192 ◽  
Author(s):  
Pinar Yazgan ◽  
Deniz Eroglu Utku ◽  
Ibrahim Sirkeci
Keyword(s):  
Human Mobility ◽  
Special Issue ◽  
Host Countries ◽  
Syrian Crisis ◽  
Mass Migration ◽  
Large Numbers ◽  
And Migration ◽  
Europe Today ◽  
The Impact ◽  
Near Future

With the growing insurrections in Syria in 2011, an exodus in large numbers have emerged. The turmoil and violence have caused mass migration to destinations both within the region and beyond. The current "refugee crisis" has escalated sharply and its impact is widening from neighbouring countries toward Europe. Today, the Syrian crisis is the major cause for an increase in displacement and the resultant dire humanitarian situation in the region. Since the conflict shows no signs of abating in the near future, there is a constant increase in the number of Syrians fleeing their homes. However, questions on the future impact of the Syrian crisis on the scope and scale of this human mobility are still to be answered. As the impact of the Syrian crisis on host countries increases, so does the demand for the analyses of the needs for development and protection in these countries. In this special issue, we aim to bring together a number of studies examining and discussing human mobility in relation to the Syrian crisis.

Relationship between big five personality model and abusive supervision

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Bibi Tahira ◽  
Naveed Saif ◽  
Muhammad Haroon ◽  
Sadaqat Ali
Keyword(s):  
Big Five ◽  
Abusive Supervision ◽  
State Universities ◽  
Big Five Personality ◽  
Big Five Model ◽  
The Impact ◽  
First Time ◽  
Supervisor Behavior ◽  
Moderating Role

The current study tries to understand the diverse nature of relationship between personality Big Five Model (PBFM) and student's perception of abusive supervision in higher education institutions of Khyber Pakhtoonkhwa Pakistan. Data was collected in dyads i.e. (supervisors were asked to rate their personality attributes while student were asked to rate the supervisor behavior) through adopted construct. For this purpose, data was collected from three government state universities and one Private Sector University. The focus was on MS/M.Phill and PhD student and their supervisors of the mentioned universities. After measuring normality and validity regression analysis was conducted to assess the impact of supervisor personality characteristics that leads to abusive supervision. Findings indicate interestingly that except agreeableness other four attributes of (PBFM) are play their role for abusive supervision. The results are novel in the nature as for the first time Neuroticism, openness to experience, extraversion and conscientiousness are held responsible for the abusive supervision. The study did not explore the demographic characteristics, and moderating role of organizational culture, justice and interpersonal deviances to understand the strength of relationship in more detail way. Keywords: Personality big five model, abusive supervision, HEIs

The Influence of TRIPS Compliant Patent Laws on Indian Pharmaceutical Industry

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Rupesh Rastogi ◽  
Virendra Kumar
Keyword(s):  
Pharmaceutical Industry ◽  
Patent Protection ◽  
Uruguay Round ◽  
Pharmaceutical Products ◽  
Trips Agreement ◽  
Patent Law ◽  
Patent Laws ◽  
The Impact ◽  
First Time ◽  
Indian Pharmaceutical Industry

The first legislation in India relating to patents was the Act VI of 1856. The Indian Patents and Design Act, 1911 (Act II of 1911) replaced all the previous Acts. The Act brought patent administration under the management of Controller of Patents for the first time. After Independence, it was felt that the Indian Patents & Designs Act, 1911 was not fulfilling its objective. Various comities were constituted to recommend, framing a patent law which can fulfill the requirement of Indian Industry and people. The Indian Patent Act of 1970 was enacted to achieve the above objectives. The major provisions of the act, provided for process, not the product patents in food, medicines, chemicals with a term of 14 years and 5-7 for chemicals and drugs. The Act enabled Indian citizens to access cheapest medicines in the world and paved a way for exponential growth of Indian Pharmaceutical Industry. TRIPS agreement, which is one of the important results of the Uruguay Round, mandated strong patent protection, especially for pharmaceutical products, thereby allowing the patenting of NCEs, compounds and processes. India is thereby required to meet the minimum standards under the TRIPS Agreement in relation to patents and the pharmaceutical industry. India’s patent legislation must now include provisions for availability of patents for both pharmaceutical products and processes inventions. The present paper examines the impact of change in Indian Patent law on Pharmaceutical Industry.

The impact of traditional plants and their secondary metabolites in the discovery of COVID-19 treatment

2020 ◽  
Vol 26 ◽  
Author(s):  
Shabana Bibi ◽  
Ayesha Sarfraz ◽  
Ghazala Mustafa ◽  
Zeeshan Ahmed ◽  
Muhammad Aurang Zeb ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Test System ◽  
Chemical Information ◽  
System Type ◽  
The Family ◽  
Comprehensive Search ◽  
Coronavirus Infection ◽  
The Impact ◽  
First Time ◽  
Plant Sources

Background: Coronavirus Disease-2019 belongs to the family of viruses which cause a serious pneumonia along with fever, breathing issues and infection of lungs for the first time in China and later spread worldwide. Objective: Several studies and clinical trials have been conducted to identify potential drugs and vaccines for Coronavirus Disease-2019. The present study listed natural secondary metabolites identified from plant sources with antiviral properties and could be safer and tolerable treatment for Coronavirus Disease-2019. Methods: A comprehensive search on the reported studies was conducted using different search engine such as Google scholar, SciFinder, Sciencedirect, Medline PubMed, and Scopus for the collection of research articles based on plantderived secondary metabolites, herbal extracts, and traditional medicine for coronavirus infections. Results: Status of COVID-19 worldwide and information of important molecular targets involved in COVID-19 is described and through literature search, is highlighted that numerous plant species and their extracts possess antiviral properties and studied with respect to Coronavirus treatments. Chemical information, plant source, test system type with mechanism of action for each secondary metabolite is also mentioned in this review paper. Conclusion: The present review has listed plants that have presented antiviral potential in the previous coronavirus pandemics and their secondary metabolites which could be significant for the development of novel and a safer drug which could prevent and cure coronavirus infection worldwide.

Individual and Combined Assessment of Ser680Asn FSH Receptor and FSHβ -211 G>T Gene Polymorphisms in Ovarian Response in IVF/ICSI Program

2020 ◽  
Vol 21 ◽  
Author(s):  
Elli Anagnostou ◽  
Alexia Kafkoutsou ◽  
Despina Mavrogianni ◽  
Ekaterini Domali ◽  
Evangelia Dimitroulia ◽  
...  
Keyword(s):  
Gene Polymorphism ◽  
Gene Polymorphisms ◽  
Ovarian Response ◽  
Greek Population ◽  
Control Group ◽  
Genotype Distribution ◽  
Β Subunit ◽  
Molecular Genetic Study ◽  
The Impact ◽  
First Time

Background: Molecular biology tools, such as the detection of single nucleotide polymorphisms (SNPs), have been considered to assist to the management of the ovarian stimulation protocols. Purpose: The aim of this study was to evaluate the impact of two polymorphisms, the Asn680Ser polymorphism of the FSHR gene, and the FSH β subunit (FSHβ) gene polymorphism -211 G>T, in a Greek population of women undergoing IVF/ICSI program in our center. In addition, a control group of fertile women was studied, to verify whether there are differences in the genotype distribution between fertile and infertile population for both polymorphisms, as the FSHβ gene polymorphism -211 G>T is studied for the first time in the Greek population. Results : The FSH β-211 G>T polymorphism, studied for the first time in the Greek infertile population, appears to be quite rare. When studying the two polymorphisms separately, statistically significant differences were obtained that concerned the LH levels. Discussion: According to the combination analysis of the two polymorphisms by the number of alleles, women with 2-3 polymorphic alleles needed more days of stimulation, but there were no differences in pregnancy rates. Conclusion: This molecular genetic study helps to elucidate whether the polygenic combination of the Asn680Ser and FSH β subunit -211 G>T gene polymorphisms is of additive value in the prediction of ovarian response to exogenous gonadotropins.

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