scholarly journals EVALUATION OF XYLANASE PRODUCTION FROM FILAMENTOUS FUNGI WITH DIFFERENT LIFESTYLES

2020 ◽  
Vol 49 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Y. Bakri ◽  
Y. Akeed ◽  
M. Jawhar ◽  
M.I.E Arabi

Xylanase plays an important role in the food, feed, and pulp/paper industry. Filamentous fungi have been considered as useful producers of this enzyme from an industrial point of view, due to the fact that they excrete xylanases into the medium. In this study, four fungal species belonging to different genera, i.e. Aspergillus, Cochliobolus, Pyrenophora, and Penicillium were isolated from different sources and compared for their ability to produce xylanase in submerged culture. The fungal species showed enzyme activity as determined by dinitrosalicylic acid (DNS) method. It was found that the two saprophytic Aspergillus strains, i.e A. terreus (Fss 129) and A. niger (SS7) had the highest xylanase activity of 474 and 294 U ml–1 at pH 7 and 8, respectively, in the presence of corn cob hulls after 120 h of incubation. The production of xylanase seemed to be strongly influenced by the interactive effect of initial pH on the fungi. Interestingly, xylanase was better produced by the saprophytic fungi of Aspergillus and Penicillium than by the plant pathogenic ones of Cochliobolus and Pyrenophora. This work provides additional information to support future research on fungi with different lifestyles for food industrial production of xylanase.

2021 ◽  
Vol 2 ◽  
Author(s):  
Xinhui Wang ◽  
Karolina Subko ◽  
Sara Kildgaard ◽  
Jens C. Frisvad ◽  
Thomas O. Larsen

Aspergillus section Flavi includes some of the most famous mycotoxin producing filamentous fungi known to mankind. In recent years a number of new species have been included in section Flavi, however these species have been much less studied from a chemical point of view. In this study, we explored one representative strain of a total of 28 fungal species in section Flavi by systematically evaluating the relationship between taxonomy and secondary metabolites with LC-MS/MS analysis for the first time and dereplication through an in-house database and the Global Natural Product Social Molecular Networking (GNPS) platform. This approach allowed rapid identification of two new cyclopiazonic acid producers (A. alliaceus and A. arachidicola) and two new tenuazonic acid producers (A. arachidicola and A. leporis). Moreover, for the first time we report species from section Flavi to produce fumifungin and sphingofungins B-D. Altogether, this study emphasizes that the chemical diversity of species in genus Aspergillus section Flavi is larger than previously recognized, and especially that understudied species are prolific producers of important mycotoxins such as fumi- and sphingofungins not previously reported from this section. Furthermore, our work demonstrates Global Natural Product Social (GNPS) Molecular Networking as a powerful tool for large-scale chemotaxonomic analysis of closely related species in filamentous fungi.


1997 ◽  
Vol 35 (2-3) ◽  
pp. 85-91
Author(s):  
D. A. Barton ◽  
J. D. Woodruff ◽  
T. M. Bousquet ◽  
A. M. Parrish

If promulgated as proposed, effluent guidelines for the U.S. pulp and paper industry will impose average monthly and maximum daily numerical limits of discharged AOX (adsorbable organic halogen). At this time, it is unclear whether the maximum-day variability factor used to establish the proposed effluent guidelines will provide sufficient margin for mills to achieve compliance during periods of normal but variable operating conditions within the pulping and bleaching processes. Consequently, additional information is needed to relate transient AOX loadings with final AOX discharges. This paper presents a simplistic dynamic model of AOX decay during treatment. The model consists of hydraulic characterization of an activated sludge process and a first-order decay coefficient for AOX removal. Data for model development were acquired by frequent collection of influent and effluent samples at a bleach kraft mill during a bleach plant shutdown and startup sequence.


Author(s):  
Jyoti Sharma ◽  
Lata Raj ◽  
Anil Gupta

The purpose of this study is to measure the existence of co-creation behavior between doctors and patients. The research also studies customer participation and customer citizenship behavior as the dimensions of co-creative behavior and tries to establish the relationship between co-creative behavior and satisfaction. This study uses Yi and Gong (2013) scale for collecting data regarding co-creation behavior and its dimensions which are customer participation (CP) and customer citizenship behavior (CCB). The data was collected from 204 patients who were suffering from various chronic/lifestyle diseases and getting their treatment from private clinics in Jammu city. The study uses 7-point Likert scale in the questionnaire ranging from 1 completely disagree through 7 completely agree, with a midpoint labeled 4 neither agree nor disagree. The analysis of paper reflects that co-creation behavior is prevalent among the patients and not only participation but the citizenship behavior also affects the co-creation behavior of patients. The study is conducted from patients point of view whereas doctors perspective should also be used in future research. The research area is restricted to Jammu city only. The research provides several implications-doctors can also use this scale for market segmentation and customer profiling for maximizing customer value co-creation behavior by gaining the useful information.


2021 ◽  
Vol 22 (8) ◽  
pp. 4214
Author(s):  
Gautam Anand ◽  
Meirav Leibman-Markus ◽  
Dorin Elkabetz ◽  
Maya Bar

Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.


1982 ◽  
Vol 3 (2) ◽  
pp. 183-194 ◽  
Author(s):  
Nicholas Dorn ◽  
Nigel South

A review of the available empirical material bearing upon the question of alcohol advertising having ‘effects’ on the general level of consumption suggests that this question is insufficiently precise as a basis for research. Studies suggesting some relationship between advertising for particular brands or products and shifts in brand or product use are potentially more interesting, if considered from a point of view that recognises that such shifts may involve shifts in milieux, comparisons, styles and meanings associated with consumption. Future research should be attentive to such qualitative changes in drinking practices attendant upon advertising or preventive campaigns (as well as to quantitative changes). The authors suggest that such quantitative and qualitative changes in drinking practices of individuals and social groups need to be considered within the context of more general, ideological and economic, consequences of alcohol advertising. These consequences-including reinforcement of images about ‘social drinking,’ and shifting of consumers onto more profitable products-consolidate the profitability of the alcohol industry (a consideration more important to the industry than levels of consumption per se). A framework broader than that of ‘effects’ on individuals' levels of consumption is required if health educators are to learn anything from advertising.


2015 ◽  
Vol 176 (1) ◽  
pp. 317-319 ◽  
Author(s):  
N. Pérez-Rodríguez ◽  
F. Oliveira ◽  
B. Pérez-Bibbins ◽  
I. Belo ◽  
A. Torrado Agrasar ◽  
...  

2017 ◽  
Vol 30 (11) ◽  
pp. 886-895 ◽  
Author(s):  
Maria Chiara Paccanaro ◽  
Luca Sella ◽  
Carla Castiglioni ◽  
Francesca Giacomello ◽  
Ana Lilia Martínez-Rocha ◽  
...  

Endo-polygalacturonases (PGs) and xylanases have been shown to play an important role during pathogenesis of some fungal pathogens of dicot plants, while their role in monocot pathogens is less defined. Pg1 and xyr1 genes of the wheat pathogen Fusarium graminearum encode the main PG and the major regulator of xylanase production, respectively. Single- and double-disrupted mutants for these genes were obtained to assess their contribution to fungal infection. Compared with wild-type strain, the ∆pg mutant showed a nearly abolished PG activity, slight reduced virulence on soybean seedlings, but no significant difference in disease symptoms on wheat spikes; the ∆xyr mutant was strongly reduced in xylanase activity and moderately reduced in cellulase activity but was as virulent as wild type on both soybean and wheat plants. Consequently, the ΔpgΔxyr double mutant was impaired in xylanase, PG, and cellulase activities but, differently from single mutants, was significantly reduced in virulence on both plants. These findings demonstrate that the concurrent presence of PG, xylanase, and cellulase activities is necessary for full virulence. The observation that the uronides released from wheat cell wall after a F. graminearum PG treatment were largely increased by the fungal xylanases suggests that these enzymes act synergistically in deconstructing the plant cell wall.


1995 ◽  
Vol 387 ◽  
Author(s):  
J. L. Hoyt ◽  
P. Kuo ◽  
K. Rim ◽  
J. J. Welser ◽  
R. M. Emerson ◽  
...  

AbstractMaterial and device challenges for Rapid Thermal Processing (RTP) of heterostructures are discussed, focusing on RTP-based epitaxy in the Si/Si1−xGex system. While RTP-based heteroepitaxy offers enhanced processing flexibility, it also poses significant challenges for temperature measurement and control. Several examples of Si/Si1−xGex device structures are discussed from the point of view of the sensitivity of device parameters to variations in layer thickness and composition. The measured growth kinetics for Si and Si1−xGex are then used to estimate growth temperature tolerances for these structures. Demanding applications are expected to require temperature control and uniformity to within 0.5°C.Future research challenges include the fabrication of structures with monolayer thickness control using self-limited growth techniques. Atomic layer epitaxy (ALE) is a well-known example of such a growth technique. In ALE, the wafer is cyclically exposed to different reactants, to achieve layer-by-layer growth. An RTP-based atomic layer epitaxy process, and its application to the growth of CdTe films, is briefly discussed. The extension to Column IV alloys follows readily. The RTP-based process enables self-limited growth for precursor combinations for which isothermal ALE is not feasible.


2019 ◽  
Vol 25 (6) ◽  
pp. 1228-1250 ◽  
Author(s):  
Lidia Sanchez-Ruiz ◽  
Beatriz Blanco ◽  
Emma Diaz

Purpose The purpose of this paper is to define a general and common construct in order to measure the level of difficulty companies experience when they implement continuous improvement (CI). Additionally, a rank of barriers is obtained together with a rank of companies. Design/methodology/approach In order to achieve the objective, first, a literature review is carried out to specify the domain of the construct; second, a sample of items is selected; third a survey is carried out in companies that have already implemented CI initiatives, the results being thus limited to this population; fourth, measures are purified by analysing the reliability and validity of the measurements, and finally results are obtained. The Rasch measurement theory will be used to provide a new perspective on a mature research topic. Findings It can be concluded that a new valid construct has been defined together with a rank of CI barriers, being lack of time the main barrier. A rank of companies is also obtained which is a first step in the development of future research studies. Practical implications Managers are provided with a better understanding of the barriers that can obstruct CI implementation. Thus, the rank of CI barriers guides managers through the most common and important obstacles so that they will be able to plan better CI strategies. In addition, the rank of companies allows each company to undertake a benchmarking exercise. Originality/value This work proposes a new way of analysing the difficulty in implementing CI as a continuum, rather than as independent barriers. From a theoretical point of view, it defines a new construct and offers a rank of CI barriers together with a rank of companies based on their level of difficulty when implementing CI initiatives. This is something new, as previous studies were mainly focussed on the items side. From a practical point of view, this study offers the surveyed companies the opportunity to see how they are positioned with respect to the other companies. Moreover, this rank of companies is the foundation on which to develop further studies with a practical orientation in the future.


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