Uloga Paecilomyces lilacinus (Thom) Samson i drugih vrsta gljiva u biodegradaciji ohratoksina A

Nine isolates of fungi of genera Aspergillus, Fusarium, Paecilomyces and Penicillium were cultured on the modified Vogel's medium with the addition of crude ochratoxin A (OTA) extract. This crude OTA extract was derived from a natural solid substrate on which Aspergillus ochraceus strain CBS 108.08 was cultivated. OTA was isolated, partially purified, dried by evaporating and dissolved in ethanol (1 mg ml-1), and added to the test medium up to the final concentration of 10 μg ml-1. The presence of OTA residues was determined after 7 and 14 day cultivation of fungi in the test medium at 27±1°C. The Paecilomyces lilacinus isolate (Inf. 2/A), which completely degraded OTA (150 μg) after only seven days, was selected for further studies. Wet sterile rice grains (50 g + 25 ml distilled water) were inoculated with individual isolates of fungi A. ochraceus (strain CBS 108.08) and P. lilacinus (isolate Inf. 2/A), and with their combination. In the case of P. lilacinus monoculture, 0.9 mg of crude OTA was also added into cultivation substrate. Each test was done in three replications. After the four week cultivation of individual and combined fungi at 27±1°C, inoculated rice grains were dried to the constant weight and pulverized. OTA was determined in these samples by the application of standard TLC method for fodder analysis. OTA in the amount of 61.310 μg kg-1 dry matter (DM) was determined only in the samples inoculated with a producer of ochratoxin A (A. ochraceus, strain CBS 108.08). On the other hand, a much smaller amount of OTA (80 μg kg-1 DM) was detected in samples inoculated with combined cultures of A. ochraceus and P. lilacinus isolates. Gained results indicate that P. lilacinus degraded, on average, 99.8% of OTA. After four week cultivation, the same fungal isolate in the samples of wet sterile rice kernels with the addition of 0.9 mg of crude OTA, completely degraded added crude OTA ( lt 8 μg kg-1).Devet izolata gljiva iz rodova Aspergillus, Fusarium, Paecilomyces i Penicillium gajeno je na modifikovanoj Vogelovoj podlozi sa dodatkom sirovog ekstrakta ohratoksina A (OTA). Sirovi ekstrakt OTA je dobijen iz čvrstog prirodnog supstrata na kojem je gajen soj Aspergillus ochraceus CBS 108.08. Izolovan i delimično prečišćen OTA, uparen do suvog ostatka i rastvoren u etanolu (1 mg ml-1), dodat je u test podlogu do finalne koncentracije 10 μg ml-1. Nakon sedam i 14 dana gajenja kultura gljiva u test podlozi na 27 ± 1°C de terminisano je prisustvo rezidua OTA primenom modifikovane metode Filtenborg-a i sar. (1983). Od devet testiranih izolata za dalja ispitivanja je odabran izolat Paecilomyces lilacinus (Inf. 2/A), koji je već posle sedam dana u potpunosti razgradio inicijalnu količinu OTA (150 μg). U drugom delu eksperimenta vlažno sterilno zrno pirinča (50 g + 25 ml destilovane vode) zasejano je sa pojedinačnim izolatima A. ochraceus (CBS 108.08) i P. lilacinus (Inf. 2-A), kao i kombinacijom oba izolata. U slučaju mono-kulture P. lilacinus u podlogu je dodat i sirovi OTA (0,9 mg). Svaki od testova je urađen u 3 ponavljanja. Nakon četiri nedelje gajenja monokultura i mešanih kul tura gljiva na 27±1°C, inokulisana zrna su osušena do konstantne težine i sa mlevena do finog praha. U ovim uzorcima izvršena je determinacija OTA primenom standardne metode tankoslojne hromatografije za analizu stočne hrane. U uzorcima koji su bili zasejani samo sa producentom OTA (A. ochraceus, soj CBS 108.08) detektovan je OTA u prosečnoj količini od 61.310 μg kg-1 suvog ostatka. U uzorcima koji su bili zasejani kombinovanim kulturama izolata A. ochraceus i P. lilacinus utvrđena je znatno manja prosečna količina OTA (80 μg kg-1). Ovi rezultati ukazuju da je izolat P. lilacinus razgradio prosečno 99,8% OTA prisutnog u podlozi za kultivaciju. U uzorcima vlažnog sterilnog zrna pirinča sa dodatkom 0,9 mg sirovog OTA isti gljivični izolat je posle četiri nedelje kultivacije kompletno biorazgradio dodat sirovi OTA ( lt 8 μg kg-1)

Synthesis and characterization of spider silk calcite composite

Spider silk poses excellent mechanical properties, tenacity and elasticity and it has been used as a template for calcite mineralization to improve load bearing strength of osteoconductive calcite. The samples were obtained by mimicking biomineralization for five days in order to follow formation and growth of calcite on the surface of spider silk. Crystal phase was detected by XRD and FTIR spectroscopy. Microstructure, crystal size and its morphology were studied by means of FESEM. After two days of processing, pure calcite phase was obtained, and a size of the formed crystals increased with prolongation of biomineralization

In vitro degradacija diacetoksiscirpenola i T-2 toksina posredstvom izolata Mucor racemosus fresen. f. racemosus

Under controlled in vitro conditions the capacity of the Mucor racemosus f. racemosus 1215/09 isolate to degrade type A trichothecenes (diacetoxyscirpenol - DAS and T-2 toxin) was observed in the liquid nutritive medium. According to previously performed experiments it was proved that the selected isolate, originating from sunflower meal, had the ability to degrade these fusariotoxins when growing on the modified Vogel's agar supplemented with crude extracts of DAS and T-2 toxin. In order to determine biodegradation of fusariotoxins, the liquid nutritive medium - SPY (5% sucrose + 0.1% peptone + 0.1% yeast extract, pH 6.2) was simultaneously inoculated with the isolate M. racemosus f. racemosus 1215/09 and: a) Fusarium semitectum SL-B (DAS producer) or b) F. sporotrichioides R-2301 (T-2 toxin producer). The SPY media, inoculated with single fungal isolates, were used as a control of toxin biosynthesis. The cultures were incubated at room temperature (21-26ºC) on the rotary shaker (175 rpm). After the 3-5-day incubation, the filtration of liquid cultures and the extraction of fusariotoxins from filtrates with ethyl-acetate were performed. Determinations of DAS and T-2 toxin were done by thin layer chromatography using silica gel G. Depending on the incubation duration, M. racemosus f. racemosus in the mixed culture with F. semitectum degraded from 90.0 to 99.97% of DAS present in the medium (40,000- 120,000 µg l-1), while in the mixed culture with F. sporotrichioides it degraded from 95.0 to 96.7% of T-2 toxin present in the medium (240,000 µg l-1). Sterile filtrates of mixed cultures and single culture of M. racemosus f. racemosus, obtained by passing liquid cultures through the 0.45-µm membrane filter and added to the SPY medium, did not affect degradation of type A trichothecenes that had been biosynthesised by isolates F. semitectum SL-B and F. sporotrichioides R-2301 in the liquid medium.U kontrolisanim in vitro uslovima proučavana je sposobnost izolata Mucor racemosus f. racemosus 1215/09 da degraduje trihotecene tipa A (diacetoksiscirpenol - DAS i T-2 toksin) u tečnoj hranljivoj podlozi. Prethodnim eksperimentima je dokazano da odabrani izolat, poreklom sa suncokretove sačme, poseduje sposobnost razgradnje navedenih fuzariotoksina, koji su kao sirovi ekstrakti dodati u modifikovanu Vogelovu podlogu. U cilju utvrđivanja biodegradacije fuzariotoksina tečna hranljiva podloga SPK (5% saharoza + 0,1% pepton + 0,1% ekstrakt kvasca, pH 6,2) je zasejana u isto vreme izolatom M. racemosus f. racemosus 1215/09 i: a) Fusarium semitectum SL-B (proizvođač DAS-a) ili b) F. sporotrichioides R-2301 (proizvođač T-2 toksina). Kao kontrola biosinteze toksina korišćena je SPK podloga inokulisana pojedinačnim izolatima gljiva. Kulture su inkubirane na rotacionoj tresilici (175 o/min) tokom 3-5 dana na sobnoj temperaturi (21-26ºC). Nakon 3 do 5 dana inkubacije vršeno je filtriranje tečnih kultura i ekstrakcija fuzariotoksina iz filtrata etil-acetatom. Determinacija DAS-a i T-2 toksina je rađena tankoslojnom hromatografijom na silika gelu G. Zavisno od dužine inkubacije, M. racemosus f. racemosus je u združenoj kulturi sa F. semitectum degradovala 90,0-99,97% DAS-a prisutnog u podlozi (40.000-120.000 µg l-1), dok je u združenoj kulturi sa F. sporotrichioides razgradila 95,0-96,7% T-2 toksina prisutnog u podlozi (240.000 µg l-1). Sterilni filtrati mešanih kultura i pojedinačne kulture M. racemosus f. racemosus, dobijeni propuštanjem tečnih kultura kroz 0,45 µm membranski filter i dodati SPK podlozi, nisu uticali na razgradnju trihotecena tipa A koje su biosintetisali izolati F. semitectum SL-B i F. sporotrichioides R-2301 u tečnoj podlozi

Oxidation and erosion behaviour of SiC-HfC multilayered composite

The fabrication of SiC-HfC ceramic composite via self-propagating high-temperature synthesis and simultaneous consolidation was investigated. Dense composite consisting of alternating layers of SiC and HfC was obtained by spark plasma sintering of stack of SiC cloths covered by electrophoretically deposited HfO2. The deposited HfO2 was converted into HfC during sintering. The obtained ceramics was characterized in terms of microstructure, cavitation resistance and oxidation resistance. It was shown that spark plasma sintering is effective way to preserve fibre-like mikrostructure of SiC. The obtained material showed good erosion resistance. The surface layer of HfC transformed to HfO2 during oxidation of samples and protected SiC from further oxidation

Evaluation of Watson-like Integrals for Hyper bcc Antiferromagnetic Lattice

Watson-like integrals for a d-dimensional bcc antiferromagnetic lattice I_d(\eta) and J_d(\eta) and another two similar integrals are evaluated in an exact way in terms of generalized hypergeometric functions. A simple formula connecting Id and Jd+1 is given along with the differential equations for I_d(\eta) and J_d(\eta). An application of I_d and J_d in the theory of the Heisenberg antiferromagnet is discussed, together with possible generalizations to non-integer values of d. Corresponding integrals for sc lattices are also briefly reviewed.Comment: 13 pages, 2 figures, Accepted for publication in Journal of Physics A: Mathematical & Theoretical 201

Degrees of tenant isolation for cloud-hosted software services : a cross-case analysis

A challenge, when implementing multi-tenancy in a cloud-hosted software service, is how to ensure that the performance and resource consumption of one tenant does not adversely affect other tenants. Software designers and architects must achieve an optimal degree of tenant isolation for their chosen application requirements. The objective of this research is to reveal the trade-offs, commonalities, and differences to be considered when implementing the required degree of tenant isolation. This research uses a cross-case analysis of selected open source cloud-hosted software engineering tools to empirically evaluate varying degrees of isolation between tenants. Our research reveals five commonalities across the case studies: disk space reduction, use of locking, low cloud resource consumption, customization and use of plug-in architecture, and choice of multi-tenancy pattern. Two of these common factors compromise tenant isolation. The degree of isolation is reduced when there is no strategy to reduce disk space and customization and plug-in architecture is not adopted. In contrast, the degree of isolation improves when careful consideration is given to how to handle a high workload, locking of data and processes is used to prevent clashes between multiple tenants and selection of appropriate multi-tenancy pattern. The research also revealed five case study differences: size of generated data, cloud resource consumption, sensitivity to workload changes, the effect of the software process, client latency and bandwidth, and type of software process. The degree of isolation is impaired, in our results, by the large size of generated data, high resource consumption by certain software processes, high or fluctuating workload, low client latency, and bandwidth when transferring multiple files between repositories. Additionally, this research provides a novel explanatory framework for (i) mapping tenant isolation to different software development processes, cloud resources and layers of the cloud stack; and (ii) explaining the different trade-offs to consider affecting tenant isolation (i.e. resource sharing, the number of users/requests, customizability, the size of generated data, the scope of control of the cloud application stack and business constraints) when implementing multi-tenant cloud-hosted software services. This research suggests that software architects have to pay attention to the trade-offs, commonalities, and differences we identify to achieve their degree of tenant isolation requirements

Search for Dark Matter with CRESST

The search for direct interactions of dark matter particles remains one of the most pressing challenges of contemporary experimental physics. A variety of different approaches is required to probe the available parameter space and to meet the technological challenges. Here, we review the experimental efforts towards the detection of direct dark matter interactions using scintillating crystals at cryogenic temperatures. We outline the ideas behind these detectors and describe the principles of their operation. Recent developments are summarized and various results from the search for rare processes are presented. In the search for direct dark matter interactions, the CRESST-II experiment delivers competitive limits, with a sensitivity below 5x10^(-7) pb on the coherent WIMP-nucleon cross section.Comment: Accepted for publication in New Journal of Physics. 25 pages, 18 figure

Quantification of structural changes in acute inflammation by fractal dimension, angular second moment and correlation

The aim of the study was to examine alteration and possible application of fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely inflamed tissue. Acute inflammation was induced by injection of turpentine oil into the right and left hind limb muscles of mice, whereas control animals received intramuscular saline injection. After 12h, animals were anesthetised and treated muscles collected. The tissue was stained by hematoxylin and eosin, digital micrographs produced, enabling determination of fractal dimension of the cells, angular second moment and correlation of studied tissue. Histopathological analysis showed presence of inflammatory infiltrate and tissue damage in inflammatory group, whereas tissue structure in control group was preserved, devoid of inflammatory infiltrate. Fractal dimension of the cells, angular second moment and correlation of treated tissue in inflammatory group decreased in comparison to the control group. In this study, we were first to observe and report that fractal dimension of the cells, angular second moment, and correlation were reduced in acutely inflamed tissue, indicating loss of overall complexity of the cells in the tissue, the tissue uniformity and structure regularity. Fractal dimension, angular second moment and correlation could be useful methods for quantification of structural changes in acute inflammation. Lay Description The aim of this study was to examine alteration, and possible application of mathematical parameters fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely-inflamed tissue. An acute inflammation was induced by injection of turpentine oil into mice muscles, whereas control group received intramuscular injection of saline. After 12 h animals were anesthetized, and treated muscles were collected. The tissue was stained, and photos of the tissue were made. Mathematical parameters, namely fractal dimension, angular second moment, and correlation of the tissue photo, were determined by computer program. Standard histopathological analysis showed that inflammatory infiltrate and tissue damage were present in inflammatory group, whereas tissue structure in control group was preserved, and without inflammatory infiltrate. Fractal dimension of the cells, angular second moment and correlation of the treated tissue in inflammatory group decreased, when compared to control group. In this study we reported, for the first time, that fractal dimension of the cells, angular second moment, and correlation had decreased in acutely-inflamed tissue, indicating loss of overall complexity of cells in tissue, tissue uniformity, and structure regularity. Fractal dimension, angular second moment, and correlation could be useful methods for quantification of structural changes in acute inflammation