Suchergebnisse

Two phase olive mill waste (TPOMW) is presently the major waste produced by the olive mill industry. This waste has potential to be used as substrate for solid state fermentation (SSF) despite of its high concentration of phenolic compounds and low nitrogen content. In this work, it is demonstrated that mixtures of TPOMW with winery wastes support the production of lipase by Aspergillus spp. By agar plate screening, Aspergillus niger MUM 03.58, Aspergillus ibericus MUM 03.49 and Aspergillus uvarum MUM 08.01 were chosen for lipase production by SSF. Plackett-Burman experimental design was employed to evaluate the effect of substrate composition and time on lipase production. The highest amounts of lipase were produced by A. ibericus on a mixture of TPOMW, urea and exhausted grape mark (EGM). Urea was found to be the most influent factor for the lipase production. Further optimization of lipase production by A. ibericus using a full factorial design (32) conducted to optimal conditions of substrate composition (0.073 g urea/g and 25% of EGM) achieving 18.67 U/g of lipolytic activity. ; Jose Manuel Salgado is grateful for Postdoctoral fellowship (EX-2010-0402) of Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, Portugal. Authors thank Fundacao para a Ciencia e a Tecnologia (FCT) for financial support through the project FCT ...

Not Available ; Aim: Immobilised fungal phytase production from the novel strain Aspergillus foetidus MTTC 11682 and optimisation of cultural conditions for a better and continuous economic yield. Study Design: The study was designed based on the classical method of changing one independent variable while fixing all other at a certain level- one factor at a time, a close ended system for the optimisation of fermentation process. Methodology: Physical and nutritional parameters were optimised for phytase production and subjected to statistical analysis. Adsorption and Entrapment techniques were employed to immobilise the production strain. Results: The optimum physical conditions for augmenting the yield up to 6 days incubation period were as follows: pH of 3.5, 30ºC temperatures and 5% inoculum size. Amongst the nutritional parameters, lactose and sodium nitrate were found to be the best carbon and nitrogen sources. K++, Mg++, Mn++ and Fe++ ions supported the phytase production. TritonX 100 and tween 80 showed an inducing effect on the secretion of phytase enzyme. Immobilised fungal phytase production resulted in an increased yield of 32.5% with poly urethane foam (PUF) as the matrix. A scale up fermentation resulted in an activity of 52.7 FTU/mL for immobilised cells as compared to 25.5 FTU/mL by its free counterpart. Conclusion: Phytase produced in an optimised media employing immobilised Aspergillus foetidus 11682 on poly urethane foam cubes exhibited better phytase activity, improved stability and long shelf life. ; Department of Biotechnology (S.R.C.No_Bt/PR3178/AAQ/ 01/476/01/476/2011), Government of India

This paper presents antimicrobial activity of some selected plants viz.; Tamarindus indica L, Emblica officinalis Gaertn. Linn, Alpinia nigra (L) willd, Azadiracta indica A.Juss, Cynodon dactylon (L) Pers, Dipteris wallichi L, Curcuma longa L, Chromolena odoratum L, Blechnum orientales, Centella asiatica(L) urban. Methanol and Acetone extract of these plants were used against E. coli, Staphyllococus sp, Klebsiella sp, Candida sp, Aspergillus sp, using disc diffusion method . It has been observed that zone of inhibition of Acetone extract of Alpinia nigra (10.0 mm) against Candida sp, Azadiracta indica(10.0mm) against Aspergillus sp, Apinia nigra (12.5 mm) against E. coli, showed high antimicrobial activity compared to other plant extracts. For Methanol extract, the highest zone of inhibition was observed in Azadiracta indica (20.3 mm, 12.9 mm) against Candida sp and Aspergillus sp, respectively. Whereas Centella asitica (15.0 mm ) showed highest zone of inhibition against E. coli and showed no zone of inhibition against Candida sp. For Staphyllococcus sp the zone of inhibition was found average ranging from (6.0 to9.8) in both Acetone and methanol extract.In case of Klebsiella sp the highest zone of inhibition was found in case of Alpinia nigra (10.0 mm, 11.2 mm) for Methanol and Acetone extract.

The aim of this study was to evaluate the diversity of black aspergilli isolated from berries from different agroclimatic regions of Spain. Growth characterization (in terms of temperature and water activity requirements) of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger was carried out on synthetic grape medium. A. tubingensis and A. niger showed higher maximum temperatures for growth (> 45 °C versus 40-42 °C), and lower minimum aw requirements (0.83 aw versus 0.87 aw) than A. carbonarius. No differences in growth boundaries due to their geographical origin were found within A. niger aggregate isolates. Conversely, A. carbonarius isolates from the hotter and drier region grew and produced OTA at lower aw than other isolates. However, little genetic diversity in A. carbonarius was observed for the microsatellites tested and the same sequence of β-tubulin gene was observed; therefore intraspecific variability did not correlate with the geographical origin of the isolates or with their ability to produce OTA. Climatic change prediction points to drier and hotter climatic scenarios where A. tubingensis and A. niger could be even more prevalent over A. carbonarius, since they are better adapted to extreme high temperature and drier conditions. ; The authors are grateful to the Spanish Government (AGL2010-22182-C04-01), and the Comissionat per a Universitats i Recerca, del Departament d'Innovació, Universitats i Empresa de la Generalitat de Catalunya (AGAUR).

Abstract
This study intends to present an overview from the assessments of fungal contamination and mycotoxins performed in three different occupational environments (Firefighters headquarters - FFH; Waste collection trucks – WCT and; Cemeteries - CM). Active sampling (impaction and impingement methods) and several passive sampling methods (swabs, settled dust, settled dust filters, electrostatic dust cloths – EDC, cleaning materials,…) were employed. Azole resistance screening, the molecular detection of Aspergillus sections, as well as mycotoxin analysis were also conducted. In FFH microbial contamination didn´t comply with Portuguese IAQ legal requirements in most of the FFH, the widespread of Aspergillus section Fumigati in all the FFH was observed, as well as a trend of multidrug resistance with focus on Fumigati isolates. Several mycotoxins (fumonisin B2, nivalenol, mycophenolic acid and sterigmatocystin) were detected. Concerning WCT Aspergillus sp. (4.18 %) was one of the most prevalent species. Aspergillus section Fumigati was detected in 5 samples. Mycotoxins were detected in filters (N=1) and in settled dust samples (N=16). The mycotoxin detected in the filter was fumonisin B1 and the most detected in settled dust was mycophenolic acid. In what concerns CM, Aspergillus sp. presented the highest counts in DG18 (18.38%) and it wasn´t observed in azole-supplemented SDA media. Mycophenolic acid was detected in one settled dust sample.Overall, our study reveals that a comprehensive sampling approach and combined analytic methods is an important asset in microbial exposure assessments. Furthermore, in all the three occupational environments mycotoxins were detected unveiling this occupational health threat.