199 research outputs found

    Exploring the Bacterial Communities of Infernaccio Waterfalls: A Phenotypic and Molecular Characterization of Acinetobacter and Pseudomonas Strains Living in a Red Epilithic Biofilm

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    Acquarossa river (Viterbo, Italy) was the site of a prospering Etruscan civilization thanks to metallurgical activity around 625-550 B.C. This caused the spread of heavy metals throughout the area. Rocks along the river probably act as a filter for these elements and they are covered by two different biofilms (epilithons). They differ for both color and bacterial composition. One is red and is enriched with Pseudomonas strains, while the other one is black and Acinetobacter is the most represented genus. Along the river lay the Infernaccio waterfalls, whose surrounding rocks are covered only by the red epilithon. The bacterial composition of this biofilm was analyzed through high throughput sequencing and compared to those ones of red and black epilithons of Acquarossa river. Moreover, cultivable bacteria were isolated and their phenotype (i.e., resistance against antibiotics and heavy metals) was studied. As previously observed in the case of Acquarossa river, characterization of bacterial composition of the Infernaccio red epilithon revealed that the two most represented genera were Acinetobacter and Pseudomonas. Nonetheless, these strains differed from those isolated from Acquarossa, as revealed by RAPD analysis. This work, besides increasing knowledge about the ecological properties of this site, allowed to isolate new bacterial strains, which could potentially be exploited for biotechnological applications, because of their resistance against environmental pollutants

    Marine Biocatalysts: Enzymatic Features and Applications

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    In several recent reports related to biocatalysis the enormous pool of biodiversity found in marine ecosystems is considered a profitable natural reservoir for acquiring an inventory of useful biocatalysts. These enzymes are characterized by well-known habitat-related features such as salt tolerance, hyperthermostability, barophilicity and cold adaptivity. In addition, their novel chemical and stereochemical characteristics increase the interest of biocatalysis practitioners both in academia and research industry. In this review, starting from the analysis of these featuring habitat-related properties, important examples of marine enzymes in biocatalysis will be reported. Completion of this report is devoted to the analysis of novel chemical and stereochemical biodiversity offered by marine biocatalysts with particular emphasis on current or potential applications of these enzymes in chemical and pharmaceutical fields. The analysis of literature cited here and the many published patent applications concerning the use of marine enzymes supports the view that these biocatalysts are just waiting to be discovered, reflecting the importance of the marine environment. The potential of this habitat should be thoroughly explored and possibly the way to access useful biocatalysts should avoid destructive large-scale collections of marine biomass for enzyme production. These two aspects are day by day increasing in interest and a future increase in the use of marine enzymes in biocatalysis should be expected

    Evidence-based guidelines for use of probiotics in preterm neonates

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    <p>Abstract</p> <p>Background</p> <p>Current evidence indicates that probiotic supplementation significantly reduces all-cause mortality and definite necrotising enterocolitis without significant adverse effects in preterm neonates. As the debate about the pros and cons of routine probiotic supplementation continues, many institutions are satisfied with the current evidence and wish to use probiotics routinely. Because of the lack of detail on many practical aspects of probiotic supplementation, clinician-friendly guidelines are urgently needed to optimise use of probiotics in preterm neonates.</p> <p>Aim</p> <p>To develop evidence-based guidelines for probiotic supplementation in preterm neonates.</p> <p>Methods</p> <p>To develop core guidelines on use of probiotics, including strain selection, dose and duration of supplementation, we primarily used the data from our recent updated systematic review of randomised controlled trials. For equally important issues including strain identification, monitoring for adverse effects, product format, storage and transport, and regulatory hurdles, a comprehensive literature search, covering the period 1966-2010 without restriction on the study design, was conducted, using the databases PubMed and EMBASE, and the proceedings of scientific conferences; these data were used in our updated systematic review.</p> <p>Results</p> <p>In this review, we present guidelines, including level of evidence, for the practical aspects (for example, strain selection, dose, duration, clinical and laboratory surveillance) of probiotic supplementation, and for dealing with non-clinical but important issues (for example, regulatory requirements, product format). Evidence was inadequate in some areas, and these should be a target for further research.</p> <p>Conclusion</p> <p>We hope that these evidence-based guidelines will help to optimise the use of probiotics in preterm neonates. Continued research is essential to provide answers to the current gaps in knowledge about probiotics.</p

    Anaerobic thermophiles

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    The term -extremophilenorm of matrix was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of -extremenorm of matrix environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally -hot environmentsnorm of matrix on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely made this area of investigation more exciting. Particularly fascinating are their structural and physiological features allowing them to withstand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA-polymerase, thermostable enzymes), the search and applications successful exceeded preliminary expectations, but certainly further exploitations are still needed. © 2014 by the authors; licensee MDPI, Basel, Switzerland
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