Publicaciones 2011-2020

@article{RN384,
title = {Cold-Active Pectinolytic Activity Produced by Filamentous Fungi Associated with Antarctic Marine Sponges},
author = { G. Poveda and C. Gil-Duran and I. Vaca and G. Levican and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000442838400001},
doi = {10.1186/s40659-018-0177-4},
issn = {0716-9760},
year = {2018},
date = {2018-01-01},
journal = {Biological Research},
volume = {51},
abstract = {Background: Pectinase enzymes catalyze the breakdown of pectin, a keywords component of the plant cell wall. At industrial level, pectinases are used in diverse applications, especially in food-processing industry. Currently, most of the industrial pectinases have optimal activity at mesophilic temperatures. On the contrary, very little is known about the pectinolytic activities from organisms from cold climates such as Antarctica. In this work, 27 filamentous fungi isolated from marine sponges collected in King George Island, Antarctica, were screened as new source of cold-active pectinases., Results: In semi-quantitative plate assays, 8 out 27 of these isolates showed pectinolytic activities at 15 degrees C and one of them, Geomyces sp. strain F09-T3-2, showed the highest production of pectinases in liquid medium containing pectin as sole carbon source. More interesting, Geomyces sp. F09-T3-2 showed optimal pectinolytic activity at 30 degrees C, 10 degrees C under the temperature of currently available commercial mesophilic pectinases., Conclusion: Filamentous fungi associated with Antarctic marine sponges are a promising source of pectinolytic activity. In particular, pectinases from Geomyces sp. F09-T3-2 may be potentially suitable for biotechnological applications needing cold-active pectinases. To the best of our knowledge, this is the first report describing the production of pectinolytic activity from filamentous fungi from any environment in Antarctica.},
keywords = {antarctic cold-active diversity, enzymes, filamentous fungi, geomyces geomyces, marine pectinases, polygalacturonase, purification, sp., sponges, strains yeasts},
pubstate = {published},
tppubtype = {article}
}

@article{RN180,
title = {Diversity of Cultivable Fungi Associated with Antarctic Marine Sponges and Screening for Their Antimicrobial, Antitumoral and Antioxidant Potential},
author = { M. Henriquez and K. Vergara and J. Norambuena and A. Beiza and F. Maza and P. Ubilla and I. Araya and R. Chavez and A. San-Martin and J. Darias and M.J. Darias and I. Vaca},
url = {/brokenurl#<Go to ISI>://WOS:000329248200007},
doi = {10.1007/s11274-013-1418-x},
issn = {0959-3993},
year = {2014},
date = {2014-01-01},
journal = {World Journal of Microbiology & Biotechnology},
volume = {30},
number = {1},
pages = {65-76},
abstract = {The diversity of sponge-associated fungi has been poorly investigated in remote geographical areas like Antarctica. In this study, 101 phenotypically different fungal isolates were obtained from 11 sponge samples collected in King George Island, Antarctica. The analysis of ITS sequences revealed that they belong to the phylum Ascomycota. Sixty-five isolates belong to the genera Geomyces, Penicillium, Epicoccum, Pseudeurotium, Thelebolus, Cladosporium, Aspergillus, Aureobasidium, Phoma, and Trichocladium but 36 isolates could not be identified at genus level. In order to estimate the potential of these isolates as producers of interesting bioactivities, antimicrobial, antitumoral and antioxidant activities of fungal culture extracts were assayed. Around 51 % of the extracts, mainly from the genus Geomyces and non identified relatives, showed antimicrobial activity against some of the bacteria tested. On the other hand, around 42 % of the extracts showed potent antitumoral activity, Geomyces sp. having the best performance. Finally, the potential of the isolated fungi as producers of antioxidant activity seems to be moderate. Our results suggest that fungi associated with Antarctic sponges, particularly Geomyces, would be valuable sources of antimicrobial and antitumoral compounds. To our knowledge, this is the first report describing the biodiversity and the metabolic potential of fungi associated with Antarctic marine sponges.},
keywords = {antarctic antimicrobial, antioxidant, antitumoral, bioactive coastal diversity, fungi, geomyces haliclona-simulans, identification, metabolites, microorganisms natural-products, penicillium, phylogenetic sp., sponges, suberites-zeteki, syndrome, waters, white-nose},
pubstate = {published},
tppubtype = {article}
}

@article{RN188,
title = {Cold-Active Xylanase Produced by Fungi Associated with Antarctic Marine Sponges},
author = { A. Del-Cid and P. Ubilla and M.C. Ravanal and E. Medina and I. Vaca and G. Levican and J. Eyzaguirre and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000331005200043},
doi = {10.1007/s12010-013-0551-1},
issn = {0273-2289},
year = {2014},
date = {2014-01-01},
journal = {Applied Biochemistry and Biotechnology},
volume = {172},
number = {1},
pages = {524-532},
abstract = {Despite their potential biotechnological applications, cold-active xylanolytic enzymes have been poorly studied. In this work, 38 fungi isolated from marine sponges collected in King George Island, Antarctica, were screened as new sources of cold-active xylanases. All of them showed xylanase activity at 15 and 23 A degrees C in semiquantitative plate assays. One of these isolates, Cladosporium sp., showed the highest activity and was characterized in detail. Cladosporium sp. showed higher xylanolytic activity when grown on beechwood or birchwood xylan and wheat bran, but wheat straw and oat bran were not so good inducers of this activity. The optimal pH for xylanase activity was 6.0, although pH stability was slightly wider (pH 5-7). On the other hand, Cladosporium sp. showed high xylanase activity at low temperatures and very low thermal stability. Interestingly, thermal stability was even lower after culture media were removed and replaced by buffer, suggesting that low molecular component(s) of the culture media could be important in the stabilization of cold-active xylanase activity. To the best of our knowledge, this study is the first report on extracellular xylanase production by fungi associated with Antarctic marine sponges.},
keywords = {antarctic cladosporium cold-active fungi, marine sp., sponges, stability thermostability, xylanases},
pubstate = {published},
tppubtype = {article}
}