La Producción De Enzimas Ligninolíticas

World J Microbiol Biotechnol DOI 10.1007/s11274-012-1175-2

ORIGINAL PAPER

Evaluation of a potential starter culture for enhance quality of coffee fermentation
Cristina Ferreira Silva • Danielle Marques Vilela • ´ Cecılia de Souza Cordeiro • Whasley Ferreira Duarte Disney Ribeiro Dias • Rosane Freitas Schwan
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Received: 12 June 2012 / Accepted: 18 September 2012 Ó SpringerScience+Business Media Dordrecht 2012

Abstract The coffee fermentation is characterized by the presence of different microorganisms belonging to the groups of bacteria, fungi and yeast. The objectives of this work were to select pectinolytic microorganisms isolated from coffee fermentations and evaluate their performance on coffee pulp culture medium. The yeasts and bacteria isolates were evaluated fortheir activity of polygalacturonase (PG), pectin lyase (PL) and pectin methylesterase (PME) and metabolites production. Among 127 yeasts isolates and 189 bacterial isolates, 15 were pre-selected based on their ability to produce PL and organic compounds. These isolates were strains identified as Bacillus cereus, Bacillus megaterium, Bacillus subtilis, Candida parapsilosis, Pichia caribbica, Pichiaguilliermondii and Saccharomyces cerevisiae. When cultivated in Coffee peel and pulp media in single culture or two by two mixed inocula, different behavior concerning to PME, PL and PG were found. The two principal components PC1 and PC2 accounted for 45.27 and 32.02 % of the total variance. UFLA CN727 and UFLA CN731 strains were grouped in the positive part of PC1 being characterized by1,2-propanediol, hexanoic acid, decanoic acid, nonanoic acid and ethyl acetate. The UFLA CN448 and UFLA CN724 strains were grouped in the negative part of PC1 and were mainly characterized by guaiacol, butyric acid and citronellol. S. cerevisiae UFLACN727, P. guilliermondii UFLACN731
C. F. Silva Á C. de Souza Cordeiro Á W. F. Duarte Á R. F. Schwan (&) Department of Biology, Federal University of Lavras,Lavras, MG CEP 37200-000, Brazil e-mail: rschwan@dbi.ufla.br D. M. Vilela Á D. R. Dias Department of Food Science, Federal University of Lavras, ´ Campus Universitario, Lavras, MG CEP 37200-000, Brazil

and C. parapsilosis UFLACN448 isolates are promising candidates to be tested in future studies as coffee starter cultures. Keywords Pectinolytic enzymes Á Pichia guilliermondii Á Saccharomycescerevisiae Á Organic acids Á Principal component analysis

Introduction Coffee is one of the most appreciated non-alcoholic drinks, and its consumption is distributed globally. It commands a turnover close to US$10 billion per annum, which makes it the second-most important commodity traded in world markets, next to petroleum. Brazil is the leading producer and exporter of Coffea arabica (ABIC 2010)followed by Colombia, Paraguay, Venezuela, Indonesia, Ethiopia, India, Mexico and 40 other countries. Coffee fruits are processed after harvesting to allow spontaneous or indigenous fermentation to occur. This process may be either a dry or wet process or a combination of both (a semi-dry process). Arabica coffee (Coffea arabica) in Brazil and Robusta coffee (Coffea canephora) in West Africa areusually dry processed, which makes them ‘‘natural’’ coffees. For dry processing, the fruits are harvested in several stages of maturation (green, cherry, raisin and dry). The coffee fruits remain intact after harvesting and are spread out in thin layers (5–8 cm) on cement patios without being washed to dry for up to 20 days. The pulp and mucilage within the fruit ferment during this drying period(Silva et al. 2000, 2008). Recent works point that coffee is substrate favorable to the production of ochratoxin A (OTA) especially when there is a microbiota already established which can alter the substrate and favor the production of

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OTA by Aspergillus or Penicillium species (Mantle and Chow 2000). Some yeast species isolated from coffee fruits, can...