African Journal of Microbiology Research Vol. 7(7), pp. 586-594, 12 February, 2013
Available online at http://www.academicjournals.org/AJMR
DOI: 10.5897/AJMR12.2036
ISSN 1996-0808 ©2013 Academic Journals
Full Length Research Paper
Diversity of endophytic bacteria in the fruits of Coffea
canephora
Paulo Sérgio Balbino Miguel, Julio Cesar Delvaux, Marcelo Nagem Valério de Oliveira,
Larissa Cassemiro Pacheco Monteiro, Fernanda de Souza Freitas, Maurício Dutra Costa,
Marcos Rogério Tótola, Célia Alencar de Moraes and Arnaldo Chaer Borges*
Departamento de Microbiologia /Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa,
Viçosa, Minas Gerais, 36570-000, Brazil.
Accepted 8 February, 2013
Endophytic bacteria colonize the internal tissues of plants without causing infection or negative effects
on their hosts. This study investigates the occurrence and diversity of culturable endophytic bacteria in
the fruits of Coffea canephora at three developmental stages. Isolation and quantification were
performed in R2A culture medium, and the diversity was established using molecular methods and
analysis of fatty acid methyl esters (FAME). α- and γ-Proteobacteria, Actinobacteria, Firmicutes, and
Bacteroidetes were identified in the investigated community. Kocuria turfanensis and Pantoea vagans
were identified as endophytes for the first time. Of the 18 species that were found, the following seven
had not been previously described as endophytic in coffee fruits: Bacillus thuringiensis, Bacillus
licheniformis, Agrobacterium tumefaciens, Escherichia coli, Enterobacter hormaechei,
Chryseobacterium sp., and Ochrobactrum sp. The diversity of endophytic bacteria varied during the
three developmental stages that were investigated, and the diversity was greatest in fruits during the
green stage, during which Bacillus subtilis predominated. The number of Gram-positive bacteria was
larger than the number of Gram-negative bacteria during the two earliest developmental stages,
whereas their numbers were similar during the ripe stage. The diversity was lowest during the ripe
stage, and Klebsiella oxytoca was the predominant species at this stage, probably due to the higher
caffeine and sugar contents in the fruits.
Key words: Coffee, bacterial community, sequencing, 16S rDNA, FAME.
INTRODUCTION
The economic and social importance of coffee can be
assessed using data provided by the International Coffee
Organization, which estimates that 75 to 125 million
individuals worldwide are dependent on coffee-related
activities. In Brazil, the coffee production chain generates
more than eight million jobs (MAPA, 2012).
Coffee plants belong to the family Rubiaceae, which
comprises approximately 650 genera and more than
13,000 species (Delprete and Jardim, 2012). The most
widely cultivated are Coffea arabica, which produces
superior-quality coffee beverages due to its organoleptic
*Corresponding author. E-mail: chaer@ufv.br. Tel: +55(31)
3899 2976. Fax: +55(31) 3899 2573.
properties (Judd et al., 2008), and Coffea canephora,
which produces neutral, weak-flavored, and very bitter
coffee beverages (Ky et al., 2001). The raw material for
the instant coffee industry is derived from C. canephora,
and this species was used in 50 to 55% of the blends
manufactured in Brazil in 2011, which represents a 20%
increase compared to 2000 (ABIC, 2012). The Brazilian
coffee research program is the largest in the world, and
investments in this research have produced significant
advances in breeding, plant nutrition, biotechnology, and
other areas (MAPA, 2012). Recently, the map of the C.
arabica genome was made available for functional
genomics studies (Vieira et al., 2006). Although the
International Coffee Genome Network - ICGN is currently
mapping the genome of C. canephora, no studies
investigating the colonization of its fruits by endophytes were