Diversity of endophytic bacteria in Brazilian sugarcane

Abstract

ABSTRACT. Endophytic bacteria live inside plant tissues without causing disease. Studies of endophytes in sugarcane have focused on the isolation of diazotrophic bacteria. We examined the diversity of endophytic bacteria in the internal tissues of sugarcane stems and leaves, using molecular and biochemical methods. Potato-agar medium was used to cultivate the endophytes; 32 isolates were selected for analysis. DNA was extracted and the 16S rRNA gene was partially sequenced and used for molecular identification. Gram staining, catalase and oxidase tests, and the API-20E system were used to characterize the isolates. The strains were divided into five groups, based on the 16S rRNA sequences. Group I comprised 14 representatives of the Enterobacteriaceae; group II was composed of Bacilli; group III contained one representative, Curtobacterium sp; group IV contained representatives of the Pseudomonadaceae family, and group V had one isolate with an uncultured bacterium. Four isolates were able to reduce acetylene to ethylene. Most of the bacteria isolated from the sugarcane stem and leaf tissues belonged to Enterobacteriaceae and Pseudomonaceae, respectively, demonstrating niche specificity. Overall, we found the endophytic bacteria in sugarcane to be 251 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 9 (1): 250-258 (2010) Microbial diversity in sugarcane more diverse than previously reported.

Diazotrophic bacteria associated to sugarcane varieties cropped at Northeast Region of Brazil

“…Based on this data we can assume that a site specificity of bacterial species distribution may be influencing sugarcane bacterial diversity independent of the plant genotype. In addition, representatives of other genera, such as Kosakonia, Klebsiella, Stenotrophomonas, and some Gram-positive or Gram-variable isolates were also found as previously reported by others, using culture dependent or independent methods (Magnani et al, 2010;Taulé et al, 2012;Fischer et al, 2012;Magnani et al, 2013). The occurrence of representatives of Gluconacetobacter as the most abundant and present in both roots and shoots of sugarcane varieties cropped in Alagoas could be explained by the use of LGI-P medium with addition of sugarcane juice in which the initial pH is 5.7 during isolation procedure.…”

Impact of metagenomic DNA extraction procedures on the identifiable endophytic bacterial diversity in Sorghum bicolor (L. Moench)

“…These genera have previously been detected/isolated from tissues of other graminaceous and non-graminaceous plants including maize, sugarcane, rice, poplar, grapevine and sunflower (Pereira et al, 2011;Magnani et al, 2010;Sun et al, 2008;Ulrich et al, 2008;Compant et al, 2011;Ambrosini et al, 2012), thus indicating that these genera are probably ubiquitous in endophytic environments. This study also shows that the structures of sorghum stem and root communities are significantly different, and this could be explained by the differences in the selectivity of recruitment processes of microbes into each niche environment (Hardoim et al, 2008).…”

Isolation and Characterization of Plant Growth Promoting Rhizobacteria Associated with Saccharum officinarum L.

“…Morphology and texture of each colony was recorded. Colonies were randomly selected and further purified and maintained on nutrient agar slant at 4°C for further studies [7].…”