Only three different bacterial phyla were identified: Proteobacteria, Actinobacteria, and Firmicutes (Alvarez-Perez et al. 2012). Within these phyla, Gammaproteobacteria seemed to be the most dominant. These results were paralleled in Fridman et al.’s (2012) study. Fridman and colleagues examined three plant species: Amygdalus communis, Citrus paradisi, and Nicotiana glauca. Gammaproteobacteria were the dominant species in these nectars making up 59% of the isolates in A. communis, 82% of the isolates in C. paradisi, and 45% of isolates in N. glauca. Another noteworthy finding that emerged from work by Fridman et al. (2012) was the discovery of novel bacteria species in each of the three plant species studied. The presence of novel bacteria species may be indicative of nectar playing a selective role in filtering out bacteria unsuited for the habitat within nectar as well as leading to newly developed species or genera that are better adapted for the specific characteristics in nectar. The bacteria isolated from nectar had key physiological characteristics. Species were able to grow in the presence of 3% H2 O2 indicating catalase production in these bacterial isolates. Additionally the isolates were able to grow at low levels of oxygen (microbaerobiosis) and could generally tolerate sucrose levels of 10%- 30%.
    Pozo et al. (2011) identified two species of yeasts, Metschnikowia reukaufii (73.4% nectar drops) and Metschnikowia gruessii (29.7% nectar drops) together having a frequency of 84.7% among the 216 yeast isolates – there were 12 total yeast species isolated. The yeast species M. reukaufii has been found as a chief inhabitant of nectar.

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