Publications

4833

The activity of denitrifying methanotrophic bacteria at 11–30 °C was assessed in short-term experiments. The aim was to determine the feasibility of applying denitrifying methanotrophic bacteria in low-temperature anaerobic wastewater treatment. This study showed that biomass enriched at 21 °C had an optimum temperature of 20–25 °C and that activity dropped as temperature was increased to 30 °C. Biomass enriched at 30 °C had an optimum temperature of 25–30 °C. These results indicated that biomass from low-temperature inocula adjusted to the enrichment temperature and that low-temperature enrichment is suitable for applications in low-temperature wastewater treatment. Biomass growth at ≤20 °C still needs to be studied.

ABSTRACT We report here the draft genome sequence of “ Candidatus Liberibacter asiaticus” strain HHCA, collected from a lemon tree in California. The HHCA strain has a genome size of 1,150,620 bp, 36.5% G+C content, 1,119 predicted open reading frames, and 51 RNA genes.

ABSTRACT Phytoplasmas are unculturable plant-pathogenic bacteria causing devastating damage to agricultural production worldwide. Here, we report the draft genome sequence of “ Candidatus Phytoplasma asteris” strain OY-V. Most of the known virulence factors and host-interacting proteins were conserved in OY-V. This genome furthers our understanding of genetic diversity and pathogenicity of phytoplasmas.

A set of experiments was carried out to characterize how temperature affects the spread of chrysanthemum yellows phytoplasma (CYP), a strain of Candidatus Phytoplasma asteris, in Chrysanthemum carinatum plants transmitted by the Macrosteles quadripunctulatus leafhopper. Experiments provided data on CYP latency period in insect and plant host, M. quadripunctulatus adult mortality rate, and epidemics progression in plants under controlled conditions inside climatic chambers. Experiments were conducted at temperatures ranging between 15 and 30°C. Empirical laws for temperature-dependent epidemiological parameters were next derived and used in a dynamical model of the epidemics progression. Experiments showed that CYP epidemics was faster at higher temperatures and the model could replicate these observations with relatively high accuracy (correlation >98.03% and residuals <14.5%). The epidemics spreading rate increased linearly from 0.2 plants infected per day at 15°C to about 0.7 plants per day at 30°C, possibly due to: i) faster CYP multiplication in the host plants and ii) higher frequency of feeding bouts of M. quadripunctulatus at higher temperatures.