Geography, Planning and Development

Candidatus Accumulibacter belongs to phosphate-accumulating organisms (PAOs) which exhibit a cyclic metabolism and are capable of intracellular polyphosphate accumulation and their hydrolysis under feast-famine anaerobic-aerobic cycling. In consortia of activated sludge microorganisms, these bacteria are responsible for enhanced biological phosphorus removal (EBPR). The spectrum of the substrates used by Ca. Accumulibacter remains insufficiently studied. It was investigated by measuring the oxygen uptake rates (OUR) of Ca. Accumulibacter-enriched culture supplemented with 17 different organic substrates. The highest oxygen uptake rate values were observed in the presence of tryptone, volatile fatty acids (acetate, propionate, and butyrate), succinate, pyruvate, and amino acids (aspartate and glutamate). Phosphate dynamics in the medium under shifts from anaerobic to aerobic cultivation in batch experiments were studied for these compounds (except for tryptone). All tested substrates were shown to cause phosphate cycling (release in the anaerobic phase and uptake in the aerobic one), with OURs for the substrates correlating with the number of phosphates consumed during the aerobic phase. It was concluded that OUR may be used as an indicator of the monosubstrates used by Ca. Accumulibacter in the anaerobic/aerobic cycle. The possible pathways for substrate transport and metabolism by Ca. Accumulibacter are discussed using stoichiometric data and the results of metagenomic analysis.

La producción de cítricos en Nicaragua es de importancia económica ya que genera divisas al país y además esta industria genera empleos directos e indirectos. Sin embargo, las áreas citrícolas están amenazadas por la enfermedad conocida como huanglongbing (HLB), la cual es transmitida por el psílido Diaphorina citri. Por lo tanto, la presente investigación tuvo como objetivo principal generar información relacionada con la detección del agente causal del HLB (Candidatus Liberibacter asiaticus – CLas) y la fluctuación poblacional de Diaphorina citri en cuatro viveros de cítricos del departamento de Masaya, Nicaragua. Durante cuatro meses se realizó la detección del agente causal del huanglongbing a través de la técnica de PCR, se determinó la fluctuación poblacional del vector y el efecto del uso de insecticidas sobre la fluctuación poblacional del insecto. En el estudio de fluctuación poblacional se usaron trampas amarillas, las cuales se revisaron a intervalos de ocho días. Se detectó al agente causal del huanglongbing en los cuatro viveros. Los tres estadios del psílido se presentaron durante el periodo de estudio. Los mayores picos poblacionales de los adultos se presentaron en abril, coincidiendo con altas temperaturas y bajas precipitaciones. La variante CLas es la que estuvo presente en los cuatros viveros. La fluctuación poblacional de Diaphorina citri por vivero fue variable a través del tiempo. Los picos poblacionales más altos se observaron en el mes de abril. Las aplicaciones de insecticidas redujeron las poblaciones de Diaphorina citri en cada uno de los viveros

Objective: The objective of this study was to investigate the group/subgroup of phytoplasma agent in peppers showing phytoplasma symptoms. Material and Methods: In this study, plants collected from Iğdır province in 2020 were analyzed using direct and nested PCR tests, and BLASTn, iphyClassifier, Mega 7, and pDRAW32 programs were used. Results: In the tests performed, approximately 1.2 kb of DNA fragments specific to phytoplasma were obtained. The 16S rRNA nucleotide sequence (1254 bp in length) (OM663745) revealed that it was showed more than 99.44% nucleotide similarity to other ‘Ca. P. trifolii’ members. The tentative RFLP and phylogenetic analyzes performed proved the ‘Ca. P. trifolii’ the infection from the Clover proliferation group (16SrVI) group and subgroup A in symptomatic pepper plants. Conclusion: The presence of ‘Ca. P. trifolii’ in naturally infected peppers in Iğdır province of Turkey was detected using PCR-RFLP and cladistic analysis.