Fluoranthene Biodegradation by Serratia sp. AC-11 Immobilized into Chitosan Beads.

The intensive production of polycyclic aromatic hydrocarbons by anthropogenic activities is a serious environmental problem. Therefore, new bioremediation methods are required to avoid widespread contamination. In this work, Serratia sp. AC-11 strain isolated from a tropical peat was selected for immobilization into chitosan beads, which were employed in the biodegradation of fluoranthene. The sizes of the produced beads were relatively uniform with an average diameter of 3 mm. The material was characterized by SEM and FT-IR, confirming the cells immobilization and the protective barrier formed by the chitosan surrounding the biomass. The immobilized bacteria were able to degrade 56% of fluoranthene (the initial concentration was 100 mg L-1) in just 1 day at twice the degradation rate achieved by free-living cells. Furthermore, the immobilized bacteria showed excellent removal during five reuse cycles, from 76% to 59% of biodegradation. These results showed the potential of this approach for remediation of contaminated sites.

Occurrence in Brazil of Haplaxius crudus (Hemiptera: Cixiidae), Vector of Coconut Lethal Yellowing.

The lethal yellowing (LY) is a major phytoplasma causing disease seriously threatening coconut plantations worldwide, with imminent risk of entering Brazil. The LY phytoplasma is restricted to the phloem and transmitted by the planthopper Haplaxius crudus (Van Duzee) (Cixiidae). In this study, Auchenorrhyncha were collected on the leaves of Dwarf vs. Dwarf hybrids and Brazilian Green Dwarf Jiqui in the Brazilian northern state of Para using yellow adhesive traps in May of 2016. The planthopper H. crudus was found in coconut plantations of Brazilian Green Dwarf Jiqui, accounting for 87% of the individuals captured. This is the first report of vector H. crudus in Brazilian coconut plantations. These findings are of great scientific relevance since H. crudus could negatively impact the Brazilian coconut industry and this knowledge could be used in contingency measures in the case of LY be introduced in the country.

Assessment of genetic diversity of a native population of Eplingiella fruticosa: a plant with therapeutic potential.

Eplingiella fruticosa (Salzm. ex Benth.) Harley & J.F.B. Pastore, ex Hyptis fruticosa Salzm. ex Benth. is an aromatic and medicinal plant of the family Lamiaceae, found mainly in regions with intense anthropic activity. Information on the genetic diversity of this species is scarce. However, it can be assessed using molecular markers that identify the level of diversity among phenotypically identical individuals. The present study aimed to characterize the genetic diversity of a native population of E. fruticosa from the State of Sergipe using ISSR molecular markers. Samples of 100 plants were collected in 11 municipalities of the State of Sergipe and analyzed using eight ISSR primers, resulting in 72 informative bands. The cluster analysis obtained using the neighbor joining method resulted in three groups: Group I consisted of 50 plants, mainly from the municipalities of Areia Branca, Estância, Japaratuba, Moita Bonita, Pirambu, and Salgado; Group II was formed by 21 plants, with nine representatives from the municipality of Itaporanga d'Ajuda and 13 representatives from other municipalities; Group III was composed by 29 plants, being represented mainly by the municipalities of Malhada dos Bois and São Cristóvão. The smallest genetic distance occurred between plants EPF94 and EPF96 (0.250), and the greatest distance occurred between plants EPF50 and EPF96 (0.9778). The Shannon index had a mean value of 0.42, and diversity was considered moderate. Heterozygosity had a mean value of 0.267 and was considered low. Polymorphic information content (0.253) was considered moderately informative. Genetic diversity of E. fruticosa plants was intermediate, and the results of the present study can assist in the conservation and use of the genetic resources of this species.

Genetic diversity analysis of Varronia curassavica Jacq. accessions using ISSR markers.

Varronia curassavica Jacq. is a medicinal and aromatic plant from Brazil with significant economic importance. Studies on genetic diversity in active germplasm banks (AGB) are essential for conservation and breeding programs. The aim of this study was to analyze the genetic diversity of V. curassavica accessions of the AGB of Medicinal and Aromatic Plants of the Federal University of Sergipe (UFS), using inter-simple sequence repeat molecular markers. Twenty-four primers were tested, and 14 were polymorphic and informative, resulting in 149 bands with 97.98% polymorphism. The UPGMA dendrogram divided the accessions into Clusters I and II. Jaccard similarity coefficients for pair-wise comparisons of accessions ranged between 0.24 and 0.78. The pairs of accessions VCUR-001/VCUR-503, VCUR-001/VCUR-504, and VCUR-104/VCUR-501 showed relatively low similarity (0.24), and the pair of accessions VCUR-402/VCUR- 403 showed medium similarity (0.78). Twenty-eight accessions were divided into three distinct clusters, according to the STRUCTURE analysis. The genetic diversity of V. curassavica in the AGB of UFS is low to medium, and it requires expansion. Accession VCUR-802 is the most suitable for selection in breeding program of this species, since it clearly represents all of the diversity present in the AGB.

Construction and characterization of a BAC library from the Coffea arabica genotype Timor Hybrid CIFC 832/2.

Most of the world's coffee production originates from Coffea arabica, an allotetraploid species with low genetic diversity and for which few genomic resources are available. Genomic libraries with large DNA fragment inserts are useful tools for the study of plant genomes, including the production of physical maps, integration studies of physical and genetic maps, genome structure analysis and gene isolation by positional cloning. Here, we report the construction and characterization of a Bacterial Artificial Chromosome (BAC) library from C. arabica Timor Hybrid CIFC 832/2, a parental genotype for several modern coffee cultivars. The BAC library consists of 56,832 clones with an average insert size of 118 kb, which represents a dihaploid genome coverage of five to sixfold. The content of organellar DNA was estimated at 1.04 and 0.5 % for chloroplast and mitochondrial DNA, respectively. The BAC library was screened for the NADPH-dependent mannose-6-phosphate reductase gene (CaM6PR) with markers positioned on four linkage groups of a partial C. arabica genetic map. A mixed approach using PCR and membrane hybridization of BAC pools allowed for the discovery of nine BAC clones with the CaM6PR gene and 53 BAC clones that were anchored to the genetic map with simple sequence repeat markers. This library will be a useful tool for future studies on comparative genomics and the identification of genes and regulatory elements controlling major traits in this economically important crop species.