Publications

4359

The order Solirubrobacterales is a deep-branching lineage within the phylum Actinomycetota . Most representatives have been isolated from terrestrial environments. A strain isolated from a grassland soil was found to be affiliated with this order and therefore characterized by a polyphasic approach. Cells of strain 0166_1T are Gram-positive, short rods, non-motile, non-spore-forming and divide by binary fission. A surface layer with protrusions covers the majority of the cells. Strain 0166_1T grows optimally around neutral to slightly alkaline pH (pH 7.1–7.9) and at temperatures between 24–36 °C in SSE/HD 1 : 10 medium. It grows optimally with 0–0.5% NaCl (w/v) but can withstand concentrations up to 5 %. The major fatty acids are C18 : 1 ω9c, C16 : 1  ω7c, C17 : 0 cyclo ω7c, C18 : 1  ω7c methyl and C19 : 0 cyclo ω9c. The major polar lipids are diphosphatidylglycerol, two unidentified phospholipids and one unidentified glycolipid. MK-7(H4) and MK-7(H2) are the predominant respiratory quinones. meso-2,6-Diaminopimelic acid is the diagnostic diamino acid in the cell-wall peptidoglycan. The G+C content for strain 0166_1T is 72.8 mol%. 16S rRNA gene sequence analysis indicated that this bacterium was related to Conexibacter arvalis KV-962T and Conexibacter stalactiti YC2-25T with 95.5 and 95.2 % sequence similarity, respectively. Based on the phenotypic, genomic and phylogenetic data, we propose the novel species Capillimicrobium parvum sp. nov. (type strain 0166_1T=DSM 104329T=LMG 29999T=CECT 9240T) of the novel genus Capillimicrobium gen. nov. within the novel family Capillimicrobiaceae fam. nov.

Two strains isolated from a sample of activated sludge that was obtained from a seawater-based wastewater treatment plant on the southeastern Mediterranean coast of Spain have been characterized to achieve their taxonomic classification, since preliminary data suggested they could represent novel taxa. Given the uniqueness of this habitat, as this sort of plants are rare in the world and this one used seawater to process an influent containing intermediate products from amoxicillin synthesis, we also explored their ecology and the annotations of their genomic sequences. Analysis of their 16S rRNA gene sequences revealed that one of them, which was orange-pigmented, was distantly related to Vicingus serpentipes (family Vicingaceae ) and to other representatives of neighbouring families in the order Flavobacteriales (class Flavobacteriia ) by 88–89 % similarities; while the other strain, which was yellow-pigmented, was a putative new species of Lysobacter (family Xanthomonadaceae , order Xanthomonadales , class Gammaproteobacteria ) with Lysobacter arseniciresistens as closest relative (97.3 % 16S rRNA sequence similarity to its type strain). Following a polyphasic taxonomic approach, including a genome-based phylogenetic analysis and a thorough phenotypic characterization, we propose the following novel taxa: Parvicella tangerina gen. nov., sp. nov. (whose type strain is AS29M-1T=CECT 30217T=LMG 32344T), Parvicellaceae fam. nov. (whose type genus is Parvicella), and Lysobacter luteus sp. nov. (whose type strain is AS29MT=CECT 30171T=LMG 32343T).

Health monitoring programs in animals used as experimental models are essential, since only disease-free subjects are considered suitable for research purposes. In laboratory-kept animals, hemoplasmas have been described as an important confounding variable. Different hemoplasma species have been detected infecting non-human primates (NHP) from Brazil. However, the occurrence of hemoplasma species in laboratory-kept NHP in Brazil has not-yet been assessed. Accordingly, this study aimed (i) to screen laboratory-kept rhesus monkeys for hemoplasmas, (ii) to verify if any of the hemoplasma-positive animals demonstrate hematological abnormalities, and (iii) to assess the genotype diversity of hemoplasma species in NHP from Brazil. Five out of eight (62.5%; 95% CI: 3.05–8.63) rhesus monkeys tested positive for hemotropic Mycoplasma spp. by PCR. Sequencing, phylogenetic, distance, and genotype diversity analyses of partial 16S rRNA gene demonstrate that rhesus monkeys were infected by ‘Candidatus Mycoplasma haematomacacae’ (formerly ‘Candidatus Mycoplasma haemomacaque’). Assessments of partial 16S rRNA diversity of hemoplasma species in NHP suggest that at least four genetically diverse groups may occur in Brazil. Although no hematological abnormalities were demonstrated in rhesus monkeys evaluated herein, future studies are needed to elucidate the influence of ‘Ca. M. haematomacacae’ as a confounding variable on research studies.

Huanglongbing (otherwise known as HLB or greening) is currently the most devastating citrus disease worldwide. HLB is primarily associated with the phloem-inhabiting bacterium ‘Candidatus Liberibacter asiaticus’ (CLas). Currently, there are no citrus species resistant to CLas. Genetic transformation is one of the most effective approaches used to induce resistance against plant diseases. Antimicrobial peptides (AMPs) have shown potential breakthroughs to improve resistance to bacterial diseases in plants. In this paper, we confirm the Agrobacterium-mediated transformation of Pera sweet orange expressing the AMP sarcotoxin IA (stx IA) gene isolated from the flesh fly Sarcophaga peregrina and its reaction to CLas, involving plant performance and fruit quality assessments. Four independent transgenic lines, STX-5, STX-11, STX-12, and STX-13, and a non-transgenic control, were graft-inoculated with CLas. Based on our findings, none of the transgenic plants were immune to CLas. However, the STX-5 and STX-11 lines showed reduced susceptibility to HLB with mild disease symptoms and low incidence of plants with the presence of CLas. Fruit and juice quality were not affected by the genetic transformation. Further, no residues of the sarcotoxin IA protein were found in the juice of the STX-11 and STX-12 fruits, though detected in the juice of the STX-5 and STX-13 lines, as revealed by the immunoblotting test. However, juices from all transgenic lines showed low traces of sarcotoxin IA peptide in its composition. The accumulation of this peptide did not cause any deleterious effects on plants or in fruit/juice. Our findings reinforce the challenges of identifying novel approaches to managing HLB.