Innovative spectral characterisation of beached pelagic sargassum towards remote estimation of biochemical and phenotypic properties.

In recent years, pelagic sargassum (S. fluitans and S. natans - henceforth sargassum) macroalgal blooms have become more frequent and larger with higher biomass in the Tropical Atlantic region. They have environmental and socio-economic impacts, particularly on coastal ecosystems, tourism, fisheries and aquaculture industries, and on public health. Despite these challenges, sargassum biomass has the potential to offer commercial opportunities in the blue economy, although, it is reliant on key chemical and physical characteristics of the sargassum for specific use. In this study, we aim to utilise remotely sensed spectral profiles to determine species/morphotypes at different decomposition stages and their biochemical composition to support monitoring and valorisation of sargassum. For this, we undertook dedicated field campaigns in Barbados and Ghana to collect, for the first time, in situ spectral measurements between 350 and 2500 nm using a Spectra Vista Corp (SVC) HR-1024i field spectrometer of pelagic sargassum stranded biomass. The spectral measurements were complemented by uncrewed aerial system surveys using a DJI Phantom 4 drone and a DJI P4 multispectral instrument. Using the ground and airborne datasets this research developed an operational framework for remote detection of beached sargassum; and created spectral profiles of species/morphotypes and decomposition maps to infer biochemical composition. We were able to identify some key spectral regions, including a consistent absorption feature (920-1080 nm) found in all of the sargassum morphotype spectral profiles; we also observed distinction between fresh and recently beached sargassum particularly around 900-1000 nm. This work can support pelagic sargassum management and contribute to effective utilisation of the sargassum biomass to ultimately alleviate some of the socio-economic impacts associated with this emerging environmental challenge.

Quality of life and adherence to treatment in early-treated Brazilian phenylketonuria pediatric patients

Early dietary treatment of phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism, results in normal cognitive development. Although health-related quality of life (HRQoL) of PKU patients has been reported as unaffected in high-income countries, there are scarce data concerning HRQoL and adherence to treatment of PKU children and adolescents from Brazil. The present study compared HRQoL scores in core dimensions of Brazilian early-treated PKU pediatric patients with those of a reference population, and explored possible relationships between adherence to treatment and HRQoL. Early-treated PKU pediatric patient HRQoL was evaluated by self- and parent-proxy reports of the Pediatric Quality of Life Inventory (PedsQL) core scales. Adherence to treatment was evaluated by median Phe levels and percentage of results within the therapeutic target range in two periods. Means for total and core scales scores of PedsQL self- and parent proxy-reports of PKU patients were significantly lower than their respective means for controls. Adequacy of median Phe concentrations and the mean percentage of values in the target range fell substantially from the first year of life to the last year of this study. There was no significant difference in mean total and core scale scores for self- and parent proxy-reports between patients with adequate and those with inadequate median Phe concentrations. The harmful consequences for intellectual capacity caused by poor adherence to dietary treatment could explain the observed decrease in all HRQoL scales, especially in school functioning. Healthcare system and financial difficulties may also have influenced negatively all HRQoL dimensions.

Quality of life and adherence to treatment in early-treated Brazilian phenylketonuria pediatric patients.

Early dietary treatment of phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism, results in normal cognitive development. Although health-related quality of life (HRQoL) of PKU patients has been reported as unaffected in high-income countries, there are scarce data concerning HRQoL and adherence to treatment of PKU children and adolescents from Brazil. The present study compared HRQoL scores in core dimensions of Brazilian early-treated PKU pediatric patients with those of a reference population, and explored possible relationships between adherence to treatment and HRQoL. Early-treated PKU pediatric patient HRQoL was evaluated by self- and parent-proxy reports of the Pediatric Quality of Life Inventory (PedsQL) core scales. Adherence to treatment was evaluated by median Phe levels and percentage of results within the therapeutic target range in two periods. Means for total and core scales scores of PedsQL self- and parent proxy-reports of PKU patients were significantly lower than their respective means for controls. Adequacy of median Phe concentrations and the mean percentage of values in the target range fell substantially from the first year of life to the last year of this study. There was no significant difference in mean total and core scale scores for self- and parent proxy-reports between patients with adequate and those with inadequate median Phe concentrations. The harmful consequences for intellectual capacity caused by poor adherence to dietary treatment could explain the observed decrease in all HRQoL scales, especially in school functioning. Healthcare system and financial difficulties may also have influenced negatively all HRQoL dimensions.

Molecular characterization of Oenococcus oeni genes encoding proteins involved in arginine transport.

AIMS: This work was carried out to complete the sequence of the arc cluster involved in arginine catabolism in Oenococcus oeni, and particularly to characterize the genes encoding proteins involved in arginine transport. METHODS AND RESULTS: Using molecular cloning, two loci encoding proteins involved in the arginine-ornithine antiport were isolated. Their expression patterns were monitored by RT-PCR to study the influence of arginine on their transcription. Polycistronic mRNAs were detected. PCR performed directly on colonies with primer pairs specific of arc genes was used to discriminate strains able/unable to degrade arginine. CONCLUSIONS: Oenococcus oeni contains two arcD loci encoding similar proteins. Their expression is not influenced by arginine and polycistronic messengers were detected. The inability to use arginine is due to a lack of genetic information encoding proteins of the arginine deiminase pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: The constitutive expression of arcD genes points to the positive role of arginine on O. oeni cell growth. The occasional presence of all the arc ABCD genes together in O. oeni strains might provide insights into the growth rate variability within this species.

The arcABC gene cluster encoding the arginine deiminase pathway of Oenococcus oeni, and arginine induction of a CRP-like gene.

Oenococcus oeni, the main species which induces malolactic fermentation in wine, uses arginine via the arginine deiminase (ADI) pathway. Using degenerated primers, two specific probes, one for ornithine transcarbamoylase (OTC) and the other for carbamate kinase (CK), were synthesized. These made it possible to clone and sequence a cluster containing genes encoding ADI (arcA), OTC (arcB) and CK (arcC). In addition, sequence analysis upstream of the arcA gene revealed the presence of an open reading frame (orf229) whose 3'-end was only 101 bp-distant from the start codon of the arcA gene and showed similarity with members of the FNR (regulation for fumarate and nitrate reduction) and CRP (cAMP receptor protein) family of transcriptional regulators. Moreover, a putative binding site for such regulators lies in the promoter region of the arcA gene. Induction of the arc cluster by arginine was studied first at the enzymatic level. The activities of the three enzymes strongly increased when cells were grown in the presence of the amino acid. In addition, the influence of arginine on gene transcription was monitored by RT-PCR (reverse transcriptase-polymerase chain reaction). Expression of the three arc genes, and particularly that of arcA, was positively affected by arginine supplementation and thus confirmed the enzymatic results. Moreover, transcription of the putative CRP-like gene orf229 was also stimulated by arginine. These data suggest that the protein encoded by orf229 could be a CRP-like regulator involved in the metabolism of O. oeni.

Metabolism of arginine and its positive effect on growth and revival of Oenococcus oeni.

Oenococcus oeni is the main lactic acid bacteria species which induces malolactic fermentation during wine-making. It is able to break down arginine via the arginine deiminase pathway, a potential source of energy already considered for many bacteria. The production of ATP by starved cells from arginine was quantified with a bioluminescence assay, and efficient coupling of amino acid catabolism and cell growth was monitored. Therefore, molecular growth yield was determined after glucose exhaustion. With colony plate counting and a direct epifluorescence technique, it was shown that addition of arginine to viable but non-culturable cells obtained after nutrient starvation restored their ability to grow during its degradation. Therefore, arginine produced more than maintenance energy. It is concluded that strains which are able to metabolize arginine might take advantage of this additional energy source for growth.