title: Xanthan gum capped ZnO microstars as a promising dietary Zinc supplementation

authors: Ebrahiminezhad, Alireza

subjects: Science & Technology

abstract: Zinc is one of the essential trace elements, and plays an important role in human health. Severe zinc deficiency can negatively affect organs such as the epidermal, immune, central nervous, gastrointestinal, skeletal, and reproductive systems. In this study, we offered a novel biocompatible xanthan gum capped zinc oxide (ZnO) microstar as a potential dietary zinc supplementation for food fortification. Xanthan gum (XG) is a commercially important extracellular polysaccharide that is widely used in diverse fields such as the food, cosmetic, and pharmaceutical industries, due to its nontoxic and biocompatible properties. In this work, for the first time, we reported a green procedure for the synthesis of ZnO microstars using XG, as the stabilizing agent, without using any synthetic or toxic reagent. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used to study the structure, morphology, and size of the synthesized ZnO structures. The results showed that the synthesized structures were both hexagonal phase and starlike, with an average particle size of 358 nm. The effect of different dosages of XG-capped ZnO nanoparticles (1–9 mM) against Gram-negative (Escherichia coli) and Gram-positive (Bacillus licheniformis, Bacillus subtilis, and Bacillus sphaericus) bacteria were also investigated. Based on the results, the fabricated XG-capped ZnO microstars showed a high level of biocompatibility with no antimicrobial effect against the tested microorganisms. The data suggested the potential of newly produced ZnO microstructures for a range of applications in dietary supplementation and food fortification.

text: Xanthan gum capped ZnO microstars as a promising dietary Zinc supplementation Zinc is one of the essential trace elements, and plays an important role in human health. Severe zinc deficiency can negatively affect organs such as the epidermal, immune, central nervous, gastrointestinal, skeletal, and reproductive systems. In this study, we offered a novel biocompatible xanthan gum capped zinc oxide (ZnO) microstar as a potential dietary zinc supplementation for food fortification. Xanthan gum (XG) is a commercially important extracellular polysaccharide that is widely used in diverse fields such as the food, cosmetic, and pharmaceutical industries, due to its nontoxic and biocompatible properties. In this work, for the first time, we reported a green procedure for the synthesis of ZnO microstars using XG, as the stabilizing agent, without using any synthetic or toxic reagent. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used to study the structure, morphology, and size of the synthesized ZnO structures. The results showed that the synthesized structures were both hexagonal phase and starlike, with an average particle size of 358 nm. The effect of different dosages of XG-capped ZnO nanoparticles (1–9 mM) against Gram-negative (Escherichia coli) and Gram-positive (Bacillus licheniformis, Bacillus subtilis, and Bacillus sphaericus) bacteria were also investigated. Based on the results, the fabricated XG-capped ZnO microstars showed a high level of biocompatibility with no antimicrobial effect against the tested microorganisms. The data suggested the potential of newly produced ZnO microstructures for a range of applications in dietary supplementation and food fortification.

year: 2019

title: Thermophilic methane oxidation is widespread in Aotearoa-New Zealand geothermal fields

authors: Houghton, Karen M.

abstract: Geothermal areas represent substantial point sources for greenhouse gas emissions such as methane. While it is known that methanotrophic microorganisms act as a biofilter, decreasing the efflux of methane in most soils to the atmosphere, the diversity and the extent to which methane is consumed by thermophilic microorganisms in geothermal ecosystems has not been widely explored. To determine the extent of biologically mediated methane oxidation at elevated temperatures, we set up 57 microcosms using soils from 14 Aotearoa-New Zealand geothermal fields and show that moderately thermophilic (>40°C) and thermophilic (>60°C) methane oxidation is common across the region. Methane oxidation was detected in 54% (n = 31) of the geothermal soil microcosms tested at temperatures up to 75°C (pH 1.5–8.1), with oxidation rates ranging from 0.5 to 17.4 μmol g−1 d−1 wet weight. The abundance of known aerobic methanotrophs (up to 60.7% Methylacidiphilum and 11.2% Methylothermus) and putative anaerobic methanotrophs (up to 76.7% Bathyarchaeota) provides some explanation for the rapid rates of methane oxidation observed in microcosms. However, not all methane oxidation was attributable to known taxa; in some methane-consuming microcosms we detected methanotroph taxa in conditions outside of their known temperature range for growth, and in other examples, we observed methane oxidation in the absence of known methanotrophs through 16S rRNA gene sequencing. Both of these observations suggest unidentified methane oxidizing microorganisms or undescribed methanotrophic syntrophic associations may also be present. Subsequent enrichment cultures from microcosms yielded communities not predicted by the original diversity studies and showed rates inconsistent with microcosms (≤24.5 μmol d−1), highlighting difficulties in culturing representative thermophilic methanotrophs. Finally, to determine the active methane oxidation processes, we attempted to elucidate metabolic pathways from two enrichment cultures actively oxidizing methane using metatranscriptomics. The most highly expressed genes in both enrichments (methane monooxygenases, methanol dehydrogenases and PqqA precursor peptides) were related to methanotrophs from Methylococcaceae, Methylocystaceae and Methylothermaceae. This is the first example of using metatranscriptomics to investigate methanotrophs from geothermal environments and gives insight into the metabolic pathways involved in thermophilic methanotrophy.

text: Thermophilic methane oxidation is widespread in Aotearoa-New Zealand geothermal fields Geothermal areas represent substantial point sources for greenhouse gas emissions such as methane. While it is known that methanotrophic microorganisms act as a biofilter, decreasing the efflux of methane in most soils to the atmosphere, the diversity and the extent to which methane is consumed by thermophilic microorganisms in geothermal ecosystems has not been widely explored. To determine the extent of biologically mediated methane oxidation at elevated temperatures, we set up 57 microcosms using soils from 14 Aotearoa-New Zealand geothermal fields and show that moderately thermophilic (>40°C) and thermophilic (>60°C) methane oxidation is common across the region. Methane oxidation was detected in 54% (n = 31) of the geothermal soil microcosms tested at temperatures up to 75°C (pH 1.5–8.1), with oxidation rates ranging from 0.5 to 17.4 μmol g−1 d−1 wet weight. The abundance of known aerobic methanotrophs (up to 60.7% Methylacidiphilum and 11.2% Methylothermus) and putative anaerobic methanotrophs (up to 76.7% Bathyarchaeota) provides some explanation for the rapid rates of methane oxidation observed in microcosms. However, not all methane oxidation was attributable to known taxa; in some methane-consuming microcosms we detected methanotroph taxa in conditions outside of their known temperature range for growth, and in other examples, we observed methane oxidation in the absence of known methanotrophs through 16S rRNA gene sequencing. Both of these observations suggest unidentified methane oxidizing microorganisms or undescribed methanotrophic syntrophic associations may also be present. Subsequent enrichment cultures from microcosms yielded communities not predicted by the original diversity studies and showed rates inconsistent with microcosms (≤24.5 μmol d−1), highlighting difficulties in culturing representative thermophilic methanotrophs. Finally, to determine the active methane oxidation processes, we attempted to elucidate metabolic pathways from two enrichment cultures actively oxidizing methane using metatranscriptomics. The most highly expressed genes in both enrichments (methane monooxygenases, methanol dehydrogenases and PqqA precursor peptides) were related to methanotrophs from Methylococcaceae, Methylocystaceae and Methylothermaceae. This is the first example of using metatranscriptomics to investigate methanotrophs from geothermal environments and gives insight into the metabolic pathways involved in thermophilic methanotrophy.

year: 2023-01-01

title: Āta whakarongo: Understanding whānau experiences of audiology early intervention

authors: Dargaville, Cynthia Michelle

subjects: Māori

abstract: For tamariki with hearing loss, early intervention is of critical importance in maximising speech and language, socio-emotional and academic development outcomes. Better hearing outcomes can be achieved by minimising diagnosis delays and initiating intervention treatment as soon as possible. Preliminary data from Waikato District Health Board indicated an equity gap at the point of diagnosis with persisting inequities for tamariki Māori during the delivery of early intervention services. High rates of appointment non-attendance within this group (27% Māori vs. 8% for non-Māori) are a cause for concern when approximately 50% of total appointments are for tamariki Māori. This research seeks to understand the experiences of Māori whānau accessing Waikato’s Audiology Early Intervention Service in order to identify changes the service can make to improve Māori engagement in the future. This study uses qualitative methodologies within a kaupapa Māori framework to investigate the access experiences of Māori whānau of tamariki identified with hearing loss. Interviews with six whānau from Hamilton city and rural Waikato provided rich narratives to inform changes to the Audiology Service to improve the hearing outcomes of tamariki Māori. Whānau shared systems and practical barriers that contributed to challenges with attending appointments including the location, appointment timing, travel and parking. From entering an unwelcoming waiting area, whānau described the added stress experienced to the depth of their emotional response to the hearing loss diagnosis. All shared positive interactions with staff and detailed what could have made their health experience better. After leaning into the kōrero and connecting to the whānau experience, a Manaaki-based pathway is proposed to support Māori ways of being, to ease whānau through the barriers and to combat the alienating experiences of engaging with the health system.

text: Āta whakarongo: Understanding whānau experiences of audiology early intervention For tamariki with hearing loss, early intervention is of critical importance in maximising speech and language, socio-emotional and academic development outcomes. Better hearing outcomes can be achieved by minimising diagnosis delays and initiating intervention treatment as soon as possible. Preliminary data from Waikato District Health Board indicated an equity gap at the point of diagnosis with persisting inequities for tamariki Māori during the delivery of early intervention services. High rates of appointment non-attendance within this group (27% Māori vs. 8% for non-Māori) are a cause for concern when approximately 50% of total appointments are for tamariki Māori. This research seeks to understand the experiences of Māori whānau accessing Waikato’s Audiology Early Intervention Service in order to identify changes the service can make to improve Māori engagement in the future. This study uses qualitative methodologies within a kaupapa Māori framework to investigate the access experiences of Māori whānau of tamariki identified with hearing loss. Interviews with six whānau from Hamilton city and rural Waikato provided rich narratives to inform changes to the Audiology Service to improve the hearing outcomes of tamariki Māori. Whānau shared systems and practical barriers that contributed to challenges with attending appointments including the location, appointment timing, travel and parking. From entering an unwelcoming waiting area, whānau described the added stress experienced to the depth of their emotional response to the hearing loss diagnosis. All shared positive interactions with staff and detailed what could have made their health experience better. After leaning into the kōrero and connecting to the whānau experience, a Manaaki-based pathway is proposed to support Māori ways of being, to ease whānau through the barriers and to combat the alienating experiences of engaging with the health system.

year: 2023