Screening for hydroxynitrile lyase activity in non-commercialised plants

AbstractHydroxynitrile lyases are used for the synthesis of enantiomerically pure cyanohydrins which are of great importance in the pharmaceutical and fine chemical industries. In this study, the hydroxynitrile lyase activity of 100 plants from 40 families was investigated, first by screening for cyanogenic activity, followed by a hydroxynitrile lyase activity assay. Of the 100 plants, four were found to be cyanogenic and exhibited specific hydroxynitrile lyase activity: Adenia sp. (0.44U/mg), Adenia firingalavensis (2.88U/mg), Adenia fruticosa (1.99U/mg) and, Adenia pechuelii (2.35U/mg), all from the family Passifloraceae. This is the first report of hydroxynitrile lyase activity in these plants

A marine bacterium, Oceanobacillus sp. Pinky, isolated from Algoa Bay sediment produces a thermostable glycoprotein flocculant

In this study, we report on the bioflocculant production potential of an Oceanobacillus sp. isolated from the marine sediments of Algoa Bay. The bacteria produced an extracellular bioflocculant optimally in the presence of sodium carbonate as source of carbon with flocculating activity of about 95.5%. Other optimal culture conditions included: tryptone as nitrogen source (flocculating activity, 84.5%); presence of Ca2+; inoculum size of 2% (v/v) and alkaline pH (10). Composition analyses revealed the purified bioflocculant to be thermostable and composed of polysaccharide and protein. Optimum dose of the purified bioflocculant for the clarification of 4 g/L kaolin clay suspension at neutral pH was 0.2 mg/ml. Scanning electron microscopic (SEM) observations were indicative of a porous bioflocculant structure while Fourier transform infrared (FTIR) spectrum revealed the presence of carboxyl, hydroxyl and amine groups. We proposed that the bacteria hold promise as a potential source of new bioflocculant compound(s).Keywords: Oceanobacillus sp., bioflocculant, glycoprotein, marine sediment, Algoa BayAfrican Journal of Biotechnology Vol. 12(26), pp. 4135-414

Radiative forcing from modelled and observed stratospheric ozone changes due to the 11-year solar cycle

International audienceThree analyses of satellite observations and two sets of model studies are used to estimate changes in the stratospheric ozone distribution from solar minimum to solar maximum and are presented for three different latitudinal bands: Poleward of 30° north, between 30° north and 30° south and poleward of 30° south. In the model studies the solar cycle impact is limited to changes in UV fluxes. There is a general agreement between satellite observation and model studies, particular at middle and high northern latitudes. Ozone increases at solar maximum with peak values around 40 km. The profiles are used to calculate the radiative forcing (RF) from solar minimum to solar maximum. The ozone RF, calculated with two different radiative transfer schemes is found to be negligible (a magnitude of 0.01 Wm?2 or less), compared to the direct RF due to changes in solar irradiance, since contributions from the longwave and shortwave nearly cancel each other. The largest uncertainties in the estimates come from the lower stratosphere, where there is significant disagreement between the different ozone profiles

The impact of interpersonal racism on oral health related quality of life among Indigenous South Australians: a cross-sectional study

Background: Interpersonal racism has had a profound impact on Indigenous populations globally, manifesting as negative experiences and discrimination at an individual, institutional and systemic level. Interpersonal racism has been shown to negatively influence a range of health outcomes but has received limited attention in the context of oral health. The aim of this paper was to examine the effects of experiences of interpersonal racism on oral healthrelated quality of life (OHRQoL) among Indigenous South Australians. Methods: Data were sourced from a large convenience sample of Indigenous South Australian adults between February 2018 and January 2019. Questionnaires were used to collect data on sociodemographic characteristics, cultural values, utilization of dental services, and other related factors. OHRQoL was captured using the Oral Health Impact Profile (OHIP-14) questionnaire. We defined the dependent variable ’poor OHRQoL’ as the presence of one or more OHIP-14 items rated as ‘very often’ or ‘fairly often’. Experiences of racism were recorded using the Measure of Indigenous Racism Experiences instrument. Interpersonal racism was classified into two categories (‘no racism’ vs ‘any racism in ≥ 1 setting’) and three categories (’no racism’, ’low racism’ (experienced in 1–3 settings), and ’high racism’ (experienced in 4–9 settings)). Logistic regression was used to examine associations between interpersonal racism, covariates and OHRQoL, adjusting for potential confounding related to socioeconomic factors and access to dental services. Results: Data were available from 885 participants (88.7% of the total cohort). Overall, 52.1% reported experiencing any interpersonal racism in the previous 12 months, approximately one-third (31.6%) were classified as experiencing low racism, and one-fifth (20.5%) experienced high racism. Poor OHRQoL was reported by half the participants (50.2%). Relative to no experiences of racism in the previous 12 months, those who experienced any racism (≥ 1 setting) were significantly more likely to report poor OHRQoL (Odds Ratio (OR): 1.43; 95% Confidence Interval (CI): 1.08–1.92), after adjusting for age, education level, possession of an income-tested health care card, car ownership, self-reported oral health status, timing of and reason for last dental visit, not going to a dentist because of cost, and having no family support. This was particularly seen among females, where, relative to males, the odds of having poor OHRQoL among females experiencing racism were 1.74 times higher (95% CI: 1.07–2.81). Conclusion: Our findings indicate that the experience of interpersonal racism has a negative impact on OHRQoL among Indigenous Australians. The association persisted after adjusting for potential confounding factors. Identifying this link adds weight to the importance of addressing OHRQoL among South Australian’s Indigenous population by implementing culturally-sensitive strategies to address interpersonal racism.Anna Ali, Alice R. Rumbold, Kostas Kapellas, Zohra S. Lassi, Joanne Hedges and Lisa Jamieso

Perinatal outcomes by mode of assisted conception and sub-fertility in an Australian data linkage cohort

BACKGROUND: Fertility treatment is associated with increased risk of major birth defects, which varies between in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), and is significantly reduced by embryo freezing. We therefore examined a range of additional perinatal outcomes for these exposures. METHODS: All patients in South Australia receiving assisted conception between Jan 1986-Dec 2002 were linked to the state-wide perinatal collection (all births/stillbirths ≥20 weeks gestation or 400 g birth weight, n = 306 995). We examined stillbirth, mean birth weight, low birth weight (90th percentile), preterm birth (32-<37 weeks, <32 weeks gestation), postterm birth (≥41 weeks gestation), Apgar <7 at 5 minutes and neonatal death. RESULTS: Relative to spontaneous conceptions, singletons from assisted conception were more likely to be stillborn (OR = 1.82, 95% Confidence Interval (CI) 1.34-2.48), while survivors as a group were comprehensively disadvantaged at birth, including lower birth weight (-109 g, CI -129--89), very low birth weight (OR = 2.74, CI 2.19-3.43), very preterm birth (OR = 2.30, CI 1.82-2.90) and neonatal death (OR = 2.04, CI 1.27-3.26). Outcomes varied by type of assisted conception. Very low and low birth weight, very preterm and preterm birth, and neonatal death were markedly more common in singleton births from IVF and to a lesser degree, in births from ICSI. Using frozen-embryos eliminated all significant adverse outcomes associated with ICSI but not with IVF. However, frozen-embryo cycles were also associated with increased risk of macrosomia for IVF and ICSI singletons (OR = 1.36, CI 1.02-1.82; OR = 1.55, CI 1.05-2.28). Infertility status without treatment was also associated with adverse outcomes. CONCLUSIONS: Births after assisted conception show an extensive range of compromised outcomes that vary by treatment modality, that are substantially reduced after embryo freezing, but which co-occur with an increased risk of macrosomia.Jennifer L. Marino, Vivienne M. Moore, Kristyn J. Willson, Alice Rumbold, Melissa J. Whitrow, Lynne C. Giles, Michael J. Davie

Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multi-model mean OH concentration is overestimated by 5 to 10% but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high north–south OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34%). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6%) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the change in global mean tropospheric CO and NOx burdens (ΔCO/ΔNOx, approximately represents changes in OH sinks versus changes in OH sources) in the models, pointing to a need for better constraints on natural precursor emissions and on the chemical mechanisms in the current generation of chemistry-climate models. For the 1980 to 2000 period, we find that climate warming and a slight increase in mean OH (3.5 ± 2.2%) leads to a 4.3 ± 1.9% decrease in the methane lifetime. Analysing sensitivity simulations performed by 10 models, we find that preindustrial to present-day climate change decreased the methane lifetime by about four months, representing a negative feedback on the climate system. Further, we analysed attribution experiments performed by a subset of models relative to 2000 conditions with only one precursor at a time set to 1860 levels. We find that global mean OH increased by 46.4 ± 12.2% in response to preindustrial to present-day anthropogenic NOx emission increases, and decreased by 17.3 ± 2.3%, 7.6 ± 1.5%, and 3.1 ± 3.0% due to methane burden, and anthropogenic CO, and NMVOC emissions increases, respectively