Browsing by Author "Huang Y"

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    Biochar and soil properties limit the phytoavailability of lead and cadmium by Brassica chinensis L. in contaminated soils
    (Springer Nature on behalf of the Shenyang Agricultural University, 2022-12) Houssou AA; Jeyakumar P; Niazi NK; Van Zwieten L; Li X; Huang L; Wei L; Zheng X; Huang Q; Huang Y; Huang X; Wang H; Liu Z; Huang Z
    The current study investigated the effect of biochars derived from cinnamomum woodchip, garden waste and mulberry woodchip on soil phytoavailable lead (Pb), cadmium (Cd) pools, and their uptake by Chinese cabbage (Brassica chinensis L.). The biochars were produced at 450 °C of pyrolysis temperature. The contaminated soils were collected from Yunfu (classified as Udept), Jiyuan (Ustalf) and Shaoguan (Udult) cities in China at the depth of 0–20 cm and amended with biochars at the rate of 3% w/w. After mixing the soil with biochar for 14 days, the Chinese cabbage was planted in the amended soils. Then, it was harvested on the 48th day after sowing period. In Udult soil, Chinese cabbage died 18 days after sowing period in control and soils amended with cinnamomum and mulberry biochars. Although only plants grown with the garden waste biochar treatment survived in Udult soil, amendment of garden waste or mulberry biochars at 3% w/w (450 °C) to Udult soil significantly increased (4.95–6.25) soil pH compared to other biochar treatments. In Udept and Ustalf soils, the application of garden waste and mulberry biochars significantly improved plant biomass compared to control, albeit it was dependent on both biochar and soil properties. Garden waste biochar significantly decreased soil Cd phytoavailable concentration by 26% in the Udult soil, while a decrease of soil Cd phytoavailable concentration by 16% and 9% was observed in Ustalf and Udept soils, respectively. The available phosphorus in biochar and soil pH were important factors controlling toxic metal phytouptake by the plant. Thus, the amendment of soil with biochar at 3% can effectively reduce the mobility of Cd and Pb in soil and plant uptake. However, biochar and soil properties should be well-known before being used for soil toxic metal immobilization.
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    Emetic toxin production of Bacillus cereus in a biofilm
    (Elsevier Ltd, 2022-01-15) Huang Y; Flint SH; Loo TS; Palmer JS
    Bacillus cereus sensu stricto (B. cereus) belongs to the B. cereus group, and is a well-known foodborne pathogen causing human disease including emesis which is caused by an emetic toxin, cereulide, with 105-108 cells per gram required to cause disease. The presence of this highly heat, pH and protease-resistant toxin presents a serious challenge to the food industry, as the bacteria itself may be eliminated during processing but the cereulide toxin will survive most food processing techniques. This study shows that cereulide toxin is associated with cells and biofilm structures rather than suspended in the surrounding liquid phase or environment. This is the first report investigating the cereulide toxin production in the presence of biofilms of B. cereus, showing that the cereulide toxin produced is associated with biofilm complex and also attaches to the substrate such as glass and stainless-steel on which the biofilm grows. The RT-qPCR showed that the expression of cesA and cesB were comparable between planktonic cells and biofilms. This study contributes a better understanding of food safety issues in the industry caused by cereulide toxin produced by B. cereus, and provides valuable information for developing control methods for cereulide toxin in the food industry.
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    Phenotypic properties and genotyping analysis of Bacillus cereus group isolates from dairy and potato products
    (Elsevier Ltd, 2021-04) Huang Y; Flint SH; Yu S; Ding Y; Palmer JS
    Bacillus cereus group (B. cereus sensu lato) are ubiquitously distributed in diverse environments. In this study, eight isolates including B. cereus, B. paranthracis and B. toyonensis species, from dairy and potato products, were assessed for biofilm formation, sporulation and genetic information including biofilm-related genes and toxin genes. The isolates varied in their ability to form biofilm (either at the stainless steel-liquid-air interface or floating pellicles). The amounts of biofilms of B. cereus s.l., were increased when incubated in agitation condition varied between isolates. Sporulation within the planktonic and biofilm modes of growth was compared, suggesting that biofilm is a favourable environment for B. cereus s.l. to form spores. Whole genome sequencing (WGS) was used to compare these B. cereus s.l. isolates. New sequence types (STs) of B. cereus were found in this study. Isolates that shared similar genomes had different biofilm-forming and sporulation abilities. Most of isolates tested, possessed biofilm-related genes. Different combinations of toxin-producing genes were identified in different isolates, with all isolates containing nhe while only some contained hbl and cytK. None of the food isolates contained the emetic ces gene. This study highlights the diversity of B. cereus s.l. in biofilm formation, sporulation and their genetic variables.
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    Stories of transformation: A cross-country focus group study on sustainable development and societal change
    (MDPI (Basel, Switzerland), 24/04/2019) Wibeck V; Linnér B-O; Alves T; Asplund T; Bohman A; Boykoff M; Feetham P; Huang Y; Nascimento J; Rich J; Yvon Rocha C; Vaccarino F; Xian S
    Societal transformation is one of the most topical concepts in sustainability research and policy-making. Used in many ways, it indicates that nonlinear systematic changes are needed in order to fully address global environmental and human development challenges. This paper explores what sustainability transformations mean for lay focus group participants in Cabo Verde, China, Fiji, Sweden, and the USA. Key findings include: (a) Tightly linked to interpersonal relationships, sustainability was seen as going beyond the Sustainable Development Goals to include a sense of belonging; (b) transformations were framed as fundamental changes from today’s society, but most participants stated that transformation pathways need to splice new structures into the old; (c) new technologies are key engines of change. Yet, the most common drivers were awareness, education, and knowledge sharing; and (d) regardless of whether state-centric or decentralized governance was preferred, personal action was seen as essential. The focus groups displayed a shared understanding across the geographical settings; a common realization of profound sustainability predicaments facing societies across the world; and a desire for fundamental change towards a more sustainable way of life.