Academic research on dinoflagellate, the primary causative agent of harmful algal blooms (HABs), ... more Academic research on dinoflagellate, the primary causative agent of harmful algal blooms (HABs), is often hindered by the coexistence with bacteria in laboratory cultures. The development of axenic dinoflagellate cultures is challenging and no universally accepted method suit for different algal species. In this study, we demonstrated a promising approach combined density gradient centrifugation, antibiotic treatment, and serial dilution to generate axenic cultures of Karenia mikimotoi (KMHK). Density gradient centrifugation and antibiotic treatments reduced the bacterial population from 5.79 ± 0.22 log10 CFU/mL to 1.13 ± 0.07 log10 CFU/mL. The treated KMHK cells were rendered axenic through serial dilution, and algal cells in different dilutions with the absence of unculturable bacteria were isolated. Axenicity was verified through bacterial (16S) and fungal internal transcribed spacer (ITS) sequencing and DAPI epifluorescence microscopy. Axenic KMHK culture regrew from 1000 to 940...
This study examined the accumulation of As species, Se, Cu, Zn, Cd and Pb in the halophyte Juncus... more This study examined the accumulation of As species, Se, Cu, Zn, Cd and Pb in the halophyte Juncus acutus, collected from three anthropogenically impacted estuaries in NSW, Australia. As concentration ranged from 4 to 22 μg/g at Georges River, 2-16 μg/g at Lake Macquarie and 6 μg/g at Hunter Estuary. Inorganic As was accumulated mainly in roots with low translocation to culm with a greater abundance of AsV. However, AsIII (TF = 0.32) showed greater mobility from the roots to shoots than AsV (TF = 0.04), indicating a higher quantity of AsIII specific transporter assemblages in the plasmalemma of the endodermis or cytoplasmic reduction of AsV to AsIII in culms. Metal(loid)s, including As (90%), were predominantly in root tissues and very limited translocation to culm, indicating the species is a useful phytostabiliser. As and all other metal(loid)s in roots were correlated with sediment loads (p < 0.05, R2 = 0.10-0.52), indicating the species would be an accumulative bioindicator.
The toxic affect of tributyltin (TBT) on six species of two different genera of microalgae, namel... more The toxic affect of tributyltin (TBT) on six species of two different genera of microalgae, namely Chlorella sp. and Scenedesmus sp. was examined. The resistance of the commercially available species and isolates obtained from polluted water in Hong Kong and Wuhan, PRC to TBT were also compared. Chlorella vulgaris and S. dimorphus were commercial species while C. sorokiniana, S. quadricauda, C. miniata, and S. platydiscus were isolates. Among the tested species, C. vulgaris was most resistant to TBT, and the 7-d IC50 values measured in terms of cell number and chlorophyll content were 220 and 262 µg/l, respectively. The second most resistant species was C. sorokiniana (Wuhan isolate) and their IC50 value was around 100 µg/l. On the other hand, C. miniata (Hong Kong isolate) was the most sensitive species, their growth was strongly inhibited by TBT and the 7-d IC50 was 21 µg/l. For the three Scenedesmus species, S. dimorphus and S. platydiscus (both were isolates) had similar growth ...
应用GC-MG技术分析了深圳大亚湾大鹏澳及厦门岛南岸海域沿岸几个站位沉积物中可提取性磷脂酯结合态脂肪酸的含量和组成成份;同时采用丫啶橙荧光染色计数法测定了这些沉积物中细菌的丰度、生物量。结果表明... more 应用GC-MG技术分析了深圳大亚湾大鹏澳及厦门岛南岸海域沿岸几个站位沉积物中可提取性磷脂酯结合态脂肪酸的含量和组成成份;同时采用丫啶橙荧光染色计数法测定了这些沉积物中细菌的丰度、生物量。结果表明,在这些沉积物中细菌的生物量与磷脂酯结合态脂肪酸的组分的含量有着正相关关系。说明在环境生态研究中,可提取性磷脂作为海洋和河口沉积物中微生物生物量的生物标志物的可行性。国家自然科学基金(49676302号)及大亚湾海洋生物综合实验站(MBRS)基金(S9509号)资助
Academic research on dinoflagellate, the primary causative agent of harmful algal blooms (HABs), ... more Academic research on dinoflagellate, the primary causative agent of harmful algal blooms (HABs), is often hindered by the coexistence with bacteria in laboratory cultures. The development of axenic dinoflagellate cultures is challenging and no universally accepted method suit for different algal species. In this study, we demonstrated a promising approach combined density gradient centrifugation, antibiotic treatment, and serial dilution to generate axenic cultures of Karenia mikimotoi (KMHK). Density gradient centrifugation and antibiotic treatments reduced the bacterial population from 5.79 ± 0.22 log10 CFU/mL to 1.13 ± 0.07 log10 CFU/mL. The treated KMHK cells were rendered axenic through serial dilution, and algal cells in different dilutions with the absence of unculturable bacteria were isolated. Axenicity was verified through bacterial (16S) and fungal internal transcribed spacer (ITS) sequencing and DAPI epifluorescence microscopy. Axenic KMHK culture regrew from 1000 to 940...
This study examined the accumulation of As species, Se, Cu, Zn, Cd and Pb in the halophyte Juncus... more This study examined the accumulation of As species, Se, Cu, Zn, Cd and Pb in the halophyte Juncus acutus, collected from three anthropogenically impacted estuaries in NSW, Australia. As concentration ranged from 4 to 22 μg/g at Georges River, 2-16 μg/g at Lake Macquarie and 6 μg/g at Hunter Estuary. Inorganic As was accumulated mainly in roots with low translocation to culm with a greater abundance of AsV. However, AsIII (TF = 0.32) showed greater mobility from the roots to shoots than AsV (TF = 0.04), indicating a higher quantity of AsIII specific transporter assemblages in the plasmalemma of the endodermis or cytoplasmic reduction of AsV to AsIII in culms. Metal(loid)s, including As (90%), were predominantly in root tissues and very limited translocation to culm, indicating the species is a useful phytostabiliser. As and all other metal(loid)s in roots were correlated with sediment loads (p < 0.05, R2 = 0.10-0.52), indicating the species would be an accumulative bioindicator.
The toxic affect of tributyltin (TBT) on six species of two different genera of microalgae, namel... more The toxic affect of tributyltin (TBT) on six species of two different genera of microalgae, namely Chlorella sp. and Scenedesmus sp. was examined. The resistance of the commercially available species and isolates obtained from polluted water in Hong Kong and Wuhan, PRC to TBT were also compared. Chlorella vulgaris and S. dimorphus were commercial species while C. sorokiniana, S. quadricauda, C. miniata, and S. platydiscus were isolates. Among the tested species, C. vulgaris was most resistant to TBT, and the 7-d IC50 values measured in terms of cell number and chlorophyll content were 220 and 262 µg/l, respectively. The second most resistant species was C. sorokiniana (Wuhan isolate) and their IC50 value was around 100 µg/l. On the other hand, C. miniata (Hong Kong isolate) was the most sensitive species, their growth was strongly inhibited by TBT and the 7-d IC50 was 21 µg/l. For the three Scenedesmus species, S. dimorphus and S. platydiscus (both were isolates) had similar growth ...
应用GC-MG技术分析了深圳大亚湾大鹏澳及厦门岛南岸海域沿岸几个站位沉积物中可提取性磷脂酯结合态脂肪酸的含量和组成成份;同时采用丫啶橙荧光染色计数法测定了这些沉积物中细菌的丰度、生物量。结果表明... more 应用GC-MG技术分析了深圳大亚湾大鹏澳及厦门岛南岸海域沿岸几个站位沉积物中可提取性磷脂酯结合态脂肪酸的含量和组成成份;同时采用丫啶橙荧光染色计数法测定了这些沉积物中细菌的丰度、生物量。结果表明,在这些沉积物中细菌的生物量与磷脂酯结合态脂肪酸的组分的含量有着正相关关系。说明在环境生态研究中,可提取性磷脂作为海洋和河口沉积物中微生物生物量的生物标志物的可行性。国家自然科学基金(49676302号)及大亚湾海洋生物综合实验站(MBRS)基金(S9509号)资助
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