Article
Environmental Sciences
Ganlin Wu, Fuguo Liu, Guofu Chen, Yuanyuan Wang, Yihan Wang, Chunyun Zhang
Summary: The development of techniques that can detect multiple microalgae simultaneously is critical due to the variety of algae species that form harmful algal blooms (HABs). This study established a multiplex polymerase chain reaction (mPCR) method to diagnose three dominant algae species in the East China Sea. The mPCR showed good specificity, stability, and the ability to detect H. akashiwo, P. donghaiense, and K. mikimotoi.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Jakob Karl Giesler, Daniel Alan Lemley, Janine Barbara Adams, Stefanie Devi Moorthi
Summary: This study aimed to investigate the effects of non-biological factors such as temperature and salinity on the formation and harmfulness of H. akashiwo algal blooms. The results showed that high temperature and low salinity conditions promoted the growth of H. akashiwo, while low temperature and high salinity conditions were more suitable for the growth of H. rotundata. When competing with each other, H. akashiwo dominated at high temperature, regardless of the salinity regime. However, at low temperature, it only dominated at low salinity and was suppressed by H. rotundata at high salinity. Grazing experiments revealed that H. akashiwo had negative effects on copepod nauplii survival and growth, especially at high temperatures and low salinity, while the estuarine adapted rotifers showed highest mortalities at the higher salinity level. The presence of H. rotundata significantly alleviated the harmful effects of H. akashiwo on both grazers. The selectively feeding copepod nauplii actively avoided H. akashiwo when non-harmful prey was present. Overall, this study demonstrates that the population dynamics and harmful effects of H. akashiwo are determined by both abiotic conditions and food web configuration.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Taryn Smit, Daniel Alan Lemley, Eugin Bornman, Janine Barbara Adams, Nadine Amelia Strydom
Summary: Eutrophication and harmful algal blooms (HABs) are increasing globally and pose a threat to larval fishes that rely on estuarine nursery habitats. This study investigated the effects of HABs on the environmental conditions and larval fish assemblage in a warm temperate nursery area. Findings suggest that HABs have negative impacts on the environmental conditions and larval fish assemblage, which have important implications for the early development of fishes.
ESTUARIES AND COASTS
(2023)
Article
Microbiology
Xueping Shao, Wanxin Xie, Yiling Liang, Guiying Luo, Ling Li, Wei Zheng, Qingyan Xu, Hong Xu
Summary: In this study, Bacillus tequilensis D8 isolated from an H. akashiwo bloom area was found to have high algicidal activity due to the production of extracellular metabolites. Three surfactin homologues, surfactin-C13, surfactin-C14, and surfactin-C15, were identified as the algicidal compounds. Surfactin-C13 and surfactin-C14 exhibited strong algicidal activity against multiple HAB-causing species, while surfactin-C15 showed activity against some species. These findings provide insights into the characteristics and mechanisms of action of surfactins on H. akashiwo and their potential use in controlling harmful algal blooms.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Marine & Freshwater Biology
Nanjing Ji, Zhenzhen Zhang, Lei Chen, Xueyao Yin, Xin Shen
Summary: Phosphorus is an important macronutrient for phytoplankton growth but can frequently be scarce in certain parts of the ocean. Phytoplankton have evolved various strategies to cope with phosphorus deficiency, including the utilization of different phosphorus sources. This study examined the physiological and molecular responses of the harmful algal bloom species Heterosigma akashiwo to the utilization of polyphosphate (polyP) and coping with phosphorus deficiency. The results showed that H. akashiwo can efficiently utilize certain inorganic polyphosphates to support its growth, and under phosphorus-deficient conditions, genes related to phosphorus transport, dissolved organic phosphorus utilization, sulfolipid synthesis, and energy production were significantly upregulated.
Article
Marine & Freshwater Biology
Taryn Smit, Catriona Clemmesen, Daniel A. Lemley, Janine B. Adams, Eugin Bornman, Nadine A. Strydom
Summary: This study presents a novel approach to evaluate the impact of harmful algal blooms (HABs) on the growth and body condition of estuarine resident fish larvae. It found that varying intensity levels, duration, and frequency of high-nutrient blooms significantly decreased the nutritional condition and growth of larval roundherring, impacting recruitment success and estuarine food webs.
JOURNAL OF PLANKTON RESEARCH
(2023)
Article
Food Science & Technology
Malihe Mehdizadeh Allaf, Charles G. Trick
Summary: Harmful algal blooms present a significant environmental issue, with cells releasing toxins and beneficial compounds. Researchers have developed a yeast cell assay to evaluate the toxicity of bloom-forming species on water environments. The results showed metabolic damage in yeast cells after exposure to toxin-producing algal cells or extracts.
Article
Microbiology
Nanjing Ji, Xueyao Yin, Yujiao Chen, Yifan Chen, Mingyang Xu, Jinwang Huang, Yuefeng Cai, Xin Shen
Summary: In this study, a full-length transcriptome of the harmful algal species Heterosigma akashiwo was obtained using single-molecule real-time sequencing. A total of 45.44 Gb of subread bases were generated, resulting in 16,668 unigenes after data processing. Among the annotated unigenes, phosphorus and nitrogen metabolism genes were the most detected. Additionally, putative transcription factors, long non-coding RNAs, and simple sequence repeats were also predicted. This study provides a valuable reference transcriptome for understanding the molecular mechanism of H. akashiwo blooms.
Article
Environmental Sciences
Eugin Bornman, Daniel A. Lemley, Janine B. Adams, Nadine A. Strydom
Summary: Harmful algal blooms (HABs) have a negative impact on the abundance of the estuarine-dependent fish species Mugil cephalus in Sundays Estuary. The presence of HAB species Heterosigma akashiwo alters the dissolved oxygen levels in the estuary, resulting in unfavorable conditions for the fish. The study suggests that unsustainable agricultural fertilization could lead to more severe and frequent HABs, causing a decline in fish nursery quality.
ESTUARIES AND COASTS
(2023)
Article
Biotechnology & Applied Microbiology
Bingkun Wang, Chunyun Zhang, FuQueryguo Liu, Runqi Li, Yuanyuan Wang, Guofu Chen
Summary: A novel technique called RPA-LFD was developed for detecting Heterosigma akashiwo, which demonstrated high specificity and sensitivity. The method is simple, rapid, and allows for direct visualization of results.
JOURNAL OF APPLIED PHYCOLOGY
(2021)
Review
Chemistry, Multidisciplinary
Barathan Balaji-Prasath, Ying Wang, Yu Ping Su, David P. Hamilton, Hong Lin, Luwei Zheng, Yong Zhang
Summary: This article reviews physical, chemical, and biological control methods applicable to red tide species in marine and estuarine water bodies, and discusses the mechanisms of algal bloom outbreaks and their applications.
ENVIRONMENTAL CHEMISTRY LETTERS
(2022)
Article
Marine & Freshwater Biology
Taryn Smit, Daniel A. Lemley, Janine B. Adams, Nadine A. Strydom
Summary: This study conducted in a warm-temperate South African estuary reveals that harmful algal blooms can alter the population dynamics of dominant larval fish and zooplankton species, particularly during bloom phases where there is a mismatch between prey and predator densities. The impacts of recurrent harmful algal blooms on estuarine ecosystem function are highlighted, emphasizing the importance of understanding the fine-scale consequences of these events in a future of intensifying eutrophication.
ESTUARINE COASTAL AND SHELF SCIENCE
(2021)
Article
Environmental Sciences
Renjun Wang, Qian Liu
Summary: This study investigated the allelopathic effects of linoleic acid (LA) on harmful Heterosigma akashiwo and explored the possible mechanisms. The results showed that LA inhibited the growth of H. akashiwo cells and induced morphological and physiological changes, ultimately leading to cell apoptosis. These findings suggest that LA has the potential to be used as an algaecide for controlling harmful algae.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Microbiology
Guanjing Cai, Xiaoqi Yu, Runlin Cai, Hui Wang
Summary: This study found that using microbial algicides to lyse harmful algal bloom cells could eliminate pathogenic bacteria and improve some chemical parameters in the ecosystem. Additionally, the microbial algicides were found to restore the bacterial community during the bloom period and reduce the ecological impact of carbon flow.
FEMS MICROBIOLOGY ECOLOGY
(2022)
Article
Fisheries
Nanjing Ji, Mingyang Xu, Junyue Wang, Junjia Li, Shishi Liu, Xueyao Yin, Xin Shen, Yuefeng Cai
Summary: The physiological and transcriptomic responses of the Asiatic hard clam to Heterosigma akashiwo were investigated, revealing that the clam can effectively feed on the toxic alga. Intensification of shellfish farming may be helpful in controlling and mitigating H. akashiwo blooms.
