scholarly journals Transcriptional Analysis of Microcystis aeruginosa Co-Cultured with Algicidal Bacteria Brevibacillus laterosporus

2021 ◽  
Vol 18 (16) ◽  
pp. 8615
Author(s):  
Yulei Zhang ◽  
Dong Chen ◽  
Ning Zhang ◽  
Feng Li ◽  
Xiaoxia Luo ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Control Method ◽  
Acid Synthesis ◽  
Transcriptional Analysis ◽  
Economic Losses ◽  
Algicidal Bacteria ◽  
Brevibacillus Laterosporus ◽  
Expression Of Genes

Harmful algal blooms caused huge ecological damage and economic losses around the world. Controlling algal blooms by algicidal bacteria is expected to be an effective biological control method. The current study investigated the molecular mechanism of harmful cyanobacteria disrupted by algicidal bacteria. Microcystis aeruginosa was co-cultured with Brevibacillus laterosporus Bl-zj, and RNA-seq based transcriptomic analysis was performed compared to M. aeruginosa, which was cultivated separately. A total of 1706 differentially expressed genes were identified, which were mainly involved in carbohydrate metabolism, energy metabolism and amino acid metabolism. In the co-cultured group, the expression of genes mainly enriched in photosynthesis and oxidative phosphorylation were significantly inhibited. However, the expression of the genes related to fatty acid synthesis increased. In addition, the expression of the antioxidant enzymes, such as 2-Cys peroxiredoxin, was increased. These results suggested that B. laterosporus could block the electron transport by attacking the PSI system and complex I of M. aeruginosa, affecting the energy acquisition and causing oxidative damage. This further led to the lipid peroxidation of the microalgal cell membrane, resulting in algal death. The transcriptional analysis of algicidal bacteria in the interaction process can be combined to explain the algicidal mechanism in the future.

scholarly journals Isolation and Identification of Two Algae-Lysing Bacteria against Microcystis aeruginosa

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2485
Author(s):  
Jing Yang ◽  
Kai Qiao ◽  
Junping Lv ◽  
Qi Liu ◽  
Fangru Nan ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Removal Rate ◽  
Polymerase Chain Reaction Amplification ◽  
Cyanobacterial Bloom ◽  
Practical Significance ◽  
Algicidal Bacteria ◽  
Bacterial Strains ◽  
Isolation And Identification

Algae blooms present an environmental problem worldwide. In response to the outbreak of harmful algal blooms in cyanobacteria, the role of biological control has drawn wide attention, particularly for algicidal bacteria. The mechanism underlying algicidal activity was determined in our study. Algae-lysing bacteria used were separated from water and sediment collected from the Fenhe scenic spot of Taiyuan. Genetic and molecular identification was conducted by polymerase chain reaction amplification based on 16S rDNA gene. These bacterial strains were identified as Raoultella planticola and Aeromonas sp. The algae-lysing characteristics were evaluated on Microcystis aeruginosa. For the two algicidal bacteria, the high inoculation ratio (>8%) of bacteria strains contributed to the lytic effect. M. aeruginosa could be completely removed by these strains at different cell ages. However, the time used decreased with an increase in cell age. The removal rate was increased while M. aeruginosa was in the lag and logarithmic phases. The earlier bacteria strains could be inoculated, the sooner all algae could be removed. Both algicidal substances were protein, which could destroy the photosynthetic systems and break the cell of M. aeruginosa. The algicidal bacteria strain has important theoretical and practical significance for economic and feasible algae removal and provides good germplasm resources and technical support for the control of cyanobacterial bloom.

scholarly journals Study on the metabolites of DH-e, a Halomonas marine bacterium, against three toxic dinoflagellate species

2018 ◽  
Vol 78 (7) ◽  
pp. 1535-1544 ◽  
Author(s):  
Di Wang ◽  
Liling Xie ◽  
Xingbiao Zhu ◽  
Xiao Bi ◽  
Yuzhong Zheng ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Morphological Characteristics ◽  
Alexandrium Tamarense ◽  
Algicidal Bacteria ◽  
Bacterial Strains ◽  
16S Rdna Sequence ◽  
Algicidal Bacterium ◽  
16S Rdna Sequence Analysis ◽  
Acetone Peroxide

Abstract Algicidal bacteria play an important role in mitigating harmful algal blooms (HABs). In the study, five bacterial strains were isolated from the East China Sea. One strain of algicidal bacterium, named DH-e, was found to selectively inhibit the motor ability of Prorocentrum donghaiense, Alexandrium tamarense (ATDH-47) and Karenia mikimotoi Hansen. Both 16S rDNA sequence analysis and morphological characteristics revealed that the algicidal DH-e bacterium belonged to Halomonas. Furthermore, results showed that the metabolites in the DH-e cell-free filtrate could kill algae directly, and the minimum inhibitory concentrations (MICs) of the bacterial metabolites on the cells of the three dinoflagellate species ranged from 35.0–70.0 μg/mL. Following short-term inhibitory tests, the dinoflagellates in mixed crude extract solution (0.7 mg/mL) ceased movement after 5 min. The algicidal mechanism of the metabolites was investigated through enzyme activities, including that of catalase (CAT), alkaline phosphatase (AKP), acetone peroxide (T-ATP) synthetase and nitrite reductase (NR). Results indicated that metabolites did not disrupt the energy or nutrient routes of the algae (P > 0.05), but did initiate an increase in free radicals in the algal cells, which might explain the subsequent death of sensitive algae. Thus, the metabolites of the DH-e bacterium showed promising potential for controlling HABs.

scholarly journals Economic impact of harmful algal blooms on human health: a systematic review

2019 ◽  
Vol 17 (4) ◽  
pp. 499-516 ◽  
Author(s):  
Christian R. C. Kouakou ◽  
Thomas G. Poder
Keyword(s):  
Systematic Review ◽  
Economic Impact ◽  
Human Health ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Well Being ◽  
Global Network ◽  
Economic Losses ◽  
Health Costs ◽  
Life Years

Abstract Harmful algal blooms (HABs) damage human activities and health. While there is wide literature on economic losses, little is known about the economic impact on human health. In this review, we systematically retrieved papers which presented health costs following exposure to HABs. A systematic review was conducted up to January 2019 in databases such as ScienceDirect and PubMed, and 16 studies were selected. Health costs included healthcare and medication expenses, loss of income due to illness, cost of pain and suffering, and cost of death. Two categories of illness (digestive and respiratory) were considered for health costs. For digestive illness cost, we found $86, $1,015 and $12,605, respectively, for mild, moderate and severe cases. For respiratory illness, costs were $86, $1,235 and $14,600, respectively, for mild, moderate and severe cases. We used Quality-Adjusted Life Years (QALYs) to access the loss of well-being due to illness caused by HABs. We found that breathing difficulty causes the most loss of QALYs, especially in children, with a loss of between 0.16 and 0.771 per child. Having gastroenteritis could cause a loss of between 2.2 and 7.1 QALYs per 1,000 children. Misleading symptoms of illness following exposure to HABs could cause bias in health costs estimations. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

scholarly journals Algicidal Activity of Novel Indigenous Bacterial Strain, Paracoccus Sp., Against Harmful Algal Bloom Species, Karenia Mikimotoi

2021 ◽  
Author(s):  
Ning Ding ◽  
Wenjun Du ◽  
Yanlou Feng ◽  
Yuhao Song ◽  
Chao Wang ◽  
...  
Keyword(s):  
Bacterial Strain ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Harmful Algal Bloom ◽  
Growth Conditions ◽  
Inhibitory Effect ◽  
Algicidal Bacteria ◽  
Rrna Gene ◽  
Negative Effects ◽  
Karenia Mikimotoi

Abstract Harmful algal blooms have deleterious effects on aquatic ecosystems and human health. The application of algicidal bacteria is a promising and environmentally friendly method of preventing and eradicating harmful algal blooms. In this study, a screen for algicidal agents against harmful algal blooms was used to identify an algicidal bacterial strain isolated from a Karenia mikimotoi culture. Strain O-1 exhibited a strong inhibitory effect on harmful K. mikimotoi and was identified as a Paracoccus species via 16S rRNA gene sequence analysis. This strain killed K. mikimotoi by secreting active algicidal compounds, which were stable at temperatures of -80–121 °C, but these substances were sensitive to strongly acidic conditions. The algicidal properties of strain O-1 against K. mikimotoi were cell density- and time-dependent. No significant changes or negative effects were noted for two other Chlorophyta species, which highlighted the specificity of the studied algicidal substance. Finally, single-factor experiments revealed the optimum growth conditions of strain O-1 under different pH and temperature conditions. Strain O-1 therefore has potential as a bio-agent for reducing the biomass of harmful K. mikimotoi blooms.

Unprecedented toxic algal blooms impact on Tasmanian seafood industry

2016 ◽  
Vol 37 (3) ◽  
pp. 143 ◽  
Author(s):  
Gustaaf Hallegraeff ◽  
Christopher Bolch
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
East Coast ◽  
Economic Losses ◽  
Human Society ◽  
Rock Lobster ◽  
Negative Effects ◽  
Risk Area ◽  
Seafood Industry ◽  
Hab Species

While most microscopic algae provide food for filter-feeding shellfish and larvae of crustaceans and finfish, other so-called Harmful Algal Blooms (HABs) can have negative effects, causing severe economic losses to aquaculture, fisheries and tourism. Of greatest concern to human society are blooms of toxic HAB species that cause illness and death of fish, seabirds and mammals via toxins transferred through the food web. Unprecedented Alexandrium (Dinophyceae) blooms along the East Coast of Tasmania in 2012 and 2015, a previously low biotoxin risk area, led to major impacts on the local oyster, mussel, scallop and rock lobster industries. Four human hospitalisations also occurred from eating wild shellfish.

scholarly journals Tracing the active genetic diversity of Microcystis and Microcystis phage through a temporal survey of Taihu

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244482
Author(s):  
Helena L. Pound ◽  
Steven W. Wilhelm
Keyword(s):  
Environmental Factors ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Community Dynamics ◽  
Expression Patterns ◽  
Temporal Shift ◽  
Expression Of Genes ◽  
Single Genus ◽  
Microcystis Wesenbergii ◽  
And Oxidative Stress

Harmful algal blooms are commonly thought to be dominated by a single genus, but they are not homogenous communities. Current approaches, both molecular and culture-based, often overlook fine-scale variations in community composition that can influence bloom dynamics. We combined homology-based searches (BLASTX) and phylogenetics to distinguish and quantify Microcystis host and phage members across a summer season during a 2014 Microcystis- dominated bloom that occurred in Lake Tai (Taihu), China. We found 47 different genotypes of the Microcystis-specific DNA-dependent RNA polymerase (rpoB), which included several morphospecies. Microcystis flos-aquae and Microcystis wesenbergii accounted for ~86% of total Microcystis transcripts, while the more commonly studied Microcystis aeruginosa only accounted for ~7%. Microcystis genotypes were classified into three temporal groups according to their expression patterns across the course of the bloom: early, constant and late. All Microcystis morphospecies were present in each group, indicating that expression patterns were likely dictated by competition driven by environmental factors, not phylogeny. We identified three primary Microcystis-infecting phages based on the viral terminase, including a novel Siphoviridae phage that may be capable of lysogeny. Within our dataset, Myoviridae phages consistent with those infecting Microcystis in a lytic manner were positively correlated to the early host genotypes, while the Siphoviridae phages were positively correlated to the late host genotypes, when the Myoviridae phages express putative genetic markers for lysogeny. The expression of genes in the microcystin-encoding mcy cassette was estimated using mcyA, which revealed 24 Microcystis-specific genotypes that were negatively correlated to the early host genotypes. Of all environmental factors measured, pH best described the temporal shift in the Microcystis community genotypic composition, promoting hypotheses regarding carbon concentration mechanisms and oxidative stress. Our work expounds on the complexity of HAB events, using a well-studied dataset to highlight the need for increased resolution of community dynamics.

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