Bioassay of Microalgae Toxicity

Microalgae can produce a diverse range of metabolites, including some that have harmful effects on other organisms such as humans or marine fauna. Microalgae are commonly used for ecotoxicity testing due to their ease of cultivation and rapid cell division rates. Here at Lifeasible, we provide professional solutions for the bioassay of microalgae toxicity.

Background

Microalgae are the basis of the marine ecosystem food chain, mainly composed of unicellular pelagic and benthic photosynthetic organisms. Algal cells have developed chemical strategies to communicate, defend and adapt to their environment. As a result, they are capable of producing a large number of metabolites, including those that are potentially toxic or biologically active. Microalgal toxins are secondary metabolites with a variety of compounds with different chemical structures. Of the tens of thousands of microalgae species currently known, more than 200 are considered to have harmful effects, while about 100 produce toxins. Harmful algal blooms can adversely affect marine life or human health through direct exposure to toxins or bioaccumulation of algal toxins in seafood. Over the past decade, monitoring systems have made considerable progress in optimizing the prediction of toxic algal blooms and their effects on seafood safety.

Fig 1. Development and application of a multispecies toxicity test with tropical freshwater microalgae. (Stone S, et al., 2019)

Customized Solutions

Ecotoxicity testing of microalgae typically uses a single species of algae. However, microalgae exist in the environment as complex communities of multiple species. Lifeasible is dedicated to routine multi-species toxicity testing of microalgae. In addition, we develop protocols for bio-toxicity measurement of benthic microalgae.

Batch Toxicity Bioassays

We grow standard microalgae in batches in borosilicate flasks on substances and wastewater and use flow cytometry and esterase inhibition techniques to determine microalgal biotoxicity.

Bio-Toxicity Measurement of Benthic Microalgae

(1) Sampling and preparation of benthic microalgae

We collected only the first layer of sediment. Upon entering the laboratory, sediment samples were mechanically homogenized with a non-metallic spatula and freeze-pulsed by immersion in liquid nitrogen to eliminate microfauna and microbiota.

(2) Determination of biotoxicity of benthic microalgae

• We used laboratory strains rather than local natural microalgal assemblages to reduce contamination effects.
• Studies on benthic diatoms were not conducted in sediments but the water matrix.
• Bioassays are performed on whole sediments by adding metals or surfactants to the artificial sediment.

To increase the ecological relevance of toxicity bioassays, we offer a new toxicity test method to determine the biotoxicity of benthic microalgae.

• The target organisms are brought to the field instead of bringing the samples to the laboratory.
• The benthic microalgae are exposed to the sampled water or sediment.
• Benthic diatoms are free to move and select less contaminated compartmentalized areas.
• Analyze the ability of benthic microalgae to drift when stress reduces salinity versus a standard population growth inhibition test.

Advantages of Our Solutions

• Highly sensitive, reproducible, easy-to-use, and low-cost test.
• Chronic multi-species toxicity assay based on population growth rate.
• Enables quantification of each species in a multi-species mixture of microalgae.
• May assist in environmental decision-making and risk assessment of contaminants in tropical freshwater environments.

At Lifeasible, we can quickly assist you in biotoxicity assays of tropical freshwater microalgae multispecies and benthic microalgae. We are your trusted partner in all aspects of microalgae research. If you are interested in our solutions for bioassay of microalgae toxicity, please do not hesitate to contact us.