To Örebro University

Chitinases, enzymes that degrade chitin, have long been studied for their role in various biological processes. They play crucial roles in the moulting process of invertebrates, the digestion of chitinous food, and defense against chitin-bearing pathogens. Additionally, chitinases are involved in physiological functions in crustaceans, such as chitinous food digestion, moulting, and stress response. Moreover, chitinases are universally distributed in organisms from viruses to mammals and have diverse functions including tissue degradation and remodeling, nutrition uptake, pathogen invasion, and immune response regulation. The discovery of these diverse functions expands our understanding of the biological significance and potential applications of chitinases. However, recent research has shown that chitinases possess several other functions beyond just chitin degradation. Their potential as biopesticides, therapeutic agents, and tools for bioremediation underscores their significance in addressing global challenges. More importantly, we noted that they may be applied as bioweapons if ethical regulations regarding production, engineering and application are overlooked.

Cyanobacteria harmful algal blooms (cHABs) are increasingly becoming an emerging threat to aquatic life, ecotourism, and certain real estate investments. Their spontaneous yet sporadic occurrence has made mitigation measures a cumbersome task; moreover, current trends regarding anthropogenic activities, especially in agriculture and industry portend further undesirable events. Apart from the aesthetic degeneration they create in their respective habitats, they are equally capable of secreting toxins, which altogether present grave environmental and medical consequences. In this paper, we gave an update on factors that influence cHABs, cyanotoxin exposure routes, and environmental public health implications, especially impacts on fish, pets, and livestock. We discussed social economic impacts, risk assessment, and management problems for cHABs and, thereafter, assessed the extant management approaches including prevention, control, and mitigation of the proliferation of cyanobacterial blooms. In light of this, we suggest that more intensified research should be directed to the standardization of procedures for cyanotoxin analysis. Also, the provision of standardized reference material for the quantification of cyanotoxins is vital for routine monitoring as well as the development of strong in situ sensors capable of quantifying and detecting HABs cells and toxins in waterbodies to prevent the adverse impacts of cHABs. Also, more investigations into the natural and environmentally friendly approach to cyanobacteria management and the necessary and appropriate deployment of artificial intelligence are required. Finally, we wish to redirect the focus of public health authorities to protecting drinking water supply sources, agriculture products, and food sources from cyanotoxins contamination as well as to implement proper monitoring and treatment procedures to protect citizens from this potential health threat.

Metal contamination of aquatic environments remains a major concern and has received significant attention in recent years. The present study aimed to evaluate the effects of metal mixtures of varying concentrations over time in a lake receiving runoff water from a decommissioned mine. By subjecting several organisms to this water, we aimed to identify the most susceptible species, thus enabling a comprehensive evaluation of the risk posed by different toxins to the biotic environment.

We have evaluated the effects of mixed metal exposure on survival and stress gene expression in selected invertebrate and vertebrate model species. Our observations revealed differences in sensitivity among the invertebrate models Caenorhabditis elegans, Daphnia magna, Ceriodaphnia dubia, and Heterocypris incongruens, as well as in the vertebrate model Zebrafish (Danio rerio) and two cell lines; a zebrafish liver cell line (ZFL) and a human hepatocellular carcinoma cell line (HepG2). While the sensitivity shows great variation among the tested species, the expression of metallothionein was consistent with the levels of metals found in the mixed exposure media. Despite differences in acute toxicity, the universal induction of mt1/A and mt2/B genes make them an important biomarker for assessing the environmental risk of metals.