In silico identification and expression analysis of superoxide dismutases in Tenebrio molitor.

BACKGROUND: Insects encounter various environmental stresses, in response to which they generate reactive oxygen species (ROS). Superoxide dismutase (SOD) is an antioxidant metalloenzyme that scavenges superoxide radicals to prevent oxidative damage. OBJECTIVE: To investigate expressions of SODs under oxidative stress in Tenebrio molitor. METHODS: Here, we investigated the transcriptional expression of SODs by pesticide and heavy metals in Tenebrio moltior. First, we searched an RNA-Seq database for T. molitor SOD (TmSOD) genes and identified two SOD isoforms (TmSOD1-iso1 and iso2). We examined their activities under developmental stage, tissue-specific, and various types (pesticide and heavy metal) of oxidative stress by using qPCR. RESULTS: Our results revealed two novel forms of TmSODs. These TmSODs had a copper/zinc superoxide dismutase domain, active site, Cu2+ binding site, Zn2+ binding site, E-class dimer interface, and P-class dimer interface. TmSODs (TmSOD1-iso1 and iso2) were expressed in diverse developmental phases and tissues. Pesticides and heavy metals caused an upregulation of these TmSODs. CONCLUSION: Our findings suggest that the two TmSODs have different functions in T. molitor, providing insights into the detoxification ability of T. molitor.

In silico identification and expression analyses of peroxidases in Tenebrio molitor.

Human advancements in agriculture, urbanization, and industrialization have led to various forms of environmental pollution, including heavy metal pollution. Insects, as highly adaptable organisms, can survive under various environmental stresses, which induce oxidative damage and impair antioxidant systems. To investigate the peroxidase (POX) family in Tenebrio molitor, we characterized two POXs, namely TmPOX-iso1 and TmPOX-iso2. The full-length cDNA sequences of TmPox-iso1 and TmPox-iso2 respectively consisted of an open reading frame of 1815 bp encoding 605 amino acids and an open reading frame of 2229 bp encoding 743 amino acids. TmPOX-iso1 and TmPOX-iso2 homologs were found in five distinct insect orders. In the phylogenetic tree analysis, TmPOX-iso1 was clustered with the predicted POX protein of T. castaneum, and TmPOX-iso2 was clustered with the POX precursor protein of T. castaneum. During development, the highest expression level of TmPox-iso1 was observed in the pre-pupal stage, while that of TmPox-iso2 expression were observed in the pre-pupal and 4-day pupal stages. TmPox-iso1 was primarily expressed in the early and late larval gut, while TmPox-iso2 mRNA expression was higher in the fat bodies and Malpighian tubules. In response to cadmium chloride treatment, TmPox-iso1 expression increased at 3 hours and then declined until 24 hours, while in the zinc chloride-treated group, TmPox-iso1 expression peaked 24 hours after the treatment. Both treated groups showed increases in TmPox-iso2 expression 24 hours after the treatments.

Marine crime scene investigation using Balanus sp. fouling patterns.

Marine biofouling occurs when microorganisms, plants, algae, or animals gather on any surface of a man-made object or natural structure. Biofouling organisms are important components of marine ecosystems and vary seasonally and regionally, with environmental factors such as temperature, amount of light, and nutrient availability. Since marine organisms have unique growth patterns, they can be used in marine forensic investigations to estimate time and environment. As few such studies have been done, this study analyzed the growth rates of Balanus on 100 × 100 mm panels of PVC, stainless steel, wood, and cloth and compared these with environmental factors such as temperature. Sets of panels were immersed in Sokcho Harbor, South Korea, each month, and observed monthly after immersion using American Society for Testing and Materials methods. The Balanus on the test panels grew to 1-20 mm and showed different growth patterns depending on when the panels were first immersed.

Sea urchin repelling Tannin- FeIII complex coating for ocean macroalgal afforestation.

Intense seaweed grazing by sea urchins has destroyed kelp forests and accelerated the transformation of these forests into barren areas known as urchin barrens. Once the sea urchins occupy the barren ground, it becomes more challenging to restore the kelp forests. Although phlorotannin, a primary herbivore defense chemical secreted by kelp, has been reported to discourage feeding activities of marine herbivores but the direct application of naturally extracted phlorotannin does not effectively repel sea urchins. In this study, we applied a simple and green Tannin-FeIII (TA-FeIII) coating on substrates as a sea urchin repellent using a cheap, ecofriendly tannin (TA) obtained from biomass as an alternative to phlorotannin. In a model aquarium experiment, most of the sea urchins (Anthocidaris crassispina) in the tank evaded the TA-FeIII-coated substrates. In field tests with 300 sea urchins, the majority of sea urchins could not crawl over the TA-FeIII-coated rope for more than 2 h in contrast to the control group. Hence, the safety, cost-effectiveness, and scalability of the TA-FeIII coating make it a practical candidate to protect the kelp ecosystem from sea urchins.

Immobilization of planktonic algal spores by inkjet printing.

The algal cell immobilization is a commonly used technique for treatment of waste water, production of useful metabolites and management of stock culture. However, control over the size of immobilized droplets, the population of microbes, and production rate in current techniques need to be improved. Here, we use drop-on-demand inkjet printing to immobilize spores of the alga Ecklonia cava within alginate microparticles for the first time. Microparticles with immobilized spores were generated by printing alginate-spore suspensions into a calcium chloride solution. We demonstrate that the inkjet technique can control the number of spores in an ejected droplet in the range of 0.23 to 1.87 by varying spore densities in bioink. After the printing-based spore encapsulation, we observe initial sprouting and continuous growth of thallus until 45 days of culture. Our study suggest that inkjet printing has a great potential to immobilize algae, and that the ability to control the number of encapsulated spores and their microenvironments can facilitate research into microscopic interactions of encapsulated spores.

Comparison of the effectiveness of four organic chemoattractants towards zoospores of Ulva pertusa and macrofouling.

Algal spores respond to many environmental variables, especially to chemical "cues". This chemotactic response can be utilized to attract spores, thereby colonization of a new substrata is possible to be influenced. In this attempt, four chemoattractant candidates were screened against spores of Ulva pertusa to reveal their efficiencies. Attachment and subsequent germination of Ulva spores were effectively influenced by these chemoattractant candidates. In particular 100 microg cm2 of D-glucose coating was found to enhance spore attachment by > 150%. Furthermore, field investigations carried out with test panels, clearly indicate the chemoattractive properties of test coatings. In recent years, various anthropogenic activities and natural hazards cause detrimental impacts on the benthic algae and other fishery resources. Artificial reefs have been laid on many coastal regions to increase or restore marine resources. Chemoattractant coatings can be applied on artificial surfaces to increase the colonization of benthic forms. It also can be used in the mariculture devices. Influence of chemoattractants on Ulva spores and fouling biomass estimated on test panels are discussed.