White shrimp, Litopenaeus vannamei, which had been injected with chitin at 4, 6 and 8 microg g(-1) or chitosan at 2, 4 and 6 microg g(-1), were challenged with pathogen Vibrio alginolyticus at 2 x 10(6) colony-forming units (cfu) shrimp(-1) and then placed in seawater of 34 per thousand. The survival of shrimp that received chitin or chitosan at either dose was significantly higher than that of...

The fungal metabolite kojic acid, which is produced by Aspergillus and Penicillium species fungi that may be pathogens of both insects and plants, was a significant inhibitor of phenoloxidase of different representative beetle and caterpillar insect species. Fusaric acid and picolinic acid, produced by Fusarium spp., were also significant inhibitors of phenoloxidase, while dipicolinic acid and ...

In this study, we explored the pathogenic effects of white spot syndrome virus (WSSV) and effects of yeast cell wall in the red claw crayfish, Cherax quadricarinatus, by investigating the activity of enzymes related to innate immune function following artificial infection of immunized and non-immunized crayfish. Our results reveal that the activity of four enzymes, phenoloxidase (PO), peroxidas...

In this study, we explored the pathogenic effects of white spot syndrome virus (WSSV) and effects of yeast cell wall in the red claw crayfish, Cherax quadricarinatus, by investigating the activity of enzymes related to innate immune function following artificial infection of immunized and non-immunized crayfish. Our results reveal that the activity of four enzymes, phenoloxidase (PO), peroxidas...

as oxygenic photosynthetic organisms evolved. Organisms had to develop different strategies to handle a final product of photosynthesis, dioxygen (O2), as well as its highly reactive derivatives, superoxide anions, hydrogen peroxide and hydroxyl radicals. Several enzymes, such as superoxide dismutase, catalase and peroxidase, evolved that protected the organisms. A particular class of protein, ...

The total haemocyte count (THC), phenoloxidase activity, respiratory bursts (release of superoxide anions), superoxide dismutase (SOD) activity, and phagocytic activity and clearance efficiency to the pathogen Lactococcus garvieae were measured when freshwater giant prawns Macrobrachium rosenbergii (18.2+/-2.1 g) were individually reared in water containing concentrations of trichlorfon of 0, 0...

1. Mounting an immune response is likely to be costly in terms of energy and nutrients, and so it is predicted that dietary intake should change in response to infection to offset these costs. The present study focuses on the interactions between a specialist grass-feeding caterpillar species, the African armyworm Spodoptera exempta, and an opportunist bacterium, Bacillus subtilis. 2. The main ...

Trade-offs between life-history variables can be manifested at either the phenotypic or genetic level, with vastly different evolutionary consequences. Here, we examined whether male decorated crickets (Gryllodes sigillatus) from eight inbred lines and the outbred founder population from which they were derived, trade-off immune effort [lytic activity, phenoloxidase (PO) activity or encapsulati...