Effect of sulphide in Pacific white shrimpPenaeus vannameiunder varying oxygen and pH levels

Abstract

Sulphide is one of the known environmental stressors, which potentially binds to cytochrome C oxidase (COX), a key enzyme in the electron transport chain, thereby blocking oxygen transport and ATP production. To ascertain the toxic effects of sulphide on Pacific white shrimp, Penaeus vannamei, two distinct exposure experiments were carried out with varying concentration of sulphide (0–1 mg/L), dissolved oxygen (normoxia and hypoxia) and pH values (8.2, 6 and 5). The activity of enzymes viz COX, superoxide dismutase (SOD), phenoloxidase and lactate accumulation was investigated. Outer membrane integrity and COX monomer separation were also done with the isolated crude mitochondrial preparations. Results indicated a significant reduction (p ≤ .05) in COX enzyme activity in sulphide exposed treatments when compared to control. The reduction was more intense when pH levels were reduced under hypoxia condition. Lactate accumulation as a result of anaerobic metabolism was found to be higher in hypoxic treatments. No significant difference (p ≥ .05) was observed in superoxide dismutase activity between the treatments, whereas phenoloxidase activity significantly decreased at higher concentration sulphide. Separation of mitochondrial proteins resulted in the identification of ~205 kDa of COX monomer, and significant damage was found in outer membrane integrity under hypoxia and pH treatments. From this study, it is evident that at a given concentration, sulphide is toxic to P. vannamei, and in association with hypoxia and low pH, they further intensify sulphide toxicity. Our results indicated that sulphide toxicity should not be considered as a single factor, rather it should be a considered as combination of factors.

Investigation of the Alternations in the Muscle Quality of Swimming Crab (Ovalipes punctatus) during Cold-Chain Transportation Using Physicochemical and TMT-Based Quantitative Proteomic Analysis

“…In the current study, mitochondrial cytochrome c oxidase (mtCOX), mitochondrial manganese superoxide dismutase (mtMnSOD), and glutathione S -transferase θ1 (GST-θ1) in FC/LC and DC/FC comparisons were collectively downregulated. Thulasi et al reported that COX and mitochondrial-like proteins could be associated with mitochondrial membrane damage due to the high levels of ROS production under severe oxidative stress induced by food deprivation. , The mtMnSODs, key antioxidant enzymes that contain manganese, can catalyze anion disproportionation and have been reported to be involved in the innate immune response of crabs. , They are considered the first line of defense against oxidative stress induced by excessive ROS beyond the threshold limits resulting from respiratory bursts . A GST catalyzes the conjugation of glutathione (GSH) with toxic reactive metabolites and is considered a detoxification enzyme against the chemotoxicity of xenobiotics .…”

“…Thulasi et al reported that COX and mitochondrial-like proteins could be associated with mitochondrial membrane damage due to the high levels of ROS production under severe oxidative stress induced by food deprivation. 32,33 The mtMnSODs, key antioxidant enzymes that contain manganese, can catalyze anion disproportionation and have been reported to be involved in the innate immune response of crabs. 34,35 They are considered the first line of defense against oxidative stress induced by excessive ROS beyond the threshold limits resulting from respiratory bursts.…”

The mechanism of pH recalibration by dissolved oxygen in alkaline modified aquaculture seawater

“…These results in low DO condition. Another problem that may arise from this situation is the possibility of increasing impurities in the water [4]. Those findings demonstrated that low DO is an enormous threat for the biotic components in the marine ecosystems.…”

Molybdate delays sulphide formation in the sediment and transfer to the bulk liquid in a model shrimp pond

“…The H2S formed creates a bad odour and black colour in the sediment, and is also toxic to the shrimp that dwell at the pond bottom. Sulphide toxicity to shrimp depends on both the H2S concentration and pH (Vismann, 1996;Thulasi et al, 2020), with lethal concentrations to kill 50% of the population (LC50) values ranging between 0.0087 and 0.033 mg/L H2S, depending on shrimp species and growth phase of the shrimp (H.-C. Chen, 1985;US-EPA, 2011). Exposure to sub-lethal concentrations of H2S lowers shrimp resistance to diseases and causes tissue corrosion (Suo et al, 2017).…”