Does Anisakis spp. infestation affect the proximate composition, fatty acids, and minerals contents of its host Merluccius merlucccius?

Fish play an important role in human nutrition. They are not only a great source of protein and healthy fats, but also a unique source of essential nutrients such as omega-3 fatty acids. Moreover, most fish are parasitized, and some of these parasites are able to influence the reallocation of resources in their favor and thus reduce the nutritional quality of the fish. The present study was conducted to investigate the impact of the third stage larvae (L3) of Anisakis spp. on the proximate composition, macro-minerals (potassium, calcium, and sodium), and fatty acids of European hake (Merluccius merluccius Linnaeus, 1758). In parasitized female group, our results revealed a decrease (p< 0.005) in the amount of carbohydrate by 6.5%, of calcium by 17%, and of 2 polyunsaturated fatty acids (arachidonic acid (C20: 4w-6), and eicosapentaenoic acid (C20: 5w-3) with 33% and 15% respectively. Simultaneously, an increase by 25% in the level of a single saturated fatty acid C10:0 was noticed. According to the principal component analysis, the parasitized female was wealthy of saturated fatty acids and monounsaturated fatty acids and contains less of polyunsaturated fatty acids, omega-3 fatty acids, and omega-6 fatty acids than the unparasitized female and male. No significant changes were observed in the biochemical composition of male hake, probably due to the low mean intensity of L3 larvae of Anisakis spp. in this group.

Physiological and anatomical adaptations induced by flooding in Cotula coronopifolia.

Cotula coronopifolia is a wild annual Asteraceae that grows in periodically-flooded prone environments and seems highly tolerant to periodic flooding. Seedlings of about 15 cm were collected directly from the edge of Soliman sabkha (N-E Tunisia, semi-arid stage) and grown under greenhouse conditions. Two treatments were considered: drainage and flooding. After 56 days of treatment, flooded plants showed a pronounced growth increase. This performance was essentially associated with significant increment in biomass production of both shoots and roots (about 220% of the control). The appropriate response to flooding was also characterized by the ability of the species to maintain its water status under such conditions. Neither water content nor water potential showed a significant variation as compared to those of non-flooded plants. However, transpiration rate decreased slightly but significantly in flooded plants (from 0.86 to 0.64 mmol H2O m-2 s-1). Na+ and K+ concentrations were practically maintained under waterlogging conditions, except a significant increase of Na+ content in roots of flooded plants (157% of the control). These responses were concomitant with maintenance of photosynthetic rate. However, the contents of chlorophylls a and b increased to 167% and 295%, respectively. It seems that the enhancement in these photosynthetic pigments together with a significant improvement in water use efficiency (from 4.66 to 6.07 mmol CO2 mol-1 H2O) allowed to the species to compensate the decrease in photosynthetic rate. At the anatomical level, this species responded to flooding by a significant development of its root aerenchyma (+63%) and an increase in the lignification of its stem xylem tissues (+37%). Based on the presented data, the plant fitness under flooding conditions was a result of dynamic readjustment of several morphological, physiological, and anatomical adaptive traits. Flood requirement together with salt tolerance are responsible for the predominance of C. coronopifolia in a large area in its natural biotope where most plants cannot tolerate interactive effects of flooding and salinity.

OPTIMIZATION OF SALT CONCENTRATIONS FOR A HIGHER CAROTENOID PRODUCTION IN DUNALIELLA SALINA (CHLOROPHYCEAE)(1).

Dunaliella salina (Dunal) Teodor, when treated over 25 d with a wide range of NaCl salinities (0.6-4.5 M), showed its maximal growth potentialities at 1.5-3.0 M NaCl and was able to survive even at 4.5 M NaCl. Sodium concentrations increased significantly at the supraoptimal salinities, reaching up to 5 mmol · g(-1) dry weight (dwt) at 4.5 M NaCl. Interestingly, ability of D. salina to take up essential mineral nutrients was not impaired by increased salinity. As for growth, chl concentrations were maximal in the 1.5-3.0 M NaCl range. Interestingly, carotenoid concentrations increased with the increasing salinity. The highest values of total antioxidant activity (5.2-6.9 mg gallic acid equivalents [GAE] · g(-1) dwt), antiradical activity, and reducing power were measured at 1.5-3.0 M NaCl. As a whole, these results showed that at 1.5-3.0 M NaCl, D. salina produce appreciable antioxidant level. But, once it reaches its growth maximum, a salt addition up to 4.5 M could enhance its carotenoid yield.

Phytodesalination of a salt-affected soil with the halophyte Sesuvium portulacastrum L. to arrange in advance the requirements for the successful growth of a glycophytic crop.

In the present work, we studied the potential of the obligate halophyte, Sesuvium portulacastrum L., to desalinize an experimentally-salinized soil after the following criteria: (i) decrease in soil salinity and sodicity, (ii) plant biomass capacity to accumulate sodium ions, and (iii) phytodesalinized soil quality (equivalent to growth of a glycophytic test culture of Hordeum vulgare L.). The cultivation of the halophyte on the salinized soil (phytodesalination culture) led to a marked absorption of Na(+) ions by S. portulacastrum roots and their accumulation in the above-ground biomass up to 872 mg plant(-1) and 4.36 g pot(-1) (about 1 tha(-1)). The decrease in salinity and sodicity of the phytodesalinized soil significantly reduced the negative effects on growth of the test culture of H. vulgare. Furthermore, the phytodesalination enabled H. vulgare plants to keep a high water content and to develop a higher biomass with relatively high K and low Na contents.