The potential inhibitory effects of the commercial diets on protease activities of Dentex dentex larvae and live foods

Abstract

The aim of this study was to determine the potential inhibitory effects of commercial diets on protease activities of Dentex dentex larvae and live foods. The highest and lowest protease activity of larvae was 387.08 ±0.23 U/mg protein and 54.66 ±0.15 U/mg protein, respectively. The highest and lowest protease activities of live foods were found in Artemia metanaupli (414.5 ±0.41 U/mg protein) and rotifer (156.25 ±0.09 U/mg protein), respectively. The significant differences between inhibition amounts of commercial diets on protease activities of larvae and live foods were found (p<0.05). Also, the significant differences between the inhibition percents were observed (p<0.05). The highest inhibition percents of Caviar (200-300µ), Caviar (300-500µ) and copepod were found as 91.86 ±0.26%, 90.72 ±0.13% and 90.82 ±0.22% in enriched rotifers, respectively. In addition, the highest inhibition percents of Caviar (100-200µ) and Proton (200-400µ) were observed as 93.57 ±0.18% and 93.34 ±0.22% in the larvae on day 35, respectively. The effect of Caviar (200-300µ) on protease activities of rotifer was the lowest. In general, copepod had the lower inhibitory effect than those of other commercial diets on protease activities of larvae. Copepod showed the lowest effect on protease activity of larvae on day 30. The inhibition percents of commercial diets on protease activities of live foods were high except for rotifers. Our study revealed that the inhibitory effects of commercial diets used through weaning on protease activities of larvae and live foods should be taken into account. In conclusion, the potential inhibitory effects of commercial diets on protease activities of marine fish larvae and live foods to increase the survival and growth rates in hatcheries should be investigated in future studies.Bu çalışmanın amacı, Dentex dentex larvaları ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin potansiyel inhibitör etkilerini belirlemektir. Larvaların en yüksek ve en düşük proteaz aktiviteleri sırasıyla 387,08 ±0,23 U/mg protein ve 54,66 ±0,15 U/mg protein olarak tespit edildi. Canlı gıdaların en yüksek ve en düşük proteaz aktiviteleri sırasıyla Artemia metanaupli (414,5 ±0,41 U/mg protein) ve rotiferde (156,25 ±0,09 U/mg protein) bulundu. Larvaların ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin inhibisyon miktarları arasında istatistiksel olarak önemli farklılıklar bulundu (p<0,05). Aynı zamanda, inhibisyon yüzdeleri arasında da istatistiksel olarak önemli farklılıklar gözlendi (p<0.05). Zenginleştirilmiş rotiferler üzerinde, Caviar (200-300µ), Caviar (300-500µ) ve copepod'un en yüksek inhibisyon yüzdeleri sırasıyla %91.86 ±0.26, %90.72 ±0,13 ve %90.82 ±0.22 olarak bulundu. Buna ilaveten 35 günlük larvalarda, Caviar (100-200µ) ve Protonun (200-400µ) en yüksek inhibisyon yüzdeleri sırasıyla %93.57 ±0.18 ve %93.34 ±0.22 olarak gözlendi. Rotiferlerin proteaz aktiviteleri üzerine Caviar'ın (200-300µ) etkisi en düşük seviyede oldu. Genelde, larvaların proteaz aktiviteleri üzerinde kopepod'un diğer...

The Inhibitory Effects and Positive Contributions of Live Foods on Protease Activities of Meagre, Argyrosomus regius (Asso 1801), Larvae In Vitro Assay

“…Cahu and Zambonino Infante [6] indicated that the survival and growth of marine fish larvae solely fed on microdiet are very poor, but supplementation with live foods usually results in a marked improvement. Results of this study along with those of Diken et al [23] and Naz and Yúfera [19] showed that the contributions of Artemia metanauplii on protease activities of larvae were high, while the contributions of rotifer (B. plicatilis) and Artemia nauplii were low. Yúfera et al [39] reported that during feeding gilthead seabream larvae, the contribution of rotifer on protease activity of larval intestines was not significant, thus supporting the situation of rotifer contributions in protease activities of meagre larvae.…”

“…On the other hand, Artemia nauplii protease activity level was similar to Haközü [20] and Diken et al [22]. Artemia metanauplii's protease activity level was lower than Diken et al [22], higher than Haközü [20] and Diken et al [23], and similar to Naz and Yúfera [19]. The differences between the protease activity of enriched rotifer and Artemia metanauplii and also between Artemia nauplii and Artemia metanauplii [18] agree with the results obtained in this study.…”

“…Results showed that rotifer (B. plicatilis) protease activity level was lower than what Naz and Yúfera [19] identified, higher than Diken et al [22], and similar to Haközü [20]. Additionally, Munilla-Moran et al [7] showed that the rotifer had the lowest enzymatic activity compared to Artemia sp.…”

“…Artemia, which is a feed source affected by environmental and seasonal effects, is commonly used as a live food source. However, in spite of its superiority as a feed source, the lack of copepods culture at the industrial level means that there may be differences in enzyme activities due to a lack of standardization-this represents an important problem when feeding live larvae [15][16][17][18][19][20][21][22][23]. It has been reported that external enzymes in live foods, especially in Artemia, help the larval digestion to activate the zymogens present in the larval gut [24][25][26].…”

The Inhibitory Effects and Positive Contributions of Live Foods on Protease Activities of Meagre, <em>Argyrosomus regius</em> (Asso 1801) Larvae <em>in vitro</em> Assay

“…Enzymatic differences in live foods and the fact that Artemia is a feed source due to environmental and seasonal effects and that the copepod culture has not been achieved at industrial level despite its superiority in nutrient and enzyme activities is in the problems of live food nutrition [15][16][17][18][19][20][21][22][23]. Live foods especially in Artemia, it has been reported that the external enzymes in Artemia help larval digestion or activate existing zymogens in the larval gut [24][25][26].…”