Cold-adapted structural properties of trypsins from walleye pollock (<Emphasis Type="Italic">Theragra chalcogramma</Emphasis>) and Arctic cod (<Emphasis Type="Italic">Boreogadus saida</Emphasis>)

Complementary DNA clones encoding trypsins were isolated from pyloric ceca of cold-adapted fish, walleye pollock (Theragra chalcogramma) (WP-T) and Arctic cod (Boreogadus saida) (AC-T). The isolated full-length cDNA clones of WP-T and AC-T were 852 and 860 bp, respectively, and both cDNAs were contained an open reading frame of 726 bp. WP-T and AC-T seemed to be synthesized as preproenzyme that contains a signal peptide, an activation peptide, and a mature trypsin. Although the amino acid sequence identities of WP-T and AC-T to that of bovine trypsin were 64 and 63%, respectively, they completely conserved the structural features for catalytic function of trypsin. On the other hand, WP-T and AC-T possessed the four Met residues (Met135, Met145, Met175 and Met242) in their molecules and the deletion of Tyr151 and substitution of Pro152 for Gly in their autolysis loops when aligned with the sequences of tropical-zone fish and bovine trypsins. In addition, the contents of charged amino acid residues at the N-terminal regions (positions 20–50) of WP-T and AC-T were extremely higher than those of other fish and bovine trypsins. Moreover, one amino acid (Asn72) and two amino acids (Asn72 and Val75) coordinating with Ca²⁺ in bovine trypsin were exchanged for another amino acids in WP-T (His) and AC-T (His and Glu), respectively, and the contents of negative charged amino acids at their Ca²⁺-binding regions were lower than those of tropical-zone fish and bovine trypsins. Therefore, it was considered that these structural characteristics of WP-T and AC-T are closely related to their lower thermostability.     

Purification and characteristics of trypsins from cold-zone fish,Pacific cod (Gadus macrocephalus) and saffron cod (Eleginus gracilis)

Trypsins from the pyloric ceca of Pacific cod (Gadus macrocephalus) (GM-T) and saffron cod (Eleginus gracilis) (EG-T) were purified by gel filtration on Sephacryl S-200 and Sephadex G-50. The final enzyme preparations were nearly homogeneous on SDS–PAGE and the molecular weights of both enzymes were estimated to be approximately 24 kDa by SDS–PAGE. The specific trypsin inhibitors, soybean trypsin inhibitor and TLCK, strongly inhibited the activities of GM-T and EG-T. The optimum pH and optimum temperature of both trypsins were around pH 8.0 and 50 °C, respectively, using N^α-p-tosyl-l-arginine methyl ester as substrate. The GM-T and EG-T were unstable above 30 °C and below pH 5.0, and they were stabilised by calcium ion. The N-terminal amino acid sequences of GM-T (IVGGYECTRHSQAHQVSLNS) and EG-T (IVGGYECPRHSQAHQVSLNS) were found. The percentage of hydrophobic amino acid in the N-terminal 20 amino acids sequences of these cold-zone fish trypsins was lower (28%) than those of temperate-zone fish trypsins (34%), tropical-zone fish trypsins (37%) and mammalian trypsins (34%). Whereas the content of charged amino acids in the GM-T and EG-T was relatively higher than those of trypsins from temperate-zone fish, tropical-zone fish and mammals. Moreover, the GM-T catalyzed synthesis of N^α-(tert-butoxycarbonyl)-l-alanyl-l-alanine-p-nitroanilide (N^α-Boc-l-Ala-l-Ala-pNA) has been studied by using N^α-(tert-butoxycarbonyl)-l-alanine-p-guanidinophenyl ester [N^α-Boc-l-Ala-OpGu (inverse substrate)] as acyl donor and l-alanine-p-nitroanilide (l-Ala-pNA) as acyl acceptor, respectively.     

Trypsin from zebra blenny (Salaria basilisca) viscera: Purification,characterisation and potential application as a detergent additive

An alkaline trypsin was purified from the viscera of zebra blenny (Salaria basilisca) by ammonium sulphate (40?80% saturation) precipitation, Sephadex G-100, Mono Q-Sepharose and ultrafiltration. A yield of 12% with a purification-fold of 4.2 was obtained. The trypsin had an apparent molecular weight of 27 kDa. Soybean trypsin inhibitor and phenylmethylsulfonyl fluoride showed a strong inhibitory effect on the purified trypsin. Trypsin had maximal activity at pH 9.5 and 60 °C for the hydrolysis of Nα-benzoyl-dl-arginine-p-nitroanilide (BAPNA). It was stable at low temperatures and in the pH range of 7.0?12.0. The N-terminal amino acid sequence of the first 12 amino acids of the purified protease was IVGGRECTEPSQ. S. basilisca trypsin, which showed high homology with other fish trypsins, had a charged Arg residue at position 5, where Tyr is common in marine vertebrates and mammalian trypsins. The trypsin kinetic constants, K_m and k_cat for BAPNA, were 0.6 mM and 1.38 s^?1, respectively.     

Purification and characterization of trypsin from the viscera of sardine (Sardina pilchardus)

Trypsin from the viscera of Sardina pilchardus was purified by fractionation with ammonium sulphate, heat treatment and Sephadex G-100 gel filtration with a ninefold increase in specific activity and 9% recovery. The molecular weight of the enzyme was estimated to be 25,000 Da on SDS–PAGE. This enzyme showed esterase-specific activity on Nα-benzoyl-l-arginine ethyl ester (BAEE). The purified enzyme was inhibited by benzamidine, a synthetic trypsin inhibitor, and phenylmethylsulphonyl fluoride (PMSF) a serine-protease inhibitor, but was not inhibited by the β-mercaptoethanol. The optimum pH and temperature for the enzyme activity were pH 8.0 and 60 °C, respectively. The relative activity at pH 9.0 was 95.5% and the enzyme showed pH stability between 6.0 and 9.0. The N-terminal amino acid sequence of the first 12 amino acids of the purified trypsin was IVGGYECQKYSQ. S. pilchardus trypsin, which showed high homology to other fish trypsins, had a charged Lys residue at position 9, where Pro or Ala are common in fish trypsins. The enzyme was strongly inhibited by Zn²⁺ and Cu²⁺.     

COMPARATIVE STUDY OF ENZYMATIC CHARACTERISTICS OF TRYPSINS FROM THE PYLORIC CECA OF YELLOW TAIL (SERIOLA QUINQUERADIATA) AND BROWN HAKELING (PHYSICULUS JAPONICUS)

Trypsins from the pyloric ceca of two fish species, yellow tail (Seriola quinqueradiata) and brown hakeling (Physiculus japonicus) were purified by a series of chromatographic separations. Purity increased 62‐ and 106‐fold with approximately 55 and 10% yield for yellow tail trypsin and brown hakeling trypsin, respectively. Final enzyme preparations were homogeneous in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), and the molecular weights of both enzymes were estimated to be 24 kDa by SDS‐PAGE. Yellow tail and brown hakeling trypsins had maximal activity at pH 8.0 for hydrolysis of N_α‐p‐tosyl‐L‐arginine methyl ester hydrochloride and was unstable at acidic pH. The optimum temperatures for yellow tail and brown hakeling trypsins were 60 and 50C, respectively. Yellow tail trypsin was stable up to 50C, whereas brown hakeling was stable up to 40C. Both trypsins were stabilized by calcium ions. The activities of both trypsins were strongly inhibited by soybean trypsin inhibitor and N_α‐p‐tosyl‐L‐lysine chloromethyl ketone hydrochloride, and were partially inhibited by ethylenediaminetetraacetic acid. The N‐terminal amino acid sequences of yellow tail trypsin and brown hakeling trypsin were determined as IVGGYECTPYSQPHQVSLNS and IVGGYECPKHSQPHQVSLNS, respectively.     

Purification and characterisation of trypsins from the spleen of skipjack tuna (Katsuwonus pelamis)

Three trypsin isoforms, trypsins A, B and C, from the spleen of skipjack tuna (Katsuwonus pelamis) were purified by a series of chromatographies including Sephacryl S-200, Sephadex G-50 and diethylaminoethyl-cellulose to obtain a single band on native-PAGE and SDS–PAGE. The molecular mass of all the trypsin isoforms was estimated to be 24 kDa by size exclusion chromatography and SDS–PAGE. The optimum pH and temperature of the three isoforms for the hydrolysis of N-p-tosyl-l-arginine methyl ester hydrochloride were 8.5 and 60 °C, respectively. Trypsins were stable to heat treatment up to 50 °C, and over a pH range of 6.0–11.0. All isoforms were stabilised by calcium ions. The trypsin activities were effectively inhibited by soybean trypsin inhibitor, TLCK and partially inhibited by ethylenediaminetetraacetic acid, while E-64, N-ethylmaleimide, iodoacetic acid, TPCK and pepstatin A showed no inhibitory effect. Activities decreased continuously as NaCl concentration (0–30%) increased. Trypsins A, B and C showed K_m of 0.11–0.29 mM and K_cat of 57.1–114 s⁻¹. The N-terminal amino acid sequence of 20 residues of three trypsin isoforms was IVGGYECQAHSQPHQVSLNS and had high homology to those of other fish trypsins.     

24 kDa Trypsin: A predominant protease purified from the viscera of hybrid catfish (Clarias macrocephalus × Clarias gariepinus)

Trypsin was purified to homogeneity from the viscera of hybrid catfish (Clarias macrocephalus × Clarias gariepinus) through ammonium sulphate fractionation and a series of chromatographies including Sephacryl S-200, Sephadex G-50 and DEAE-cellulose. It was purified to 47.6-fold with a yield of 12.7%. Based on native-PAGE, the purified trypsin showed a single band. The molecular weight of purified trypsin was estimated as 24 kDa by size exclusion chromatography and SDS–PAGE. The optimum pH and temperature for N^α-p-tosyl-l-arginine methyl ester hydrochloride (TAME) hydrolysis were 8.0 and 60 °C, respectively. Trypsin was stable to heat treatment up to 50 °C, and over a pH range of 6.0–11.0. Trypsin was stabilized by calcium ion. The trypsin activity was strongly inhibited by soybean trypsin inhibitor and N-p-tosyl-l-lysine chloromethyl ketone and partially inhibited by ethylenediaminetetraacetic acid. Activity decreased continuously as NaCl concentration (0–30%) increased. Apparent K_m value of trypsin was 0.3 mM and K_cat value was 92.1 S⁻¹ for TAME. The N-terminal amino acid sequence of 20 residues of trypsin was IVGGYECQAHSQPPTVSLNA, which is highly homologous with trypsins from other species of fish.     

Purification and characterisation of trypsins from the pyloric caeca of mandarin fish (Siniperca chuatsi)

Two trypsins of anionic form (trypsin A) and cationic form (trypsin B) from the pyloric caeca of mandarin fish (Siniperca chuatsi) were highly purified by a series of chromatographies, including DEAE-Sephacel, Sephacryl S-200 HR, Q-Sepharose or SP-Sepharose. Purified trypsins revealed a single band on native-PAGE. The molecular weights of trypsin A and B were 21 kDa and 21.5 kDa, respectively, as estimated by SDS–PAGE, both under reducing and non-reducing conditions. Zymography analysis showed that both trypsins were active in degrading casein. Trypsin A and B exhibited maximal activity at 35 °C and 40 °C, respectively, and shared the same optimal pH of 8.5, using Boc-Phe-Ser-Arg-MCA as substrate. The two trypsins were stable up to 45 °C and in the pH range from 4.5 to 11.0. Trypsin inhibitors are effective on these two enzymes and their susceptibilities were similar. Both trypsins were activated by metal ions such as Ca²⁺ and Mg²⁺ and inactivated by Fe²⁺, Zn²⁺, Mn²⁺, Cu²⁺, Al³⁺, Ba²⁺ and Co²⁺ to different degrees. Apparent K_m values of trypsin A and B were 2.18 μM and 1.88 μM, and K_cat values were 81.6 S⁻¹ and 111.3 S⁻¹ for Boc-Phe-Ser-Arg-MCA, respectively. Immunoblotting analysis using anti-common carp trypsin A positively cross-reacted with the two enzymes, suggesting their similarity. The N-terminal amino acid sequence of trypsin B was determined as IVGGYECEAH, which is highly homologous with trypsins from other species of fish.     

A heat-stable trypsin from the hepatopancreas of the cuttlefish (Sepia officinalis): Purification and characterisation

Thermostable trypsin from the hepatopancreas of Sepia officinalis was purified by fractionation with ammonium sulphate, Sephadex G-100 gel filtration, DEAE-cellulose an ion-exchange chromatography, Sephadex G-75 gel filtration and Q-Sepharose anion-exchange chromatography, with a 26.7-fold increase in specific activity and 21.8% recovery. The molecular weight of the purified enzyme was estimated to be 24,000 Da by SDS-PAGE and size exclusion chromatography. The purified enzyme showed esterase specific activity on Nα -benzoyl-L-arginine ethyl ester (BAEE) and amidase activity on Nα -benzoyl-DL-arginine-p-nitroanilide (BAPNA). The optimum pH and temperature for the enzyme activity were pH 8.0 and 70 °C, respectively, using BAPNA as a substrate. The enzyme was extremely stable in the pH range 6.0–10.0 and highly stable up to 50 °C after 1 h of incubation. The purified enzyme was inhibited by soybean trypsin inhibitor (SBTI) and phenylmethylsulphonyl fluoride (PMSF), a serine-protease inhibitor. The N-terminal amino acid sequence of the first 12 amino acids of the purified trypsin was IVGGKESSPYNQ. S. officinalis trypsin, which showed high homology with trypsins from marine vertebrates and invertebrates, had a charged Lys residue at position 5 and a Ser residue at position 7, where Tyr and Cys are common in all marine vertebrates and mammalian trypsins. Further, the enzyme had an Asn at position 11, not found in any other trypsins.     

Physicochemical and sensory characteristics of soya protein isolate hydrolysates with added substrate‐like amino acids

Soya protein isolate (SPI) with or without added substrate‐like amino acid was subject to enzymatic hydrolysis catalysed by commercial proteases (Alcalase 2.4 L, flavourzyme and pancreatin). Addition of a small amount of amino acids (amino acid: SPI = 1: 2500, mol g^?1) during hydrolysis would cause a significantly (P < 0.05) reduced protein recovery, increased degree of hydrolysis, and altered amino acid composition and antioxidant activities of SPI hydrolysates. The SPI hydrolysates prepared with added Asp, Arg or Lys exhibited a higher antioxidant activity than the control. The bitterness of SPI hydrolysates was largely reduced upon addition of Met, Asp or Glu during hydrolysis, whilst the umami taste and mouthfeel‐liking were remarkably increased. Therefore, adding amino acid during hydrolysis is a feasible and beneficial approach to improve both the functional and sensory properties of SPI hydrolysate.     

Properties of Trypsin from the Pyloric Ceca of Atlantic Cod (Gadus morhua)

Trypsin (EC 3.4.21.4) was isolated from the pyloric ceca of Atlantic cod and purified to homogeneity by affinity chromatography. The enzyme catalyzed the hydrolysis of benzoyl arginine p-nitroanilide (BAPA, pH 8.2 and 25°C) such that V_max was 250 BAPA units per micromole trypsin and K_m was 1.48 mM. For the hydrolysis of tosyl arginine methyl ester (TAME, pH 8.1 and 25°C), V_max was 18.2 × 10³ TAME units/micromole trypsin, and K_m 0.22 mM. The pH and temperature optima with BAPA substrate were 7.5 and 40°C, respectively. Atlantic cod trypsin was most active and stable at alkaline pH. The enzyme was heat labile, losing more than 50% of its activity after incubation at 50°C for 30 min. Amino acid analysis of Atlantic cod trypsin revealed that the enzyme was rich in residues such as serine, glycine, glutamate and aspartate, but poor in basic amino acid residues compared to trypsins from warm blooded animals.     

Biochemical properties of two isoforms of trypsin purified from the Intestine of skipjack tuna (Katsuwonus pelamis)

Two trypsins (A and B) from the intestine of skipjack tuna (Katsuwonus pelamis) were purified by Sephacryl S-200, Sephadex G-50 and DEAE-cellulose with a 177- and 257-fold increase in specific activity and 23% and 21% recovery for trypsin A and B, respectively. Purified trypsins revealed a single band on native-PAGE. The molecular weights of both trypsins were 24 kDa as estimated by size exclusion chromatography and SDS–PAGE. Trypsin A and B exhibited the maximal activity at 55 °C and 60 °C, respectively, and had the same optimal pH at 9.0. Both trypsins were stable up to 50 °C and in the pH range from 6.0 to 11.0. Both trypsin A and B were stabilised by calcium ion. Activity of both trypsins continuously decreased with increasing NaCl concentration (0–30%) and were inhibited by the specific trypsin inhibitors – soybean trypsin inhibitor and N-p-tosyl-l-lysine chloromethyl ketone. Apparent K_m and K_cat of trypsin A and B were 0.22–0.31 mM and 69.5–82.5 S⁻¹, respectively. The N-terminal amino acid sequences of the first 20 amino acids of trypsin A and B were IVGGYECQAHSQPPQVSLNA and IVGGYECQAHSQPPQVSLNS, respectively.     

Identification of active peptides from backbones of Nemipterus japonicus and Exocoetus volitans by electrospray ionisation–mass spectrometry

In our present investigation, Nemipterus japonicus and Exocoetus volitans backbone protein were hydrolysed by proteases like trypsin and pepsin, respectively. The protein hydrolysates were purified by different chromatographic methods, and the resulted purified peptides were analysed for their amino acid sequences by electrospray ionisation–MS/MS. The analysis of peptides showed sequences as Gly‐His‐Met‐Ser (451.8 Da) and Leu‐Glu‐Val‐Lys‐Pro (596.9 Da) for N. japonicus and E. volitans muscle, respectively. The presence of hydrophobic amino acids contributes more to the antioxidant activities of peptides than other amino acids. Moreover, sequence of amino acids in peptides plays an important role in their antioxidant activities.     

Stability of antioxidant peptides from duck meat after post‐mortem ageing

The stability of antioxidant peptides from aged duck meat during processing and simulated gastrointestinal digestion was investigated. The antioxidant peptides preserved a high stability in the presence of diverse NaCl or upon various time heating. The antioxidant activities were strengthened by the addition of 4–8% glucose or by heating at 100 °C, whereas they were lost under alkaline conditions. During in vitro digestion, the antioxidant activities increased with pepsin treatment but then decreased following trypsin digestion. Pepsin hydrolysed peptides into short fragments and results in the increased exposure of internal hydrophobic amino acids. With further treatment by trypsin, peptides can be hydrolysed completely and more free amino acids were released, leading to the decline in surface hydrophobicity. These variations might be responsible for the change in antioxidant activity during in vitro digestion. The antioxidant peptides from aged duck with high stability can be used as functional food ingredients to improve human health.     

Effects of rice koji inoculated with Aspergillus luchuensis on the biochemical and sensory properties of a sailfin sandfish (Arctoscopus japonicus) fish sauce

The effects of rice koji inoculated with Aspergillus luchuensis on the biochemical and sensory properties of fish sauce produced from sailfin sandfish (Arctoscopus japonicus) with different salt concentrations (10% and 20%) were investigated over 10 months. Fish sauces prepared from sailfin sandfish with rice koji and a low salt concentration had higher total nitrogen, amino nitrogen and total free amino acid than did those without rice koji or with a high salt concentration. Sensory evaluation of fish sauces prepared with rice koji and a low salt concentration found better taste, flavour and overall acceptance than those prepared without rice koji during fermentation (P < 0.05). The use of rice koji increased the total nitrogen, amino nitrogen and free amino acid and also enhanced the sensory qualities during fermentation. These results suggest that the use of rice koji can result in a low‐salt fish sauce with better flavour.     

Effect of mixed kojis on physiochemical and sensory properties of rapid‐fermented fish sauce made with freshwater fish by‐products

The objective of this study was to investigate the effect of mixed kojis on essential indices of fish sauce. Fish sauce inoculated with mixed kojis (FSB, Aspergillus oryzae koji:Aspergillus niger koji = 3:1) and A. oryzae koji (FSA, control) was prepared. At the end of fermentation, the content of amino nitrogen, total soluble nitrogen, Free amino acid (FAA) and glutamic acid in FSB increased by 7.50%, 7.84%, 9.80% and 28.43% compared to FSA, due to higher acid protease activity in mixed kojis. Moreover, flavour groups including phenols, ketones and nitrogen‐containing compounds in FSB were also improved. According to the results of sensory evaluation, FSB showed higher intensity of umami and caramel attributes, lower intensity of ammonia and sour attributes. All the results suggested that the usage of mixed kojis to produce fish sauce was an effective method that can accelerate the fermentation process and improve the flavour of fish sauce made with freshwater fish by‐products.     

INFLUENCE OF G187W/K188F/D189Y MUTATION IN THE SUBSTRATE BINDING POCKET OF TRYPSIN ON β-CASEIN PROCESSING

Undertaking to modulate the catalytic properties of trypsin, highly conserved G187, K188 and D189 were replaced with aromatic amino acid residues in order to perturb the electrostatics and to amplify hydrophobic interactions of the substrate binding site. The kinetic parameters of the wild-type trypsin and G187W/K188F/D189Y mutant were determined with synthetic tetrapeptide substrates and β-casein at different pHs. Compared with trypsin, the mutant G187W/K188F/D189Y exhibits 1.3-fold increase in K_m values for the substrates containing arginine and lysine. This mutant shows a 30- to 40-fold decrease of its kcat and its second-order rate constant k_cm/k_m decreases = 40- and 55-fold for substrates containing arginine and lysine, respectively. The kinetic analysis reveals that the mutant conserves the native trypsin capacity to hydrolyze peptide bonds containing arginyl and lysyl residues. Surprisingly, as demonstrated only by proteolysis of a natural substrate (β-casein), the mutant cleaves also peptide bonds involving asparagine and glutamine.     

南极磷虾胰蛋白酶的结构分析及适冷性机制研究

本文基于酶的纯化鉴定、动力学分析、序列比对和结构预测,对南极磷虾胰蛋白酶的结构及适冷性进行研究,通过与其他几种适冷、中温胰蛋白酶进行差异性分析,探讨南极磷虾胰蛋白酶等适冷酶在催化反应过程中应对低温环境的机制。结果显示适冷胰蛋白酶和中温胰蛋白酶的催化中心严格保守,遵循一致的催化机制;但南极磷虾胰蛋白酶等适冷酶为了适应低温环境,各级结构都表现出一定的应对机制:疏水性残基含量偏高、带正负电荷残基含量偏低,分子内部疏水作用增强、盐桥减少,这些因素致使适冷胰蛋白酶蛋白质分子内的相互作用减弱,分子柔性增强。适冷胰蛋白酶具有更高比例的呈松散状的无规卷曲结构,一定程度提高了其柔性;底物专一性口袋周围空间位阻更小,底物更容易接近活性中心,这也是加快催化反应的关键因素。     

Characterization of an i-type lysozyme gene from the sea cucumber Stichopus japonicus, and enzymatic and nonenzymatic antimicrobial activities of its recombinant protein

Because sea cucumbers lack a well-developed immune system and can ingest pathogenic bacteria together with food, some form of active antibacterial substances must be present in the body for defense. In this study, the cDNA of an i-type lysozyme from the sea cucumber Stichopus japonicus (designated SjLys) was cloned by RT-PCR and RACE PCR techniques. The full length cDNA of SjLys was 713 bp with an open reading frame of 438 bp coding for 145 amino acids. Two catalytic residues (Glu34 and Asp47), conserved in i-type lysozymes, and a highly conserved region near the active site, MDVGSLSCG(P Y)(Y F)QIK, were detected in SjLys. In addition, the domain structure analysis of SjLys showed that it is highly similar to the medicinal leech destabilase, which belongs to a new phylogenetic family of invertebrate lysozymes possessing both glycosidase and isopeptidase activities. To gain insight into the in vitro antimicrobial activities of SjLys, the mature peptide coding region was heterologously expressed in Escherichia coli. The recombinant SjLys protein displayed an inhibitive effect on the growth of the tested Gram-positive and Gram-negative bacteria. A remarkable finding is that the recombinant SjLys exhibited more potent activities against all tested bacterial strains after heat-treating at 100 °C for 50 min. These results indicated that the S. japonicus lysozyme is an enzyme with combined enzymatic (glycosidase) and nonenzymatic antibacterial action.     

Fatty acid composition and oxidative stability of oils recovered from acid silage and bacterial fermentation of fish (Sea bass – Dicentrarchus labrax) by‐products

Lipid quality and fatty acid compositions of fish oils recovered from fish (Sea bass – Dicentrarchus labrax) waste silages produced with formic acid (FA) and five different LAB strains (Lactobacillus plantarum (LP), Pediococcus acidilactici (PA), Enterococcus gallinarum (EG), Lactobacillus brevis (LB) and Streptococcus spp. (ST)) were assessed to ensure for the usage for human consumption. Generally, it was observed that there were no significant differences between PUFA contents (23.27–23.64%). Peroxide (PV) (2.12 meq active O₂/per kg of oil) and TBA values (1.07 mg malonaldehyde (MA) g^?1 oil) of fish oils from acid silage were significantly higher than those of the fermented ones (1.14–1.91 meq active O₂ kg^?1, 0.67–0.81 mgMA g^?1 oil, respectively). Anisidine values (AV) were determined in range of 8.04–11.14 for fermented silages and 13.08 from acid silage. The highest totox value (17.33 ± 0.88) was also detected in acid silage oil whereas fermented groups gave totox value in the range of 10.40–13.88. It can be concluded that the initial lipid quality of fermented fish waste silages was better than the initial lipid quality of acid fish waste silage. Therefore, fish oils recovered from fermented silages can be used as food additives or supplements for animal and human diets.