Optimal Immobilization of Acidic Proteases from Monterey Sardine (Sardinops sagax caeurelea) on Partially Deacetylated Chitin from Shrimp Head Waste

ABSTRACT

Response surface methodology was employed to optimize the immobilization yield of acidic proteases from Monterey sardine (Sardinops sagax caeurelea) using partially deacetylated chitin as immobilization support. A rotatable central composite design was applied to evaluate the effects of immobilization conditions such as enzyme loading (X₁), immobilization pH (X₂), and tripolyphosphate concentration (X₃) on the immobilization yield. The analysis of variance revealed that the established model was significant (p < 0.05), and the adjustment of the quadratic model with the experimental data was satisfactory. Under optimal conditions (X₁ = 0.05 mg/mL, X₂ = 3.16, and X₃ = 0.75%), an immobilization yield of 79.1% was achieved; a value that was in accordance with the predicted one.     

The use of Kluyveromyces marxianus in the diet of Red‐Stirling tilapia (Oreochromis niloticus,Linnaeus) exposed to natural climatic variation: effects on growth performance,fatty acids,and protein deposition

The purpose of this study was to evaluate the use of single cell proteins (Kluyveromyces marxianus) as fishmeal substitutes for Oreochromis niloticus during long‐term feeding under natural climatic conditions. Juveniles (150) were divided into two groups: the control group, fed with conventional fish diet (T1); and the experimental group, fed with the alternative diet (T2). T1 animals had a higher final weight and per cent weight gain than T2 animals, which we mainly observed in winter and autumn. The lipid content ranged from 1.9% to 3.8% in liver and from 0.2% to 1% in white muscle for both groups. T2 animals had a higher protein concentration in the fillet and the lipid content in this tissue was not altered by diet. Liver and plasma protein content in both groups and the muscle content in T1 decreased during growth. Specific fatty acids (FAs) were selectively retained in fillet phospholipids (PLs), primarily as C22:6n3, which was found at high levels in the PLs of both groups during all seasons. Despite the differences observed, the percentage of polyunsaturated FAs in the fillet was similar throughout the experiment for both diets, reaching approximately 50% of the total FA in the PLs.     

Diversity of secondary woody species in relation to species richness and cover of dominant trees in thermophilous deciduous forests

One of the prominent compositional features of thermophilous deciduous forests of southern Europe is their richness in secondary woody species (AWS). To date, no studies have focused on the diversity and contribution to the ecosystem functions and socio-economic benefits provided by these species. Here, we first characterized species richness and diversity for three main functional groups of AWS, sporadic trees, shrubs and vines, in 53 representative stands of central Italy. Secondly, we explored variations in AWS diversity and composition along a four-level gradient of species richness of dominant trees under comparable site conditions. The 40 AWS taxa recorded showed a remarkable taxonomic singularity at both the genus and the family rank. Dominant tree species richness had no significant effect on AWS species richness and composition, while Shannon diversity of AWS, especially shrubs, was associated with cover of the dominant trees. Each AWS possessed, on average, ca. five ability traits over a total of 13 considered that contributed to important ecosystem functions or expected socio-economic benefits such as wood and food production, conservation of genetic resources (wild crop relatives) and ornamentals. This highlights the key role of AWS, and in particular of sporadic trees, for enhancing multifunctionality of thermophilous deciduous forests.     

In vitro and in vivo susceptibility of two-drug and three-drug combinations of terbinafine, itraconazole, caspofungin, ibuprofen and fluvastatin against Pythium insidiosum

The present study investigated the in vitro inhibitory activity of terbinafine, itraconazole, caspofungin, fluvastatin and ibuprofen against 15 isolates of Pythium insidiosum in double and triple combinations and determined in vivo correlations using rabbits with experimental pythiosis. The minimal inhibitory concentration (MIC) was determined in accordance with the Clinical and Laboratory Standards Institute M 38-A2 protocol (2008), and the in vitro interactions were evaluated using a checkerboard microdilution method. For the in vivo study, 20 rabbits inoculated with P. insidiosum zoospores were divided into four groups: group 1 was treated with terbinafine and itraconazole; group 2 was treated with terbinafine, itraconazole and fluvastatin; group 3 was treated with terbinafine and caspofungin; and group 4 was the control group. Combinations of terbinafine with caspofungin or ibuprofen were synergistic for 47% of the isolates, and antagonism was not observed in any of the double combinations. The triple combinations were mostly indifferent, but synergism and antagonism were also observed. In the in vivo study, the histological aspect of the lesions was similar among the groups, but group 2 showed the lowest amount of hyphae and differed significantly from the other groups.     

The role of cytoskeleton, components of inositol phospholipid signaling pathway and iron in Ehrlichia canis in vitro proliferation

Ehrlichia canis, etiologic agent of Canine Monocytic Ehrlichiosis, is an obligatory intracellular bacterium that parasitizes monocytes and macrophages. In this study we analyzed the role of the cytoskeleton specifically actin microfilaments and microtubules, components of inositol phospholipid signaling pathway such as phospholipase C (PLC), protein kinase (PTK) and calcium channels as well as the role of iron in the E. canis proliferation in DH82 cells. Different inhibitory compounds were used for each component: Cytochalasin D (inhibits actin polymerization), Nocodazole (inhibits microtubule polymerization), Neomycin (PLC inhibitor), Genistein (PTK inhibitor), Verapamil (calcium channel blocker) and Deferoxamine (iron chelator). We observed a significant decrease in the total number of bacteria in infected cells treated suggesting that these cellular components analized are essentials to E. canis proliferation.