Gelatinous Aggregates Research Articles

Oscillatory rheometry for elucidating the influence of non-network biopolymer aggregation on pectin-gelatin composite gels

Gel networks formed from biopolymers have intrigued rheological interest, especially in the food industry. Despite ubiquitous non-network biopolymer aggregation in real gel food systems, its fundamental rheological implications remain less understood. This study addresses this by preparing pectin-gelatin composite gels with dispersed or aggregated biopolymers and comparatively analyzing viscoelastic responses using rheometry. Subtle discrepancies in non-network biopolymer states were revealed through oscillatory shearing at different frequencies and amplitudes. Biopolymer aggregation in the network notably influenced loss tangent frequency dependency, particularly at high frequencies, elevating I3/I1 values and sensitizing the yield point. Non-network biopolymers weakened Payne effects and gel non-linearity. A combination of strain stiffening and shear thinning nonlinear responses characterized prepared gel systems. Aggregation of pectin and gelatin enhanced shear thinning, while strain stiffening was notable in highly aggregated pectin cases. This study enhances understanding of the link between non-network structural complexity and viscoelastic properties in oscillatory rheometry of food gels.

Exploring the interaction between Lycium barbarum polysaccharide and gelatin: Insights into gelation behaviors, water mobility, and structural changes

Gelatin-polysaccharide interactions have garnered significant attention in recent years due to their profound effects on the properties (rheology and structure) of various food products. This study investigates the interaction between Lycium barbarum polysaccharide (LBP) and gelatin, focusing on the impact of different concentrations LBP (0–2.0%, w/v) on gelation behavior, water mobility, and gelatin structure. The results show that the addition of LBP initially increases and then decreases the gel strength and hardness of the gelatin. Incorporating LBP into gelatin leads to decreased brightness, gelling temperature (Tg), gelation rate (kgel), immobile water content, and residue, while increasing the redness, yellowness, bound and free water content, and thermal stability. Fourier transform infrared spectroscopy (FTIR), x-ray diffractometer (XRD), cryogenic scanning electron microscopy (Cryo-SEM), and atomic force microscopy (AFM) analyses provide evidence for the existence of hydrogen bonds, electrostatic interactions, and ionic bond interactions between LBP and gelatin, in addition to covalent bonds formed through the Maillard reaction. Moreover, LBP induces changes in the structure of gelatin, including alterations in secondary structure, crystalline structure, and microstructure. AFM observations further indicate that LBP promotes the formation of gelatin aggregates. These findings present promising avenues for the application of LBP-gelatin composite gels as novel materials in the food industries.

Bacterial Cellulose Cultivations Containing Gelatin Form Tunable, Highly Ordered, Laminae Structures with Fourfold Enhanced Productivity.

Manipulation of bacterial cellulose (BC) morphology is important to tune BC properties to meet specific application requirements. In this study, gelatin was added to cultivation media at 0.1-7.5 wt %. After cultivations, gelatin was removed from the BC matrix, and its effects on BC matrix characteristics and fermentation production efficiency were determined. Higher contents of gelatin in cultivation media (up to 5%) resulted in BC that, from scanning electron microscopy observations, had larger pore sizes and formation of a lamina morphology that was highly unidirectional. Crystallinity remained unchanged between 0.1 and 5 wt % gelatin concentrations (92-95%); however, it decreased to 86% at a gelatin concentration of 7.5 wt %. Mechanical properties showed a positive trend as both the specific modulus and specific strength values increased as the gelatin concentration increased to 5 wt %. A breakdown in the ordered structure of the BC matrix occurs at 7.5 wt % gelatin, with corresponding decreases in the specific modulus and specific strength of the BC. The productivity increased by almost 4-fold relative to the control, reaching 1.64 g·L-1h-1 at the 2.5 wt % gelatin content. Also, the water holding capacity increased by 3-fold relative to the control, reaching 306.6 g of water per g BC at the 5.0 wt % gelatin content. The changes observed in these BC metrics can be explained based on literature findings associated with the formation of gelatin aggregates in the cultivation media and an increase in gel stiffness seen at higher media gelatin concentrations. Overall, this work provides a roadmap for manipulating BC properties while creating highly organized lamina morphologies.

Succeeded high-temperature acid hydrolysis of granular maize starch by introducing heat-moisture pre-treatment

Acid hydrolysis is a crucial method for modifying granular starch, but it is often conducted at low temperatures (below 55 °C) for an extended period of time to prevent crystallinity loss. The high-temperature acid hydrolysis (HTAH) behavior of heat-moisture treated (HMT) starch at 69 °C was investigated for the first time. The crystalline structure of starch was enhanced by HMT, confirmed by its rheological, thermal, and infrared Fourier transform spectroscopy results. The amorphous structure of HMT starch was preferentially hydrolyzed with high reactivity, related to a fast hydrolysis stage (4.17 × 10−2 min−1). And the crystalline flakes were separated from starch granules, accompanied by strengthened molecular interactions. HMT starch was transformed from 16.98 μm granules to 158 nm thick and 2.57 μm broad flakes with a 6.40 % increase in crystallinity after 40 min of hydrolysis. For native starch, the HTAH destroyed the crystalline structure due to gelatinization, resulting mainly gelatinous aggregates. These evidenced that the hydrolysis of granular starch was successfully performed at a relatively high temperature by introducing heat-moisture pre-treatment. This study could provide a novel perspective on the combination of increasing temperature and pre-treatment for granular starch hydrolysis intensification design, as well as a strategy for efficiently preparing small-sized crystalline starch, which has promising applications in Pickering emulsion and material filler.

Elucidation of interactions between gelatin aggregates and hsian-tsao gum in aqueous solutions

Interactions between gelatin aggregates (G, 0.5 wt%) and an anionic polysaccharide hsian-tsao gum (HG, 0–0.25 wt%) in aqueous solutions were investigated at 25 °C using zeta potentiometry, turbidimetric analysis, dynamic light scattering, confocal laser scanning microscopy (CLSM), fluorescence spectra and circular dichroism measurements. The results indicated that soluble and insoluble G-HG complexes formed mainly through electrostatic interactions followed critical pH-dependent structure-forming events. The phase transition points (pHφ1, pHopt and pHφ2) shifted to lower pH with HG increased, whereas pHc kept constant. Conformational transitions of G from α-helix to β-sheet were promoted by interacting with HG, concurrent with changes in environment of hydrophobic residues. Additionally, CLSM evidenced phase transitions of G from homogeneity to separation occurred by interaction with HG, forming G-HG complexes with G centered and HG absorbed on the periphery. Findings aided in understanding interactions mechanism between G and HG to further apply HG in designing new food matrixes.

Sealing capacity of siderite-bearing strata: The effect of pore dimension on abundance and micromorphology type of siderite in the Lopingian (Late Permian) coal-bearing strata, western Guizhou province

We conducted a series of core observation, thin section evaluation, and integrated with low-temperature nitrogen adsorption/desorption, porosity, permeability, breakthrough pressure analysis of the siderite-bearing strata. This paper aims to discuss the sealing capacity of siderite-bearing strata as a function of siderite abundance andmicromorphology type. The siderite-bearing strata can be potential gas barrier layers in multiply-superposed gas-bearing systems. In the transitional Lopingian coal-bearing succession of western Guizhou, the siderite content of siderite-bearing mudstone is 18.6–90.7% (wt.), with an average 53.4% (wt.). There are three morphologies of siderite, including S1 (gelatinous aggregates), S2 (microcrystal-silt size crystal aggregates), and S3 (sphaerosiderites). It shows that different abundance of siderite and type of siderite micromorphology affected the pore structure. The sealing capacity of siderite-bearing mudstone at the study area is somewhat or significantly larger, and the sealing capacity of the siderite-free mudstone is moderate. The development of siderite-bearing strata is controlled by the stratigraphy of the sequence.

Alginate/gelatin blended hydrogel fibers cross-linked by Ca2+ and oxidized starch: Preparation and properties

Alginate/gelatin blended hydrogel fibers were successfully prepared based on sodium alginate cross-linked by Ca2+ and gelatin cross-linked by oxidized starch through the wet spinning process. The structure, surface morphologies, swelling properties of alginate hydrogel fibers and alginate/gelatin blended hydrogel fibers were examined by Fourier transform infrared analysis (FTIR), cross-linking degree test, element analysis test and scanning electron microscopy (SEM). While mechanical properties test, water absorption and retention properties test provide the mechanical, water absorption and retention properties. FTIR, cross-linking degree and element analysis results indicate that there is gelatin remaining in alginate/gelatin blended hydrogel fibers. However, the cross-linking of gelatin by oxidized starch is not completed with some dissociative gelatin solvated in the coagulation bath. Among the mentioned fibers, FS10G2 is the best to improve the properties of alginate/gelatin blended hydrogel fibers with an optimal mass ratio of sodium and gelatin. The excessive additive amount of gelatin leads to the aggregation of gelatin in alginate/gelatin blended hydrogel fibers, making the worse compatibility between alginate and gelatin. It also destroys the mechanical properties of alginate/gelatin blended hydrogel fibers. These alginate/gelatin blended hydrogel fibers might have a potential application in the biomedical fields.

Identification of Structural Features of Condensed Tannins That Affect Protein Aggregation.

A diverse panel of condensed tannins was used to resolve the confounding effects of size and subunit composition seen previously in tannin-protein interactions. Turbidimetry revealed that size in terms of mean degree of polymerisation (mDP) or average molecular weight (amw) was the most important tannin parameter. The smallest tannin with the relatively largest effect on protein aggregation had an mDP of ~7. The average size was significantly correlated with aggregation of bovine serum albumin, BSA (mDP: r = -0.916; amw: r = -0.925; p<0.01; df = 27), and gelatin (mDP: r = -0.961; amw: r = -0.981; p<0.01; df = 12). The procyanidin/prodelphinidin and cis-/trans-flavan-3-ol ratios gave no significant correlations. Tryptophan fluorescence quenching indicated that procyanidins and cis-flavan-3-ol units contributed most to the tannin interactions on the BSA surface and in the hydrophobic binding pocket (r = 0.677; p<0.05; df = 9 and r = 0.887; p<0.01; df = 9, respectively). Circular dichroism revealed that higher proportions of prodelphinidins decreased the apparent α-helix content (r = -0.941; p<0.01; df = 5) and increased the apparent β-sheet content (r = 0.916; p<0.05; df = 5) of BSA.

Spontaneous Formation of Nano‐fibrillar Boehmite and the Enhancement Effect of Polyethylene Glycol

Nano‐fibrillar boehmite is a desirable product due to its high specific surface area and potential application in a wide variety of engineering applications. Inorganic salts are the preferred raw materials for fabricating such products because of their low cost. In this study, nano‐sized (10–20 nm in diameter) boehmite fibrils were fabricated by the hydrothermal (105°C) digestion of a suspension prepared from either aluminum sulfate or nitrate salt under a neutral pH. It appears that the formation of fibrils is spontaneous and thermodynamically favorable. The presence of polyethylene glycol (PEG) was found to further enhance the formation of fibrils by promoting the transportation of aluminum ions to the crystal nuclei. The growth direction of the crystals in the fibrils is normal to the boehmite (020) plane. The formation of boehmite fibrils was greatly reduced under an acidic pH and at a lower digestion temperature due to kinetic restriction. The structures of the immediate products generated from aluminum sulfate and aluminum nitrate were different, which is probably due to the stronger adsorption of sulfate ions on the surface of gelatinous aggregates. The fibrils derived from as‐precipitated and coagulated amorphous aluminum hydroxide grains experienced a series of structural evolutions in which they progressed from a sponge‐like structure to a fibrillar structure with time.

Aluminium in Lake Cuicocha, Ecuador, an Andean Crater Lake: Filterable, Gelatinous and Microcrystal Al Occurrence

In Lake Cuicocha watershed, a young caldera lake, soils consist of volcanic deposits with a high SiO2 and Al2O3 content; these andisols are in an early stage of development; and in drainage water from the watershed, aluminium concentrations reach 15.0 μmol L−1. Total aluminium concentrations in Lake Cuicocha water raises up to 7.2 μmol L−1, with nearly 70% occurring as filterable Al at neutral to weak alkaline conditions. Al polymerization to gelatinous aggregates of a few hundred micrometres in diameter as well as the occurrence of Al microcrystals like gibbsite as an ageing product of gelatinous Al polymers was noted in the lake water. The gelatinous Al leads to the formation of larger aggregates resulting in flocs of bacteria, algae, microorganisms and detritus.

A Facile and Green Route to Silver Nanoparticles in Water

Stable water-dispersible silver nanoparticles with a narrow size distribution are obtained by light-assisted spontaneous reduction of silver nitrate with gelatin, which acts as both the reducing and the stabilizing agents, in water. The formation mechanism of the silver nanoparticles involves an in-situ conversion of Ag(+)-gelatin aggregates to gelatin-stabilized silver nanoparticles via a Ag(+)-mediated oxidation of primary amine groups of the gelatin to carboxylic acid groups. The resultant silver nanoparticles are well within the quantum size domain (10 nm). In addition, the nanoparticles are stable in aqueous solutions and can be separated easily by simple pH adjustment.

Nanostructural Characterization of Catfish Skin Gelatin Using Atomic Force Microscopy

To determine the nanostructure of gelatin from catfish (Ictalurus punctatus) skin, atomic force microscopy (AFM) was used to study gelatin aggregates. The gelatin was extracted at an optimized acid concentration after alkaline processing. First, the AFM imaging parameters were optimized to obtain high-quality images. Then height mode with a 2-dimensional plane, 3-dimensional topographical images, and error signal mode images, which removed slow variations in surface topography but highlighted the edges of sample features, were used to analyze the structure of particles. The results describe fish gelatin at a nanoscale level for the first time and are compared with AFM images of mammalian gelatins. Both annular pores with diameters averaging 118 nm and spherical aggregates with an average diameter of 267 nm were seen in the AFM images of fish gelatin. From the AFM images, we propose that the structures formed were determined by whether the solution penetrated into the gelatin molecules evenly or not during hydrolysis. A scheme for the formation of annular pores and spherical aggregates is proposed.

Major inter-annual variations in microbial dynamics in the Gulf of Trieste (northern Adriatic Sea) and their ecosystem implications

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 46:163-175 (2007) - doi:10.3354/ame046163 Major inter-annual variations in microbial dynamics in the Gulf of Trieste (northern Adriatic Sea) and their ecosystem implications Serena Fonda Umani1,*, Paola Del Negro2, Chiara Larato2, Cinzia De Vittor2, Marina Cabrini2, Massimo Celio3, Claus Falconi2, Francesco Tamberlich3, Farooq Azam4 1Department of Biology, University of Trieste, v. Valerio, 28/A, 34143 Trieste, Italy 2Biological Oceanography Department, National Institute of Oceanography and Experimental Geophysics, v. Piccard 54, 34010 Trieste, Italy 3Osservatorio Alto Adriatico, ARPA F.V.G., v. Piccard, 54, 34010 Trieste, Italy 4Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0210, USA *Email: labbioma@units.it ABSTRACT: Comprehensive, multi-year studies of microbial processes in an ecosystem context are important in understanding microbial regulation of ecosystem structure, function and variability. A 3 yr study on microbial community was carried out in a coastal area in the northern Adriatic Sea (Gulf of Trieste). It is a semi-enclosed shallow system, mostly controlled by pulsed external inputs, which determine a high variability of plankton communities. Samples were collected monthly at 2 stations from January 1999 to December 2001. Data illustrate remarkable inter- and intra-annual variability in parameters relevant to carbon biogeochemistry and ecosystem energy flow patterns. Integrated primary production (PP; 135 g C m–2 yr–1) in 1999 tripled (414 g C m–2 yr–1) in 2000, returning to a low level (150 g C m–2 yr–1) in 2001. Bacterial production (by 3H-leucine incorporation) accounted, on average, for 35.3% of net PP in 1999, 9.5% in 2000 and 29.4% in 2001. Flux into the microbial loop via bacterial C demand, assuming 30% growth efficiency, was the dominant C flow pathway in 1999 and 2001, accounting for almost 100% of the net PP but a lesser fraction (40%) of net PP in 2000. Total microbial respiration (<200 µm fraction, R<200µm) exceeded PP for almost the whole period, indicating that the system was potentially net heterotrophic at the expense of external input of organic matter. Our results suggest that in 1999 and 2001, when PP was low, it mostly fuelled, and was respired within, the microbial loop. During 2000 there was a major shift in C flux partitioning. The coupling between PP and bacteria was loose, and larger fractions of PP were presumably channelled into other paths of C flow such as grazing food chain, sedimentation and ‘storage’ in the water column as dissolved and colloidal organic phases. Organic C in excess produced over the 2 mo preceding visible accumulation of gelatinous aggregates (mucilage) was sufficient in magnitude to account for the mucilage C pool. Our results are consistent with the hypothesis that mucilage is derived from accumulated slow-to-degrade dissolved organic matter. KEY WORDS: Microbial dynamics · Mucilage · Northern Adriatic Sea Full text in pdf format PreviousNextExport citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in AME Vol. 46, No. 2. Online publication date: February 02, 2007 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2007 Inter-Research.

Relevance of the dinoflagellate Gonyaulax fragilis in mucilage formations of the Adriatic Sea

Oceanographic cruises were carried out monthly from June 1999 to July 2002 to follow the mucilage formation process in the Northern Adriatic Sea. Results show that in correspondence with these events the dinoflagellate Gonyaulax fragilis (Schütt) Kofoid was observed both in the water column and within mucilage aggregates. In the water column, increasing abundances were observed from May until July, with values never exceeding 8500 cells l − 1 . Much higher densities were observed within superficial gelatinous aggregates (22 800–3 400 000 cells l − 1 ). In mucilage samples, a large number of decomposing cells were present, together with abundant alive cells, enveloped in exudates. G. fragilis isolated from mucilage samples was cultured in three different culture media; it was characterized by a low growth rate but it produced a high amount of polysaccharides. The highest yield both in terms of cell number and carbohydrate production was observed in the medium having the highest nitrogen and phosphorus content and the lowest N/P ratio. The monomeric composition of G. fragilis carbohydrates, compared with that of mucilage samples, showed that in both natural and cultured samples galactose was the most abundant sugar; in addition, an overall good correlation, especially between the monomeric carbohydrate composition of G. fragilis grown in f/2 medium and that of a mucilage sample in which this species was present in high density, was observed.

Spectroscopic evidence of the marine origin of mucilages in the Northern Adriatic Sea

Vibrational Fourier transform infrared (FTIR) and UV–Visible spectroscopies coupled to thermogravimetry were used to characterise the gelatinous aggregates as well as the humin and humic fractions extracted from the aggregates. Spectroscopic analysis made it possible to identify the main classes of compounds present in the samples. The FTIR spectra of the aggregates showed the presence of carbohydrates, saturated aliphatic compounds, aminic, esteric, amidic (proteins) and ketonic compounds, organic and inorganic phosphates, silica and, in some cases, carbonates. The FTIR spectra of humin and humic acids showed functional groups similar to those found in the spectra of the aggregates. The high aliphatic character and the absence of aromatic compounds observed in many aggregates sampled far from estuarine areas suggest the marine origin of mucilages. These results were also confirmed by the 270/407 nm (A2/A4) and 465/665 nm (E4/E6) absorbance ratio in humic acids.

Nanometer‐Sized Gold‐Loaded Gelatin/Silica Nanocapsules

Electrostatic-force-driven self-assembling behavior of gelatin polypeptides has been investigated through the predominantly seeded-aggregation growth of denatured gelatin molecules on citrate-stabilized gold nanoparticles (see Figure). The resulting self-assembled gelatin aggregates have been used as soft templates to prepare nanometer-sized gold-loaded silica/gelatin nanocapsules. This synthetic approach has been extended to various silica-coated biomolecules and provides further insight for creating novel smart bionanostructures.

Cr3+/COO-Complexation Induced Aggregation of Gelatin in Dilute Solution

The Cr3+/COO- complexation induced aggregation of linear gelatin chains in aqueous solutions under different conditions, such as the Cr3+ and gelatin concentrations, was investigated by a combination of static and dynamic laser light scattering (LLS). The results reveal a competition between the intrachain and interchain complexation. For a given gelatin concentration, there exists a “critical” Cr3+ concentration at which the interchain complexation became dominant. The intensity I(q) of the light scattered from the resultant aggregates was scaled to the scattering vector q as I(q) ∝ q-dq with dq = 1.61−1.84, suggesting that the aggregation was a diffusion-limited process. The variation of the Cr3+ concentration had less influence on the structure of the resultant aggregates. On the other hand, the decrease of the gelatin concentration led to an increase of dq from 1.61 to 2.04, indicating that the aggregation changed from a diffusion-limited process to a reaction-limited one. Precipitation is independent of the size of the aggregates but closely related to the gelatin concentration as well as the Cr3+/gelatin molar ratio. Two-dimensional AFM topographs of the aggregates revealed a clear growing fractal, supporting the results observed by LLS.

Characterization of mucilage aggregates in Adriatic and Tyrrhenian Sea: structure similarities between mucilage samples and the insoluble fractions of marine humic substance

The appearance of gelatinous aggregates called mucilages causes serious damages to tourism and fishery industries of the Adriatic Sea. So, many studies have been planned and some of them are still in progress to clarify the origin and causes of the phenomenon. The scientific research has showed that mucilages are produced by several marine organisms when peculiar climatic and trophic conditions occur. Moreover, as far as the mucilage composition is concerned, although it is well known that polysaccharides give a high contribution, knowledge of the structural characteristics of mucilages and their relationship with the natural organic matter of the marine environment has not been clarified yet. In this paper a study on the characterization of the marine mucilage samples collected in the Adriatic and Tyrrhenian Seas is described. The study was performed by spectroscopic (infrared and colorimetric) techniques, and elemental analysis. The results showed that mucilage samples have chemical and structural similarities with the insoluble fraction of the marine humic substance (humin). According to experimental evidences it is possible to establish the relationship between mucilages and the dissolved organic matter (DOM) in the marine environment in order to identify the most likely pathways of mucilage formation.

The effect of the melting of the collagen-like gelatin aggregates on the stability against aggregation of the bovine casein micelles

The effect of the melting of the collagen-like acid and alkaline gelatin aggregates on the stability against aggregation of bovine casein micelles was investigated by turbidimetry, DSC and circular dichroism in the wide range of biopolymers concentrations, gelatin/casein ratio (R) in initial mixture (R=0.03–20), pH (4.9–6.7), ionic strength (I=10−3 to 1.0/NaCl/), and temperature (10°–70 °C), using glucono-δ-lactone (GL) as acidifier. At low ionic strength (10−3/milk salts/) and neutral pH interaction between gelatin molecules and casein micelles is suppressed significantly above 36 °C. The melting of the collagen-like acidic gelatin above this temperature shifts the pH at which the complex formation is maximal to the acidic range. The cause may be that some of the functional ionized groups of gelatin molecules are inaccessible due to the conformational changes. The presence of gelatin B molecules had no effect on the aggregation stability of micellar casein in the range 0.03<R<20. At very high total protein concentration (above 10%) depletion flocculation of casein micelles was observed. The reason for the very high stability of casein micelles in this case cannot be explained by volume exclusion.

Antibacterial Effects of Different Food-Related Phosphates Using Aeromonas hydrophila

Aeromonas hydrophila is considered to be an emergent food-related bacterium. Phosphates are used as additives, mainly in meat products, to improve the quality of these foods. The antibacterial properties of phosphates are also well known. In this work, two A. hydrophila strains in early exponential phase were used: (A) A. hydrophila ATCC 7965 and (B) A. hydrophila derived from food, isolated in our laboratory. MIC and MBC studies were performed to assess the antibacterial effects of four phosphates assayed in brain heart infusion broth (BHI) and modified complete defined synthetic medium (mCDS) as compared to cooked ground meat medium (CM). The MBC values of the phosphates in CM were significantly higher than MIC values in BHI broth and mCDS medium (P < 0.05). In the two latter media, the growth of both A. hydrophila strains was totally inhibited by concentrations between 0.5 and 3.0%. Although all the assayed phosphates proved to have bactericidal effects on A. hydrophila, 0.5% sodium acid pyrophosphate (SAPP) exhibited greater effects in both strains and was selected for subsequent experiments. The bacteriolytic effect of SAPP was spectrophotometrically determined (260nm of absorbance) by means of the leakage of intracellular nucleotides and microscopically confirmed by the presence of massive gelatinous aggregates. These were identified by enzymes (RNase, DNase, and proteinase) that hydrolyzed the nucleotides and proteins released during cellular lysis in the presence of SAPP. It was concluded that 0.5% SAPP can have bactericidal and bacteriolytic effects in early exponential phase A. hydrophila cells.