Peptone production from marine and culture wastes by commercial enzymes for bacterial culture media

Thirty to 40% of total fish catch is converted to waste. Using different methods of hydrolysis of the protein can be recovered of fish waste and increase the amount of protein efficiency. In this study, the four enzymes Alcalase, protamex, pepsin and trypsin were used for hydrolysis of four fish species including common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and the Big head (Hypophthalmichthys nobilis). The effects of pH, temperature and hydrolysis time on the rate of hydrolysis were studied on soluble proteins and degree of hydrolysis (phase I). In the second step, proximate factors of peptone been evaluated and eventually replace commercial peptone media MRS (Lactobacillus plantarum, Lactobacillus delberuki, Lactobacillus casei, Streptococcus thermophilus) and TSB (Listeria monocytogenes, two species of Bacillus and Pseudomonas, Streptococcus faecium) and the optical density of bacteria at different times were compared with control samples. Results showed that the highest degree of hydrolysis and soluble proteins were referred to alcalase and protamex, pepsin and trypsin respectively. The highest value of hydrolysis, in all treatments, was attributed to grass carp and silver carp, common carp and big head respectively. The best pH and temperature for alcalase, protamex, pepsin and trypsin 8.5and 55, 7.5 and 55, 3.5, 37, 7 and 37 respectively. Best time to achieve the highest degree of hydrolysis and soluble protein was 90 minutes. Qualitative analysis showed that the highest and lowest amounts of protein and fat in the treatment of alcalase (about 70 % protein and less than 0.5 % fat) and protamex, pepsin and trypsin was then. The results of bacteria culture showed that the highest percentage growth of lactic acid bacteria was referred to Streptococcus thermophilus and Lactobacillus casei had the lowest rate of growth. In other bacteria, Pseudomonas and Bacillus species were the highest percentage of growth and Listeria monocytogenes and Streptococcus faecium respectively. In all treatments, alcalase had the best results and the peptone prepared from fish waste grass carp had the best condition for growth of used bacteria. It seems that the initial substrate , the parameters used such as temperature, pH, and enzyme hydrolysis time , have a significant effect on the quality of peptone and protein content in the final product is determined value of protein for culture of bacteria

Dietary tuna hydrolysate modulates growth performance, immune response, intestinal morphology and resistance to Streptococcus iniae in juvenile barramundi, Lates calcarifer

This study investigated the effects of tuna hydrolysate (TH) inclusion in fishmeal (FM) based diets on the growth performance, innate immune response, intestinal health and resistance to Streptococcus iniae infection in juvenile barramundi, Lates calcarifer. Five isonitrogenous and isoenergetic experimental diets were prepared with TH, replacing FM at levels of 0% (control) 5%, 10%, 15% and 20%, and fed fish to apparent satiation three times daily for 8 weeks. The results showed that fish fed diets containing 5% and 10% TH had significantly higher final body weight and specific growth rate than the control. A significant reduction in blood glucose was found in fish fed 10%, 15% and 20% TH compared to those in the control whereas none of the other measured blood and serum indices were influenced by TH inclusion. Histological observation revealed a significant enhancement in goblet cell numbers in distal intestine of fish fed 5 to 10% TH in the diet. Moreover, fish fed 10% TH exhibited the highest resistance against Streptococcus iniae infection during a bacterial challenge trial. These findings therefore demonstrate that the replacement of 5 to 10% FM with TH improves growth, immune response, intestinal health and disease resistance in juvenile barramundi

Preparation and testing of an autolysate of fish viscera as growth substrate for bacteria.

The aqueous soluble phase of acidified and autolyzed fish viscera was used as the nitrogen source in a growth medium for bacteria. The bacteria tested grew faster and produced higher yields of cell mass on this growth medium than on corresponding media with standard tryptone preparations as the nitrogen source

Why do women with eating disorders decline treatment? A qualitative study of barriers to specialized eating disorder treatment

Despite the fact that eating disorders (EDs) are conditions that are potentially life-threat-ening, many people decline treatment. The aim of this study was to investigate why women decline specialized ED treatment, including their viewpoints on treatment services. Eighteen semi-struc-tured qualitative interviews were conducted with women who had declined inpatient or outpatient specialized ED treatment. A thematic analysis revealed five main themes: (1) Disagreement on treatment needs, (2) rigid standard procedures, (3) failure to listen, (4) deprivation of identity, and (5) mistrust and fear. The women had declined ED treatment because they believed that treatment was only focused on nutritional rehabilitation and that it failed to address their self-identified needs. From their perspectives treatment was characterized by rigid standard procedures that could not be adapted to their individual situations and preferences. They felt that the therapists failed to listen to them, and they felt deprived of identity and reduced to an ED instead of a real person. This investigation is one of the first of its kind to provide clues as to how treatment could be moderated to better meet the needs of women who decline specialized ED treatment