RAST I DUŽINSKO MASENI ODNOSI VRSTE Trichopodus trichopterus (Pallas, 1770) HRANJENE NADOMJESTKOM RAZLIČITIH KONCENTRACIJA PROBIOTIKA

The aim of the present study was to evaluate the effects of diet with different microbial concentrations on the growth and length-weight relationship of Trichopodus trichopterus. For this aim a study was designed with four experimental treatments and the control to evaluate different microbial concentrations on growth and length-weight relationship. The counts of bacteria that were used for dietary supplementation were 1×104, 2×104, 3×104 and 4×104 CFU g-1 in T1, T2, T3 and T4 treatments, respectively. The results indicated that the use of 3×104 CFU g-1 concentration increased the length, and a positive allometric growth was observed. The higher length frequency was estimated in T3. The results indicated that the use of microbial additives with proper concentration causes different allometric growth.Cilj ovog istraživanja bio je ispitati učinke hranidbe nadomjestkom različitih koncentracija mikroorganizama na rast i dužinsko masene odnose Trichopodus trichopterus. U svrhu tog cilja, studija je dizajnirana s četiri eksperimentalna tretmana i kontrolom za procjenu različitih koncentracija mikroorganizama na rast i odnos duljine i mase. Broj bakterija koje su se koristile za hranidbeni dodatak su 1×104, 2×104, 3×104 i 4×104 CFU g-1 u T1, T2, T3 i T4 tretmanu. Rezultati su ukazali da se upotrebom 3×104 CFU g-1 koncentracije povećava duljina, a uočen je pozitivan alometrijski rast kod istraživane vrste. Veća frekvencija duljina procijenjena je u T3. Dobiveni rezultati ukazuju da primjena različitih koncentracija probiotičkih organizama u odgovarajućem slučaju uzrokuje različit alometrijski rast riba

Enhancement of growth performance and hematological changes in rainbow trout (Onchorhynchus mykiss) alevins fed with Bifidobacterium bacteria

The study of probiotic application as an important rearing strategy was started more than 30 years ago and most of these studies were carried out to increase growth and survival of larvae. Effect of Bifidobacterium animalis PTTC-1631 and B. lactis PTTC-1736 as probiotic supplement has been studied on growth performance and hematological changes on rainbow trout, Oncorhynchus mykiss alevins with initial body weight of 0.583 ± 0.197 g. The commercial diet was supplemented with graded levels of probiotics (1×107, 2×107 and 3×107 CFU g-1 dry feed) to obtain 3 sets of experimental diets (T1, T2, and T3 respectively) and fed four times a day for 60 days. T1 alevin showed the best growth performance in terms of specific growth rate, weight gain, metabolic growth rate, feed conversion ratio and survival rate. The highest red and white blood cell concentrations were noticed in fish fed T2 and T3 diets, respectively, no significant difference was observed in hemoglobin content. T1 showed the significant elevation of serum biochemical parameters and reduction of cortisol level. The results of present study might suggest likely positive effects of probiotic supplements with concentration of 1×107 CFU g-1 dry feed on growth and hematology on rainbow trout alevins

The use of selected bacteria and yeasts to control vibrio spp. in live food

Vibrio species are a significant causative of mass mortality in mariculture worldwide, which can quickly accumulate in live food and transmit into the larval gut. With restrictions on the use of antibiotics in aquaculture, finding a proper solution to reduce the risk of Vibriosis is vital. This study aimed to evaluate the susceptibility of Vibrio harveyi, V. campbellii, V. anguillarum, and V. parahaemolyticus to twenty-six bacterial and yeast strains and use the beneficial ones to enrich live food (Branchiopod, Artemia franciscana, rotifer, Brachionus plicatilis and copepod, Tigriopus japonicus). Thus, a modified disk diffusion method was applied. After a susceptibility assay, the bacteria and yeast beneficial in suppressing the Vibrio species were labeled by fluorescent stain and used to measure the accumulation potential in different live foods. Also, the beneficial bacteria and yeast were used to enrich live foods, and then the count of loaded Vibrio was estimated after 5, 10, 15, and 20 h by the serial dilution method. From the total bacteria and yeast strains that were used, Candida parapsilosis, Pseudoalteromonas flavipulchra, Lactobacillus sakei, Bacillus natto, and B. amyloliquefaciens inhibited all four Vibrio species. The results of microbial labeling showed that L. sakei in Artemia, C. parapsilosis in rotifers, and V. harveyi in copepods had the highest accumulation rate. The results of the estimation of loaded Vibrio in different live foods also showed that the use of beneficial bacteria and yeast each significantly reduced the count of Vibrio. Application of bacteria and yeast to suppress pathogenic Vibrio maybe a sustainable method for preventing this pathogen from harmfully invading aquaculture and may also aid in reducing the chances of antibiotic resistance in pathogenic Vibrio

Culture of Artemia franciscana nauplii with selected microbes suppressed Vibrio loading and enhanced survival, population stability, enzyme activity, and chemical composition

This study evaluated the effects of four microbes, Candida parapsilosis, Pseudoalteromonas flavipulchra, Lactobacillus sakei, and Bacillus natto on suppression of Vibrio, survival rate, enzyme activity, chemical composition, and microbial longevity in the brine shrimp, Artemia franciscana. Five treatments, including four experimental groups and a control group, each with four replicates, were studied. The concentration of 10(8) CFU mL(-1) of each mentioned strain was used to feed the nauplii for 2 weeks. The results demonstrated that the use of L. sakei, P. flavipulchra, and B. natto significantly suppressed the concentration of Vibrio over 5, 10, 15, and 20 h of enrichment respectively. From the selected microbes, B. natto and L. sakei were significantly colonized in the population and increased the enzyme activity. The longevity of B. natto in the Artemia was recorded as the best bacteria for long-term inoculation as after 8 days of starvation of Artemia, the count of B. natto was increased. The findings showed that B. natto appears to be a promising probiotic for Artemia in the suppression of Vibrio and also in increasing population growth, enzyme activity, and long-term colonization potential