Indonesia

Evaluation of probiotic potential of Bacillus spp. isolated from the digestive tract of freshwater fish Labeo calbasu (Hamilton, 1822)

Chronic toxicity to fathead minnow Pimephales promelas of wastewater from a conventional wastewater treatment system receiving organic priority pollutants

Bacillus indicus and Bacillus subtilis as alternative health and colouration promoters to synthetic astaxanthin in cyprinid aquaculture species

The main problems faced by fish farmers are waste, uneaten feed and feces. Which can reduce water quality and have a significant impact on fish growth and survival. This study aims to determine the effect of giving various types of probiotics on the growth rate and viability of Mutiara catfish raised using the biofloc system. We used Lactobacillus sp., Bacillus subtilis, and Nitrobacter as probiotic bacteria. This study used a completely randomized design experimental method with 4 treatments and 3 replications, namely K = probiotic less/control, P1= Lactobacillus probiotic, P2= Bacillus subtilis probiotic, P3= Nitrobacter probiotic. Catfish are reared for 30 days, feeding 3 times a day with FR 5% of body biomass. The parameters observed were absolute length growth, survival, Feed Conversion Ratio (FCR) and Specific Growth Rate (SGR) which were analyzed using ANOVA (P <0.05) and Duncan's test to see the differences between treatments. The results showed that the bacteria probiotic treatment had no significant effect on FCR and fish survival, but had a Lactobacillus sp significant effect on growth in absolute length (3.96 ± 0.06 cm) and the growth rate of daily specific weight (5,45±0,18 %/day). To increase the length and weight growth of catfish fry, probiotic bacteria of the type Lactobacillus sp. on cultivation media.Key words :biofloc, growth rate, lactobacillus, mutiara catfish, probiotics

This research aims to determine types of pathogen bacteria presented in body parts (liver and kidneys) of Tilapia (Oreochromis nilotics), types of bacteria attacks wild Tilapia and fish in Floating Culture Net (FCN) of Batur Lake as well as its prevalence bacteria found in Tilapia on Batur lake. Method used in this research is descriptive method, with a sampling method based on purposive sampling technique. According to identification’s result obtained, types of bacteria that infect liver were including to Aeromonas hydrophila, Plesiomonas shigelloides and Citrobacter freundii bacteria. Meanwhile, bacteria that infect kidneys are Aeromonas hydrophila, Aeromonas caviae, Plesiomonas shigelloides and Citrobacter freundii. Bacteria that infect wild fish are Aeromonas hydrophila, Aeromonas caviae and Plesiomonas shigelloides , while fishes in FCN are infected by Aeromonas hydrophila, Aeromonas caviae, Plesiomonas shigelloides and Citrobacter freundii bacteria. Infection prevalence of pathogen bacteria in Tilapia in Batur Lake is Aeromonas hydrophila at 55,5%, Plesiomonas shigelloides for 27,7%, Aeromonas caviae and Citrobacter freundii at 11,1%. According to sampling location, prevalence of bacteria that attacks wild fish are Aeromonas hydrophila and Plesiomonas shigelloides at 44,4%, Aeromonas caviae for 11,1%. Prevalence of bacteria that attacks fish in FCN is Aeromonas hydrophila for 66,6%, Citrobacter freundii infection at 22,2%, Aeromonas caviae and Citrobacter freundii at 11,1%.

In this study, the use of Lactobacillus acidophilus as a probiotic for Nile tilapia (Oreochromis niloticus) culture was studied. Fish survival and the expression of some genes involved in the immune response were assessed. Diet supplementation with L. acidophilus for 15 days caused a significant increase in fish survival during a challenge with Aeromonas hydrophila and variations in immune response related to IL-1β and transferrin expression in Nile tilapia spleen and kidney. Moreover, extracellular products (ECPs) of L. acidophilus showed high antibacterial activity against fish pathogens such as A. hydrophila and Streptococcus agalactiae in vitro. It was also observed that viable L. acidophilus was able to disrupt quorum sensing activity in Chromobacterium violaceum.

Primary cell cultures were developed from the pronephros of juvenile rainbow trout (Oncorhynchus mykiss, Walbaum), and used to determine their interaction with bacterial pathogens as compared to whole fish pathogenicity experiments. Overall, there was excellent agreement with Aeromonas hydrophila, A. salmonicida, Citrobacter freundii, Streptococcus iniae, Vibrio anguillarum, V. damsela, V. harveyi, V. ordalii, ‘V. viscosus’, V. vulnificus and Yersinia ruckeri, which were harmful to cell cultures and pathogenic to Atlantic salmon (Salmo salar L.) and rainbow trout. Also, a culture of Enterococcus faecium, which is not a recognised fish pathogen, caused mortalities in salmonids and damaged the cell cultures. In contrast, negligible damage to fish and/or cell cultures resulted from challenge with a Carnobacterium sp., Escherichia coli, Lactobacillus sp., V. alginolyticus and commercial formalin- inactivated vaccines for enteric redmouth (= Y. ruckeri) and furunculosis (= A. salmonicida). Use of cell cultures and whole fish experiments revealed that inactivation of V. harveyi for use in vaccines was troublesome, insofar as the addition of formalin and chloroform resulted in harmful preparations. In contrast, cultures of V. harveyi, which were inactivated by heat (100 °C for 1 hour), lysis at pH 9.5 and glutaraldehyde (to 0.5% w/v), were less harmful.

Due to increasing demand about the application of natural feed additives in aquaculture, the efficacy of separate and the combination of rosemary ( Rosmarinus officinalis ) and Bacillus subtilis on the growth performance, blood indices, innate immunity, antioxidant defense, digestive enzymes activity, the expression levels of genes with immunity modulation, as well as resistance against Aeromonas hydrophila , in common carp, Cyprinus carpio is reported. Fish (44.63±0.04 g) were divided into four treatments including the T0 (control treatment) fed with basal diet, T1 fed with rosemary at the rate of 3%, T2 fed with 1.5×10 7 CFU g–1 B. subtilis , and T3 fed with a combination of rosemary at the rate of 3% and 1.5×10 7 CFU g–1 B. subtilis. After 56 days enriched feed with B. subtilis and combination of rosemary and B. subtilis caused significant improvement in weight gain (WG %), feed conversion ratio (FCR), hematological and biochemical indices, the innate immune responses including total Ig level, lysozyme and ACH50 activities as well as the chymotrypsin, pepsin, protease, and amylase activities correlated to the control group (P<0.05). Additionally, the serum CAT and GPX activities were significantly enhanced in the T3 group (P<0.05). The mRNA expression of CAT and LYS genes significantly increased in T2 and T3 contrary to T0 (P<0.05). Fish challenged with A. hydrophila had variable survival and the best survival was in the T3. In summary, the combination of the rosemary and B. subtilis enhanced immune parameters and the ability of fish to cope with A. hydrophila as a fish pathogen. These findings indicate the potential of these substances as a promising feed additive.

Aeromonas hydrophila is the main reason of epidemic septicaemia for freshwater fish. In the present study, the effect of Aeromonas hydrophila infection on the non-specific immunity of blunt snout bream (Megalobrama amblycephala) was studied. After Aeromonas hydrophila challenge, lysozyme activity was significantly increased at 4 h, 1 d, 3 d, 5 d, 14 d and 21 d. An increased level of lysozyme activity indicated a natural protective mechanism in fish. The significant increases of superoxide dismutase activity and catalase activity in treatment group were detected at 4 h, 1 d, 3 d, 5 d, 14 d and 21 d after Aeromonas hydrophila challenge. Increase in the superoxide anion and H2O2 is considered to be beneficial for self-protection from disease. Acid phosphatase activity increased significantly at 1 d, 3 d and 5 d after Aeromonas hydrophila challenge. Alkaline phosphatase activity in treatment group showed significant increase at 4 h, 1 d, 3 d, 5 d, 14 d and 21 d compared to control group. Increased phosphatase activity indicates higher breakdown of the energy reserve, which is utilized for the growth and survival of fish. These results revealed that the non-specific immunity of fish played an important role in self-protection after pathogens infection.

Fish gut microbiota contains many potential probiotics that can be used in aquaculture. The aim of this study was to isolate beneficial probiotic bacteria from the gut of African catfish, Clarias gariepinus, and to evaluate the most suitable in vivo probiotic candidates. Eighty-nine gut bacterial isolates were screened for in vitro antibacterial activities against five common isolated fish pathogens, Aeromonas sobria, A. hydrophila, Pseudomonas aeruginosa, P. putida, and Staphylococcus aureus. Results found that nine out of 89 isolates had antibacterial activities with at least one pathogen. Two out of nine isolates demonstrated pathogenic effects following intraperitoneal injection. The remaining non-pathogenic seven strains were able to survive in high bile concentration (10%) and at different acidic pH values. Three out of seven strains were sensitive to all selected antibiotics. Four out of seven strains had amylase and protease activities. Based on 16S rRNA gene analysis, the isolated strains were identified as follows: Bacillus subtilis (6HN), B. amyloliquefaciens (7HN), B. cereus (29HN), Leuconostoc mesenteroides (13HN), Edwardsiella sp. (34HN), and Citrobacter freundii (24HN and 31HN). Comparative in vivo study of dietary supplementations of heat-inactivated and live L. mesenteroides (13HN) and Edwardsiella sp. (34HN) showed better improvements in growth, immunity, and the expression of myostatin (MSTN) and pituitary adenylate cyclase-activating polypeptide (PACAP) in the spleen of C. gariepinus of heat-inactivated probiotics than live one.

The aim of this research was to identify the microbiota that was found in C, jordani, C. humboldtianum and C. estor to obtain those strains with probiotic capacity and can be used in Chirostoma sp. culture. Pre-adult stages were obtained for dissection and gain an intestinal tissue portion and get pure strains throughout consecutive reseeding in NHI and TSA agar plates. Then proceeded to the molecular identification with RNAr 16S sequencing gen and establish their probiotic capacity growing them in acid pH, bile salts, pathogen inhibition to Aeromonas hydrophila and Vibrio fluvialisin vitro and with antibiotics according to FAO (2006) and Balcazar et al . (2006) techniques. Results shown that analyzed Chirostoma sp. from intestinal tract were dominated by Proteobacteria, Actinobacteria and Firmicutes identifying 60 strains, 40% of them were from C. jordani ; 30% from C. humboldtianum and 20% of strains were from C. estor . The three analyzed species share some bacterial groups even if they were grown in different environmental conditions. The common species strains were Lactobacillus sp., L.crispatus , Bacillus subtilis , B. sp., Aeromonashydrophila, A. hydrophila caviae, Vibrio fluvialis and Pseudomonaluteola . The only bacterial species that resisted stress experiments, correspond to Bacillus sp. genus represented by Bacillus subtilis , Bacillus sp. and Bacillus laterodporus , so they are good probiotics candidates for culture of Chirostoma sp. genus.

Background and ObjectivesIn the present study, isolation of Streptomyces associated with marine sponges and its bioactive potential against fish and shellfish pathogens were assessed. The Streptomyces sp. were isolated from the marine sponges namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis collected from Vizhinjam port, situated in the South-West coast of India.Materials and MethodsThe Streptomyces associated with marine sponges were isolated using specific ISP media. The isolates of Streptomyces were characterized for their colony characteristics, morphological properties, physiological and biochemical properties and were tentatively identified. The strains were cultivated on a lab scale level as shake-flask cultures and the crude extracts of the bioactive compounds obtained with ethyl acetate were screened biologically and chemically. By biological screening, the extracts were analyzed for their activity against fish and shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp, using the disk and agar-well diffusion bioassay method, while by chemical screening the crude culture extracts were analyzed by TLC and UV–Vis spectrophotometer.ResultsNinety-four isolates were found to be associated with marine sponges, among them only seven strains showed antagonism against fish and shellfish pathogens. Analysis of morphological, physiological and biochemical characteristics suggested that these strains belonged to the genus Streptomyces. The initial screening of the isolates by spot inoculation method exhibited antibacterial activity against Aeromonas hydrophila. In-vitro screening of the submerge culture extracts showed positive inhibition against the fish and shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp. The screening of bioactive compounds confirmed the production of polyene substances by UV spectrum, which resulted in absorbance peaks ranging from 225 to 245 nm and TLC analysis yielded Rf values ranging from 0.40 to 0.78.ConclusionThe results suggest that the seven Streptomyces strains isolated from marine sponges produce potential antibacterial compounds against fish and shellfish pathogens.

Background: Antimicrobial resistance (AMR) is a rising concern in the global aquaculture sector due to the rampant prophylactic use of antibiotics. This study is aimed to determine the AMR pattern in freshwater ornamental fishes. Methods: Fish pathogens were isolated and identified from infected Guppy and Molly collected from ornamental fish farms. Antibiotic susceptibility testing (ABST) using disc diffusion with 36 antibiotics was performed following the disc diffusion method. The resistance gene cassettes such as Class 1 and Class 2 integron were also detected from resolved isolates. Result: Fish pathogens were isolated and identified as Aeromonas hydrophila, A. dhakensis, A. veronii, A. sobria, Bacillus subtilis, Comamonas testosteroni, Edwardsiella tarda, Enterobacter cloacae, Enterococcus faecalis, Kurthia gibsonii and Klebsiella aerogenes. Shannon Weiner diversity index of resolved isolates was found to be 1.366 and 2.101 for Guppy and Molly, respectively. ABST results showed an elevated resistance pattern for A. veronii, E. faecalis (Guppy), K. aerogenes, B. subtilis, E. faecalis, C. testosteroni (Molly) with higher multiple antibiotic resistance indexes ( greater than 0.33). Meanwhile, all the recovered isolates were susceptible to sulphafurazole, enrofloxacin, norfloxacin and ciprofloxacin. Detection of class 1 integron in genomic and plasmid DNA reminds the rapid spread of the AMR gene through horizontal gene transfer.

The effect of leaves extracts of Clitoria ternatea Linn against the fish pathogens

The present study was conducted to examine the physicochemical parameters of water and parameters of Sona river sites at siwan district of Bihar and their impact on fish survival and growth. The parameters of water and soil parameter include temperature, pH, conductivity, total dissolve solids, color, odor and elasticity. The results of the present study revealed that some selected parameter was found to be in permissible range for fish growth and survival except the conductivity values of soil and sediment found to be low, but proved to be not lethal for growth of fishes. Thus, our present work revealed that the environmental conditions in Sona river have been found to be more suitable for fish growth and survival with precautions and improvement in quality. Hence, our present study will provide useful assistance to the local fishermen and fisheries managers to improve more the conditions of such rivers for fish growth and survival. Furthermore, such information could also be valuable for determining the growth rate and productivity of fishes.