Effect of Actinobacteria as a single cell protein on growth performance of Xiphophorus helleri

The potential of Marine Actinobacteria particularly Streptomyces as a single cell protein (SCP) feed for the growth of ornamental fish, Xiphophorus helleri has been investigated. The Streptomyces strains used as SCP were isolated from the marine sponges, namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Six SCP feeds were prepared and their effects were compared with those of control diet. After 30 days of feeding trials, the growth parameters including absolute growth rate, specific growth rate and feed conversion efficiency were found to be significantly (P<0.001) higher in groups that received SCP feed than those of control one, whereas feed conversion ratio was lower. Thus it was found that in addition to being effective antibiotic agents against harmful pathogens, Streptomyces could also promote the growth of fish effectively. Marine Actinobacteria, particularly Streptomyces, could play an important role as a single cell protein (SCP) in aquaculture nutrition and is a promising microbe for the development of marine biotechnology

Procjena utjecaja hranidbe probiotikom Streptomyces sp. na rast ukrasne ribe Xiphophorus helleri

The potential of Streptomyces as a probiotic feed for the growth of ornamental fish Xiphophorus helleri has been investigated. The Streptomyces strains used as probiotics were isolated from the marine sponges, namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Seven probiotic feeds were prepared and their effects were compared with those of control diet containing no probiotics. After 50 days of feeding trials, the growth parameters, namely absolute growth rate, specific growth rate, relative growth rate and feed conversion efficiency were found to be significantly (p<0.05) higher in groups that received probiotic feed additive than in the control, whereas feed conversion ratio was lower. The fish fed with probiotic feed showed significant improvement in length than the fish fed with control feed. Thus it was found that in addition to being effective antibiotic agents against harmful pathogens, Streptomyces could also promote the growth of fish effectively. Marine Actinobacteria, particularly Streptomyces, could thus be a promising probiotic in aquaculture.U radu je ispitana mogućnost dodavanja probiotika Streptomyces sp. hrani i njegov utjecaj na rast ukrasne ribe Xiphophorus helleri. Sojevi Streptomyces, upotrijebljeni kao probiotici, izolirani su iz morskih spužvā, i to iz vrsta Callyspongia diffusa, Mycale mytilorum, Tedania anhelans i Dysidea fragilis. Pripremljeno je sedam probiotičkih pripravaka i procijenjen njihov učinak u usporedbi s kontrolnim uzorkom, tj. hranom bez dodatka probiotika. Nakon 50 dana hranidbenih pokusa parametri rasta, i to apsolutni, specifični i relativni rast te učinkovitost pretvorbe hrane, bili su kudikamo veći (p<0,05) u skupini riba hranjenih probiotikom nego u kontrolnoj skupini, dok je stopa pretvorbe hrane bila manja. Ribe hranjene probiotikom znatno su porasle u usporedbi s kontrolnom skupinom. Utvrđeno je da Streptomyces sp., osim što djeluje antibiotički na štetne patogene, uspješno potiče i rast riba. Aktinobakterije iz mora, a osobito vrsta Streptomyces, mogu se uspješno koristiti kao probiotik pri uzgoju riba

Evaluation of Streptomyces as a Probiotic Feed for the Growth of Ornamental Fish Xiphophorus helleri

The potential of Streptomyces as a probiotic feed for the growth of ornamental fish Xiphophorus helleri has been investigated. The Streptomyces strains used as probiotics were isolated from the marine sponges, namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Seven probiotic feeds were prepared and their effects were compared with those of control diet containing no probiotics. After 50 days of feeding trials, the growth parameters, namely absolute growth rate, specific growth rate, relative growth rate and feed conversion efficiency were found to be significantly (p<0.05) higher in groups that received probiotic feed additive than in the control, whereas feed conversion ratio was lower. The fish fed with probiotic feed showed significant improvement in length than the fish fed with control feed. Thus it was found that in addition to being effective antibiotic agents against harmful pathogens, Streptomyces could also promote the growth of fish effectively. Marine Actinobacteria, particularly Streptomyces, could thus be a promising probiotic in aquaculture