Microbial biomass as an antioxidant for tilapia feed

Abstract

Microbial biomass (MB) produced by different industries is thought to be a beneficial supplement in fish feed due to high contents of antioxidants and pigments.However, little is known about their impact on fish health. In this experiment, 960 tilapia (26.84 AE 1.03 g) were fed one of eight experimental diets-a control diet with no MB (C), a control diet with vitamin E (VE) and six diets with three types of MB at two concentrations (0.25% and 0.5%): Rubrivivax gelatinosus (RG25 and RG50), Spirulina platensis (SP25 and SP50) and Saccharomyces cerevisiae (SC25 and SC50). Adding MB to diets decreased plasma total oxidant status, malonaldehyde and leucocyte respiratory burst; increased the total antioxidant status; and did not affect the blood biochemical parameters. In flesh, the use of the MB lowered the thiobarbituric acid-reactive substances and increased redness (except for SC) and carotenoid deposition (except SC25). So, it was concluded that the use of the MB provided an antioxidant effect in tilapia blood plasma, decreased lipid oxidation and increased pigmentation and carotenoid deposition in the fish flesh, without imparting a negative impact on the animals' health. K E Y W O R D Sbiochemical analysis, carotenoids, colour, leucocyte respiratory burst, lipid oxidation, TBARS

The Application of Single-Cell Ingredients in Aquaculture Feeds—A Review

“…Some biofloc-based products have also been reported to have positive effects on the immune system of various species [67,216,219,220]. In black tiger shrimp, improvements to specific pathogen (gill-associated virus) resistance have been reported through the use of a biofloc-based product (Novacq™) [98].…”

“…In black tiger shrimp, improvements to specific pathogen (gill-associated virus) resistance have been reported through the use of a biofloc-based product (Novacq™) [98]. Grassi et al [219] also reported an increased antioxidant status (based on reduced levels of TBARS of the plasma) of Nile tilapia when fed various microbial biomasses (bacterial and fungal) at very low levels (<5 g/kg). Positive effects on the immune response (phenoloxidase and respiratory burst) and disease resistance of Pacific white shrimp to infectious myonecrosis virus fed a microbial biofloc grown on different carbon sources were reported by Ekasari et al [67].…”

“…Various flesh quality responses with other microbial SCP and other aquaculture species have been reported [195,219,223]. Lu et al [223] fed Nile tilapia with raw Spirulina as the sole feed input and found a series of flesh quality traits, assessed both mechanically and sensorially, had improved, making the fish more suitable for sashimi.…”

Oxidative stability of tilapia feeds containing Saccharomyces cerevisiae and Spirulina platensis

“…The tubes were heated in boiling water bath (100 °C) for 40 min and cooled in running water for 10 min. The TBARS were measured at 538 nm and the values were expressed as mg malonaldehyde/kg (GRASSI et al, 2016(GRASSI et al, , 2018.…”

“…More than benefits to the preservation of the ration, S. platensis and S. cerevisiae biomasses can improve fish health and meat quality. GRASSI et al (2018) included microbial biomasses in tilapia diets and reported an improvement in the oxidative status of the animals and a delay in the fillets oxidation up to 60 days of storage. Moreover, S. platensis biomass increased redness and carotenoids in the tilapia fillets, so improving sensory and functional properties of the flesh (GRASSI et al, 2018).…”