In vitro assessment of gastrointestinal viability of two photosynthetic bacteria, Rhodopseudomonas palustris and Rhodobacter sphaeroides

Abstract

Abstract:The objectives of this study were to assess the potential of two photosynthetic bacteria (PSB), Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions (pH 2.0, pH 3.0 and pH 4.0 gastric juices) and in simulated small intestinal transit conditions (pH 8.0, with or without 0.3% bile salts) was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochromis nilotica, were also detected. All the treatments were determined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and correspondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference (P>0.05) among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias.

Intestinal microbiota and immune related genes in sea cucumber (Apostichopus japonicus) response to dietary β-glucan supplementation

“…found in the sea cucumber of either CT or PO group. Rhodobacteraceae is aquatic, photosynthetic bacteria that is potentially used as a probiotic for a high gastrointestinal transit tolerance and safe for intestinal epithelial cells of tilapias [24,25]. In contrast, little is known about 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 the metabolism and ecological roles of Verrucomicrobiaceae except that Verrucomicrobiaceae was found capable of degrading polysaccharide [26].…”

In vitro and in vivo selection of probiotic purple nonsulphur bacteria with an ability to inhibit shrimp pathogens: acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus and other vibrios

“…The ability of selected PNSB to survive the pancreatic enzymes was tested in vitro according to the method of Zhou et al . () by growing PNSB in BIM broth under microaerobic‐light conditions for 48 h. This experiment was carried out after secondary screening based on the antivibrio activity obtained from 1 mL of culture broth that had been centrifuged at 5860 g for 10 min and the cell pellet was washed three times with phosphate‐buffered saline (PBS, pH 7.0), consisting of 0.02% KCl, 0.144% Na 2 HPO 4 , 0.8% NaCl and 0.024% KH 2 PO 4 . A cell count was also made on BIM agar using the spread plate method and incubated under aerobic‐dark conditions.…”

“…However, probiotics can act as biocontrol agents against pathogenic Vibrio species and they can be a more attractive way to achieve the target goal of using economical culture methods. In aquaculture, probiotics means the use of live microbes to help the host animal survive by providing it with beneficial effects for example by modifying the local microbial community, improving the animals ability to digest feed and/or enhance the ability of the host to resist disease (Verschuere, Rombaul, Sorgeloos & Verstrate ; Zhou, Pan, Wang & Li ). Among the probiotics used in shrimp aquaculture, purple nonsulphur bacteria (PNSB) are one of the groups with good potential because they can clean up water, reduce sulphide levels and act as probiotics to promote shrimp growth by secreting bioactive compounds that control shrimp pathogens (Qi, Zhang, Boon & Bossier ; Luo, Deng, Zeng & Zheng ).…”

Novel isolates of lactobacilli from fermented Portuguese olive as potential probiotics

“…lactis) and bifidobacteria (Bifidobacterium animalis subsp. lactis, Bifidobacte-rium longum, Bifidobacterium breve and Bifidobacterium infantis) that were claimed to be probiotic strains (Abe et al, 2010;Fernández, Boris, & Barbes, 2005;Zhou, Gopal, & Hill, 2001). …”