Encapsulated Bdellovibrio Powder as a Potential Bio-Disinfectant against Whiteleg Shrimp-Pathogenic Vibrios

Abstract

Liquid preparations of bdellovibrios are currently commercialized as water quality improvers to control bacterial pathogens in whiteleg shrimp Penaeus vannamei. However, the efficacy of these liquid preparations is significantly impaired due to a dramatic loss of viable cells during long-term room temperature storage. Thus, new formulations of bdellovibrios are greatly needed for high-stablility room-temperature storage. In the present study, the encapsulated powder of Bdellovibrio sp. strain F16 was prepared using spray drying with 20 g L−1 gelatin as the coating material under a spray flow of 750 L h−1, a feed rate of 12 mL min−1, and an air inlet temperature of 140 °C. It was found to have a cell density of 5.4 × 107 PFU g−1 and to have spherical microparticles with a wrinkled surface and a diameter of 3 μm to 12 μm. In addition, the encapsulated Bdellovibrio powder presented good storage stability with its cell density still remaining at 3.5 × 107 PFU g−1 after 120 days of room-temperature storage; it was safe for freshwater-farmed whiteleg shrimp with an LD50 over 1200 mg L−1, and it exhibited significant antibacterial and protective effects at 0.8 mg L−1 against shrimp-pathogenic vibrios. To our knowledge, this is the first report on a promising Bdellovibrio powder against shrimp vibrios with high stable room-temperature storage.

Active Biopolymeric Films Inoculated with Bdellovibrio bacteriovorus, a Predatory Bacterium

“…strain F16 was encapsulated in gelatin microparticles by spray drying [40]. The cell density obtained in the present work for the CA-S film (see Table 1) was higher than the cell density (5.4 × 10 7 PFU/g) reported for B. bacteriovorus microcapsules [40] produced by spray drying at 140 • C (inlet temperature). In the aforementioned study, no encapsulation yield was reported for B. bacteriovorus.…”

Towards enhancing coral heat tolerance: a “microbiome transplantation” treatment using inoculations of homogenized coral tissues

“…were transmitted to pocilloporid recipients and may have acted as the main drivers of the microbiome changes after inoculation, whereas BALOs were absent in the stable microbiomes of Porites . Noteworthy, BALOs constitute a suitable bacterial group to be considered for microbiome manipulation approaches as already implemented in aqua farming projects [ 54 , 55 ]. Many BALOs are culturable and can protect corals from pathogenic and coral bleaching-associated Vibrios [ 29 ].…”

Biotechnological Potential of Bdellovibrio and Like Organisms and Their Secreted Enzymes

“…It has also been proposed that B. bacteriovorus might be useful in the freshwater farming industry as a biological control agent of the shrimp pathogens V. cholerae (Cao et al, 2015) and V. parahaemolyticus (Kongrueng et al, 2017). The same group subsequently showed that Bdellovibrio could be prepared as an encapsulated powder and stored at room temperature over several months for later use as a biodisinfectant in shrimp aquaculture (Cao et al, 2019).…”