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Peter Bossier - One of the best experts on this subject based on the ideXlab platform.

  • Application of poly-β-hydroxybutyrate (PHB)-based biodegradable plastic as artificial substratum in Litopenaeus vannamei culture
    Journal of Polymers and the Environment, 2018
    Co-Authors: Gladys Ludevese‐pascual, Peter Bossier, Joseph Leopoldo Q. Laranja, Edgar C. Amar, Peter De Schryver
    Abstract:

    The use of artificial substratum made out of Poly-Beta-Hydroxybutyrate (PHB) based biodegradable plastic for penaeid shrimp culture was investigated for the first time. Provision of PHB substratum consisting of PHB type P209 (Biomer, Krailling, Germany) to postlarval whiteleg shrimp Litopenaeus vannamei (106 +/- 52 mg) resulted in significantly higher survival (P ae 0.05) of 83.6 +/- 3.4% as compared to 73.9 +/- 3.0% for postlarvae provided with conventional substratum consisting of polyvinylchloride (PVC) pipes. Results on final weight showed significantly higher weight (P ae 0.05) of 1008.2 +/- 4.5 mg in postlarval whiteleg shrimp provided PHB substratum as compared to 893.4 +/- 30.0 mg for postlarvae provided with PVC substratum. The trends of higher visit and preference by postlarval whiteleg shrimp on 10-day and 70-day aged PHB substrata over 10-day and 70-day aged PVC substrata suggest the importance of PHB substratum as grazing area rather than as shelter. Test conducted on water quality also showed a trend towards higher total ammonia-nitrogen (TAN) conversion from an initial concentration of 1.75 +/- 0.0 mg L-1 to 0.35 mg +/- 0.04 mg L-1 after 72 h with PHB substratum while using no substratum and PVC substratum lead to TAN concentrations of 1.28 +/- 0.06 mg L-1 and 1.23 +/- 0.10 mg L-1, respectively. Overall, this study indicates that artificial substratum consisting of PHB-based biodegradable plastic increases the quality of postlarval whiteleg shrimp and that it contributes to maintaining good water quality.

  • a probiotic bacillus strain containing amorphous poly beta hydroxybutyrate phb stimulates the innate immune response of penaeus monodon postlarvae
    Fish & Shellfish Immunology, 2017
    Co-Authors: Joseph Leopoldo Q. Laranja, Edgar C. Amar, Peter De Schryver, Gladys Ludevesepascual, Yufeng Niu, Mary Joy Geaga, Peter Bossier
    Abstract:

    In this study, the PHB-accumulating Bacillus sp. JL47 strain (capable of accumulating 55% PHB on cell dry weight) was investigated for its effects on the immune response of giant tiger shrimp (Penaeus monodon) postlarvae (PL) before and after the Vibrio campbellii challenge. Briefly, shrimp PL were cultured and fed with Artemia nauplii enriched with Bacillus sp. JL47. Shrimp receiving the Artemia nauplii without JL47 enrichment were used as control. After 15 days of feeding, the shrimp were challenged with pathogenic V. campbellii LMG 21363 at 106 cells mL-1 by immersion. Relative expression of the immune related genes encoding for prophenoloxidase (proPO), transglutaminase (TGase) and heat shock protein 70 (Hsp70) in the shrimp were measured before (0 h) and after (3, 6, 9, 12, 24 h) the Vibrio challenge by quantitative real-time PCR using β-actin as the reference gene. The expressions of TGase and proPO were significantly up-regulated (p < 0.05) within 9 h and 12 h, respectively after challenge in shrimp receiving the Bacillus sp. JL47 as compared to the challenged and non-challenged controls. Hsp70 expression was significantly increased (p < 0.05) at 3 h post-challenge in all challenged shrimp. Interestingly, proPO and TGase genes were significantly up-regulated (p < 0.05) in Bacillus sp. JL47 treated shrimp even before the Vibrio challenge was applied. No up-regulation in the Hsp70 gene, however, was observed under these conditions. The data suggest that the protective effect of the PHB-accumulating Bacillus sp. JL47 in shrimp was due to its capacity to stimulate the innate immune related genes of the shrimp, specifically the proPO and TGase genes. The application of probiotic Bacillus species, capable of accumulating a significant amount of PHB, is suggested as potential immunostimulatory strategy for aquaculture.

  • effect of poly β hydroxybutyrate on chinese mitten crab eriocheir sinensis larvae challenged with pathogenic vibrio anguillarum
    Journal of Fish Diseases, 2012
    Co-Authors: Liying Sui, J Cai, H X Sun, Mathieu Wille, Peter Bossier
    Abstract:

    This study investigated the protective effect of Poly-Beta-Hydroxybutyrate (PHB) on Chinese mitten crab, Eriocheir sinensis, zoea larvae challenged with pathogenic Vibrio anguillarum. PHB was delivered to the crab larvae through rotifer and Artemia bioencapsulation. Zoea 3 larvae were challenged with V.similar to anguillarum at a final concentration of 105 CFU mL-1. PHB-enriched rotifers and Artemia nauplii were added to the culture water 24 h prior to, upon and 24 h after challenge. The results confirmed that PHB could enhance the survival and growth of unexposed E.similar to sinensis larvae. Moreover, PHB protected larvae from the pathogen as the larvae fed PHB-enriched live food showed the highest survival and development rate in all challenged groups (P < 0.05). Furthermore, larval performance was the best when PHB was delivered to the larvae 24 h before challenge (P < 0.05). In conclusion, our results indicate that PHB can be used as part of an effective strategy to protect E.similar to sinensis larvae from V.similar to anguillarum resulting in higher survival and better growth, especially when applied before the challenge.

  • effects of poly β hydroxybutyrate phb on siberian sturgeon acipenser baerii fingerlings performance and its gastrointestinal tract microbial community
    FEMS Microbiology Ecology, 2012
    Co-Authors: Ebrahim H Najdegerami, Tom Defoirdt, Nico Boon, Patrick Sorgeloos, Tiet Ngoc Tran, Massimo Marzorati, Peter Bossier
    Abstract:

    Poly-Beta-Hydroxybutyrate (PHB) is a natural polymer that can be depolymerized into water-soluble short-chain fatty acid monomers. These monomers can act as microbial control agents. In this study, the effects of partially replacing the diet of Siberian sturgeon fingerlings with 2% and 5% PHB were investigated. Replacing 2% of the diet with PHB improved weight gain, specific growth rate (SGR) and survival in the sturgeon fingerlings during the 10-week experimental period. Community-level physiological profiling and PCR-denaturing gradient gel electrophoresis (PCR-DGGE) were used to analyze the microbial community diversity and community organization in the sturgeon gastrointestinal tract. DGGE analysis revealed that PHB affected the intestinal microbial species richness and diversity. The highest species richness was observed with 2% PHB. DNA sequencing of the dominant bands in 2% and 5% PHB treatments revealed that PHB stimulated bacteria belonging to the genera Bacillus and Ruminococcaceae. Principal component analysis, Lorenz curves and the Shannon index of Biolog(TM) Ecoplate data revealed that aerobic metabolic potential of the bacterial community was different in the PHB-treated fishes as compared with the control situation. Overall, our results indicate that PHB act as microbial control agents and replacement of 2% of Siberian sturgeon fingerling diet with PHB has beneficial effects.

  • the bacterial storage compound poly β hydroxybutyrate protects artemia franciscana from pathogenic vibrio campbellii
    Environmental Microbiology, 2007
    Co-Authors: Tom Defoirdt, Dirk Halet, Han Vervaeren, Nico Boon, Patrick Sorgeloos, Peter Bossier, Tom Van De Wiele, Willy Verstraete
    Abstract:

    Infections caused by antibiotic-resistant luminescent Vibrios can cause dramatic losses in aquaculture. In this study, the short-chain fatty acid beta-hydroxybutyrate and its polymer Poly-Beta-Hydroxybutyrate were investigated as possible new biocontrol agents. beta-Hydroxybutyrate was shown to completely inhibit the growth of pathogenic Vibrio campbelli at 100 mM. Moreover, the addition of 100 mM of this fatty acid to the culture water of Artemia nauplii infected with the V. campbelli strain significantly increased the survival of the nauplii. As Artemia is a non-selective and particle filter feeder, we also investigated whether Poly-Beta-Hydroxybutyrate particles could be used to protect Artemia from the pathogenic V. campbellii. The addition of 100 mg l(-1) Poly-Beta-Hydroxybutyrate or more to the Artemia culture water offered a preventive and curative protection from the pathogen as a significantly enhanced survival was noticed. If added as a preventive treatment, a complete protection of infected nauplii (no significant mortality compared with uninfected nauplii) was observed at 1000 mg l(-1) Poly-Beta-Hydroxybutyrate. Our data indicate that the use of Poly-Beta-Hydroxybutyrate might constitute an ecologically and economically sustainable alternative strategy to fight infections in aquaculture.

J J Heijnen - One of the best experts on this subject based on the ideXlab platform.

  • poly β hydroxybutyrate metabolism in dynamically fed mixed microbial cultures
    Water Research, 2002
    Co-Authors: J J Beun, M C M Van Loosdrecht, Klaus Dircks, J J Heijnen
    Abstract:

    The kinetics of production and degradation of Poly-Beta-Hydroxybutyrate (PHB) by a mixed activated sludge culture growing on acetate was studied in a sequencing batch reactor (SBR). Occasionally a very high amount of acetate was added to the steady state system in order to obtain high PHB concentrations in the cells (fPHB). This made it possible to follow PHB production and degradation over a wide range of fPHB-data (between 0 and 0.8 Cmol/Cmol). The results were compared with data available in literature and with equations derived by metabolic modeling. This led to some remarkable observations. For the feast period, the ratio q(feast)PHB/-q(feast)Ac (specific PHB production rate over specific acetate uptake rate) was used to indicate which fraction of the substrate is stored. Experimentally and theoretically it was shown that this ratio has a constant value for dynamically fed systems operated at a sludge retention time (SRT) > 2d. This value is 0.6 Cmol/Cmol under aerobic conditions and 0.4-0.5 Cmol/Cmol under anoxic conditions, irrespective of the specific growth rate of the biomass and the specific acetate uptake rate in the feast period. Degradation of internal stored PHB could be described with a first order degradation rate with respect to the PHB content of the cells. Degradation of PHB appeared to be independent of the type of electron acceptor present in the system and independent of the SRT of the system. The kinetic descriptions can be used to predict PHB production and consumption in general in dynamic fed wastewater treatment systems, and they provide some trends for modeling purposes.

  • n removal in a granular sludge sequencing batch airlift reactor
    Biotechnology and Bioengineering, 2001
    Co-Authors: J J Beun, J J Heijnen, M C M Van Loosdrecht
    Abstract:

    The removal of N-compounds in the sequencing batch airlift reactor (SBAR) containing granular sludge was studied under conditions of decreased dissolved oxygen (DO). A simulation model was developed to describe and evaluate the effects of several process conditions in the SBAR on N-removal performance. The model described the experimental data reasonable well. It has been shown that nitrification, denitrification, and removal of chemical oxygen demand (COD) can occur simultaneously in a granular sludge SBR. It has also been shown that the exact location of the autotrophic biomass influences the net N-removal. The distribution of the autotrophic biomass is influenced by the DO in the reactor. The optimal DO value is expected to be around 40% air saturation. It was shown that storage and subsequent degradation of Poly-Beta-Hydroxybutyrate (PHB) benefit the denitrification. In particular, PHB is stored in bacteria situated in deeper layers of the granules below where the autotrophic activity occurs, serves as a C-source for denitrification.

  • glycogen metabolism in aerobic mixed cultures
    Biotechnology and Bioengineering, 2001
    Co-Authors: Klaus Dircks, M C M Van Loosdrecht, J J Heijnen, J J Beun, Mogens Henze
    Abstract:

    In this study, the metabolism of glycogen storage and consumption in mixed cultures under aerobic conditions is described. The experimental results are used to calibrate a metabolic model, which as sole stoichiometric variables has the efficiency of oxidative phosphorylation (delta) and maintenance requirement in units of adenosine triphosphate (m(ATP)). Using the experimental data and values from the literature we show that delta and m(ATP) are strongly coupled and that the values determined for glycogen and Poly-Beta-Hydroxybutyrate (PHB) metabolism are similar. We also demonstrate that storage of glycogen and subsequent growth occur without significant loss of energy, as compared with direct growth on glucose. For kinetic modeling, Monod kinetics is used most commonly in activated sludge models to describe the rate of microbial transformation. Monod kinetics, however, does not provide a good description of the data obtained. Second-order kinetics gives a better description of the rate of glycogen degradation. Formation and consumption of glycogen appears to be much faster than for PHB.

  • stoichiometry and kinetics of poly β hydroxybutyrate metabolism in aerobic slow growing activated sludge cultures
    Biotechnology and Bioengineering, 2000
    Co-Authors: J J Beun, M C M Van Loosdrecht, F Paletta, J J Heijnen
    Abstract:

    This paper discusses the Poly-Beta-Hydroxybutyrate (PHB) metabolism in aerobic, slow growing, activated sludge cultures, based on experimental data and on a metabolic model. The dynamic conditions which occur in activated sludge processes were simulated in a 2-L sequencing batch reactor (SBR) by subjecting a mixed microbial population to successive periods of external substrate availability (feast period) and no external substrate availability (famine period). Under these conditions intracellular storage and consumption of PHB was observed. It appeared that in the feast period, 66% to almost 100% of the substrate consumed is used for storage of PHB, the remainder is used for growth and maintenance processes. Furthermore, it appeared that at high sludge retention time (SRT) the growth rate in the feast and famine periods was the same. With decreasing SRT the growth rate in the feast period increased relative to the growth rate in the famine period. Acetate consumption and PHB production in the feast period both proceeded with a zero-order rate in acetate and PHB concentration respectively. PHB consumption in the famine period could best be described kinetically with a nth-order degradation equation in PHB concentration. The obtained results are discussed in the context of the general activated sludge models.

  • stoichiometry and kinetics of poly β hydroxybutyrate metabolism in aerobic slow growing activated sludge cultures
    Biotechnology and Bioengineering, 2000
    Co-Authors: J J Beun, F Paletta, M C M Van Loosdrecht, J J Heijnen
    Abstract:

    This paper discusses the poly-{beta}-hydroxybutyrate (PHB) metabolism in aerobic, slow growing, activated sludge cultures, based on experimental data and on a metabolic model. The dynamic conditions which occur in activated sludge processes were simulated in a 2-L sequencing batch reactor (SBR) by subjecting a mixed microbial population to successive periods of external substrate availability (feast period) and no external substrate availability (famine period). Under these conditions intracellular storage and consumption of PHB was observed. It appeared that in the feast period, 66% to almost 100% of the substrate consumed is used for storage of PHB, the remainder is used for growth and maintenance processes. Furthermore, it appeared that at high sludge retention time (SRT) the growth rate in the feast and famine periods was the same. With decreasing SRT the growth rate in the feast period increased relative to the growth rate in the famine period. Acetate consumption and PHB production in the feast period both proceeded with a zero-order rate in acetate and PHB concentration respectively. PHB consumption in the famine period could best be described kinetically with a nth order degradation equation in PHB concentration. The obtained results are discussed in the context of the general activated sludgemore » models.« less

Jorge Quillaguaman - One of the best experts on this subject based on the ideXlab platform.

  • optimizing conditions for poly beta hydroxybutyrate production by halomonas boliviensis lc1 in batch culture with sucrose as carbon source
    Applied Microbiology and Biotechnology, 2007
    Co-Authors: Jorge Quillaguaman, Bo Mattiasson, Marlene Munoz, Rajni Hattikaul
    Abstract:

    Halomonas boliviensis LC1 is able to accumulate poly(beta-hydroxybutyrate) (PHB) under conditions of excess carbon source and depletion of essential nutrients. This study was aimed at an efficient production of PHB by growing H. boliviensis to high cell concentrations in batch cultures. The effect of ammonium, phosphate, and yeast extract concentrations on cell concentration [cell dry weight (CDW)] and PHB content of H. boliviensis cultured in shake flasks was assayed using a factorial design. High concentrations of these nutrients led to increments in cell growth but reduced the PHB content to some extent. Cultivations of H. boliviensis under controlled conditions in a fermentor using 1.5% (w/v) yeast extract as N source, and intermittent addition of sucrose to provide excess C source, resulted in a polymer accumulation of 44 wt.% and 12 g l(-1) CDW after 24 h of cultivation. Batch cultures in a fermentor with initial concentrations of 2.5% (w/v) sucrose and 1.5% (w/v) yeast extract, and with induced oxygen limitation, resulted in an optimum PHB accumulation, PHB concentration and CDW of 54 wt.%, 7.7 g l(-1) and 14 g l(-1), respectively, after 19 h of cultivation. The addition of casaminoacids in the medium increased the CDW to 14.4 g l(-1) in 17 h but reduced the PHB content in the cells to 52 wt.%.

  • poly beta hydroxybutyrate production by a moderate halophile halomonas boliviensis lc1 using starch hydrolysate as substrate
    Journal of Applied Microbiology, 2005
    Co-Authors: Jorge Quillaguaman, Suhaila Hashim, F Bento, Bo Mattiasson, Rajni Hattikaul
    Abstract:

    Aim: The objective of the present work was to enable the use of starch hydrolysate, generated by the action of a recombinant maltooligosaccharide forming amylase from Bacillus halodurans LBK 34, as the carbon source for the production of poly-beta- hydroxybutyrate ( PHB) by Halomonas boliviensis LC1. Methods and Results: In this work, different amounts of the alpha- amylase ( Amy 34) were utilized for starch hydrolysis, resulting in the production of mixtures of maltooligosaccharides ( G1 - G6) at varying ratios. The highest PHB accumulation ( 56 wt%) by H. boliviensis cultivated in shake flasks ( with agitation at 160 rev min(-1)) was obtained when 6.4 U ml(-1) of the amylase was used for starch hydrolysis. When H. boliviensis cells were grown in a fermentor with no oxygen limitation the accumulation of PHB was decreased to 35 wt%. Although some improvements in PHB accumulation and cell mass concentration were reached by the addition of peptone and phosphate, respectively, major enhancements were attained when oxygen limitation was induced in the fermentor. Conclusions: Halomonas boliviensis uses preferentially maltose for PHB formation from starch hydrolysate. It is also able to hydrolyse higher sugars if no other simpler carbon source is available but with a significantly lower polymer yield. Furthermore, H. boliviensis is able to adjust its metabolism to oxygen limitation, most probably by directing the excess NAD( P) H to PHB accumulation. Significance and Impact of the Study: There have been no reports related to PHB production amongst the members of the genus Halomonas. The use of a maltooligosaccharide forming alpha- amylase, which is active at a temperature and pH close to that required for growth of H. boliviensis, and the versatility of this bacterium in the selection of the carbon source may provide an attractive alternative for the utilization of starch- derived raw materials. (Less)

Joseph Leopoldo Q. Laranja - One of the best experts on this subject based on the ideXlab platform.

  • Application of poly-β-hydroxybutyrate (PHB)-based biodegradable plastic as artificial substratum in Litopenaeus vannamei culture
    Journal of Polymers and the Environment, 2018
    Co-Authors: Gladys Ludevese‐pascual, Peter Bossier, Joseph Leopoldo Q. Laranja, Edgar C. Amar, Peter De Schryver
    Abstract:

    The use of artificial substratum made out of Poly-Beta-Hydroxybutyrate (PHB) based biodegradable plastic for penaeid shrimp culture was investigated for the first time. Provision of PHB substratum consisting of PHB type P209 (Biomer, Krailling, Germany) to postlarval whiteleg shrimp Litopenaeus vannamei (106 +/- 52 mg) resulted in significantly higher survival (P ae 0.05) of 83.6 +/- 3.4% as compared to 73.9 +/- 3.0% for postlarvae provided with conventional substratum consisting of polyvinylchloride (PVC) pipes. Results on final weight showed significantly higher weight (P ae 0.05) of 1008.2 +/- 4.5 mg in postlarval whiteleg shrimp provided PHB substratum as compared to 893.4 +/- 30.0 mg for postlarvae provided with PVC substratum. The trends of higher visit and preference by postlarval whiteleg shrimp on 10-day and 70-day aged PHB substrata over 10-day and 70-day aged PVC substrata suggest the importance of PHB substratum as grazing area rather than as shelter. Test conducted on water quality also showed a trend towards higher total ammonia-nitrogen (TAN) conversion from an initial concentration of 1.75 +/- 0.0 mg L-1 to 0.35 mg +/- 0.04 mg L-1 after 72 h with PHB substratum while using no substratum and PVC substratum lead to TAN concentrations of 1.28 +/- 0.06 mg L-1 and 1.23 +/- 0.10 mg L-1, respectively. Overall, this study indicates that artificial substratum consisting of PHB-based biodegradable plastic increases the quality of postlarval whiteleg shrimp and that it contributes to maintaining good water quality.

  • a probiotic bacillus strain containing amorphous poly beta hydroxybutyrate phb stimulates the innate immune response of penaeus monodon postlarvae
    Fish & Shellfish Immunology, 2017
    Co-Authors: Joseph Leopoldo Q. Laranja, Edgar C. Amar, Peter De Schryver, Gladys Ludevesepascual, Yufeng Niu, Mary Joy Geaga, Peter Bossier
    Abstract:

    In this study, the PHB-accumulating Bacillus sp. JL47 strain (capable of accumulating 55% PHB on cell dry weight) was investigated for its effects on the immune response of giant tiger shrimp (Penaeus monodon) postlarvae (PL) before and after the Vibrio campbellii challenge. Briefly, shrimp PL were cultured and fed with Artemia nauplii enriched with Bacillus sp. JL47. Shrimp receiving the Artemia nauplii without JL47 enrichment were used as control. After 15 days of feeding, the shrimp were challenged with pathogenic V. campbellii LMG 21363 at 106 cells mL-1 by immersion. Relative expression of the immune related genes encoding for prophenoloxidase (proPO), transglutaminase (TGase) and heat shock protein 70 (Hsp70) in the shrimp were measured before (0 h) and after (3, 6, 9, 12, 24 h) the Vibrio challenge by quantitative real-time PCR using β-actin as the reference gene. The expressions of TGase and proPO were significantly up-regulated (p < 0.05) within 9 h and 12 h, respectively after challenge in shrimp receiving the Bacillus sp. JL47 as compared to the challenged and non-challenged controls. Hsp70 expression was significantly increased (p < 0.05) at 3 h post-challenge in all challenged shrimp. Interestingly, proPO and TGase genes were significantly up-regulated (p < 0.05) in Bacillus sp. JL47 treated shrimp even before the Vibrio challenge was applied. No up-regulation in the Hsp70 gene, however, was observed under these conditions. The data suggest that the protective effect of the PHB-accumulating Bacillus sp. JL47 in shrimp was due to its capacity to stimulate the innate immune related genes of the shrimp, specifically the proPO and TGase genes. The application of probiotic Bacillus species, capable of accumulating a significant amount of PHB, is suggested as potential immunostimulatory strategy for aquaculture.

De Schryver Peter - One of the best experts on this subject based on the ideXlab platform.

  • Determination of poly‐β‐hydroxybutyrate assimilation by postlarval whiteleg shrimp, Litopenaeus vannamei using stable 13C isotope tracing
    'Wiley', 2020
    Co-Authors: Ludevese‐pascual Gladys, Laranja, Joseph Leopoldo, Amar Edgar, Bossier Peter, Ahmed Farhana, De Troch Marleen, Bodé Samuel, Boeckx Pascal, De Schryver Peter
    Abstract:

    A preliminary study was conducted to demonstrate fate of the bacterial storage compound Poly-Beta-Hydroxybutyrate (PHB) once ingested and degraded in vivo in crustaceans. The 2% supplementation of C-13-labeled Ralstonia eutropha DSM545 containing 75% PHB on dry weight in postlarval whiteleg shrimp, Litopenaeus vannamei resulted in consistent enrichment of two fatty acids (containing 14-24 carbons [C] in length) pentadecanoic acid (15:0) and palmitic acid (16:0) in all lipid fractions. This could indicate that C-13 signal may not only originate from the PHB but partly from the structural components of the bacterial cell. There was a trend of lower C-13 enrichment in various lipid fractions of the postlarvae as compared to the diet. These findings may have important implications as to potential of PHB as energy source rather than as building block. There was a rapid transfer of C-13 in the postlarvae as seen by the significant C-13 enrichment in the tissues 4 hr after feeding with labeled bacterial cells. Overall, the assimilation of PHB in crustacean tissues is demonstrated for the first time. Our results indicate that PHB once ingested is rapidly assimilated in the tissues and could probably act as an energy source rather than as a building block

  • Determination of poly‐beta‐hydroxybutyrate assimilation by postlarval whiteleg shrimp, Litopenaeus vannamei using stable 13C isotope tracing
    'Wiley', 2020
    Co-Authors: Ludevese-pascual Gladys, Laranja, Joseph Leopoldo, Amar Edgar, Bossier Peter, Ahmed Farhana, De Troch Marleen, Bodé Samuel, Boeckx Pascal, De Schryver Peter
    Abstract:

    A preliminary study was conducted to demonstrate fate of the bacterial storage compound poly-β-hydroxybutyrate (PHB) once ingested and degraded in vivo in crustaceans. The 2% supplementation of 13C-labeled Ralstonia eutropha DSM545 containing 75% PHB on dry weight in postlarval whiteleg shrimp, Litopenaeus vannamei resulted in consistent enrichment of two fatty acids (containing 14–24 carbons [C] in length) pentadecanoic acid (15:0) and palmitic acid (16:0) in all lipid fractions. This could indicate that 13C signal may not only originate from the PHB but partly from the structural components of the bacterial cell. There was a trend of lower 13C enrichment in various lipid fractions of the postlarvae as compared to the diet. These findings may have important implications as to potential of PHB as energy source rather than as building block. There was a rapid transfer of 13C in the postlarvae as seen by the significant 13C enrichment in the tissues 4 hr after feeding with labeled bacterial cells. Overall, the assimilation of PHB in crustacean tissues is demonstrated for the first time. Our results indicate that PHB once ingested is rapidly assimilated in the tissues and could probably act as an energy source rather than as a building block

  • Artificial substratum consisting of poly-β-hydroxybutyrate-based biodegradable plastic improved the survival and overall performance of postlarval tiger shrimp Penaeus monodon
    'Wiley', 2019
    Co-Authors: Ludevese-pascual Gladys, Laranja, Joseph Leopoldo, Amar Edgar, Bossier Peter, De Schryver Peter
    Abstract:

    The use of artificial substratum consisting of Poly-Beta-Hydroxybutyrate (PHB)-based biodegradable plastic for penaeid shrimp culture was investigated in the present study. The survival of postlarval tiger shrimp Penaeus monodon (30 +/- 5 mg) provided with PHB substratum made out of PHB type DP9002 (Metabolix GmbH, Koln, Germany) was 88.7 +/- 3.4% and this was significantly higher as compared to postlarvae provided conventional substratum consisting of polyvinylchloride (PVC) pipes (67.3 +/- 6.5%). However, no significant weight improvement was observed for the postlarval tiger shrimp indicating that PHB could not be used as growth promoter. Nevertheless, a trend of improved robustness against adverse environmental conditions (lethal ammonium chloride concentration) and increased resistance to pathogenic Vibrio was observed in postlarval tiger shrimp provided with PHB substratum as compared to postlarvae provided with PVC substratum. Results indicate higher preference by postlarvae on PHB substratum over PVC substratum. Overall, this study indicates the potential of artificial substratum consisting of PHB-based biodegradable plastic as replacement for conventional substratum consisting of PVC pipes in enhancing the survival of postlarval tiger shrimp and improving its performance against adverse environmental conditions and disease resistance

  • Does Ralstonia eutropha, rich in poly‐β hydroxybutyrate (PHB), protect blue mussel larvae against pathogenic vibrios?
    'Wiley', 2019
    Co-Authors: Van Hung Nguyen, Bossier Peter, Hong, Nguyen Thi X, Ludeseve Christine, Garcia‐gonzalez Linsey, Nevejan Nancy, De Schryver Peter
    Abstract:

    The natural amorphous polymer Poly-Beta-Hydroxybutyrate (PHB-A: lyophilized Ralstonia eutropha containing 75% PHB) was used as a biological agent to control bacterial pathogens of blue mussel (Mytilus edulis) larvae. The larvae were supplied with PHB-A at a concentration of 1 or 10 mg/L for 6 or 24 hr, followed by exposure to either the rifampicin-resistant pathogen Vibrio splendidus or Vibrio coralliilyticus at a concentration of 10(5) CFU/ml. Larvae pretreated 6 hr with PHB-A (1 mg/L) survived a Vibrio challenge better relative to 24 hr pretreatment. After 96 hr of pathogen exposure, the survival of PHB-A-treated mussel larvae was 1.41- and 1.76-fold higher than the non-treated larvae when challenged with V. splendidus and V. coralliilyticus, respectively. Growth inhibition of the two pathogens at four concentrations of the monomer beta-HB (1, 5, 25 and 125 mM) was tested in vitro in LB35 medium, buffered at two different pH values (pH 7 and pH 8). The highest concentration of 125 mM significantly inhibited the pathogen growth in comparison to the lower levels. The effect of beta-HB on the production of virulence factors in the tested pathogenic Vibrios revealed a variable pattern of responses

  • Poly-Beta-Hydroxybutyrate-enriched Artemia sp. for giant tiger prawn Penaeus monodon larviculture
    'Wiley', 2017
    Co-Authors: Ludevese-pascual Gladys, Bossier Peter, Laranja, Joseph Leopoldo Q., Amar, Edgar C., Sorgeloos Patrick, De Schryver Peter
    Abstract:

    The beneficial effects of PHB as supplement for giant tiger prawn Penaeus monodon postlarvae using a short-term enrichment strategy via Artemia were examined. The effects of co-supplementing with a lipid emulsion were also evaluated to determine whether it yielded an additional benefit. Results on the average weight and larval development were not significantly different among postlarvae fed the different dietary treatments, indicating that PHB supplementation could not be used to stimulate growth in P. monodon postlarvae while such positive results have been reported in other aquaculture species. Nonetheless, significantly higher survival was obtained in postlarvae fed PHB-enriched Artemia irrespective of lipid enrichment. In addition, PHB increased the survival of the postlarvae after exposure to a lethal dose of ammonia. Lipid supplementation nullified this effect. The cumulative mortality of postlarvae subjected to a sublethal concentration of ammonia for 24 h and subsequent exposure to pathogenic Vibrio campbelli showed that PHB but not lipids could effectively enhance the resistance of the postlarvae. Co-supplementing lipids even significantly decreased this outcome. Our study indicates that PHB supplementation increases the quality of larval P. monodon and their chance of surviving under adverse environmental conditions. The short-term co-supplementation with lipid emulsion did not add to these effects