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1.
Fish Shellfish Immunol ; 151: 109753, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38977111

ABSTRACT

Bimetallic (Au/Ag) nanoparticles (BNPs) have shown enhanced antibacterial activity compared to their monometallic counterparts. Sulfated galactans (SG) are a naturally occurring polymer commonly found in red seaweed Gracilaria fisheri. They are biocompatible and biodegradable and environmentally friendly. In this study, we utilized SG in combination with BNPs to develop composite materials that potentially enhance antibacterial activity against shrimp pathogens Vibrio parahaemolyticus and Vibrio harveyi, compared to BNPs or SG alone. BNPs were coated with sulfated galactan (SGBNPs) and characterized using UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, zeta potential, and transmission electron microscopy (TEM). UV-vis spectroscopy analysis revealed that the surface plasmon peaks of BNPs and SGBNPs appeared at 530 nm and 532 nm, respectively. Zeta potential measurements showed that SGBNPs had a negative charge of -32.4 mV, while the BNPs solution had a positive charge of 38.7 mV. TEM images demonstrated the spherical morphology of both BNPs and SGBNPs with narrow size distributions (3-10 nm). Analysis of the FTIR spectra indicated that SG maintained its backbone structure in SGBNPs, but some functional groups were altered. Notably, SGBNPs showed superior antimicrobial and antibiofilm activities against V. parahaemolyticus and V. harveyi compared to SG and BNPs. Furthermore, treatment with SGBNPs significantly down-regulated the expression of virulence-related genes (toxR, cpsQ, and mfpA) for V. parahaemolyticus 3HP compared to the respective control, bacteria treated with BNPs or SG. Diets supplemented with SGBNPs, BNPs, or SG showed no detrimental impact on the growth of shrimp Penaeus vannamei. Shrimp fed with SGBNPs-supplemented feed showed significantly higher survival rates than those fed with BNPs-supplemented feed when infected with 3HP after being on the supplemented feed for seven days and a subsequent number of fifteen days. These findings collectively demonstrate the benefit of using SG capped Au-Ag BNPs as an antibacterial agent for the prevention and control of Vibrio sp. Infection in shrimp while reducing the risk of environmental contamination.

2.
Front Plant Sci ; 15: 1367271, 2024.
Article in English | MEDLINE | ID: mdl-38606065

ABSTRACT

Introduction: Ramularia leaf spot (RLS) disease is a growing threat to barley cultivation, but with no substantial resistance identified to date. Similarly, the understanding of the lifestyle of Ramularia collo-cygni (Rcc) and the prediction of RLS outbreak severity remain challenging, with Rcc displaying a rather untypical long endophytic phase and a sudden change to a necrotrophic lifestyle. The aim of this study was to provide further insights into the defense dynamics during the different stages of colonization and infection in barley in order to identify potential targets for resistance breeding. Methods: Utilizing the strength of proteomics in understanding plant-pathogen interactions, we performed an integrative analysis of a published transcriptome dataset with a parallel generated proteome dataset. Therefore, we included two spring barley cultivars with contrasting susceptibilities to Rcc and two fungal isolates causing different levels of RLS symptoms. Results: Interestingly, early responses in the pathogen recognition phase of the host were driven by strong responses differing between isolates. An important enzyme in this process is a xylanase inhibitor, which protected the plant from cell wall degradation by the fungal xylanase. At later time points, the differences were driven by cultivar-specific responses, affecting mostly features contributing to the pathogenesis- and senescence-related pathways or photosynthesis. Discussion: This supports the hypothesis of a hemibiotrophic lifestyle of Rcc, with slight differences in trophism of the two analyzed isolates. The integration of these data modalities highlights a strength of protein-level analysis in understanding plant-pathogen interactions and reveals new features involved in fungal recognition and susceptibility in barley cultivars.

3.
Animals (Basel) ; 14(6)2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38540051

ABSTRACT

The present study aimed to investigate the effects of Moringa oleifera leaf (MLE) extract-supplemented diets on the growth, feed utilization, hematology, innate immune response, and disease resistance of Nile tilapia against Streptococcus agalactiae Biotype 2. Four hundred and fifty Nile tilapia (32.61 ± 0.2 g/fish) were randomly allocated into fifteen tanks (30 fish/tank). Different concentrations of MLE at 0%, 0.5%, 1%, 1.5%, and 2% were fed to the Nile tilapia for 30 days, and the growth, feed utilization, hematology, and innate immune response of the Nile tilapia were determined. After the feeding trial, the Nile tilapia were challenged with a S. agalactiae Biotype 2 infection, and the relative percentage of survival (RPS) was determined. Results revealed the presence of quercetin, kaempferol, and p-coumaric acid in the MLE extract, exhibiting stronger antimicrobial activity against S. agalactiae Biotype 2. The diets supplemented with the MLE-0.5 group showed a significantly higher growth, feed utilization, hematology, and innate immune response in the Nile tilapia compared to the control and other MLE groups. Additionally, the MLE-0.5 group exhibited a significantly higher RPS of the Nile tilapia against S. agalactiae Biotype 2. Therefore, MLE-0.5 can be employed as an alternative feed supplement in sustainable Nile tilapia farming to protect against S. agalactiae Biotype 2.

4.
Fish Shellfish Immunol ; 146: 109383, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38246266

ABSTRACT

A mucoadhesive chitosan polymer-based nanoplatform has been increasingly recognized as an effective mucosal vaccine delivery system for fish. The present study aimed to investigate the effectiveness of immersion vaccination with a chitosan polymer-based nanovaccine to elicit an immune response in serum and mucus of red tilapia and evaluate its protective efficacy after immersion challenge with a heterogenous strain of Aeromonas veronii UDRT09. Six hundred red tilapia (22 ± 1.8 g) were randomly allocated into four experimental groups: control, empty-polymeric nanoparticle (PC), formalin-killed vaccine (FKV), and chitosan polymer-based nanovaccine (CS-NV) in triplicate. The specific IgM antibody levels and their bactericidal activity were assessed in serum and mucus for 28 days after immersion vaccination and followed by immersion challenge with A. veronii. The immersion vaccine was found to be safe for red tilapia, with no mortalities occurring during the vaccination procedure. The specific IgM antibody levels and bactericidal activity against A. veronii in both serum and mucus were significantly higher in red tilapia vaccinated with CS-NV compared to the FKV and control groups at all time points. Furthermore, the serum lysozyme activity, ACH50, and total Ig levels demonstrated a significant elevation in the groups vaccinated with CS-NV compared to the FKV and control groups. Importantly, the Relative Percentage Survival (RPS) value of the CS-NV group (71 %) was significantly higher than that of the FKV (15.12 %) and PC (2.33 %) groups, respectively. This indicates that the chitosan polymer-based nanovaccine platform is an effective delivery system for the immersion vaccination of tilapia.


Subject(s)
Chitosan , Cichlids , Fish Diseases , Tilapia , Animals , Nanovaccines , Aeromonas veronii , Immunity, Mucosal , Polymers , Immersion , Vaccination/veterinary , Vaccination/methods , Vaccines, Inactivated , Immunoglobulin M
5.
Foods ; 12(24)2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38137284

ABSTRACT

Stink bean, Parkia speciosa, is recognized as a significantly underutilized legume with versatile utility and diverse benefits. However, information on the impact of different processing methods, such as germination and hydrothermal cooking, is scarce on stink beans (SBs). Therefore, the current research aimed to explore the efficacy of germination (G) and hydrothermal cooking (HTC) on the physiochemical properties, proximate composition, techno-functional properties, and antioxidant potential of SB flour. Furthermore, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were employed to assess structural and morphological changes. The results revealed that the physiochemical properties of SB were significantly enhanced through processing, with more pronounced improvements observed during germination. Additionally, SBG exhibited a significantly higher protein content and lower fat content compared to SBHTC and stink bean raw (SBR). Moreover, techno-functional properties such as color intensity, least gelation concentration, and pasting properties were significantly improved in SBG compared to SBHTC and SBR. FTIR analysis of SBG and SBHTC indicated structural modifications in the lipid, protein, and carbohydrate molecules. FESEM examination revealed morphological changes in SBG and SBHTC when compared to SBR. Importantly, SBG exhibited higher antioxidant activity and total phenolic content in comparison to SBHTC and SBR. Therefore, processed SB flour can be incorporated and utilized in product development, highlighting its potential as a plant-based protein source for protein-rich breakfast bars and cookies.

6.
Animals (Basel) ; 13(11)2023 May 29.
Article in English | MEDLINE | ID: mdl-37889734

ABSTRACT

Nanotechnology can enhance nutrient delivery and bioavailability; hence, it has recently been considered the most practical alternative technology for nutritional supplements and disease control in fish farming. The present study was designed to evaluate the effects of mangosteen peel extract loaded in nanoemulsion (MSNE) on the inhibition of A. veronii (in vitro) and in vivo growth performance, serum biochemical parameters, the immune response, and the disease resistance of Nile tilapia (Oreochromis niloticus) against A. veronii challenge. The particle size, polydispersity index, and particle surface charge of MSNE were 151.9 ± 1.4 nm, >0.3, and -30 mV, respectively. Furthermore, MSNE, mangosteen peel extract (MPE), and nanoemulsion (NE) improved the antimicrobial activity against A. veronii. Fish fed MSNE, MPE, and NE-supplemented diets had a significantly lower (p < 0.05) feed conversion ratio (FCR) and higher specific growth rate (SGR) than fish fed the control diet. Furthermore, the MSNE had significantly higher serum glucose and protein levels than the control group in Nile tilapia. Total immunoglobulin, serum lysozyme, alternative complement activity, and survival of Nile tilapia fed with MSNE were significantly higher (p < 0.05) than the control diet. Therefore, MSNE has the potential to be employed as a supplement in sustainable Nile tilapia farming.

7.
Fish Shellfish Immunol ; 139: 108913, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37393062

ABSTRACT

Streptococcus agalactiae is one of Thailand's most important pathogens in tilapia aquaculture. Vaccination is a very effective method for protecting fish against disease in aquaculture. Oral vaccination is an interesting route for vaccine delivery as it mimics the pathogenesis of S. agalactiae and provides convenient administration for mass vaccination of fish. Moreover, gut mucosal immunity is associated with a mucus layer on the gastrointestinal tract. Therefore, this study aimed to develop a novel cationic-based nanoemulsion vaccine containing bile salts (NEB) coated by chitosan (CS) and determined its physicochemical characterization, morphology, in vitro mucoadhesive property, permeability, and acid-base tolerance. In addition, the efficacy of NEB-CS as an oral vaccination for Nile tilapia was evaluated in order to investigate the innate immune response and protection against S. agalactiae. The groups of fish consisted of: (1) deionized water as a non-vaccinated control (Control); (2) an inactivated vaccine formulated from formalin-killed bacteria (IB); and (3) a novel cationic-based nanoemulsion vaccine containing bile salts (NEB) coated by chitosan (CS). The control, IB, and NEB-CS were incorporated into commercial feed pellets and fed to Nile tilapia. In addition, we evaluated the serum bactericidal activity (SBA) for 14 days post-vaccination (dpv) and protective efficacy for 10 days post-challenge, respectively. The mucoadhesiveness, permeability, and absorption within the tilapia intestine were also assessed in vivo. The NEB-CS vaccine appeared spherical, with the nanoparticles having a size of 454.37 nm and a positive charge (+47.6 mV). The NEB-CS vaccine had higher levels of mucoadhesiveness and permeability than the NEB (p < 0.05). The relative percent survival (RPS) of IB and NEB-CS, when administered orally to fish, was 48% and 96%, respectively. Enhanced SBA was noted in the NEB-CS and IB vaccine groups compared to the control group. The results demonstrate that a feed-based NEB-CS can improve the mucoadhesiveness, permeability, and protective efficacy of the vaccine, and appear to be a promising approach to protecting tilapia in aquaculture against streptococcosis.


Subject(s)
Chitosan , Cichlids , Fish Diseases , Streptococcal Infections , Tilapia , Animals , Streptococcus agalactiae , Bacterial Vaccines , Streptococcal Infections/prevention & control , Streptococcal Infections/veterinary
8.
Animals (Basel) ; 13(8)2023 Apr 16.
Article in English | MEDLINE | ID: mdl-37106927

ABSTRACT

The aim of the present study was to optimize a masculinization platform for the production of all-male red tilapia fry by oral administration of 30 and 60 ppm of MT and alkyl polyglucoside nanostructured lipid carriers (APG-NLC) loaded with MT, respectively, for 14 and 21 days. The characterization, encapsulation efficiency and release kinetics of MT in lipid-based nanoparticles were assessed in vitro. The results showed that the MT-loaded nanoparticles were spherical, ranging from 80 to 125 nm in size, and had a negative charge with a narrow particle distribution. The APG-NLC loaded with MT provided higher physical stability and encapsulation efficacy than the NLC. The release rate constants of MT from MT-NLC and MT-APG-NLC were higher than those of free MT, which is insoluble in aqueous media. There was no significant difference in survival between the fish administered MT or the those fed orally with MT-APG-NLC fish. According to the logistic regression analysis, the sex reversal efficacy of MT-APG-NLC (30 ppm) and MT (60 ppm), resulted in significantly higher numbers of males after 21 days of treatment compared with the controls. The production cost of MT-APG-NLC (30 ppm) after 21 days of treatment was reduced by 32.9% compared with the conventional MT treatment group (60 ppm). In all the treatments, the length-weight relationship (LWR) showed negatively allomeric growth behavior (b < 3), with a relative condition factor (Kn) of more than 1. Therefore, MT-APG-NLC (30 ppm) would seem to be a promising, cost-effective way to reduce the dose of MT used for the masculinization of farmed red tilapia.

9.
Animals (Basel) ; 12(20)2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36290267

ABSTRACT

The aim of the present study was to evaluate the effects of a Jerusalem artichoke-supplemented diet on the blood chemistry, growth performance, intestinal morphology, expression of antioxidant-related genes, and disease resistance against Aeromonas veronii challenge in juvenile red tilapia. A completely randomized design (CRD) was followed to feed red tilapias with three experimental diets: control, 5.0 g/kg JA-supplemented (JA5), or 10.0 g/kg JA-supplemented (JA10) diets in triplicates for 4 weeks. The results revealed that the growth performance, weight gain (WG), specific growth rate (SGR), and average daily gain (ADG) of fish fed diets JA5 and JA10 were significantly higher (p < 0.05) than those of fish fed the control diet. Fish fed the control diet had significantly higher T-bilirubin, D-bilirubin, and ALT in blood serum than fish fed JA5 and JA10, as well as higher BUN than fish fed JA5. The number of goblet cells in the proximal and distal parts of the intestine revealed that the number of acid, neutral, and double-staining mucous cells of fish fed diets JA5 and JA10 was significantly higher (p < 0.05) than in fish fed the control diet. The diets including the prebiotic (JA5 and JA10) were associated with a significant increase in the expression of gpx1 and gst antioxidant-related genes and disease resistance against A. veronii in juvenile red tilapia. Therefore, JA5 and JA10 can be employed as promising prebiotics for sustainable red tilapia farming.

10.
Mar Drugs ; 20(8)2022 Jul 23.
Article in English | MEDLINE | ID: mdl-35892937

ABSTRACT

Various seaweed sulfated polysaccharides have been explored for antimicrobial application. This study aimed to evaluate the antibacterial activity of the native Gracilaria fisheri sulfated galactans (NSG) and depolymerized fractions against the marine pathogenic bacteria Vibrio parahaemolyticus and Vibrio harveyi. NSG was hydrolyzed in different concentrations of H2O2 to generate sulfated galactans degraded fractions (SGF). The molecular weight, structural characteristics, and physicochemical parameters of both NSG and SGF were determined. The results revealed that the high molecular weight NSG (228.33 kDa) was significantly degraded to SGFs of 115.76, 3.79, and 3.19 kDa by hydrolysis with 0.4, 2, and 10% H2O2, respectively. The Fourier transformed spectroscopy (FTIR) and 1H- and 13C-Nuclear magnetic resonance (NMR) analyses demonstrated that the polysaccharide chain structure of SGFs was not affected by H2O2 degradation, but alterations were detected at the peak positions of some functional groups. In vitro study showed that SGFs significantly exerted a stronger antibacterial activity against V. parahaemolyticus and V. harveyi than NSG, which might be due to the low molecular weight and higher sulfation properties of SGF. SGF disrupted the bacterial cell membrane, resulting in leakage of intracellular biological components, and subsequently, cell death. Taken together, this study provides a basis for the exploitation and utilization of low-molecular-weight sulfated galactans from G. fisheri to prevent and control the shrimp pathogens.


Subject(s)
Gracilaria , Rhodophyta , Vibrio parahaemolyticus , Anti-Bacterial Agents/pharmacology , Galactans/chemistry , Galactans/pharmacology , Gracilaria/chemistry , Hydrogen Peroxide/pharmacology , Polysaccharides/pharmacology , Sulfates , Vibrio
11.
Foods ; 11(13)2022 Jun 21.
Article in English | MEDLINE | ID: mdl-35804637

ABSTRACT

The present study was undertaken to analyze the impact of germination (NBG) and hydrothermal cooking (NBHTC) on the nutritional profile and physicochemical, functional and microstructural properties of Nitta bean (Parkia timoriana) (NBR) seeds. Results demonstrated that the highest crude protein and fat content could be found in NBG and NBHTC, whereas the ash content was significantly higher in NBG. Compared to NBHTC and NBR, NBG has higher emulsion capacity and stability, with values determined to be 58.33 ± 1.67 and 63.89 ± 2.67, respectively. In addition, the highest color intensity was also reported for NBG, followed by NBHTC and NBR. Likewise, NBG showed complete gel formation at a lower concentration (12 g/100 mL) than NBR flour (18 g/100 mL). Furthermore, structural changes in the lipid, protein, and carbohydrate molecules of NBG and NBHTC were evidenced by FTIR studies. Morphological changes were noticed in different samples during microscopic observations subjected to germination and hydrothermal treatment. In contrast to NBR and NBHTC, NBG showed the highest total polyphenol content, ORAC antioxidant, and DPPH radical scavenging activity, which demonstrated the potential utilization of Nitta bean flour as a natural plant-based protein source in food security product formulations.

12.
Foods ; 11(20)2022 Oct 11.
Article in English | MEDLINE | ID: mdl-37430911

ABSTRACT

Whiteleg shrimp (Penaeus vannamei) have been vulnerable to the stress induced by different aquaculture operations such as capture, handling, and transportation. In this study, we developed a novel clove oil-nanostructured lipid carrier (CO-NLC) to enhance the water-soluble capability and improve its anesthetic potential in whiteleg shrimp. The physicochemical characteristics, stability, and drug release capacity were assessed in vitro. The anesthetic effect and biodistribution were fully investigated in the shrimp body as well as the acute multiple-dose toxicity study. The average particle size, polydispersity index, and zeta potential value of the CO-NLCs were 175 nm, 0.12, and -48.37 mV, respectively, with a spherical shape that was stable for up to 3 months of storage. The average encapsulation efficiency of the CO-NLCs was 88.55%. In addition, the CO-NLCs were able to release 20% of eugenol after 2 h, which was lower than the standard (STD)-CO. The CO-NLC at 50 ppm observed the lowest anesthesia (2.2 min), the fastest recovery time (3.3 min), and the most rapid clearance (30 min) in shrimp body biodistribution. The results suggest that the CO-NLC could be a potent alternative nanodelivery platform for increasing the anesthetic activity of clove oil in whiteleg shrimp (P. vannamei).

13.
Front Plant Sci ; 12: 747661, 2021.
Article in English | MEDLINE | ID: mdl-34745181

ABSTRACT

Ramularia collo-cygni is the causal agent of Ramularia leaf spot disease (RLS) on barley and became, during the recent decades, an increasing threat for farmers across the world. Here, we analyze morphological, transcriptional, and metabolic responses of two barley cultivars having contrasting tolerance to RLS, when infected by an aggressive or mild R. collo-cygni isolate. We found that fungal biomass in leaves of the two cultivars does not correlate with their tolerance to RLS, and both cultivars displayed cell wall reinforcement at the point of contact with the fungal hyphae. Comparative transcriptome analysis identified that the largest transcriptional differences between cultivars are at the early stages of fungal colonization with differential expression of kinases, calmodulins, and defense proteins. Weighted gene co-expression network analysis identified modules of co-expressed genes, and hub genes important for cultivar responses to the two R. collo-cygni isolates. Metabolite analyses of the same leaves identified defense compounds such as p-CHDA and serotonin, correlating with responses observed at transcriptome and morphological level. Together these all-round responses of barley to R. collo-cygni provide molecular tools for further development of genetic and physiological markers that may be tested for improving tolerance of barley to this fungal pathogen.

14.
Science ; 369(6504): 663-670, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32764065

ABSTRACT

Plants evolved lysine motif (LysM) receptors to recognize and parse microbial elicitors and drive intracellular signaling to limit or facilitate microbial colonization. We investigated how chitin and nodulation (Nod) factor receptors of Lotus japonicus initiate differential signaling of immunity or root nodule symbiosis. Two motifs in the LysM1 domains of these receptors determine specific recognition of ligands and discriminate between their in planta functions. These motifs define the ligand-binding site and make up the most structurally divergent regions in cognate Nod factor receptors. An adjacent motif modulates the specificity for Nod factor recognition and determines the selection of compatible rhizobial symbionts in legumes. We also identified how binding specificities in LysM receptors can be altered to facilitate Nod factor recognition and signaling from a chitin receptor, advancing the prospects of engineering rhizobial symbiosis into nonlegumes.


Subject(s)
Lotus/enzymology , Plant Proteins/chemistry , Protein Kinases/chemistry , Amino Acid Motifs , Chitin/chemistry , Ligands , Protein Domains
15.
Mol Plant Microbe Interact ; 32(2): 176-193, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30681911

ABSTRACT

Ramularia leaf spot disease (RLS), caused by the ascomycete fungus Ramularia collo-cygni, has emerged as a major economic disease of barley. No substantial resistance has been identified, so far, among barley genotypes and, based on the epidemiology of the disease, a quantitative genetic determinacy of RLS has been suggested. The relative contributions of barley and R. collo-cygni genetics to disease infection and epidemiology are practically unknown. Here, we present an integrated genome-wide analysis of host and pathogen transcriptome landscapes identified in a sensitive barley cultivar following infection by an aggressive R. collo-cygni isolate. We compared transcriptional responses in the infected and noninfected leaf samples in order to identify which molecular events are associated with RLS symptom development. We found a large proportion of R. collo-cygni genes to be expressed in planta and that many were also closely associated with the infection stage. The transition from surface to apoplastic colonization was associated with downregulation of cell wall-degrading genes and upregulation of nutrient uptake and resistance to oxidative stresses. Interestingly, the production of secondary metabolites was dynamically regulated within the fungus, indicating that R. collo-cygni produces a diverse panel of toxic compounds according to the infection stage. A defense response against R. collo-cygni was identified in barley at the early, asymptomatic infection and colonization stages. We found activation of ethylene signaling, jasmonic acid signaling, and phenylpropanoid and flavonoid pathways to be highly induced, indicative of a classical response to necrotrophic pathogens. Disease development was found to be associated with gene expression patterns similar to those found at the onset of leaf senescence, when nutrients, possibly, are used by the infecting fungus. These analyses, combining both barley and R. collo-cygni transcript profiles, demonstrate the activation of complex transcriptional programs in both organisms.


Subject(s)
Ascomycota , Hordeum , Host-Pathogen Interactions , Transcriptome , Ascomycota/genetics , Ascomycota/physiology , Hordeum/genetics , Hordeum/microbiology , Host-Pathogen Interactions/genetics
16.
Appl Biochem Biotechnol ; 184(2): 630-643, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28836237

ABSTRACT

With increasing demand for perfumes, flavors, beverages, and pharmaceuticals, the various associated industries are resorting to different approaches to enhance yields of desired compounds. The use of fixed-bed biocatalytic reactors in some of the processes for making fine chemicals will be of great value because the reaction times could be reduced substantially as well as high conversion and yields obtained. In the current study, a continuous-flow packed-bed reactor of immobilized Candida antarctica lipase B (Novozym 435) was employed for synthesis of various geraniol esters. Optimization of process parameters such as biocatalyst screening, effect of solvent, mole ratio, temperature and acyl donors was studied in a continuous-flow packed-bed reactor. Maximum conversion of ~ 87% of geranyl propionate was achieved in 15 min residence time at 70 °C using geraniol and propionic acid with a 1:1 mol ratio. Novozym 435 was found to be the most active and stable biocatalyst among all tested. Ternary complex mechanism with propionic acid inhibition was found to fit the data.


Subject(s)
Bioreactors , Enzymes, Immobilized/chemistry , Fungal Proteins/chemistry , Lipase/chemistry , Models, Chemical , Acyclic Monoterpenes , Propionates/chemistry , Terpenes/chemistry
17.
Plant J ; 91(3): 394-407, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28407380

ABSTRACT

Studies of protein N-glycosylation are important for answering fundamental questions on the diverse functions of glycoproteins in plant growth and development. Here we generated and characterised a comprehensive collection of Lotus japonicusLORE1 insertion mutants, each lacking the activity of one of the 12 enzymes required for normal N-glycan maturation in the glycosylation machinery. The inactivation of the individual genes resulted in altered N-glycan patterns as documented using mass spectrometry and glycan-recognising antibodies, indicating successful identification of null mutations in the target glyco-genes. For example, both mass spectrometry and immunoblotting experiments suggest that proteins derived from the α1,3-fucosyltransferase (Lj3fuct) mutant completely lacked α1,3-core fucosylation. Mass spectrometry also suggested that the Lotus japonicus convicilin 2 was one of the main glycoproteins undergoing differential expression/N-glycosylation in the mutants. Demonstrating the functional importance of glycosylation, reduced growth and seed production phenotypes were observed for the mutant plants lacking functional mannosidase I, N-acetylglucosaminyltransferase I, and α1,3-fucosyltransferase, even though the relative protein composition and abundance appeared unaffected. The strength of our N-glycosylation mutant platform is the broad spectrum of resulting glycoprotein profiles and altered physiological phenotypes that can be produced from single, double, triple and quadruple mutants. This platform will serve as a valuable tool for elucidating the functional role of protein N-glycosylation in plants. Furthermore, this technology can be used to generate stable plant mutant lines for biopharmaceutical production of glycoproteins displaying relative homogeneous and mammalian-like N-glycosylation features.


Subject(s)
Glycoproteins/isolation & purification , Lotus/genetics , Lotus/metabolism , Plant Proteins/metabolism , Polysaccharides/metabolism , Glycoproteins/genetics , Glycosylation , N-Acetylglucosaminyltransferases/genetics , N-Acetylglucosaminyltransferases/metabolism , Plant Proteins/genetics
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