In vitro fermentability of xylo-oligosaccharide and xylo-polysaccharide fractions with different molecular weights by human faecal bacteria

Xylo-oligosaccharides and xylo-polysaccharides (XOS, XPS) produced by autohydrolysis of the fibre from oil palm empty fruit bunches (OPEFB) were purified using gel filtration chromatography to separate the XOS and XPS from the crude autohydrolysis liquor. Six mixed fractions of refined XOS and XPS with average degree of polymerisation (avDP) of 4-64 were obtained. These were characterised in terms of their composition and size by HPLC, MALDI-ToF-MS (selected fractions) and carbohydrate gel electrophoresis (PACE). They were assessed in batch culture fermentations using faecal inocula to determine their ability to modulate the human faecal microbiota in vitro by measuring the bacterial growth, organic acid production and the XOS assimilation profile. The gut microbiota was able to utilise all the substrates and there was a link between the XOS/XPS degree of polymerisation with the fermentation properties. In general, XOS/XPS preparations of lower avDP promote better Bifidobacterium growth and organic acid production

Expression profiles of putative defence-related proteins in oil palm (Elaeis guineensis) colonized by Ganoderma boninense.

Basal stem rot (BSR) is a major disease of oil palm caused by a pathogenic fungus, Ganoderma boninense. However, the interaction between the host plant and its pathogen is not well characterized. To better understand the response of oil palm to G. boninense, transcript profiles of eleven putative defence-related genes from oil palm were measured by quantitative reverse-transcription (qRT)-PCR in the roots of oil palms treated with G. boninense from 3 to 12 weeks post infection (wpi). These transcripts encode putative Bowman-Birk serine protease inhibitors (EgBBI1 and 2), defensin (EgDFS), dehydrin (EgDHN), early methionine-labeled polypeptides (EgEMLP1 and 2), glycine-rich RNA binding protein (EgGRRBP), isoflavone reductase (EgIFR), metallothionein-like protein (EgMT), pathogenesis-related-1 protein (EgPRP), and type 2 ribosome-inactivating protein (EgT2RIP). The transcript abundance of EgBBI2 increased in G. boninense-treated roots at 3 and 6. wpi compared to those of controls; while the transcript abundance of EgBBI1, EgDFS, EgEMLP1, EgMT, and EgT2RIP increased in G. boninense-treated roots at 6 or 12. wpi. Meanwhile, the gene expression of EgDHN was up-regulated at all three time points in G. boninense-treated roots. The expression profiles of the eleven transcripts were also studied in leaf samples upon inoculation of G. boninense and Trichoderma harzianum to identify potential biomarkers for early detection of BSR. Two candidate genes (EgEMLP1 and EgMT) that have different profiles in G. boninense-treated leaves compared to those infected by T. harzianum may have the potential to be developed as biomarkers for early detection of G. boninense infection

Effect of Garlic and Turmeric Powders on In Vitro Digestibility of the Cooked Rice

Consumers nowadays are interested in foods with low glycemic index (GI) and high indigestible carbohydrate content. In Asia, white rice is the staple food and is generally considered as a readily digestible and high GI food. Occasionally, white rice is cooked by mixing with other ingredients such as herbs and spices. This study is carried out to determine the total phenolic content and the effect of in vitro digestibility on cooked white rice with added garlic and turmeric powders. Rice cooked with addition of turmeric powder (3 % w/w) showed the highest total phenolic content (92.02 mg GAE/100 g) among all the cooked rice samples. The effect of incorporating garlic powder (3 % w/w) and turmeric powder (3 % w/w) into the rice preparation was determined using an in vitro digestion protocol. Results show that by incorporating either garlic or turmeric powder into the rice, starch digestibility was significantly reduced. Rice with added turmeric powder showed a greater reduction in digestibility with significantly lower fraction of rapidly digestible starch (41.5 %; white rice 57.6 %) beside higher fraction of slowly digestible starch (36.1 %; white rice 28.4 %) and resistant starch fraction (22.6 %; white rice 14%). Overall, both spices were able to inhibit starch digestion which can be considered as a potential ingredient in lowering starch digestibility in the cooked rice

Profiling the differentially expressed genes in two rice varieties during rapid grain-filling stages

Grain filling is an important agronomic trait, which directly affects the final yield of rice. Partially filled and empty rice grains are among the factors that limit the yield of MR219, one of the highest yielding rice varieties in Malaysia. In this study, the NSF 20 K rice oligonucleotide array, which contains 20,000 70-mer oligonucleotide probes, was used for direct comparison of the transcriptomes of MR219 and MR84 (a rice variety that has higher percentage of filled grains compared to MR219), during rapid grain-filling period at 5 and 10 days after fertilization (DAF). A total of 155 and 233 genes were differentially expressed in MR219 compared to MR84 at 5 and 10 DAF, respectively; and 9 of these expression ratios were tested using quantitative real-time RT PCR. Among the differentially expressed genes identified were those encoding hexokinase, various sugar transporters, GSDL-like lipase/acylhydrolase, brassinosteroid-insensitive 1-associated receptor kinase 1 precursor and homeobox protein GLABRA2, which were analyzed by real-time RT PCR in this study. The differences demonstrated by these genes in their transcript levels and profiles, between the two rice varieties understudied at different stages of grain filling may contribute to the formulation of hypotheses toward the understanding of poor percentage of filled grains in MR219

Sequence analysis and gene expression of putative oil palm chitinase and chitinase-like proteins in response to colonization of Ganoderma boninense and Trichoderma harzianum

Chitinases are glycosyl hydrolases that cleave the β-1,4-glycosidic linkages between N-acetylglucosamine residues in chitin which is a major component of fungal cell wall. Plant chitinases hydrolyze fungal chitin to chitin oligosaccharides that serve as elicitors of plant defense system against fungal pathogens. However, plants synthesize many chitinase isozymes and some of them are not pathogenesis-related. In this study, three full-length cDNA sequences encoding a putative chitinase (EgChit3-1) and two chitinase-like proteins (EgChit1-1 and EgChit5-1) have been cloned from oil palm (Elaeis guineensis) by polymerase chain reaction (PCR). The abundance of these transcripts in the roots and leaves of oil palm seedlings treated with Ganoderma boninense (a fungal pathogen) or Trichoderma harzianum (an avirulent symbiont), and a combination of both fungi at 3, 6 and 12 weeks post infection were profiled by real time quantitative reverse-transcription (qRT)-PCR. Our findings showed that the gene expression of EgChit3-1 increased significantly in the roots of oil palm seedlings treated with either G. boninense or T. harzianum and a combination of both; whereas the gene expression of EgChit1-1 in the treated roots of oil palm seedlings was not significantly higher compared to those of the untreated oil palm roots. The gene expression of EgChit5-1 was only higher in the roots of oil palm seedlings treated with T. harzianum compared to those of the untreated oil palm roots. In addition, the gene expression of EgChit1-1 and EgChit3-1 showed a significantly higher gene expression in the leaf samples of oil palm seedlings treated with either G. boninense or T. harzianum

Identification of overexpressed cytokines as serum biomarkers of hepatitis C virus-induced liver fibrosis using bead-based flexible multiple analyte profiling

Hepatic inflammation is the stimulator to activate hepatic stellate cells (HSCs) and triggers fibrogenesis. Cytokines are produced during liver inflammation and maybe considered as liver fibrosis biomarker. The aim of this study was to investigate whether cytokines can be used as reliable biomarkers of liver fibrosis using flexible multi-analyte profiling (xMAP). A total of 61 chronic hepatitis C patients with different severity of liver fibrosis were enrolled. Liver biopsy was used as standard to assess the severity of fibrosis according to METAVIR classification. Afterward, 15 samples from healthy controls were analyzed and totally 50 cytokines were screened using flexible multi-analyte profiling to discover differential biomarkers. Finally, levels of protein expressions of individual stages of liver fibrosis were measured. In histological examination, the necroinflammatory score (histology activity index, HAI) was increased from F1 to F4 stage in hepatitis C virus (HCV) infected patients, indicating that inflammation was accompanied with the progression of liver fibrosis. Using flexible multi-analyte profiling, four serum cytokines, including IFN-α2 (p=0.023), GRO-α (p=0.013), SCF (p=0.047) and SDF-1α p=0.024), were identified under antibody specific recognition and elevated with HAI score. This study reveals the relationship between cytokines and liver fibrosis, and demonstrated that IFN-α2, GRO-α, SCF and SDF-1 α may be used as biomarkers to predict liver fibrosis. The overexpressed cytokines may play a role in the progression of liver fibrosis and deserves further investigation.Keywords: Cytokine, flexible multi-analyte profiling, hepatitis C virus, liver fibrosisAfrican Journal of Biotechnology Vol. 11(29), pp. 7535-7541, 29 April, 201

Transcriptional response of oil palm (Elaeis guineensis Jacq.) inoculated simultaneously with both Ganoderma boninense and Trichoderma harzianum

Application of beneficial microbes offers an environmentally friendly alternative for mitigation of basal stem rot (BSR) disease in oil palm. However, the biocontrol mechanisms of Trichoderma against the pathogenic Ganoderma spp. which cause BSR are largely unknown at the molecular level. To identify the transcripts involved during induced systemic resistance (ISR), we analyzed the root transcriptomes of oil palm seedlings inoculated simultaneously with both G. boninense and T. harzianum, and un-inoculated oil palm seedlings, as well as those that were inoculated with either pathogenic or beneficial fungi. Our analyses revealed that the biocontrol mechanisms of T. harzianum against G. boninense involve modulation of genes related to biosynthesis of phytohormones (ethylene, MeJA and MeSA), antioxidant (l-ascorbate and myo-inositol) and unique secondary metabolites such as momilactone, cell wall metabolisms, and detoxification of phytotoxic compounds; in addition to its role as a biofertilizer which improves nutritional status of host plant. The outcomes of this study have fueled our understanding on the biocontrol mechanisms involving T. harizianum against G. boninense infection in oil palm roots

Enzymatic synthesis of polyphenol glycosides catalyzed by transglycosylation reaction of cyclodextrin glucanotransferase derived from Trichoderma viride

Present study was conducted to evaluate the ability of Trichoderma viride as a source of cyclodextrin glucanotransferase that has shown transglycosylation activity in the presence of polyphenolic constituents extracted from Moringa oleifera leaves as its acceptor and wheat flour as its substrate to catalyze synthesis of polyphenolic glycosides as transglycosylation (transfer) reaction products. The enzymatic synthesized polyphenolic glycosides were then purified using octa-dodecyl-functionalized silica gel column chromatography prior to analysis using thin layer chromatography and high performance liquid chromatography and identified using nuclear magnetic resonance (NMR) spectroscopy. The high performance liquid chromatogram performed that the isolated transglycosylation products had retention times and concentration at 1.446 min (0.0017 mg/ml), 1.431 min (0.14 mg/ml), and 1.474 min (0.012 mg/ml), respectively, compared to the retention time of arbutin (1.474 min) that was applied as authentic standard for polyphenol glycoside. Moreover, observation using 1H NMR as well as 13C NMR showed that structures of the transglycosylation products were identified as gallic acid-4-O-β-glucopyranoside, ellagicacid-4-O-β-glucopyranoside, and catechin-4′-O-glucopyranoside, respectively

Lignocellulosic saccharification by a newly isolated bacterium, Ruminiclostridium thermocellum M3 and cellular cellulase activities for high ratio of glucose to cellobiose

Background: Lignocellulosic biomass is one of earth's most abundant resources, and it has great potential for biofuel production because it is renewable and has carbon-neutral characteristics. Lignocellulose is mainly composed of carbohydrate polymers (cellulose and hemicellulose), which contain approximately 75 % fermentable sugars for biofuel fermentation. However, saccharification by cellulases is always the main bottleneck for commercialization. Compared with the enzyme systems of fungi, bacteria have evolved distinct systems to directly degrade lignocellulose. However, most reported bacterial saccharification is not efficient enough without help from additional β-glucosidases. Thus, to enhance the economic feasibility of using lignocellulosic biomass for biofuel production, it will be extremely important to develop a novel bacterial saccharification system that does not require the addition of β-glucosidases. Results: In this study, a new thermophilic bacterium named Ruminiclostridium thermocellum M3, which could directly saccharify lignocellulosic biomass, was isolated from horse manure. The results showed that R. thermocellum M3 can grow at 60 °C on a variety of carbon polymers, including microcrystalline cellulose, filter paper, and xylan. Upon utilization of these substrates, R. thermocellum M3 achieved an oligosaccharide yield of 481.5 ± 16.0 mg/g Avicel, and a cellular β-glucosidase activity of up to 0.38 U/mL, which is accompanied by a high proportion (approximately 97 %) of glucose during the saccharification. R. thermocellum M3 also showed potential in degrading natural lignocellulosic biomass, without additional pretreatment, to oligosaccharides, and the oligosaccharide yields using poplar sawdust, corn cobs, rice straw, and cornstalks were 52.7 ± 2.77, 77.8 ± 5.9, 89.4 ± 9.3, and 107.8 ± 5.88 mg/g, respectively. Conclusions: The newly isolated strain R. thermocellum M3 degraded lignocellulose and accumulated oligosaccharides. R. thermocellum M3 saccharified lignocellulosic feedstock without the need to add β-glucosidases or control the pH, and the high proportion of glucose production distinguishes it from all other known monocultures of cellulolytic bacteria. R. thermocellum M3 is a potential candidate for lignocellulose saccharification, and it is a valuable choice for the refinement of bioproducts