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Ng, S. B.

Publications and source records attributed to Ng, S. B..

5 recordsLinked to original sources

Sustainable biotransformation of microalgae via probiotic fermentation for enhanced functional, nutritional, and sensory properties

Microalgae represent a sustainable food source with exceptional CO{square} fixation efficiency; however, their integration into the food chain is hindered by undesirable organoleptic properties. This study establishes a green biotransformation platform using Generally Recognized As Safe (GRAS) bacterium Lactiplantibacillus plantarum to ferment Chlorella vulgaris biomass. This fermentation process operates without the use of harsh chemicals and organic solvents, enabling the full utilization of the biomass while improving sensory quality. Notably, the L. plantarum fermentation maintained dried biomass weight, in contrast to [~]15-40% loss seen with Bacillus spp., further enhancing the carbon-negative profile of microalgae. Tiered olfactory analysis and gas chromatography-mass spectrometry revealed selective reduction of polyunsaturated fatty acid-derived aldehydes and accumulation of flavor-active volatiles, including pyrazines and phenylethyl derivatives. Electronic tongue and liquid chromatography-mass spectrometry confirmed elevated umami taste, via increased glutamate and nucleotide levels. Additionally, the fermentation of microalgae with L. plantarum converted aromatic amino acids into antioxidant aromatic lactates, exemplifying catalytic, rather than stoichiometric efficiency. Overall, this renewable fermentation strategy converts photoenergy-fuelled, CO{square}-derived microalgal biomass into direct functional food ingredients under mild, organic solvent-free conditions, while bypassing conventional downstream extraction and purification steps. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/670464v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@951462org.highwire.dtl.DTLVardef@16d542forg.highwire.dtl.DTLVardef@b1da64org.highwire.dtl.DTLVardef@78f435_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Cost-effective hybrid long-short read assembly delineates alternative GC-rich Streptomyces chassis for natural product discovery

With the advent of rapid automated in silico identification of biosynthetic gene clusters (BGCs), genomics presents vast opportunities to accelerate natural product (NP) discovery. However, prolific NP producers, Streptomyces, are exceptionally GC-rich (>80%) and highly repetitive within BGCs. These pose challenges in sequencing and high-quality genome assembly which are currently circumvented via intensive sequencing. Here, we outline a more cost-effective workflow using multiplex Illumina and Oxford Nanopore sequencing with hybrid long-short read assembly algorithms to generate high quality genomes. Our protocol involves subjecting long read-derived assemblies to up to 4 rounds of polishing with short reads to yield accurate BGC predictions. We successfully sequenced and assembled 8 GC-rich Streptomyces genomes whose lengths range from 7.1 to 12.1 Mb at an average N50 of 5.9 Mb. Taxonomic analysis revealed previous misrepresentation among these strains and allowed us to propose a potentially new species, Streptomyces sydneybrenneri. Further comprehensive characterization of their biosynthetic, pan-genomic and antibiotic resistance features especially for molecules derived from type I polyketide synthase (PKS) BGCs reflected their potential as NP chassis. Thus, the genome assemblies and insights presented here are envisioned to serve as gateway for the scientific community to expand their avenues in NP discovery. Graphic abstractSchematic of hybrid long- and short read assembly workflow for genome sequencing of GC-rich Streptomyces. Boxes shaded blue and grey correspond to experimental and in silico workflows, respectively. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/519232v2_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1395af0org.highwire.dtl.DTLVardef@81798forg.highwire.dtl.DTLVardef@539c92org.highwire.dtl.DTLVardef@14c366f_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIA cost-effective genome sequencing approach for GC-rich Streptomyces is presented C_LIO_LIHybrid assembly improves BGC annotation and identification C_LIO_LIA new species, Streptomyces sydneybrenneri, identified by taxonomic analysis C_LIO_LIGenomes of 8 Streptomyces species are reported and analysed in this study C_LI

genomics↗

Application of Cas12j for Streptomyces editing and cluster activation

In recent years, CRISPR-Cas toolboxes for Streptomyces editing have rapidly accelerated natural product discovery and engineering. However, Cas efficiencies are also oftentimes strain dependent, subsequently a variety of Cas proteins would allow for flexibility and enable genetic manipulation within a wider range of Streptomyces strains. In this work, we have further expanded the Cas toolbox by presenting the first example of Cas12j mediated editing in Streptomyces sp. A34053. In our study, we have also observed significantly improved editing efficiencies with Acidaminococcus sp. Cas12j compared to Cas12a, Francisella tularensis subsp. novicida U112s type V-A Cas (FnCpf1).

microbiology↗

Heatrich-BS enables efficient CpG enrichment and highly scalable cell-free DNA methylation profiling

Genome wide analysis of cell-free DNA (cfDNA) methylation profile has been shown to be a promising approach for sensitive and specific multi-cancer detection. However, scaling these assays for clinical translation is impractical due to the high cost of whole genome bisulfite sequencing. We showed that the small fraction of GC-rich genome is highly enriched in CpG sites and disproportionately harbored the majority of cancer-specific methylation signature. Here, we report on the simple but effective Heat enrichment of CpG-rich regions for Bisulfite Sequencing (Heatrich-BS) platform that enables focused methylation profiling in these highly informative regions. Our novel method and bioinformatics algorithm enable high accuracy and sensitivity in tumor burden estimation and quantitative monitoring of colorectal patient response to treatment, at much reduced sequencing requirement. Heatrich-BS holds great potential for highly scalable screening and regular monitoring of cancer using liquid biopsy.

genomics↗

Liquid biopsy in gastrointestinal stromal tumors -- Simultaneous detection of primary and secondary mutations with an NGS based circulating tumor DNA assay

Introduction Introduction Methods Results Discussion References Gastrointestinal Stromal tumors (GISTs) are the most common neoplasms of mesenchymal origin arising from the gastrointestinal tract. GISTs are mostly characterised by one predominant activating mutation in KIT (KIT proto-oncogene receptor tyrosine kinase) or PDGFRA (platelet derived growth factor receptor alpha) genes1-3. Under pharmacological pressure, one or more secondary mutations can develop in KIT, conferring resistance to tyrosine kinase inhibitor, imatinib. In imatinib-resistant GISTs, secondary mutations can occur in the ATP binding pocket, encoded by exons 13 and 14 or in the kinase activation loop, encoded predominantly by exon 174. In vitro studies ha ...

molecular biology↗