Different Combinations of Nitrogen and Carbon Sources Influence the Growth and Postbiotic Metabolite Characteristics of Strains Isolated from Malaysian Foods.

Postbiotic metabolites produced by strains isolated from Malaysian food have been extensively reported for their positive effects on health. Understanding the effects of different combinations of carbon and nitrogen sources on the growth and corresponding characteristics of postbiotic metabolites produced by different strains of is important for various applications. Hence, the effects of different combinations of carbon (glucose, lactose, sucrose and dextrose) and nitrogen (X-SEED Kat, X-SEED Peptone, X-SEED Nucleo Advanced, Nucel875 MG, FM888 and FM902) sources on the growth of six strains of (RG11, RG14, RI11, RS5, TL1 and UL4) and the functional characteristics (bacteriocin inhibitory activity, antioxidant activity and lactic acid concentration) of their respective postbiotic metabolites were investigated in this study.

Development of a recombinant non-replicating Newcastle disease virus.

Development of nr-NDV.Reverse transfection was applied for the recovery of nr-NDV.Propagation of nr-NDV was done by sub-passaging transfected BSR T7/5 cells.

Development of optimized functional clove fortified probiotic yoghurt.

We focused on assessing the antimicrobial effects of functional yoghurts supplemented with clove and probiotics. The formulation of aqueous clove extract (ACE) incorporated with probiotic yoghurt (, and ) was optimised in terms of aqueous clove extract concentrations (2.5-7.

Effect of Domain Manipulation in the Staphylococcal Phage Endolysin, Endo88, on Lytic Efficiency and Host Range.

The bacteriophage endolysin Endo88 targeting Staphylococcus aureus PS88 consists of the CHAP and Amidase-2 enzymatic domains and one SH3b targeting domain. In this study, the effects of domain manipulations on Endo88 functionality were determined. Three truncated mutants of Endo88 (CHAP, CHAPAmidase and CHAPSH3) and two chimeras (CHAPAmidase-Cpl7Cpl7 and Endo88-Cpl7Cpl7) containing the Cpl7Cpl7 targeting domains of the streptococcal LambdaSa2-ECC endolysin were cloned in E.

Genome mining of Lactiplantibacillus plantarum PA21: insights into its antimicrobial potential.

Background: The dramatic increase of antimicrobial resistance in the healthcare realm has become inexorably linked to the abuse of antibiotics over the years. Therefore, this study seeks to identify potential postbiotic metabolites derived from lactic acid bacteria such as Lactiplantibacillus plantarum that could exhibit antimicrobial properties against multi-drug resistant pathogens.

Results: In the present work, the genome sequence of Lactiplantibacillus plantarum PA21 consisting of three contigs was assembled to a size of 3,218,706 bp.

Comprehensive Characterization of a Phage Isolated from a Tilapia Farm in Selangor, Malaysia, and Its Potential for Phage Therapy.

The outbreak in tilapia has caused huge losses in the aquaculture industry worldwide. In Malaysia, several studies have reported the isolation of , but no study has reported the isolation of phages from tilapia or from the culture pond. Here, the isolation of the phage from infected tilapia is reported and it is named as vB_Sags-UPM1.

Effect of Secretion Efficiency of Mutant KRAS Neoantigen by on the Immune Response of a Mucosal Vaccine Delivery Vehicle Targeting Colorectal Cancer.

Colorectal cancer (CRC) is often caused by mutations in the KRAS oncogene, making KRAS neoantigens a promising vaccine candidate for immunotherapy. Secreting KRAS antigens using live Generally Recognized as Safe (GRAS) vaccine delivery hosts such as is deemed to be an effective strategy in inducing specific desired responses. Recently, through the engineering of a novel signal peptide SPK1 from an optimized secretion system was developed in the NZ9000 host.

Effects of Individual and Combined Fermentation Factors on Antimicrobial Activity of Nisin by Lactococcus lactis ATCC 11454.

There is an increasing demand for natural food preservatives due to consumers' concern on the negative effects of chemical preservatives in food products. Nisin (bacteriocin) is an effective food biopreservative that has been approved globally. However, its low yield proves to be a limiting factor and must be addressed to meet the increasingly high demand from the food industry.

Optimization of Signal Peptide via Site-Directed Mutagenesis for Enhanced Secretion of Heterologous Proteins in .

Secretion efficiency of heterologous proteins in the Generally Regarded As Safe (GRAS) is often reported to be insufficiently low due to limitations such as poor targeting and translocation by the signal peptide or degradation by the host proteases. In this study, the secretion efficiency in the host was enhanced through the utilization of a heterologous signal peptide (SP) SPK1 of . The SPK1 was subjected to site-directed mutations targeting its tripartite N-, H-, and C-domains, and the effect on secretion efficiency as compared to the wild-type SPK1 and native lactococcal USP45 was determined on a reporter nuclease (NUC) of .

Endolysins against Streptococci as an antibiotic alternative.

Multi-drug resistance has called for a race to uncover alternatives to existing antibiotics. Phage therapy is one of the explored alternatives, including the use of endolysins, which are phage-encoded peptidoglycan hydrolases responsible for bacterial lysis. Endolysins have been extensively researched in different fields, including medicine, food, and agricultural applications.

secreting phage lysins as a potential antimicrobial against multi-drug resistant .

Background: is an opportunistic Gram-positive bacterium that can form biofilm and become resistant to many types of antibiotics. The treatment of multi-drug resistant (MDRSA) infection is difficult since it possesses multiple antibiotic-resistant mechanisms. Endolysin and virion-associated peptidoglycan hydrolases (VAPGH) enzymes from bacteriophage have been identified as potential alternative antimicrobial agents.

Kinetic studies and homology modeling of a dual-substrate linalool/nerolidol synthase from Plectranthus amboinicus.

Linalool and nerolidol are terpene alcohols that occur naturally in many aromatic plants and are commonly used in food and cosmetic industries as flavors and fragrances. In plants, linalool and nerolidol are biosynthesized as a result of respective linalool synthase and nerolidol synthase, or a single linalool/nerolidol synthase. In our previous work, we have isolated a linalool/nerolidol synthase (designated as PamTps1) from a local herbal plant, Plectranthus amboinicus, and successfully demonstrated the production of linalool and nerolidol in an Escherichia coli system.

Development of a single-chain fragment variable fused-mutant HALT-1 recombinant immunotoxin against G12V mutated olorectal cancer cells.

Background: oncogenes harboring codon G12 and G13 substitutions are considered gatekeeper mutations which drive oncogenesis in many cancers. To date, there are still no target-specific vaccines or drugs available against this genotype, thus reinforcing the need towards the development of targeted therapies such as immunotoxins.

Methods: This study aims to develop a recombinant anti-m scFv-fused mutant actinoporin-like-toxin-1 (mHALT-1) immunotoxin that is capable of recognizing and eradicating codon-12 mutated k-ras antigen abnormal cells.

K-Ras Peptide Mimotope Induces Antigen Specific Th1 and B-Cell Immune Responses against G12A-Mutated K-Ras Antigen in Balb/c Mice.

G12A somatic point mutation in adenocarcinomas is categorized clinically as ineligibility criteria for anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapies. In this study, a modified G12A-K-ras epitope (139A) with sequence-specific modifications to improve immunogenicity was developed as a potential vaccine against G12A-mutant cancers. Additionally, coupling of the 139A epitope with a tetanus toxoid (TTD) universal T-cell epitope to improve antigenicity was also reported.

Development of a T7 RNA polymerase expressing cell line using lentivirus vectors for the recovery of recombinant Newcastle disease virus.

The development of a T7 RNA polymerase (T7 RNAP) expressing cell line i.e. BSR T7/5 cells marks an improvement of reverse genetics for the recovery of recombinant Newcastle disease virus (rNDV).

Anti-cancer and anti-inflammatory effects elicited by short chain fatty acids produced by Escherichia coli isolated from healthy human gut microbiota.

Background: Extracellular metabolites of short chain fatty acids (SCFA) excreted by gut microbiota have been reported to play an important role in the regulation of intestinal homeostasis. Apart from supplying energy, SCFA also elicit immune stimulation in animal and human cells. Therefore, an attempt was conducted to isolate SCFA producing bacteria from healthy human microbiota.

Klebsiella virus UPM2146 lyses multiple drug-resistant Klebsiella pneumoniae in vitro and in vivo.

Klebsiella pneumoniae are opportunistic bacteria found in the gut. In recent years they have been associated with nosocomial infections. The increased incidence of multiple drug-resistant K.

Functional characterization of a new terpene synthase from Plectranthus amboinicus.

Plectranthus amboinicus (Lour.) Spreng is an aromatic medicinal herb known for its therapeutic and nutritional properties attributed by the presence of monoterpene and sesquiterpene compounds. Up until now, research on terpenoid biosynthesis has focused on a few mint species with economic importance such as thyme and oregano, yet the terpene synthases responsible for monoterpene production in P.

Promising discovery of beneficial in the human gut.

Ingested dietary fibres are hydrolysed by colon microbiota to produce energy-providing short-chain fatty acids (SCFA) that stimulate anti-inflammatory effects. SCFA-producing bacteria were screened from bacteria isolated from human faeces using bromothymol blue as an acid indicator and gas chromatography for SCFA profiling. The beneficial functions (antagonistic activity, haemolytic activities, antibiotic susceptibility, mucus adherent percentage and toxin gene detection) were evaluated for the top five SCFA-producing bacteria isolated from three healthy volunteers that identified as strains.

Effects of lysine and methionine in a low crude protein diet on the growth performance and gene expression of immunity genes in broilers.

Globally, the poultry industry is 1 of the most advanced livestock industries. Feed contributes to the biggest proportion (65-70%) of the production cost. Most feed ingredients in Malaysia are imported, which contributes to the high food bill annually, and alternative feed formulation may help decrease the cost of poultry feed.

Secretion of recombinant xylanase in Lactococcus lactis using signal peptides Usp45 and Spk1.

Objective: The effect of two signal peptides, namely Usp45 and Spk1 on the secretion of xylanase in Lactococcus lactis was analysed.

Results: Xylanase was successfully expressed in Lactococcus lactis. Recombinant xylanase fused to either signal peptide Usp45 or Spk1 showed halo zone on Remazol Brilliant Blue-Xylan plates.

An improved method for the rescue of recombinant Newcastle disease virus.

Reverse genetics has been used to generate recombinant Newcastle disease virus with enhanced immunogenic properties for vaccine development. The system, which involves co-transfecting the viral antigenomic plasmid with three helper plasmids into a T7 RNA polymerase-expressing cell to produce viral progenies, poses a great challenge. We have modified the standard transfection method to improve the transfection efficiency of the plasmids, resulting in a higher titer of virus progeny production.

Engineering integrative vectors based on phage site-specific recombination mechanism for Lactococcus lactis.

Background: Site-specific integration system allows foreign DNA to be integrated into the specific site of the host genome, enabling stable expression of heterologous protein. In this study, integrative vectors for secretion and surface display of proteins were constructed based on a lactococcal phage TP901-1 integrating system.

Results: The constructed integration system comprises of a lactococcal promoter (P or P), phage attachment site (attP) from bacteriophage TP901-1, a signal peptide (USP45 or SPK1) for translocation of the target protein, and a PrtP anchor domain in the case of the integrative vectors for surface display.

Terpene Derivatives as a Potential Agent against Antimicrobial Resistance (AMR) Pathogens.

The evolution of antimicrobial resistance (AMR) in pathogens has prompted extensive research to find alternative therapeutics. Plants rich with natural secondary metabolites are one of the go-to reservoirs for discovery of potential resources to alleviate this problem. Terpenes and their derivatives comprising of hydrocarbons, are usually found in essential oils (EOs).