Shiau Pin Tan

• PhD
• Project Manager at Waterford Institute of Technology

Recently, there has been emphasis on the need to shift away from the use of synthetic chemical herbicides to low risk alternatives derived from natural sources. This is aimed at lowering or averting the negative impact synthetic herbicides have on the environment and to deal with the emergence of weed species becoming resistant to these chemicals....

Synthetic chemical herbicides available to farmers and foresters are known to be hazardous, and their overuse, without possible alternatives, have resulted in some weed species developing resistance. Therefore, seaweed species were explored due to their known bioactive capability to see if they would potentially be effective as an alternative, nove...

Biosecurity is emerging as one of the most important issues facing the agricultural and forestry communities, with the use of chemical pesticides being the main protocol for controlling plant pathogens. However, as a result of the emergence of resistance against these controls and the negative impact chemicals have on the environment, coupled with...

Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search for novel antimicrobial compounds. Naturally sourced bioactives, for instance those from seaweeds, have the potential to ameliorate this issue. As such, solvent extracts from the edible Irish seaweeds Fucus serratus and Fucus vesiculosus were screened...

Chemical pesticides have a major impact on biological diversity, alongside habitat loss and climate change with the need to replace the use of these hazardous chemicals with ecologically sound alternatives. Four seaweed species collected along the southeast coast of Ireland were tested against nine plant pathogens using the disk diffusion assay. Th...

Extremely high volatile fatty acids (VFAs) and ammonia concentrations can accumulate during dry co-digestion of organic wastes, which may inactivate pathogenic microorganisms. In this study, inactivation of Salmonella during dry co-digestion of pig manure (PM) and food waste (FW), which are both reservoirs of zoonotic pathogens, was examined. The e...

Olive processing wastewaters (OPW), namely olive mill wastewater (OMW) and table-olive wastewaters (TOW) were evaluated for their antibacterial activity against five Gram-positive and two Gram-negative bacteria using the standard disc diffusion and thin layer chromatography (TLC)-bioautography assays. Disc diffusion screening and bioautography of O...

HPLC and MS chromatogram of OMW samples. (PDF)

TLC data of OMW1 phenolic extract using different solvent ratios. (PDF)

Summary results of the possible polyphenols from different olive processing wastewaters extracts as identified by HPLC analysis. (PDF)

Antibacterial activity of OMW phenolic extracts (1mg/disc). Diameter of zone of inhibition (mm) including diameter of 6 mm disc; Results quoted as the average of a minimum of six measurements ± standard deviation; “-”indicates no visible zone of inhibition. PC: positive control; NC: negative control; OMW1: phenolic extract of OMW from semi-modern t...

Photographs of the developed TLC bioautography plates (4:6, v/v Hexane: Acetone). (a) overlaid with seeded molten agar (10 μL of OMW1 at 100 mg/mL) and (b) sprayed with an overnight culture of S. aureus (10 μL of OMW1 at 10 mg/l and 10 μL of GTOW at 50 mg/mL). OMW1: olive mill wastewater from a semi-modern process, GTOW: green table-olive wastewate...

Six antimicrobial-producing seaweed-derived Bacillus strains were evaluated in vitro as animal probiotics, in comparison to two Bacillus from an EU-authorized animal probiotic product. Antimicrobial activity was demonstrated on solid media against porcine Salmonella and E. coli. The marine isolates were most active against the latter, had better ac...

Forty eight individual pigs (8.7±0.26 kg) weaned at 28±1 d of age were used in a 22-d study to evaluate the effect of oral administration of a Bacillus pumilus spore suspension on growth performance and health indicators. Treatments (n = 16) were: (1) non-medicated diet; (2) medicated diet with apramycin (200 mg/kg) and pharmacological levels of zi...

Seaweeds are known to contain a range of bioactive compounds, including ones with antimicrobial activity. Some studies have succeeded in isolating, purifying, and identifying seaweed-derived antimicrobial compounds. Although this is a challenging process, it is crucial if a compound is to be exploited commercially. This chapter reviews the differen...

The objective of this study was to develop a novel antimicrobial seaweed wound dressing. The seaweed extract was active against nine clinically-relevant wound pathogens. A hydrogel formulation was prepared using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), followed by addition of 1% seaweed extract. The antimicrobial properties of the no...

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The objectives of this study were (1) to assess the bacteriocinogenic potential of bacteria derived mainly from seaweed, but also sand and seawater, (2) to identify at least some of the bacteriocins produced, if any and (3) to determine if they are unique to the marine environment and/or novel. Fifteen Bacillus licheniformis or pumilus isolates wit...

Chlorogenic acid (CGA) or 5-caffeoylquinic acid, was found to be the dominant phenolic compound in leaves of Etlingera elatior (Zingiberaceae). The CGA content of E. elatior leaves was significantly higher than flowers of Lonicera japonica (honeysuckle), the commercial source. In this study, a protocol to produce a standardised herbal CGA extract f...

This study aimed to optimize an extraction and separation procedure to obtain a concentrated fraction with antibacterial activity from the macroalga Ulva lactuca. Antibacterial compounds were extracted using eight solvents, and consistent activity against Staphylococcus aureus, Bacillus subtilis and methicillin-resistant (MR) S. aureus was observed...

Leaf extracts of five medicinal ferns, Acrostichum aureum L. (Pteridaceae), Asplenium nidus L. (Aspleniaceae), Blechnum orientale L. (Blechnaceae), Cibotium barometz (L.) J. Sm. (Cyatheaceae) and Dicranopteris linearis (Burm.) underwood var. linearis (Gleicheniaceae), were investigated for their total phenolic content (TPC), and antioxidative, tyro...

3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid (chlorogenic acid), and 5-O-caffeoylquinic acid methyl ester, as elucidated by 1H and 13C NMR, were isolated from leaves of Etlingera elatior. This is the first report of caffeoylquinic acids (CQA) including chlorogenic acid (CGA) in Zingiberaceae. Leaves of Etlingera species were rich in total pheno...

Effects of five different drying methods on the antioxidant properties (AOP) of leaves of Alpinia zerumbet, Etlingera elatior, Curcuma longa, and Kaempferia galanga were assessed. All methods of thermal drying (microwave-, oven-, and sun-drying) resulted in drastic declines in total phenolic content (TPC), ascorbic acid equivalent antioxidant capac...