Research

In the anaerobic digestion of agro-industrial wastewater for biomethane production, microbial consortia are naturally aggregated and retained in the form of a granular sludge or biofilms. These types of microbial community have been reported as a significant factor in methanogenesis process. However, the conversion efficiency is biologically limited by syntrophism of two principal bacteria, including acetogens and methanogens. Nowadays, the initiation mechanism of such bacterial biofilm is, therefore, a subject undergoing intense exploration. Instead of using a conventional wastewater bioreactor, we will employ a microfluidic-integrated device to simulate controlled growth environments in such a way that biofilm formation can be microscopically studied thereon.

Furthermore, this device is an ideal platform for introducing surface functionalities of interest (Bio-interface) that are hypothesized for improving an initial microbial adhesion. In this work, the effects of bio-interfaces producing negative, positive, and neutral charges on enriched co-culture of bacteria derived from agro-industrial wastewater will be systematically studied in controlled environments. Also, we will report the response of biofilm formation in terms of metabolite fingerprints, nutrient profiles, and surface morphology. We hypothesize that the provision of such bio-interfaces and ruling parameters will lead us a better insight into the microbial biofilm formation and can be implemented to existing biogas technologies.

Spirulina has been recognized as an excellent source of protein comprising more than 60% of its dry weight. It has been approved by the US Food and Drug Administration (FDA) since 2003, and long been used as a dietary supplement. It is well known for its nutritional qualities and bioactive compounds rich food source. In recent years, great attention has been paid to bioactive peptides from Spirulina due to its biological activities and health benefits. Basically, bioactive peptides comprise 2-20 amino acids that allow them to cross the intestinal wall to exhibit biological activities. Depending on amino acid sequences, these bioactive peptides have been found involved in several bioactivities such as antihypertensive, anti-inflammatory, antioxidant, antitumor and antimicrobial activities as well as featuring dipeptidyl peptidase IV (DPP-IV) inhibitory property.

Accordingly, we aim to study more in details of bioactive peptides derived from Spirulina. The SpirPep: Spirulina Bioactive Peptide Prediction Tool will be used for in silico proteolytic enzyme digestion of protein derived from Spirulina. Following this, the in vitro proteolytic enzyme digestion will be carried out. Then, LC-MS/MS will be utilized to identify and characterize amino acids sequences and molecular masses of peptides. The bioactive peptides will be determined according to the SpirPep bioactive peptides database and the interesting activity will be tested.

This research project is the continuation from our previous publication on Zwitterionic peptide-capped gold nanoparticles for colorimetric detection of Ni2+ (Nanoscale, 2018, DOI: 10.1039/C7NR07998B).

Screen printed carbon electrodes (SPCEs), a type of electrodes made from graphite paste, are an important component in the development of electroanalytical techniques. Their cost effectiveness offers promising opportunities in mass production and commercialization for real and practical applications in inexpensive, single-use, and on-site monitoring in healthcare, food safety, and environmental contamination. However, SPCEs are known to display limited electrochemical performances due to non-conductive polymer adhesives in carbon inks that covers on the electrode surfaces. Literature has shown that removing adhesive impurities from the electrode surfaces significantly improves the electron transfer rates. Furthermore, SPCEs are still less sensitive to some of key organic analytes, particularly in biological contexts. Research suggests that heteroatomic doping with non-metallic elements, such as nitrogen, oxygen, boron, etc., renders higher electrocatalytic activities of graphene-based materials. Here, the aim of the project is to alter the electrocatalytic properties of commercially-available SPCEs with nitrogen dopants using an inductively-coupled plasma method. Plasma conditions such as exposure time, gas pressure, and plasma power will be systematically studied. Later, the surface chemical compositions and the electrocatalytic enhancement of benchmark compounds will be investigated.