Olivier Habimana

GTIIT · Biotechnology and Food Engineering

Contaminants in freshwater environments, as well as the associated negative impacts on agricultural produce, have emerged as a critical theme of the water-energy-food nexus affecting food safety and irrigation management. Agricultural produce exposed to irrigation with questionable freshwater can internalize and concentrate pollutants. However, the...

Abstract In recent years, most biofilm studies have focused on fundamental investigations using multispecies biofilm models developed preferentially in simulated naturally occurring low-nutrient medium than in artificial nutrient-rich medium. Because biofilm development under low-nutrient growth media is slow, natural media are often supplemented w...

The presence of antibiotics such as erythromycin, even in trace amounts, has long been acknowledged for negatively impacting ecosystems in freshwater environments. Although many studies have focused on the impact of antibiotic pollution at a macroecological level, the impact of erythromycin on microecosystems, such as freshwater biofilms, is still...

Advances in high-throughput sequencing technologies have enabled extensive studies of freshwater biofilms and significant breakthroughs in biofilm meta-omics. To date, however, no standardized protocols have been developed for the effective isolation of RNA from freshwater benthic biofilms. In this study, we compared column-based kit RNA extraction...

The possibility of breaking down cellulose-rich food waste through biofilm engineering was investigated. Six previously isolated strains from naturally degrading fruits and vegetables, screened for biofilm-forming ability and cellulolytic activity, were selected to enrich a biocarrier seeding microbial consortium. The food waste model used in this...

Biofilms formed by Escherichia coli are composed of amyloid curli and cellulose and have been shown to be linked to pathogenicity, antibiotic resistance, and chronic infections. Guanabenz acetate (GABE), an antihypertensive drug, was identified as a potential strategic repurposing drug due to its biofilm inhibitory properties following an extensive...

Properly using controllable atmospheric containers can facilitate investigations of the survival abilities and physiological states of key and emerging-foodborne pathogens under recreated applicable food processing environmental conditions. Notably, saturated salt solutions can efficiently control relative humidity in airtight containers. This chap...

As one of the highest carbon-emitting nations, South Africa is working tirelessly to swiftly transition to sustainable technologies in order to strengthen its green economy initiatives. Amongst the technologies that are explored in the scientific and industrial community, biorefineries are seen as the most efficient technologies that can be used to...

The emergence of antimicrobial-resistant bacterial strains has led to novel approaches for combating bacterial infections and surface contamination. More specifically, efforts in combining nanotechnology and biomimetics have led to the development of next-generation antimicrobial/antifouling nanomaterials. While nature-inspired nanoscale topographi...

Amongst the biofuels described in the literature, biohydrogen has gained heightened attention over the past decade due to its remarkable properties. Biohydrogen is a renewable form of H2 that can be produced under ambient conditions and at a low cost from biomass residues. Innovative approaches are continuously being applied to overcome the low pro...

Biohydrogen production is regarded as the cleanest process of producing H2 due to its non-polluting features and its ability to valorize wastes. However, its industrialization remains stagnant due to the process barriers facing this technology. Research is now geared towards the beneficiation of acidogenic-derived metabolites to improve its competi...

The presence of erythromycin, an antibiotic commonly used to treat bacterial infections, at high concentrations in freshwater bodies remains a significant ecological hazard. However, the effects of free erythromycin on microorganisms, especially freshwater biofilms, are still not fully understood with regard to microbial diversity, active constitue...

A comprehensive global profile of the distribution of ARGs in freshwater biofilms is lacking. We utilized metagenomic approaches to reveal the diversity, abundance, transferability and hosts of ARGs in 96 freshwater biofilm samples from 38 sampling sites across four countries. The abundant ARGs were associated with bacitracin, multidrug, polymyxin...

In this study, a phylogenic analysis was performed on pathogens previously identified in Hong Kong wet markets' cutting boards. Phylogenetic comparisons were made between phylotypes obtained in this study and environmental and clinical phylotypes for establishing the possible origin of selected bacterial species isolated from wet market cutting boa...

A composition comprising a silica-based nanobead having its surface functionalized by a moiety selected from moieties that are reactive to and combine with a fouling layer on a material surface.

Recent studies have shown that insect wings have evolved to have micro- and nanoscale structures on the wing surface, and biomimetic research aims to transfer such structures to application- specific materials. Herein, we describe a simple and cost-effective method of replica molding the wing topographies of four cicada species using UV-curable pol...

In recent years, much attention has been directed towards the integration of dark fermentation process into a biorefinery concept to enhance the energetic gains, thereby improving the competitiveness of this process. The volatile fatty acids (VFAs) from dark fermentative H2-producing processes serve as precursors for the microbial synthesis of a br...

Microbial lipids, also known as single-cell oils (SCOs), are highly attractive feedstocks for biodiesel production due to their fast production rates, minimal labor requirements, independence from seasonal and climatic changes, and ease of scale-up for industrial processing. Among the SCO producers, the less explored filamentous fungi (molds) exhib...

Accessing food through wet markets is a common global daily occurrence, where fresh meat can be purchased to support an urbanizing world population. Similar to the wet markets in many other metropolitan cities in Asia, Hong Kong wet markets vary and are characterized by differing hygiene routines and access to essential modern technologies. The lac...

Celtis africana Burm. f. is a medicinal plant native to Southern Africa and used for various ailments. Since crude extracts from mature leaves, stems, and fruits are the most common parts of this plant used for medicinal preparations, the same were selected for isolation of endophytes to assess the medicinal utility of their metabolite extracts as...

Melanosomes are membrane-bound organelles of varying geometry, commonly found within a range of vertebrate tissues, that contain the pigment melanin. Melanosomes have been identified in the fossil record in many exceptionally preserved fossils allowing reconstructions of the coloration of many extinct animals. However, these microstructures have al...

Melanosomes are membrane-bound organelles of varying geometry, commonly found within a range of vertebrate tissues, that contain the pigment melanin. Melanosomes have been identified in the fossil record in many exceptionally preserved fossils allowing reconstructions of the coloration of many extinct animals. However, these microstructures have al...

APPENDIX 2 SUPPLEMENTAL FIGURES S3-S9 Fig. S3. Experimental grid developed for scanning electron microscope (SEM) survey of bedding planes in exceptionally preserved fossil specimens. The 3×3 grid with nine centred points, each at a vertical and horizontal distance of 100 µm apart were set up at the rear ends of the copper tape pointer away into th...

Melanosomes are membrane-bound organelles of varying geometry, commonly found within a range of vertebrate tissues, that contain the pigment melanin. Melanosomes have been identified in the fossil record in many exceptionally preserved fossils allowing reconstructions of the coloration of many extinct animals. However, these microstructures have al...

Hong Kong's wet markets play a crucial role in the country's supply of safe, fresh meat to satisfy the dietary needs of its population. Whilst food safety regulations have been introduced over the past few years to maintain the microbial safety of foods sold from these wet markets, it remains unclear whether the hygiene maintenance that is performe...

Novel alternative antibacterial compounds have been persistently explored from plants as natural sources to overcome antibiotic resistance leading to serious foodborne bacterial illnesses. In this study, the ethanolic extracts from 239 traditional Chinese medicinal plants (TCMP)' materials were screened to discover promising candidates that have st...

Staphylococcus aureus, a foodborne pathogen, poses serious problems to the food industries owing to biofilm formation, and over 25% of the foodborne illnesses in China have been attributed to S. aureus only. Phytochemicals are widely used as anti-biofilm agents with promising efficacy, and most of them are widely available and safe. This study repo...

Millions every day purchase their raw meat in wet markets around the globe, especially in Hong Kong city, where modern and a traditional way of living is made possible. While food hygiene standards in Hong Kong have more recently focused on the safety of meat sold in these wet markets, the hygienic surface level of wooden cutting boards used for pr...

Lactobacillus rhamnosus strain ASCC 1520 with high soy isoflavone transformation ability was used to ferment soymilk and added to the diet of mice. The impact of L. rhamnosus fermentation on soy isoflavone metabolites and intestinal bacterial community, in conjunction with fecal enzyme activity and short‐chain fatty acids (SCFA) excretion was evalu...

Most biofilm studies employ single species, yet in nature biofilms exist as mixed cultures, with inevitable effects on growth and development of each species present. To investigate how related species of bacteria interact in biofilms, two Pseudomonas spp., Pseudomonas fluorescens and Pseudomonas putida, were cultured in capillary bioreactors and t...

Biofilms in irrigation water distribution systems (IWDSs) play an essential role in spreading pathogens, chemical pollutants, and environmental pollutants into downstream irrigated crops and thus should be considered a potential threat to food safety. Although the role of biofilms in drinking water distribution systems has been extensively studied...

The proper use of controllable atmospheric containers can facilitate investigations related to the survival abilities, and physiological states of key and emerging foodborne pathogens under recreated applicable food processing environmental conditions. Of particular note, the use of saturated salt solutions can efficiently control relative humidity...

Biofouling is a significant operational impediment in pressure-driven membrane processes. The early stage of biofouling involves bacterial adhesion at the membrane-liquid interface where the physical and chemical conditions are very complex. This study employed a sophisticated model of bacterial adhesion and was combined with a computational fluid...

Attempts to deal with the problem of detrimental biofilms using nanoparticle technologies have generally focussed on exploiting biocidal approaches. However, it is now recognised that biofilm matrix-components may be targets for the disruption or dispersion of biofilms. Here, we show that the functionalization of gold nanoparticles with the enzyme,...

The growth of biofilms on surfaces is a complicated process influenced by several environmental factors such as nutrient availability and fluid shear. In this study, combinations of growth conditions were selected for the study of Pseudomonas fluorescens biofilms including as cultivation time (24- or 48 h), nutrient levels (1:1 or 1:10 King B mediu...

Appendix S1. Materials and Methods. Fig. S1. Microbial Fouling Simulator cross flow system experimental rig.

It is now generally accepted that biofouling is inevitable in pressure-driven membrane processes for water purification. A large number of published articles describe the development of novel membranes in an effort to address biofouling in such systems. It is reasonable to assume that such membranes, even those with antimicrobial properties, when a...

Objectives: The aim of the study was to evaluate the antibacterial efficacy of Lugol's solution, acetic acid, and boric acid against Staphylococcus aureus biofilm. Methods: The efficacy of Lugol's solution 1%, 0.1%, and 0.05%, acetic acid 5% or boric acid 4.7% for treatment of Staphylococcus aureus biofilm in vitro was tested using 30 clinical s...

In an effort to mitigate biofouling on thin film composite membranes such as nanofiltration and reverse osmosis, a myriad of different surface modification strategies has been published. The use of silver nanoparticles (Ag-NPs) has emerged as being particularly promising. Nevertheless, the stability of these surface modifications is still poorly un...

The performance of pressure-driven membrane filtration processes for water treatment is hampered by biofouling. A relevant, but often overlooked aspect of this phenomenon concerns the localized microenvironment at the membrane interface. A key question is the level of stress on adhering cells and how this impacts on the developing biofilm. In this...

Analytics: A better look at biofilms Combining two distinct techniques allows analysis of the structure and physical properties of bacterial biofilms in fine detail. Eoin Casey and colleagues, from University College Dublin, Ireland, and the University of Hong Kong, applied a combined non-destructive procedure to cultured biofilms, for determining...

Two polymers, polymethylmethacrylate (PMMA) and cyclic olefin copolymer (COC), containing a range of nano- to micron- roughness surfaces (Ra 0.01, 0.1, 0.4, 1.0, 2.0, 3.2 and 5.0μm) were fabricated using electrical discharge machining (EDM) and replicated using micro injection moulding (μIM). Polymer samples were characterized using optical profilo...

Table S1. FTIR assignments of the analysis of the functionalized Si‐NanoB. Figure S1. A schematized overview of the chemical preparation of enzyme functionalized silica nanobeads. Figure S2. FTIR spectra of functionalized (Silica+PK) and non‐functionalized (Si‐NanoB) nanobeads Figure S3. Representative SEM micrographs of Si‐NanoB (a‐b) and Si‐Na...

Recently, the surface of the wings of the Psaltoda claripennis cicada species has been shown to possess bactericidal properties and it has been suggested that the nanostructure present on the wings was responsible for the bacterial death. We have studied the surface-based nanostructure and bactericidal activity of the wings of three different cicad...

The amelioration of biofouling in industrial processing equipment is critical for performance and reliability. While conventional biocides are effective in biofouling control, they are potentially hazardous to the environment and in some cases corrosive to materials. Enzymatic approaches have been shown to be effective and can overcome the disadvan...

The amelioration of biofouling in industrial processing equipment is critical for performance and reliability. While conventional biocides are effective in biofouling control, they are potentially hazardous to the environment and in some cases corrosive to materials. Enzymatic approaches have been shown to be effective and can overcome the disadvan...

In the context of biofilm development, detachment is of practical importance when placed in a biofilm management perspective. The objective of the present study was to examine biofilm structure and biofilm detachment under controlled conditions for two distinct microorganisms grown under constant shear conditions. Detached biofilm biomass was regul...

Organic conditioning films have been shown to alter properties of surfaces, such as hydrophobicity and surface free energy. Furthermore, initial bacterial adhesion has been shown to depend on the conditioning film surface properties as opposed to the properties of the virgin surface. For the particular case of nanofiltration membranes under permeat...

The influence of permeate flux on bacterial adhesion to NF and RO membranes was examined using two model Pseudomonas species, namely Pseudomonas fluorescens and Pseudomonas putida. To better understand the initial biofouling profile during NF/RO processes, deposition experiments were conducted in cross flow under permeate flux varying from 0.5 up t...

It is imperative that nanofiltration membranes are disinfected before they are used for laboratory-scale bacterial adhesion or biofouling experiments, yet currently no suitable disinfection protocol exists. This study aimed to determine if an ethanol treatment at a minimum inhibitory concentration (MIC) could be used to effectively disinfect nanofi...

The purpose of this study was to investigate the effects of calcium ions on the structural and mechanical properties of Pseudomonas fluorescens biofilms grown for 48 h. Advanced investigative techniques such as confocal laser scanning microscopy and atomic force spectroscopy were employed to characterize biofilm structure as well as biofilm mechani...

Nanofiltration (NF) is a high pressure membrane filtration process increasingly applied in drinking water treatment and water reuse processes. NF typically rejects divalent salts, organic matter and micropollutants. However, the efficiency of NF is adversely affected by membrane biofouling, during which microorganisms adhere to the membrane and pro...

Unlabelled: Although Salmonella persistence has been predominantly linked to biofilm formation, the physiological state of Salmonella should also be considered as a possible pathway for persistence and survival in the feed industry. Hence, the purpose of this study was to assess the extent of viability of Salmonella cells through long-term desicca...

The purpose of this study was to investigate the feasibility of cultivating the biotechnologically important bacterium Streptomyces griseus in single-species and mixed- species biofilms using a Tubular Biofilm Reactor (TBR). Streptomyces griseus biofilm development was found to be cyclical, starting with the initial adhesion and subsequent developm...

Investigate the use of a synthetic brominated furanone (F202) against the establishment of biofilm by Salmonella ser. Agona and E. coli O103:H2 under temperature conditions relevant for the food and feed industry as well as under temperature conditions optimum for growth. Effect of F202 on biofilm formation by Salmonella ser. Agona and E. coli O103...

Biofouling of nanofiltration (NF) and reverse osmosis (RO) membranes for water treatment has been the subject of increased research effort in recent years. A prerequisite for undertaking fundamental experimental investigation on NF and RO processes is a procedure called compaction. This involves an initial phase of clean water permeation at high pr...

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Staphylococcus aureus is a pathogenic bacterium capable of developing biofilms on food-processing surfaces, a pathway leading to cross contamination of foods. The purpose of this study was to investigate the influence of environmental stress factors found during seafood production on the adhesion and biofilm-forming properties of S. aureus. Adhesio...