The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing con... more The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing concern, and threatens public health globally. A total of 129 Escherichia coli isolates were recovered from lowland aqueous environments near hospitals and medical service centers in the vicinity of Kuala Lumpur, Malaysia. Among the eleven antibacterial agents tested, the isolates were highly resistant to trimethoprim-sulfamethoxazole (83.7%) and nalidixic acid (71.3%) and moderately resistant to ampicillin and chloramphenicol (66.7%), tetracycline (65.1%), fosfomycin (57.4%), cefotaxime (57.4%), and ciprofloxacin (57.4%), while low resistance levels were found with aminoglycosides (kanamycin, 22.5%; gentamicin, 21.7%). The presence of relevant resistance determinants was evaluated, and the genotypic resistance determinants were as follows: sulfonamides (sulI, sulII, and sulIII), trimethoprim (dfrA1 and dfrA5), quinolones (qnrS), β-lactams (ampC and blaCTX-M), chloramphenicol (cmlA1 and cat...
We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil ... more We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil palm empty fruit bunch (OPEFB) in Negeri Sembilan, Malaysia, which yields potential genes encoding lignin degradation enzymes. This genome of 9,722,071 bp exhibited 58.9% GC content, 10,416 coding genes, and 12 RNAs.
Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of sea... more Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of seafood. To control this pathogenic Vibrio spp., the implementation of bacteriophages in aquaculture and food industries have shown a promising alternative to antibiotics. In this study, six bacteriophages isolated from the seafood samples demonstrated a narrow host range specificity that infecting only the V. parahaemolyticus strains. Morphological analysis revealed that bacteriophages Vp33, Vp22, Vp21, and Vp02 belong to the Podoviridae family, while bacteriophages Vp08 and Vp11 were categorized into the Siphoviridae family. All bacteriophages were composed of DNA genome and showed distinctive restriction fragment length polymorphism. The optimal MOI for bacteriophage propagation was determined to be 0.001 to 1. One-step growth curve revealed that the latent period ranged from 10 to 20 min, and the burst size of bacteriophage was approximately 17 to 51 PFU/cell. The influence of temperatu...
The conversion of lignocellulosic biomass into bioethanol or biochemical products requires a cruc... more The conversion of lignocellulosic biomass into bioethanol or biochemical products requires a crucial pretreatment process to breakdown the recalcitrant lignin structure. This research focuses on the isolation and characterization of a lignin-degrading bacterial strain from a decaying oil palm empty fruit bunch (OPEFB). The isolated strain, identified as Streptomyces sp. S6, grew in a minimal medium with Kraft lignin (KL) as the sole carbon source. Several known ligninolytic enzyme assays were performed, and lignin peroxidase (LiP), laccase (Lac), dye-decolorizing peroxidase (DyP) and aryl-alcohol oxidase (AAO) activities were detected. A 55.3% reduction in the molecular weight (Mw) of KL was observed after 7 days of incubation with Streptomyces sp. S6 based on gel-permeation chromatography (GPC). Gas chromatography-mass spectrometry (GC-MS) also successfully highlighted the production of lignin-derived aromatic compounds, such as 3-methyl-butanoic acid, guaiacol derivatives, and 4,6...
Green chemistry has drawn attention for synthesizing nanoparticles as it utilizes an eco-friendly... more Green chemistry has drawn attention for synthesizing nanoparticles as it utilizes an eco-friendly nontoxic chemical in the synthesis protocol. In addition, researchers start looking into the potential of organism such as bacteria, fungi and plants for synthesizing nanoparticles. Synthesis of nanoparticles requires details on structural analysis before/after synthesis in order to evaluate and control the quality of nanoparticles. Scanning electron microscope (SEM) has been widely used as an imaging instrument to structurally characterize nanoparticles before/after synthesis process. Maintaining the vacuum level in SEM system and controlling contamination originated from the sample are crucially important to enable high resolution imaging. In addition, sample surface need to be conductive to prevent image distortion due to the electron charging effect. Hence, raise the importance to study the method in preparing biological sample for SEM imaging. This work focuses on the three approac...
Staphylococcus sp. as gram-positive and Escherichia coli as gram-negative are bacterial pathogens... more Staphylococcus sp. as gram-positive and Escherichia coli as gram-negative are bacterial pathogens and can cause primary bloodstream infections and food poisoning. Coagulation, flocculation, and sedimentation processes could be a reliable treatment for bacterial removal because suspended, colloidal, and soluble particles can be removed. Chemical coagulants, such as alum, are commonly used. However, these chemical coagulants are not environmentally friendly. This present study evaluated the effectiveness of coagulation, flocculation, and sedimentation processes for removing Staphylococcus sp. and E. coli using diatomite with standard jar test equipment at different pH values. Staphylococcus sp. demonstrated 85.61% and 77.23% significant removal in diatomite and alum, respectively, at pH 5. At pH 7, the removal efficiency decreased to 79.41% and 64.13% for Staphylococcus sp. and E. coli, respectively. At pH 9, there was a decrease in Staphylococcus sp. after adding diatomite or alum co...
TonB-dependent receptors (TBDRs) mediate substrate-specific transport across the outer membrane, ... more TonB-dependent receptors (TBDRs) mediate substrate-specific transport across the outer membrane, utilizing energy derived from the proton motive force transmitted from the TonB−ExbB−ExbD complex located in the inner membrane (TonB system). Although a number of TonB systems involved in the uptake of siderophores, vitamin B12 and saccharides have been identified, their involvement in the uptake and catabolism of aromatic compounds was previously unknown. Here, we show that the outer membrane transport of a biphenyl compound derived from lignin is mediated by the TonB system in a Gram-negative bacterium capable of degrading lignin-derived aromatic compounds, Sphingobium sp. strain SYK-6. Furthermore, we found that overexpression of the corresponding TBDR gene enhanced the uptake of this biphenyl compound, contributing to the improved rate of platform chemical production. Our results will provide an important basis for establishing engineered strains optimized for use in lignin valorisa...
Abstract Food waste is a serious issue that has significant environmental, economic, and social i... more Abstract Food waste is a serious issue that has significant environmental, economic, and social impacts. Huge amounts of food are lost worldwide during the process of food production, from the stage of agricultural production to the disposal of food waste. This paper presents a review on: (1) the delivery of food waste reduction programs that aim to motivate a change in consumer behavior at the household level, (2) the impacts, and (3) the conditions or approaches for conducting these programs based on household food waste programs in developed and developing countries. In other words, we discuss the delivery and impacts of program measures that have been adopted to reduce food waste. In developed and developing countries, many activities (e.g., campaigns, talks, exhibitions, the publication of articles) have been implemented to raise awareness about how to make significant impacts concerning food waste issues. While environmental and economic approaches have been widely used in intervention programs, the application of a faith-based approach has not been investigated in detail. So, in this review paper, we gathered all of the cases that have been conducted in both developed and developing countries to compare what has been done to curb the food waste issue. Although many activities to reduce food waste have been conducted in developing countries, their impacts are not always completely reported, and in some cases, the corresponding programs were discontinued due to financial constraints. For future studies, a faith-based approach should also be considered as a way to educate people in food waste reduction.
Agricultural wastes such as lignocellulosic residues are renewable resources can be used for mush... more Agricultural wastes such as lignocellulosic residues are renewable resources can be used for mushroom cultivation. Spent mushroom substrate (SMS) is defined as leftover of biomass generated by commercial mushroom industries after harvesting period of mushroom. Mushroom cultivation using agricultural wastes promises a good quality of SMS for producing beneficial products such as animal feeding and fertilizers. Based on the published papers, the major applications of SMS are animal feedstock, fertilizer, energy production and wastewater treatment. For instance, some species of mushroom such as Pleurotus spp. and Agaricus bisporus are suitable for applications of ruminant feedstock and fertilizers. This paper reviews the recent studies about the beneficial usage of SMS which is considered as a waste since 2013.
This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under diff... more This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under different conditions such as initial concentration, sodium chloride and applied voltage. In this present study, HDZ was treated by electrochemical oxidation process using graphite-PVC composite electrode as anode and Platinum (Pt) as cathode. All results were analyzed using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). It was found that at high applied voltages, and high amounts of NaCl, the electrochemical treatment process was more efficient. The removal% of HDZ was 92% at 5 V after 60 min. From the obtained results, the electrochemical oxidation process of HDZ followed pseudo first order with rate constant values ranged between 0.0009 and 0.0502 min−1, depending on the experimental conditions. Energy consumption was also considered in this study, it was ranged between 0.9058 and 5.56 Wh/mg using 0.5, 0.3 and 0.1 g NaCl within interval times of (10, 20, 30, 40, 50, 60...
The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing con... more The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing concern, and threatens public health globally. A total of 129 Escherichia coli isolates were recovered from lowland aqueous environments near hospitals and medical service centers in the vicinity of Kuala Lumpur, Malaysia. Among the eleven antibacterial agents tested, the isolates were highly resistant to trimethoprim-sulfamethoxazole (83.7%) and nalidixic acid (71.3%) and moderately resistant to ampicillin and chloramphenicol (66.7%), tetracycline (65.1%), fosfomycin (57.4%), cefotaxime (57.4%), and ciprofloxacin (57.4%), while low resistance levels were found with aminoglycosides (kanamycin, 22.5%; gentamicin, 21.7%). The presence of relevant resistance determinants was evaluated, and the genotypic resistance determinants were as follows: sulfonamides (sulI, sulII, and sulIII), trimethoprim (dfrA1 and dfrA5), quinolones (qnrS), β-lactams (ampC and blaCTX-M), chloramphenicol (cmlA1 and cat...
We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil ... more We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil palm empty fruit bunch (OPEFB) in Negeri Sembilan, Malaysia, which yields potential genes encoding lignin degradation enzymes. This genome of 9,722,071 bp exhibited 58.9% GC content, 10,416 coding genes, and 12 RNAs.
Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of sea... more Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of seafood. To control this pathogenic Vibrio spp., the implementation of bacteriophages in aquaculture and food industries have shown a promising alternative to antibiotics. In this study, six bacteriophages isolated from the seafood samples demonstrated a narrow host range specificity that infecting only the V. parahaemolyticus strains. Morphological analysis revealed that bacteriophages Vp33, Vp22, Vp21, and Vp02 belong to the Podoviridae family, while bacteriophages Vp08 and Vp11 were categorized into the Siphoviridae family. All bacteriophages were composed of DNA genome and showed distinctive restriction fragment length polymorphism. The optimal MOI for bacteriophage propagation was determined to be 0.001 to 1. One-step growth curve revealed that the latent period ranged from 10 to 20 min, and the burst size of bacteriophage was approximately 17 to 51 PFU/cell. The influence of temperatu...
The conversion of lignocellulosic biomass into bioethanol or biochemical products requires a cruc... more The conversion of lignocellulosic biomass into bioethanol or biochemical products requires a crucial pretreatment process to breakdown the recalcitrant lignin structure. This research focuses on the isolation and characterization of a lignin-degrading bacterial strain from a decaying oil palm empty fruit bunch (OPEFB). The isolated strain, identified as Streptomyces sp. S6, grew in a minimal medium with Kraft lignin (KL) as the sole carbon source. Several known ligninolytic enzyme assays were performed, and lignin peroxidase (LiP), laccase (Lac), dye-decolorizing peroxidase (DyP) and aryl-alcohol oxidase (AAO) activities were detected. A 55.3% reduction in the molecular weight (Mw) of KL was observed after 7 days of incubation with Streptomyces sp. S6 based on gel-permeation chromatography (GPC). Gas chromatography-mass spectrometry (GC-MS) also successfully highlighted the production of lignin-derived aromatic compounds, such as 3-methyl-butanoic acid, guaiacol derivatives, and 4,6...
Green chemistry has drawn attention for synthesizing nanoparticles as it utilizes an eco-friendly... more Green chemistry has drawn attention for synthesizing nanoparticles as it utilizes an eco-friendly nontoxic chemical in the synthesis protocol. In addition, researchers start looking into the potential of organism such as bacteria, fungi and plants for synthesizing nanoparticles. Synthesis of nanoparticles requires details on structural analysis before/after synthesis in order to evaluate and control the quality of nanoparticles. Scanning electron microscope (SEM) has been widely used as an imaging instrument to structurally characterize nanoparticles before/after synthesis process. Maintaining the vacuum level in SEM system and controlling contamination originated from the sample are crucially important to enable high resolution imaging. In addition, sample surface need to be conductive to prevent image distortion due to the electron charging effect. Hence, raise the importance to study the method in preparing biological sample for SEM imaging. This work focuses on the three approac...
Staphylococcus sp. as gram-positive and Escherichia coli as gram-negative are bacterial pathogens... more Staphylococcus sp. as gram-positive and Escherichia coli as gram-negative are bacterial pathogens and can cause primary bloodstream infections and food poisoning. Coagulation, flocculation, and sedimentation processes could be a reliable treatment for bacterial removal because suspended, colloidal, and soluble particles can be removed. Chemical coagulants, such as alum, are commonly used. However, these chemical coagulants are not environmentally friendly. This present study evaluated the effectiveness of coagulation, flocculation, and sedimentation processes for removing Staphylococcus sp. and E. coli using diatomite with standard jar test equipment at different pH values. Staphylococcus sp. demonstrated 85.61% and 77.23% significant removal in diatomite and alum, respectively, at pH 5. At pH 7, the removal efficiency decreased to 79.41% and 64.13% for Staphylococcus sp. and E. coli, respectively. At pH 9, there was a decrease in Staphylococcus sp. after adding diatomite or alum co...
TonB-dependent receptors (TBDRs) mediate substrate-specific transport across the outer membrane, ... more TonB-dependent receptors (TBDRs) mediate substrate-specific transport across the outer membrane, utilizing energy derived from the proton motive force transmitted from the TonB−ExbB−ExbD complex located in the inner membrane (TonB system). Although a number of TonB systems involved in the uptake of siderophores, vitamin B12 and saccharides have been identified, their involvement in the uptake and catabolism of aromatic compounds was previously unknown. Here, we show that the outer membrane transport of a biphenyl compound derived from lignin is mediated by the TonB system in a Gram-negative bacterium capable of degrading lignin-derived aromatic compounds, Sphingobium sp. strain SYK-6. Furthermore, we found that overexpression of the corresponding TBDR gene enhanced the uptake of this biphenyl compound, contributing to the improved rate of platform chemical production. Our results will provide an important basis for establishing engineered strains optimized for use in lignin valorisa...
Abstract Food waste is a serious issue that has significant environmental, economic, and social i... more Abstract Food waste is a serious issue that has significant environmental, economic, and social impacts. Huge amounts of food are lost worldwide during the process of food production, from the stage of agricultural production to the disposal of food waste. This paper presents a review on: (1) the delivery of food waste reduction programs that aim to motivate a change in consumer behavior at the household level, (2) the impacts, and (3) the conditions or approaches for conducting these programs based on household food waste programs in developed and developing countries. In other words, we discuss the delivery and impacts of program measures that have been adopted to reduce food waste. In developed and developing countries, many activities (e.g., campaigns, talks, exhibitions, the publication of articles) have been implemented to raise awareness about how to make significant impacts concerning food waste issues. While environmental and economic approaches have been widely used in intervention programs, the application of a faith-based approach has not been investigated in detail. So, in this review paper, we gathered all of the cases that have been conducted in both developed and developing countries to compare what has been done to curb the food waste issue. Although many activities to reduce food waste have been conducted in developing countries, their impacts are not always completely reported, and in some cases, the corresponding programs were discontinued due to financial constraints. For future studies, a faith-based approach should also be considered as a way to educate people in food waste reduction.
Agricultural wastes such as lignocellulosic residues are renewable resources can be used for mush... more Agricultural wastes such as lignocellulosic residues are renewable resources can be used for mushroom cultivation. Spent mushroom substrate (SMS) is defined as leftover of biomass generated by commercial mushroom industries after harvesting period of mushroom. Mushroom cultivation using agricultural wastes promises a good quality of SMS for producing beneficial products such as animal feeding and fertilizers. Based on the published papers, the major applications of SMS are animal feedstock, fertilizer, energy production and wastewater treatment. For instance, some species of mushroom such as Pleurotus spp. and Agaricus bisporus are suitable for applications of ruminant feedstock and fertilizers. This paper reviews the recent studies about the beneficial usage of SMS which is considered as a waste since 2013.
This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under diff... more This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under different conditions such as initial concentration, sodium chloride and applied voltage. In this present study, HDZ was treated by electrochemical oxidation process using graphite-PVC composite electrode as anode and Platinum (Pt) as cathode. All results were analyzed using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). It was found that at high applied voltages, and high amounts of NaCl, the electrochemical treatment process was more efficient. The removal% of HDZ was 92% at 5 V after 60 min. From the obtained results, the electrochemical oxidation process of HDZ followed pseudo first order with rate constant values ranged between 0.0009 and 0.0502 min−1, depending on the experimental conditions. Energy consumption was also considered in this study, it was ranged between 0.9058 and 5.56 Wh/mg using 0.5, 0.3 and 0.1 g NaCl within interval times of (10, 20, 30, 40, 50, 60...
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Papers by Hirofumi Hara