Identification and Assessment of Fluroquinolone Multidrug Efflux Pump in Multidrug Resistant Staphylococcus aureus isolated from Hospital Wastewater in Kuala Lumpur

Apart from alterations of target proteins of fluroquinolones, multidrug resistant (MDR) S. aureus can also mediated their resistance via overexpression of efflux pump. However, this mechanism is not well characterized. Absence of known antibiotic resistance genes (ARGs) in the MDR S. aureus isolates have led us to find other mechanism of resistance which could be responsible for their resistance. Therefore, this study was performed to identify the MDR efflux pump genes and evaluate the activity through Ethidium Bromide Cartwheel (EtBrCW) method. The MDR S. aureus were isolated from local hospital wastewater in Kuala Lumpur. 9 of the MDR S. aureus isolates were subjected to PCR for the detection of MDR efflux pump genes. The EtBrCW was used to demonstrate efflux activity as a mechanism of resistance in S. aureus. The result showed only 2 isolates possessed efflux pump genes with low efflux activity. It was observed that many of the isolates did not have conserved MDR efflux pump genes, suggesting there may be other mechanisms of resistance that need further exploration. The fast spreading of these resistance genes could pose serious risk to public health and emergence of superbug which is difficult to treat with available antibioti

Effects of number of connections and pipe length to the water losses in Melaka

One of the major challenges facing our water utilities is the high level of Non-Revenue Water (NRW) in the distribution networks. This paper assessed the performance of current management practices by Syarikat Air Melaka Berhad (SAMB) to deal with NRW. Information and NRW management data (from 2012 to 2013) were gathered and analysed. Statistical methods were used to evaluate the effects of pipe length and number of connections of the distribution network to the leakage level; and to determine the causes of leakage (water loss). In 2014, Melaka’s NRW percentage was 21.4% as compared to the national average of 35.6%, which is the second lowest rate among the states in Malaysia. Results of the study revealed significant positive relationships between average MNF (L/s) with number of connections and pipe length, with the prediction model of average MNF (L/s)=-4.42+1.088*10-2(NC)+1.07*10-4(PL), R2= 73.19%. The results also indicated that in a compact and urbanized city like Melaka, number of connections in the network appears to be most influential to the average MNF (water loss) (shown by a strong positive relationship, r = 0.847) as compared to the less compact zone (such as Perak) where pipe length appears to be more influential

Utilization of lignin in empty fruit bunch for production of fine chemicals: development of subcritical water technology and ΔpcaHG-ΔcatA Rhodococcus jostii RHA1

Lignin is an alternative source of chemicals particularly phenolic compounds if it could broken down into smaller molecular units. Subcritical water (SCW) is a known technology that has the ability to break down lignin by hydrolysis. In this study, the SCW depolymerizes empty fruit bunch derived lignin into a mixture of aromatic compounds. The mixture, however, is impractical to be utilized and the cost to separate each of the components is relatively high. Rhodococcus jostii RHA1 is a bacterium that can degrade a wide range of aromatic compounds. Specific gene deletion of RHA1 has shown that the RHA1 loses its ability to catabolize specific chemicals. This research project aims to utilize empty fruit bunch derived lignin via SCW technology and subsequently biological process using mutant Rhodococcus jostii RHA1, ΔpcaHG-ΔcatA mutant RHA1

Characterization of musty odor producing actinomycetes in Malaysia

The presence of geosmin and 2-methylisoborneol (2-MIB) becomes an increasing concern as they are known to cause earthy or musty odor in freshwater environments. Geosmin and 2-MIB outbreaks in Malaysia are not well understood and since Malaysia has a stable temperature throughout the year, no information has been reported on effect of temperature to the odor production. In this study, 6 isolated strains were selected for study of the effect of temperature (20, 25, 30, 35, 40, 45 & 50°C) on geosmin and 2-MIB production. Preliminary results indicate that at temperature 30 °C, Strain 5 showed highest geosmin production (129.06 µg/L) and Strain 2 produced highest 2-MIB (19.89 µg/L). PCR band was obtained in a test whether these isolated strains had geoA gene or not

Effect of nitrate concentration on cell growth and astaxanthin accumulation in four different species of isolated microalgae in Malaysia

Astaxanthin possess a red color pigment, a type of xanthophylls carotenoid and is mainly found in algae, fish and bird. In this study, cell growth and astaxanthin accumulation from four different isolated microalgae species based on their morphology were investigated. Isolated microalgae were cultured at three different nitrate concentration (1.64, 0.82, and 0.41 mM) and cell growth and astaxanthin were measured spectrophotometrically at 750 and 475 nm respectively. All species showed high growth rates at 1.64 mM nitrate concentration except for Pediastrum sp that is favorable in 0.82 mM nitrate. Among the four species, Ankistrodesmus sp showed the fastest growth rate. For the astaxanthin production, Ankistrodesmus and Pediastrum showed the highest yield. Thus it have a potential in production of astaxanthin in the future work

Degradation of persistent endosulfan by isolated actinomycetes and Rhodococcuss jostii, RHA1

The property of organochlorine endosulfan which is persistent and toxic can cause environmental pollution and pose human health and has raised concern worldwide. Hence, biodegradation serves as promising tool in overcoming the problem of pesticides pollution. The effective approach of removal of endosulfan from the environment is by using Gram-positive microorganisms such as actinomycetes, predominant microorganisms found in soil habitat are less exploited and studied in biodegradation of endosulfan. The diverse metabolic diversity and unique enzymatic capabilities of actinomycetes has gained interest in biodegradation to remove the endosulfan from the environment. This study aims to isolate indigenous actinomycetes from soil habitat and screening the ability of isolated actinomycetes to degrade the endosulfan. Cameron Highland where intensive agricultural activities were carried out was chosen as the sampling site for isolation of actinomycetes that could have potential in degradation of endosulfan. Screening of the ability of endosulfan degradation by isolated actinomycetes in sulphur free broth culture and followed by determination by residual endosulfan by using GC-ECD analysis which is sensitive and specific assay in detecting the endosulfan

Simulation study on enhancing hydrogen production in an ocean thermal energy (OTEC) system utilizing a solar collector

This article reports the simulation study on the performance of utilizing a solar collector at the inlet of an evaporator to provide auxiliary heat into a system for hydrogen generation in an OTEC cycle. The conventional method of OTEC is simulated by FORTRAN programming and the results were compared with the presence of solar collector on the system. In the simulation experimental, the incoming temperature of warm seawater was boosted by using a flat plate solar collector. For the purpose of the experiment, a 100 kW OTEC cycle that was designed incorporated a solar boosting capability. Its thermodynamic efficiency was then compared through a series of simulation involving several control parameters. The results reveal that the proposed solar boosted OTEC enhanced the thermal efficiency, TE. Increase in solar power absorption can increase the net power output, thus increasing the amount of hydrogen produced. The results obtained provided insights, from a thermodynamic perspective, on the outcome of combining sustainable energy with solar thermal energy to improve the system performance

Extraction of hemicellulose from oil palm biomass using subcritical water extraction to produce value-added product or fine chemicals

Renewable energy sources such as wind, hydro, solar, hydrogen, nuclear and biomass are various type of alternatives energy available to replace non-renewable fossil fuels. The total oil palm biomass produced by Malaysia alone is about 53.04 million tonnes (mt), which include 17.08 mt of empty fruit bunches, 9.66 mt of fibre, 5.2 mt of shell, 12.9 and 8.2 mt of fronds and trunks. This research will focused on the production of value-added product or fine chemicals based on extraction of xylose and xylooligosaccharides from hemicellulose of lignocellulosic biomass. As preliminary results, the pH value, TOC value and total sugar concentration were determined

Microbial diversity in decaying oil palm empty fruit bunch (OPEFB) and isolation of lignin degrading bacteria from tropical environment

Oil palm empty fruit bunches (OPEFB) are the most abundant, inexpensive, and environmentally friendly lignocellulosic biomass in Malaysia. Investigations on the microbial diversity of decaying OPEFB may reveal microbes with complex enzymes that have the potential to enhance the conversion of lignocellulose into second-generation biofuels as well as the production of other value-added products. In the present study, fungal and bacterial diversities in decaying OPEFB were identified using Illumina MiSeq sequencing of the V3 region of the 16S rRNA gene and V4 region of the 18S rRNA gene. Fungal diversity in decaying OPEFB was dominated by the phylum Ascomycota (14.43%), while most of the bacterial sequences retrieved belonged to Proteobacteria (76.71%). Three bacterial strains isolated from decaying OPEFB, designated as S18, S20, and S36, appeared to grow with extracted OPEFB-lignin and Kraft lignin (KL) as the sole carbon source. 16S rRNA gene sequencing identified the 3 isolates as Paenibacillus sp.. The molecular weight distribution of KL before and after degradation showed significant depolymerization when treated with bacterial strains S18, S20, and S36. The presence of low-molecular-weight lignin-related compounds, such as vanillin and 2-methoxyphenol derivatives, which were detected by a GC-MS analysis, confirmed the KL-degrading activities of isolated Paenibacillus strains

Investigation on H2S removal factors of activated carbons derived from waste palm trunk

Critical factors for H2S removal of activated carbons prepared from a waste palm trunk were investigated. Two kinds of activated carbons were prepared by different methods, steam and KOH activations. Regardless of high specific surface area and oxygen content of the KOH-activated carbon, the steam-activated showed more than 11 times higher H2S removal performance, which was even higher than a commercial activated carbon fiber. It was suggested that minerals contained in the steam-activated carbon acted effectively to remove H2S. The results suggest a potential utilization of waste palm trunks as an available cheap precursor for the H2S removal adsorbent