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@#Aims:This study focus on the presence of cyanobacterial toxin in Malaysia and anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified.Methodology and results:As part of status determination of cyanobacterial toxins in Malaysia, cyanobacterial strains have been isolated from different environments and identified using cyanobacterial16S rRNA gene sequence. PCR assay was carried out to detect the presence of cyanobacterial toxin-encoding genes in these isolated strains by amplifying genes encoded for microcystin, anatoxin-a, cylindrospermopsin and saxitoxin. Using molecular identification of 16S rRNA gene sequences, a total of forty-two cyanobacterial strains were identified, which belongs to eighteen different genera of Synechococcus, Cyanobium, Synechocystis, Chroococcidiopsis, Leptolyngbya, Nodosilinea, Limnothrix, Pseudanabaena, Cephalothrix, Aerosakkonema, Oscillatoria, Alkalinema, Pantanalinema, Planktolyngbya, Scytonema, Nostoc, Hapalosiphonand Symphyonemopsis. The toxicity of these strains was tested using PCR amplification of toxin-encoding genes using specific primers.Conclusion, significance and impact of study:Anatoxin-a (ATX) gene,which involved in the biosynthesis of anatoxin-Awas detected in two isolated strains namelyLimnothrixsp. B15 and Leptolyngbyasp. D1C10.This study focus on the the presence of cyanobacterial toxin in Malaysia can now be determined as potential threat because anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified.
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@#Aims:This research aims to investigate the potential of biohythane (biohydrogen and biomethane) production from palm oil mill effluent (POME) in a two-stage anaerobic digestion (AD) system.Methodology and results:A two-stage AD system was configured with a thermophilic dark fermenter (TDF) for biohydrogen (H2) production and a thermophilic anaerobic contact digester (TACD) for biomethane (CH4) production. To adjust pH 5.5 for dark fermentation, the settled sludge was recirculated from TACD to TDF. The hydraulic retention time (HRT) applied in TDF and TACD was 3.75 and 6.25 day, respectively.Conclusion, significance and impact of study:The sludge recirculation from TACD was able to adjust the pH in TDF to the optimum value of 5.5. The total COD and TSSdegradation were 63.12 and 77.94 %, respectively. The H2production in TDF was 1.54 L H2/L POME and the CH4production in TACD was 19.87 L CH4/L POME. The H2and CH4yielded 0.085 L/g CODremovedand 0.339 L/g CODremoved, respectively, with total energy recovery equivalent to 661.02 MJ/m3POME. Only 2.28 % of this energy was contributed by H2and the remaining was dominated by CH4.
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@#Aims:Increasing of organic solvent waste contributed as one of the most critical environmental problems. Huge amount of solvents hasbeen applied in the industrial process, but it is not followed by a good waste treatment. Up to our knowledge only a few studieshas been conducted in applying the biological treatment on the solvent waste mixtures specifically by Gram’s positive organic solvent tolerant bacteria (OSTB). The study aims to identify the ability of OSTB survival in solvent waste mixture of the semiconductor industry in comparison to synthetic organic solvent by OSTB inoculation.Methodology and results:Strain of OSTB named as Bacillus subtilis, BSIAs was applied in the study. The growth of this OSTB in different concentration of synthetic solvent isopropyl alcohol (IPA) and in actual solvent waste mixture consists of IPA was monitored and measured. There are three different concentrations (v/v) of synthetic solvent IPA was used as a media that are 20%, 10% and 5% for testing the growth of B.subtilisBSIAs. The 5% concentration of IPA was suitable for B.subtilisBSIAs growth. After 14 hof growth, distillation process was used to separate the remaining solvent from the mixture. It was found that, the volume after biological treatment was reduced by 1 mL from the initial volume of solvent before the biological treatment. This OSTB also utilized solvent in 1% concentration of real solvent waste mixture within 120 h.Conclusion, significance and impact of study:As a conclusion, the findings reveal that the strain of Gram-positive B.subtilis,BSIAs has the ability to utilize synthetic organic solvent (IPA)and the solvent waste mixture from the semiconductor industry as their carbon sources. The selected OSTB can be considered as bio-agents in the industrial waste management pertaining to solvent waste problems thru green technology approaches.
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@#Aims: To study the performance of SMFC in the terms of power generation and toxic metals removal. This study was also focused on the characterization of SMFC electro-microbiology. Methodology and results: A SMFC was designed and loaded with sediment and overlying water. This SMFC was synchronized with wireless data logger acquisition system. The toxic metals removal capacity was measured by atomic absorption spectroscopy. The characterization of SMFC bacteria was done by 16S rRNA.In this study the experiments were carried out in a dual-chamber SMFC with external resistances 30 kΩ-50 Ω. The SMFC was produced power about 630 mV with maximum power density 40 mW/m2and current density 250 mA/m2. After 120 days of operation, SMFC removed cadmium and copper about 22.6 and 150 mg/kg, respectively. The SMFC also showed high cadmium (86%) and copper (90%) removal at pH 7.0 and temperature 40 °C. The most dominant bacterial community at anode and cathode was identified as Pseudomonas spp. which could be function as exoelectrogen. Conclusion, significance and impact of the study: The results indicated that the SMFC system could be applied as a long term and effective tool for the removal of cadmium and copper contaminated sediments and supply power for commercial devices. The Pseudomonas spp. may be used as a genetic donor for the other non-exoelectrogens strains.
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Aims@#Cyanbacterial bloom can cause unpleasant smell and taste. It can also produce toxins that can be harmful to animals or human. The capability of plant materials to control cyanobacterial bloom has been reported by many researchers. Among the plant materials were barley straw, banana skin, orange peel and many more. It was also showed that the ability of the plant material, especially barley straw to control cyanobacteria might likely involved complex microbial degradation and enhanced by fungal degradation. Therefore, experiments were set up to test the effect of fungi-degraded palm oil trunk on cyanobacterial growth. @*Methodology and results@#In the study, 1 g of palm oil trunk was pre-treated with fungus Lichtheimia sp, for 30 days to allow degradation to occur. After the incubation, the fresh and degraded palm oil trunk was introduced to cyanobacterial culture for 30 days. Growth of culture were estimated based on its chlorophyll a concentration. This study showed an increase ability of fungi-degraded palm oil trunks in inhibiting cyanobacterial growth. @*Conclusion, significance and impact of study@#The results strengthened the theory of involvement of microbial degradation in controlling cyanobacterial growth.
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Background: Application of membrane technology to wastewater treatment has expanded over the last decades due to increasingly stringent legislation, greater opportunities for water reuse/recycling processes and continuing advancement in membrane technology
Objectives: In the present study, a bench-scale submerged microfiltration membrane bioreactor [MBR] was used to assess the treatment of textile wastewater
Materials and Methods: The decolorization capacity of white-rot fungus coriolus versicolor was confirmed through agar plate and liquid batch studies. The temperature and pH of the reactor were controlled at 29+/-1[degree]C and 4.5+/-2, respectively. The bioreactor was operated with an average flux of 0.05 m.d[-1] [HRT=15hrs] for a month
Results: Extensive growth of fungi and their attachment to the membrane led to its fouling and associated increase of the transmembrane pressure requiring a periodic withdrawal of sludge and membrane cleaning. However, stable decoloration activity [approx. 98%], BOD [40-50%], COD [50-67%] and total organic carbon [TOC] removal [>95%] was achieved using the entire system [fungi + membrane], while the contribution of the fungi culture alone for TOC removal, as indicated by the quality of the reactor supernatant, was 35-50% and 70%, respectively
Conclusions: The treated wastewater quality satisfied the requirement of water quality for dyeing and finishing process excluding light coloration. Therefore, textile wastewater reclamation and reuse is a promising alternative, which can both conserve or supplement the available water resource and reduce or eliminate the environmental pollution