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Oil spill introduces hydrocarbons into the marine environment and forms oil slicks, which aggregate with other debris to form tarballs. Tarballs are composed of toxic hydrocarbons, which persist in the environment, causing economic and ecological damages. This work studied the isolation and optimization of diesel-oil biodegradation by an indigenous bacterium, identified by 16S rRNA gene sequence analysis, in tarball. An experimental methodology using a Taguchi orthogonal array was applied to optimize the effects of diesel concentration, salinity, nitrate concentration, pH, temperature, agitation speed and time. An isolated bacterium identified as Cellulosimicrobium cellulans removed 88.4% of diesel oil under optimized conditions, where initial diesel-oil concentration was 5% (v/v), NaCl concentration was 20 gL-1 and NH4NO3 concentration was 2 gL-1 in Minimal Salt Media at pH 7, 40oC and 100 revolutions per minute for 5 days. Tarballs harbor hydrocarbon-degrading C. cellulans that can be used under optimized conditions to design an effective oil spill bioremediation technique for mitigating oil pollution. [ABSTRACT FROM AUTHOR]

Carbamates are poisonous pesticides which have been used widely in agriculture production for decades. Unlike other pesticides such as organophosphate, carbamate pesticides are not persistent in the environment however, their degradation is crucial due to their toxicity to living system. The World Health Organization, categorized carbamate pesticide as toxic, hazardous and restricted for use. Example of carbamates pesticides include Carbaryl, Aldicarb, Methomyl, Carbofuran, and Propoxur. They are extensively used to control many insect and pests of crops. Presently, there is signifcant awareness regarding the negative effects of pesticides due to their ability to pollute soil and water bodies. Most pesticides are readily degraded or metabolized by microbes. Carbamate pesticide degradation by microorganisms relies not only on the availability of microbes with suitable biodegradative enzymes, but also on the various ecological factors. This review- article outlines the present development in biodegradation of carbamate pesticides, their toxicity and enzymatic degradation as well as their degradative pathways. [ABSTRACT FROM AUTHOR]

There is no virtual report on the commercial cultivation of Arthrospira in Malaysia beyond the laboratory scale probably because of the high costs of production and the lower yield which are highly interconnected with the algal cultivation techniques. One way to alleviate the production cost is through outdoor mass cultivation under natural conditions using all available resources. Therefore, the present study was conducted to investigate the prospects of the production of Arthrospira platensis under Malaysian tropical climate using enhanced cultivation techniques to reach a maximum yield. In this study, the growth and yield of A. platensis were investigated under three different cultivation conditions: laboratory (control), outdoor shaded (greenhouse, T1), and outdoor non-shaded (field, T2). The algal growth was measured through optical density, biomass dry weight, and chlorophyll a content. The algal yield was determined by calculating its productivity and specific growth rate. The A. platensis cultivation under outdoor non-shaded conditions achieved significantly higher growth (p < 0.05) with 1.62 ± 0.038 ABS of maximum optical density, 0.88 ± 0.020 g L-1 of maximum biomass dry weight, 8.77 ± 0.219 mg L-1 of maximum chlorophyll a content, 0.091 ± 0.0022 g L-1 d-1 of productivity and 0.220 ± 0.0017 μ d-1 of specific growth rate over a cultivation period of eight days. The present finding showed that the Malaysian climate is suitable for a satisfactory A. platensis productivity with proper cultivation techniques such as the pre-adaptation of the algal culture, inoculation in the late evening, continuous agitation and compensation of the evaporated culture medium. [ABSTRACT FROM AUTHOR]

The current study is one of the first studies evaluating the levels of linear alkylbenzenes (LABs) in surface sediments of Sarawak and Sembulan rivers which are located in the east coast of Malaysia. The LABs, which are molecular tracers of sewage contamination, were measured in 15 surface sediment samples collected from these rivers. The samples were extracted, fractioned and analyzed by gas chromatography mass spectrometry (GC-MS). The findings revealed that the concentrations of ΣLABs ranged from 156.47 to 7386.19 ng/g dry weight (dw) in the sediments of Sarawak River and from 643.18 to 5567.12 ng/g dw in the sediments of Sembulan River. The highest LABs levels were detected in the sediments collected from the sampling location SS9 in Sembulan River whereas the lowest levels were observed in the SS1 sampling location in Sarawak River. The I/E ratios (ratio of internal to external isomers of LABs) for Sarawak River sediments ranged from 0.52 to 0.98 while for Sembulan River they fell within the range 0.87-1.79. The I/E ratio at the sampling station SS4 was much lower than the I/E ratios at the other stations, thus indicating that the wastewater discharged into Sarawak River from the areas surrounding station SS4 was poorly treated. [ABSTRACT FROM AUTHOR]