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Lactic acid recently became an important chemical where it is widely used in many industries such as food, cosmetic, chemical and pharmaceutical industry. The present study focuses on the screening for lactic acid production from rice starch waste using a thermophilic amylolytic bacterium, Geobacillus stearothermophilus. There is no information available on direct fermentation of lactic acid from rice starch waste using G. stearothermophilus. The effects of different parameters such as temperature, pH, incubation time, agitation speed, concentration of nitrogen and carbon sources on the lactic acid production were assessed. The highest concentration of lactic acid produced was 5.65 ± 0.07 g/L at operating conditions of 60°C, pH 5.5, 48 h, 200 rpm of agitation speed with 5% concentrations of both carbon and nitrogen source. The findings indicated that rice starch waste can be successfully converted to lactic acid by G. stearothermophilus.

Composites consisting of a polymeric matrix and renewable resources have attracted scientific attention due to the idea of sustainable development. The objective of this study was to blend the polyvinyl alcohol (PVOH) and oil palm ashes (OPA) using solution casting approach. The results revealed that increasing the OPA loading in PVOH film would decrease both tensile strength and elongation at break of the blended films. The morphology of the tensile fractured surface was examined which supported the result obtained from tensile properties. Also, the thermal characteristics of PVOH/OPA films were studied. The glass transition temperature and crystallization temperature were increased when the OPA loading was increased. Thermogravimetric analysis indicated that the thermal stability of PVOH/OPA film was higher than the unfilled PVOH film. [ABSTRACT FROM AUTHOR]

The adsorptive performance of phenol, 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) onto carbon-coated monolith (CCM) was comparatively evaluated by batch mode. Experiments were carried out by varying pH, contact time, initial adsorbate concentration and reaction temperature. Regeneration performance of CCM was also assessed. The studies showed optimum 2,4-DCP adsorption, followed by 4-CP and phenol at pH 5. The adsorption equilibration time for phenol, 4CP, 2 and 4-DCP were 600, 470 and 400 min, respectively. The equilibrium adsorption capacities were increased 13.1–37.6 mg/g for 50–250 mg/L (phenol), 51.9–93.7 mg/g for 250–450 mg/L (4-CP) and 84.3–117.5 mg/g for 400–600 mg/L (2,4-DCP), respectively. The adsorption at different temperatures was monolayer as depicted by linear and non-linear isotherm models. Kinetic studies showed better applicability of pseudo-second-order kinetics model. The adsorption increases with increase in reaction temperature from 30 to 50°C showing endothermic adsorption process. Desorption and regeneration studies showed optimum phenol recovery with ethanol with 12.9% loss in adsorption after four consecutive cycles. [ABSTRACT FROM PUBLISHER]

This study reports the biodiversity of thermophilic cellulolytic bacterial strains that present in the north Malaysian mangrove ecosystem. Soil samples were collected at the four most northern state of Malaysia (Perak, Pulau Pinang, Kedah and Perlis). The samples obtained were first enriched in nutrient broth at 45°C and 55°C prior culturing in the carboxymethylcellulose (CMC) agar medium. Repeated streaking was performed on the CMC agar to obtain a pure culture of each isolate prior subjecting it to hydrolysis capacity testing. The isolates that showing the cellulolytic zone (halozone) were sent for 16S rRNA sequencing. Total seven isolates (two from Perak, three from Kedah, another two were from Perlis and Penang each) showed halozone. The isolate (KFX-40) from Kedah exhibited highest halozone of 3.42 ± 0.58, meanwhile, the one obtained from Perak (AFZ-0) showed the lowest hydrolysis capacity (2.61 ± 0.10). Based on 16S rRNA sequencing results, 5 isolates (AFY-40, AFZ-0, KFX-40, RFY-20, and PFX-40) were determined to be Anoxybacillus sp . The other two isolates were identified as Bacillus subtilis (KFY-40) and Paenibacillus dendritiformis (KFX-0). Based on growth curve, doubling time of Anoxybacillus sp . UniMAP-KB06 was calculated to be 32.3 min. Optimal cellulose hydrolysis temperature and pH of this strain were determined to be 55°C and 6.0 respectively. Addition of Mg 2+ and Ca 2+ were found to enhance the cellulase activity while Fe 3+ acted as an enzyme inhibitor.