Comparison on decolorization of palm oil mill effluent by biological, chemical and physical methods

Decolorization of palm oil mill effluent pretreated by enzyme from Aspergillus niger ATCC 6275 was investigated. The culture filtrate after separation of suspended solids was used for decolorization by biological, chemical and physical methods. Results indicated that the chemical method (using coagulant) was more effective than the biological method (using commercial peroxidase, two strains of white-rot fungi Phanerochaete chrysosporium and Coriolus versicolor) and physical method (using activated carbon, pararubber seed and sand filter). Studies on the effect of coagulant concentrations on decolorization revealed that using the combination of 10 ml/l polyferric sulphate and 10 g/l calcium oxide gave the highest color removal of 84.5% and organic matter (in term of chemical oxygen demand, COD) removal of 86.5%

Semi-pilot scale-up of a continuous packed-bed bioreactor system developed for the lipase-catalyzed production of pseudo-ceramides

Ceramides are sphingolipid compounds that are very attractive as active components in both the pharmaceutical and the cosmetic industries. In this study, the synthesis of 1-O,3-N-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides was developed at the semi-pilot scale, starting from a two-step continuous enzymatic process with immobilized Candida antarctica lipase B (Novozym® 435) in a packed-bed bioreactor, previously optimized at the laboratory scale. This process involved the selective N-acylation of 3-amino-1,2-propanediol (step 1), followed by the selective O-acylation of the N-acyl 3-amino-1,2-propanediol synthesized in the first step, with various fatty acids as acyl donors, to produce N,O-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides (step 2). Under partially optimized operating conditions, high synthesis yields and production rates were obtained, within the ranges 76–92% and 3.7–4.6 g h−1 (step 1), or 23–36% and 1–1.4 g h−1 (step 2), respectively, depending on the fatty acids used as acyl donors. The overall synthesis yields varied from 20 to 33%: the best yield was obtained using palmitic acid and lauric acid as first and second acyl donors, respectively. Together with the high production rates also obtained with these acyl donors, this confirms that this two-step process has great potential for the production of differently functionalized 1-O,3-N-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides on an industrial scale

Screening of thermotolerant microorganisms and application for oil separation from palm oil mill wastewater

The characteristics of palm oil mill wastewater (POMW) were brown color, pH 3.8-4.3, temperature 48-55oC, total solids 68.2-82.1 g/l, suspended solids 26.2-65.6 g/l, oil and grease 19.1-25.1 g/l, COD 49.9-160.7g/l and BOD 32.5-75.3 g/l. After centrifugation (3,184 xg) of 50 ml POMW for 10 min, the POMW was separated into 3 layers: top (oil), middle (supernatant) and bottom layer (sediment). The sediment containeddry weight 1.19 g and oil and grease 1.07 g. In order to release oil and grease trapped in palm fiber debris in the POMW, cellulase- and/or xylanase-enzyme-producing and thermotolerant microorganisms wereisolated. The isolates SO1 and SO2 were isolated from soil near the first anaerobic pond of the palm oil mill. They were aerobic, Gram positive, rod shaped, thermotolerant microorganisms and produced cellulase 12.11 U/ml (3 days) and 7.2 U/ml (4 days), and xylanase 50.98 U/ml (4 days) and 20.42 U/ml (4 days), respectivelyin synthetic medium containing carboxymethycellulose as a carbon source. When these 2 isolates were added into the steriled POMW under shaking condition for 7 days, after centrifugation at 3,184 xg the isolate SO1gave the better % reduction of dry weight (64.66 %) and of oil and grease in the bottom layer (85.32 %) of the POMW

Combined effect of crude herbal extracts, pH and sucrose on the survival of Candida parapsilosis and Zygosaccharomyces fermentati in orange juice

The purpose of this study was to evaluate the antimicrobial activity of crude extracts of cinnamon and clove compared with potassium sorbate against food spoilage yeasts isolated from orange juice (Candidaparapsilosis and Zygosaccharomyces fermentati). The ethanolic extract of both cinnamon and clove showed activity against C. parapsilosis and Z. fermentati with minimum inhibitory concentrations (MIC) of 1.0 and0.5 mg/ml by agar dilution method, respectively. While potassium sorbate showed activity against both yeasts with MIC 0.4 mg/ml. The combined effect of pH, concentration of sucrose and cinnamon extract or cloveextract or potassium sorbate in orange juice on the survival of the isolated yeasts were studied using Response Surface Methodology. The pH of orange juice and the concentration of cinnamon or clove extracthad the most significant (P<0.05) effect on the survival of C. parapsilosis and Z. fermentati while concentration of sucrose had the least effect. Survival of C. parapsilosis and Z. fermentati was mostly affected by theconcentration of potassium sorbate but pH and the concentration of sucrose did not have significant effect on the survival of Z. fermentati

Optimization of exopolysaccharides production by Weissella confusa NH 02 isolated from Thai fermented sausages

Exoploysaccharides (EPSs) producing lactic acid bacteria (LAB) were isolated from Thai traditional fermented foods. Colonies exhibiting a clear zone and ropiness on modified MRS agar containing 2% (w/v) sucrose and 0.02% (w/v) bromocresol purple were selected for Gram staining and catalase test. From 140 isolates, 120 isolates were identified as LAB. However, only 14 strains were able to produce a large amount of EPSs (>5.9 g/l) when cultivated in modified MRS broth containing 2% (w/v) sucrose at 37ºC for 24 hrs. The highest viscosity and yield of EPSs were obtained from isolate NH 02. Based on 16S rDNA analysis, strain NH 02 was identified as Weissella confusa. Sucrose (40 g/l), an initial pH of modified MRS at 7.0, and a cultivation temperature of 37ºC were the optimum conditions, in which EPSs were produced at levels up to 18.08 g/l within 12 hrs. EPSs produced by W. confusa NH 02 contained only glucose and had a molecular mass of 1.13106Da. to 18.08 g/l within 12 hrs

Optimization of lipase entrapment in alginate gel bead for palm olein hydrolysis

Lipase from Pseudomonas sp. was entrapped by drop-wise addition of an aqueous mixture of alginate and the biocatalyst to hardening solution of CaCl2 for the purpose of palm olein hydrolysis. Effects ofimmobilization conditions including alginate concentration, CaCl2 concentration, enzyme concentration and bead size on immobilized yield, immobilized lipase activity and recovery of activity (specific activity ratio ofentrapped lipase to free lipase) were investigated. An increase in alginate concentration raised immobilized yield, but decreased immobilized lipase activity and recovery of activity. CaCl2 concentration in the testedrange of 50-200 mM had slight effects on immobilized yield, immobilized lipase activity and recovery of activity. In contrast to immobilized lipase activity, immobilized yield and recovery of activity decreased withincreasing enzyme concentration. With increasing bead size, immobilized lipase activity and recovery of activity decreased due to mass transfer resistance whereas immobilized yield was unchanged. The optimumcondition for lipase entrapment in alginate gel bead was alginate concentration at 2% (w/v), CaCl2 concentration at 100 mM, enzyme concentration at 30 U/ml and bead size at 2 mm. Under this entrapmentcondition, 8.11 U/ml of immobilized lipase was obtained with 95.2% of immobilized yield and 22.2% of recovery of activity

Saccharification of cassava starch by Saccharomycopsis fibuligera YCY1 isolated from Loog-Pang (rice cake starter)

The main objectives of this study were to select amylolytic yeasts from Loog-Pang, a traditional starter culture for production of alcoholic foods and drinks in southern Thailand, and to optimize the saccharification of cassava starch to reducing sugar by the selected yeast isolate. Seventy-four yeast isolates were obtained from ten samples of Loog-Pang. The isolates were tested for amylolytic activity on Yeast-Peptone Cassava medium (YPC) contained 30 g/l of cassava starch.Only three isolates showed amylolytic activity which produced clear zone on the YPC agar. The best amylolytic strain with clear zone of 8 mm was identified by 26s rDNA as Saccharomycopsis fibuligera. The optimum medium for saccharification by Saccharomycopsis fibuligera. YCY1 was only 50 g/l of cassava starch in distilled water without nitrogen sources added and pH adjustment. The optimal saccharification conditions were 200 ml cassava starch (50 g/l) in 500 ml Erlenmeyer flask, shaking at 100 rpm and 37oC. Under these conditions, the highest reducing sugar was obtained 46±0.53 g/l after 120 h cultivation (84% of the theoretical yield)