Biodiesel production from Jatropha curcas oil catalyzed by whole cells of Aureobasidium pullulans var. melanogenum SRY 14-3

The main obstacle to using lipase as a catalyst in industrial scale biodiesel production is the cost and availability of the enzyme. To overcome this obstacle, the potential of using a whole cell biocatalyst (for at least partial in situ lipase production) was evaluated as a means to reduce the cost of the lipase. The reaction conditions for biodiesel production via transesterification between Jatropha curcas (physic nut) oil and methanol when catalyzed in the presence of lipase-producing Aureobasidium pullulans yeast cells was investigated. The appropriate conditions for optimal biodiesel production were found to be 1:3 oil:methanol molar ratio at 30°C with constant stirring at 250 rpm. Under these conditions a maximum fatty acid methyl ester (biodiesel) production level of 71.8% was obtained after 72 h.Keywords: Lipase, Aureobasidium pullulans, physic nut oil, biodiesel, green energyAfrican Journal of Biotechnology Vol. 12(27), pp. 4380-438

NirK and nirS Nitrite reductase genes from non-agricultural forest soil bacteria in Thailand

The genetic heterogeneity of the nitrite reductase gene (nirK and nirS) fragments from denitrifying prokaryotes in a non-agricultural forest soil in Thailand was investigated using soil samples from the Plant Germplasm-Royal Initiation Project area in Kanchanaburi Province, Thailand. Soil bacteria were screened for denitrification activity and 13 (from 211) positive isolates were obtained and further evaluated for their ability to reduce nitrate and to accumulate or reduce nitrite. Three species with potentially previously unreported denitrifying activities were recorded. Analysis of the partial nirK and nirS sequences of these 13 strains revealed a diverse sequence heterogeneity in these two genes within the same environment and even potentially within the same host species, the potential existence of lateral gene transfer and the first record of both nirK and nirS homologues in one bacterial species. Finally, isolates of two species of bacteria (Corynebacterium propinquum and Micrococcus lylae) are recorded as denitrifiers for the first time

Overexpression of Fusarium solani lipase in Pichia pastoris and its application in lipid degradation

Fusarium solani NAN103 lipase was successfully overexpressed in Pichia pastoris using inducible expression system and constitutive expression system under the control of alcohol oxidase 1 promoter (pAOX1) and glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP), respectively. Lipase obtained using the constitutive promoter showed the highest activity of 18.8 U/mg in 3days of cultivation time. Optimal lipase activity was observed at pH 7.0 and 35 degrees C using p-nitrophenyl laurate as the substrate. Lipase activity was enhanced by Mn2+, Ba2+, Li+, Ca2+, Ni2+, CHAPS and Triton X-100 but was inhibited by Hg2+, Ag+ and SDS. The addition of 10% v/v of octanol, p-xylene, hexane and isopropanol increased lipase activity. Cultivation of lipase-expressing P. pastoris under pGAP in synthetic wastewater containing 1% w/v palm oil resulted in degradation of 87% of the oil within 72h. P. pastoris expressing F. solani lipase from constitutive expression system has the potential to be used as an alternative microorganism for lipid degradation

Bioethanol Production from Ceratophyllum demersum L. and Carbon Footprint Evaluation

The aim of this research was to find the suitable conditions for bio-ethanol production from Ceratophyllum demersum L., an abundant aquatic plant. The parameters affected to alcohol production were evaluated. Percentage of solid (10, 20, and 30% (w/v)), the amount of yeast (5, 10, and 15% (w/v)), pH value (4, 5, and 6) and temperature (30, 35, and 40°C) were carried out. The results elucidated that the conditions to produce the maximum bio-ethanol from Ceratophyllum demersum L. was applied with 10% (w/v) of solid, 10% (w/v) of yeast, controlled pH value of 6 and temperature of 30°C. The highest yield of bio-ethanol production was reached 2.92 g ethanol/L within 24 h. Moreover, the Carbon Footprint for ethanol production was calculated only from 2 steps of life cycle analysis which were the step of raw material acquisition from macro algae cultivation and manufacturing process from bio-ethanol production. Consequently, the carbon footprint for ethanol production from Ceratophyllum demersum L. was 77.88 kg CO2 equivalent.

Evaluation of Biodiesel Production Using Oil Feedstock from Contaminated Macro Algae in Shrimp Farming

This research was aimed to manage and utilize 3 contaminated macro algae from shrimp farming, Caulerpa lentillifera, Caulerpa racemosa and Acanthophora spicifera as an alternative oil feedstock for biodiesel production. Oil extraction was performed and biodiesel production was conducted in further to get the maximum yield. The optimization of condition, such as the molar ratio of oil to methanol, effect of reaction time, reaction temperature, and percentage of catalyst were carried out. The results were discovered that the average amount of oil from these macro algae were approximately 3.3% from dried basis. The optimum condition for biodiesel production with these 3 macro algae was nearly the same. The reaction was completed within 8 h and the achievement of biodiesel yield was 55.58% from Caulerpa lentillifera with the suitable condition of oil to methanol molar ratio 1:15 using 1% of KOH at 60°C. Caulerpa racemosa can be produced 58.36% of biodiesel from the condition of oil to methanol ratio 1:15 with 1.5% of KOH at 60°C. As well, the optimum condition for biodiesel production from Acanthophora spicifera was using 1:12 of oil to methanol ratio with 1% of KOH and obtained 49.29% of biodiesel

Overexpression of Fusarium solani lipase in Pichia pastoris and its application in lipid degradation

Fusarium solani NAN103 lipase was successfully overexpressed in Pichia pastoris using inducible expression system and constitutive expression system under the control of alcohol oxidase 1 promoter (pAOX1) and glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP), respectively. Lipase obtained using the constitutive promoter showed the highest activity of 18.8 U/mg in 3days of cultivation time. Optimal lipase activity was observed at pH 7.0 and 35 degrees C using p-nitrophenyl laurate as the substrate. Lipase activity was enhanced by Mn2+, Ba2+, Li+, Ca2+, Ni2+, CHAPS and Triton X-100 but was inhibited by Hg2+, Ag+ and SDS. The addition of 10% v/v of octanol, p-xylene, hexane and isopropanol increased lipase activity. Cultivation of lipase-expressing P. pastoris under pGAP in synthetic wastewater containing 1% w/v palm oil resulted in degradation of 87% of the oil within 72h. P. pastoris expressing F. solani lipase from constitutive expression system has the potential to be used as an alternative microorganism for lipid degradation

Cloning, expression, and characterization of Aureobasidium melanogenum lipase in Pichia pastoris

cDNA of Aureobasidium melanogenum lipase comprises 1254bp encoding 417 amino acids, whereas genomic DNA of lipase comprises 1311bp with one intron (57bp). The lipase gene contains a putative signal peptide encoding 26 amino acids. The A. melanogenum lipase gene was successfully expressed in Pichia pastoris. Recombinant lipase in an inducible expression system showed the highest lipase activity of 3.8 U/mL after six days of 2% v/v methanol induction. The molecular mass of purified recombinant lipase was estimated as 39kDa using SDS-PAGE. Optimal lipase activity was observed at 35-37 degrees C and pH 7.0 using p-nitrophenyl laurate as the substrate. Lipase activity was enhanced by Mg2+, Mn2+, Li+, Ca2+, Ni2+, CHAPS, DTT, and EDTA and inhibited by Hg2+, Ag+, SDS, Tween 20, and Triton X-100. The addition of 10% v/v acetone, DMSO, p-xylene, and octanol increased lipase activity, whereas that of propanol and butanol strongly inhibited it