Ultrasonic intensification as a tool for enhanced microbial biofuel yields.

Ultrasonication has recently received attention as a novel bioprocessing tool for process intensification in many areas of downstream processing. Ultrasonic intensification (periodic ultrasonic treatment during the fermentation process) can result in a more effective homogenization of biomass and faster energy and mass transfer to biomass over short time periods which can result in enhanced microbial growth. Ultrasonic intensification can allow the rapid selective extraction of specific biomass components and can enhance product yields which can be of economic benefit. This review focuses on the role of ultrasonication in the extraction and yield enhancement of compounds from various microbial sources, specifically algal and cyanobacterial biomass with a focus on the production of biofuels. The operating principles associated with the process of ultrasonication and the influence of various operating conditions including ultrasonic frequency, power intensity, ultrasonic duration, reactor designs and kinetics applied for ultrasonic intensification are also described.

Molecular characterization of a Xylanase-producing fungus isolated from fouled soil

Xylanase (EC 3. 2. 1. 8), hydrolyzes xylo-oligosaccharides into D-xylose and required for complete hydrolysis of native cellulose and biomass conversion. It has broad range of applications in the pulp and paper, pharmaceutical and Agri-food industries. Fifty fungal species were isolated from the fouled soil around an oil refinery and screened for the production of xylanase enzyme by enrichment culture techniques. The isolated fungal strain was identified as Hypocrea lixii SS1 based on the results of biochemical tests and 18s rRNA sequencing. The phylogenetic tree was constructed using the MEGA 5 software. Further, Hypocrea lixii SS1 was tested for the ability to utilize the sunflower oil sludge (waste from the oil industry) as the sole carbon source for xylanase production. The growth characteristics of Hypocrea lixii SS1 were also studied and maximum growth was found on the 7th day of incubation. The fungus showed a remarkable xylanase production of 38.9 U/mL. Xylanase was purified using a combination of 0-50% NH4SO2 precipitation, DEAE-sepharose and Sephacryl S-200 chromatography. Single peak obtained in RP-HPLC confirms the purity of xylanase. Further the enzyme produced was affirmed as xylanase with its molecular weight (29 kDa) using SDS-PAGE.

Molecular characterization of a Xylanase-producing fungus isolated from fouled soil.

Xylanase (EC 3. 2. 1. 8), hydrolyzes xylo-oligosaccharides into D-xylose and required for complete hydrolysis of native cellulose and biomass conversion. It has broad range of applications in the pulp and paper, pharmaceutical and Agri-food industries. Fifty fungal species were isolated from the fouled soil around an oil refinery and screened for the production of xylanase enzyme by enrichment culture techniques. The isolated fungal strain was identified as Hypocrea lixii SS1 based on the results of biochemical tests and 18s rRNA sequencing. The phylogenetic tree was constructed using the MEGA 5 software. Further, Hypocrea lixii SS1 was tested for the ability to utilize the sunflower oil sludge (waste from the oil industry) as the sole carbon source for xylanase production. The growth characteristics of Hypocrea lixii SS1 were also studied and maximum growth was found on the 7(th) day of incubation. The fungus showed a remarkable xylanase production of 38.9 U/mL. Xylanase was purified using a combination of 0-50% NH4SO2 precipitation, DEAE-sepharose and Sephacryl S-200 chromatography. Single peak obtained in RP-HPLC confirms the purity of xylanase. Further the enzyme produced was affirmed as xylanase with its molecular weight (29 kDa) using SDS-PAGE.

An efficacious degradation of pesticide by salt tolerant Streptomyces venezuelae ACT 1.

Degradation of the organophosphorus pesticide has been studied using the marine isolate, Streptomyces venezuelae ACT1. The organism exhibited a specific growth rate of 0.371h(-1) and the organophosphorus hydrolase activity rate as 0.273h(-1). Hence the organism was found to be very effective towards the pesticide degradation. Further the substrate assimilation and inhibition model of the organism were demonstrated using Monod and Haldane model equations which depicted that the inhibition model fits well for both the cell growth and enzyme activity. The maximum specific growth rate and the enzyme activity rate were found to be 0.571h(-1) and 0.472h(-1), respectively. Effect of P0/X0 ratio on degradation and COD reduction rate revealed that higher these ratios raise the degradation rate and the COD reduction rate.

Enhanced production of thrombinase by Streptomyces venezuelae: kinetic studies on growth and enzyme production of mutant strain.

This investigation provides the enhanced production of thrombinase, a fibrinolytic enzyme using mutant Streptomyces venezuelae. Initially the mutagenesis of the marine isolate was done by UV and Ethyl methane sulfonate (EMS) and their mutational efficiencies were compared. The mutants were selected based on their high thrombinase activity and used for further studies. The mutant was found to be more halo and thermo tolerant comparing to wild. The effect of Dissolved oxygen level was also determined and the mutant offered the maximum specific growth rate as 0.2404 (h(-1)). The mutant showed high resistance to higher initial lactose concentration and the inhibition concentration was found to be 155.1mg/mL. The effect of S(0)/X(0) ratio on specific substrate consumption and production rate were also investigated. Both mutant and wild showed increase in specific substrate consumption and production rate at higher S(0)/X(0) ratio but the mutant showed better values than the wild strain.