Vanillin bioproduction from alkaline hydrolyzate of corn cob by Escherichia coli JM109/pBB1

Hydrolysis of corn cob performed for 6 h with 0.5 N NaOH at solid/liquid ratio of 0.084 g/g allowed obtaining a hydrolyzate containing 1171 ± 34 mg/l ferulic acid and 2156 ± 63 mg/l p-coumaric acid that was used as a medium for vanillin bioproduction by the engineered strain Escherichia coli JM109/pBB1. Aiming at maximizing vanillin bioproduction, the effects of medium heat sterilization, one-stage or two-stage pre-cultivation, adaptation of the microorganism to the hydrolyzate and inoculum biomass level were investigated. Biomass pre-cultivated once in unsterilized hydrolyzate was able to effectively convert ferulic and p-coumaric acids to a mixture of vanillin, vanillic acid and vanillyl alcohol provided with the typical vanilla flavor. At initial biomass concentration of 0.5 g_DM/l, maximum values of vanillin concentration (239 ± 15 mg/l), vanillin yield on consumed ferulic acid (0.66 ± 0.03 mol/mol) and vanillin volumetric productivity (10.9 ± 0.7 mg/lh) were obtained after 22 h.     

Non-Thermal Plasmas Affect Plant Growth and DNA Methylation Patterns in Glycine max

Journal of Plant Growth Regulation - Non-thermal plasmas (NTP) are partially ionized gases that represent a promising technology for seed treatment to enhance seed health while promoting...     

Adenosine triphosphate concentration and beta-D-glucuronidase activity as indicators of sea bass semen quality

The most common parameters used to evaluate sperm quality are motility rate and duration and fertilization ability. In this study, chemical and biochemical parameters of sea bass (Dicentrarchus labrax) sperm were investigated to find an alternative method for evaluating sperm fertilization ability before and after cryopreservation. The biochemical and chemical analyses were performed with fresh and frozen-thawed sperm and seminal plasma. To cryopreserve sperm, 250-microl straws were used. Fertilization ability was evaluated by inseminating eggs (obtained from hormonally stimulated females) with fresh and cryopreserved sperm. The results revealed a linear relationship (P < 0.05) between semen fertilization capacity and some seminal plasma (beta-D-glucuronidase activity, potassium concentration) and sperm (ATP concentration, aspartate aminotransferase activity) parameters. Variations in semen fertilization rate could be best described by two multiple regression models: one including the sperm parameters and another including the seminal plasma parameters. For practical application, the use of simple regression models is of value. Fertilization rate in both fresh and cryopreserved sperm was reliably predicted by determining the ATP concentration or the beta-D-glucuronidase activity or both.     

Evaluation of DNA damage in Dicentrarchus labrax sperm following cryopreservation

In this paper, DNA laddering analysis and single-cell gel electrophoresis (SCGE) or Comet assay, were used to detect DNA damage in response to a cryopreservation process in sea bass spermatozoa. The results obtained demonstrate that the cryopreservation protocol used to cryopreserve the sea bass sperm cause significantly damage at DNA level. In fact, the degree of DNA damage in frozen-thawed sperm (%DNAT=38.2+/-11.2, MT=498.9+/-166.4, n=3) was different (P<0.01) from that measured in fresh sperm (%DNAT=32.7+/-11.1, MT=375.2+/-190.7, n=3). Data here reported also demonstrated the fundamental role played by cryoprotectants (BSA and Me2SO) in reducing fish sperm DNA fragmentation. Finally, from our results, the ability of SCGE to reveal DNA fragmentation in fish sperm is also confirmed.     

Batch kinetics of Pseudomonas sp. growth on benzene. Modeling of product and substrate inhibitions

Batch tests of benzene degradation were performed in liquid phase at 30 degrees C, pH 6.8 +/- 0.2, and 200 rpm in two 3-L stirred tank bioreactors, using the benzene-degrading bacterium Pseudomonas sp. NCIMB 9688. A relatively high starting biomass level (220-270 mg(X)/L) and starting benzene concentration ranging from 20 to 200 mg(S)/L were selected as conditions to investigate possible inhibition phenomena. Volumetric as well as specific rates of biomass formation and substrate consumption were calculated from experimental data of both growth and benzene degradation and used to propose and check a new overall kinetic model for cell growth simultaneously accounting for both product and substrate inhibitions. The results of the present study evidenced the occurrence of a competitive-type product inhibition due to 2-hydroxymuconic semialdehyde (K(iP)' = 0.902 mg(S)/L), which was stronger than the uncompetitive-type inhibition exerted by substrate (K(iS) = 7.69 mg(S)/L).     

Synthesis of ethyl phenylacetate by lyophilized mycelium of Aspergillus oryzae

Lyophilized mycelia of Aspergillus oryzae CBS 102.07, Aspergillus oryzae MIM, Rhizopus oryzae CBS 112.07, Rhizopus oryzae CBS 391.34, Rhizopus oryzae CBS 260.28 and Rhizopus oryzae CBS 328.47 were tested in this study to select the best biocatalysts for ethanol acylation with phenylacetic acid. The mycelium-bound carboxylesterase activity of A. oryzae MIM, which exhibited the best performances, was initially investigated at 50°C, either in 0.1 M phosphate buffer or in n-heptane to catalyse the hydrolysis or the synthesis, respectively, of ethyl phenylacetate. The results in terms of product and substrate concentrations versus time were used to estimate the maximum molar conversions at equilibrium, the equilibrium constants, and the times needed to reach half maximum conversions, thus providing sufficient information about this biotransformation. The values of the apparent equilibrium constants, estimated at 20°C<T<50°C, were finally used to estimate the thermodynamic parameters of ethanol acylation by this biocatalyst.     

The adenovirus E3 region 14.7 kDa protein, heat and sodium arsenite inhibit the TNF-induced release of arachidonic acid.

In this report we show that the adenovirus E3 region 14.7 kDa protein, heat and sodium arsenite, which have been defined previously as inhibitors of cytolysis, inhibit the tumor necrosis factor-alpha (TNF)-induced release of 3H-arachidonic acid from cycloheximide-sensitized C3HA fibroblasts. Since the A23187-induced release of 3H-a.a. was unaffected, our results suggest that these inhibitors provide resistance to lysis by selectively interfering with the lytic response pathway. Our results also show that heat and sodium arsenite can themselves induce the release of 3H-arachidonic acid. These results raise the possibility that stressor-induced resistance to TNF results from the selective desensitization of phospholipase A2.     

Spathaspora brasiliensis sp. nov., Spathaspora suhii sp. nov., Spathaspora roraimanensis sp. nov. and Spathaspora xylofermentans sp. nov., four novel d-xylose-fermenting yeast species from Brazilian Amazonian forest

Four new d-xylose fermenting yeast species of the clade Spathaspora were recovered from rotting-wood samples in a region of Amazonian forest, Northern Brazil. Three species produced unconjugated asci with a single elongated ascospore with curved ends. These species are described as Spathaspora brasiliensis, Spathaspora suhii and Spathaspora roraimanensis. Two isolates of an asexually reproducing species belonging to the Spathaspora clade were also obtained and they are described as Spathaspora xylofermentans. All these species are able to ferment d-xylose during aerobic batch growth in rich YP (1 % yeast extract, 2 % peptone and 2 % D-xylose) medium, albeit with differing efficiencies. The type strains are Spathaspora brasiliensis sp. nov UFMG-HMD19.3 (=CBMAI 1425=CBS 12679), Spathaspora suhii sp. nov. UFMG-XMD16.2 (=CBMAI 1426=CBS 12680), Spathaspora roraimanensis sp. nov. UFMG-XMD23.2 (CBMAI 1427=CBS 12681) and Spathaspora xylofermentans sp. nov. UFMG-HMD23.3 (=CBMAI 1428=CBS 12682).     

Effect of cryopreservation on phosphorylation state of proteins involved in sperm motility initiation in sea bream

We have previously demonstrated that in sea bream Sparus aurata motility initiation determined changes in the phosphorylation state of some proteins. This paper describes an investigation of the effect of a freezing-thawing procedure on the protein phosphorylation/dephosphorylation pattern. Proteins extracted from fresh and cryopreserved spermatozoa (before and after motility activation) were separated on SDS-PAGE, blotted on nitrocellulose membrane and treated with anti-phosphotyrosine, anti-phosphothreonine, or anti-phosphoserine antibodies. The results obtained demonstrate that the cryopreservation protocol has a strong effect on the phosphorylation state of proteins. In general, compared to fresh sperm, phosphorylated proteins are most numerous in both activated and non-activated cryopreserved sperm, and in particular we observed a dramatic increase in threonine phosphorylation. However, frozen-thawed sperm showed a minor number of proteins that changed their phosphorylation state after motility activation. Among these, we identified the acetyl-coenzyme A synthetase that plays a role in sperm motility initiation in both fresh and cryopreserved sperm.