Macro-kinetic investigation on phenol uptake from air by biofiltration: Influence of superficial gas flow rate and inlet pollutant concentration

The macro-kinetic behavior of phenol removal from a synthetic exhaust gas was investigated theoretically as well as experimentally by means of two identical continuously operating laboratory-scale biological filter bed columns. A mixture of peat and glass beads was used as filter material. After sterilization it was inoculated with a pure strain of Pseudomonas putida, as employed in previous experimental studies. To determine the influence of the superficial gas flow rate on biofilter performance and to evaluate the phenol concentration profiles along the column, two series of continuous tests were carried out varying either the inlet phenol concentration, up to 1650 mg . m(-3), or the superficial gas flow rate, from 30 to 460 m(3) . m(-2) . h(-1). The elimination capacity of the biofilter is proved by a maximum volumetric phenol removal rate of 0.73 kg . m(-3) . h(-1). The experimental results are consistent with a biofilm model incorporating first-order substrate elimination kinetics. The model may be considered a useful tool in scaling-up a biofiltration system. Furthermore, the deodorization capacity of the biofilter was investigated, at inlet phenol concentrations up to 280 mg . m(-3) and superficial gas flow rates ranging from 30 to 92 m(3) . m(-2) . h(-1). The deodorization of the gas was achieved at a maximum inlet phenol concentration of about 255 mg . m(-3), operating at a superficial gas flow rate of 30 m(3) . m(-2) . h(-1). (c) 1996 John Wiley & Sons, Inc.     

First report of Garella musculana (Erschov, 1874) (Lepidoptera: Nolidae) in Italy with insights into its identity

The Asian walnut moth, Garella musculana (Erschov, 1874) (Lepidoptera: Nolidae), is a major pest of walnut. Native to Central Asia, it was found to be invasive in 2008 in Sevastopol (Crimea) and nowadays widespread in Turkey, Bulgaria, Romania and Russia. Here, we account for the finding of G. musculana in NE Italy (Veneto region) in 2021, where adults were found in a light lamp, representing the first record of the Asian walnut moth for this country and Western Europe. Adult specimens were identified morphologically on both external characters and genitalia features. G. musculana larvae and damage were also observed on a plantation of Juglans regia L. (Fagales: Juglandaceae) located in Veneto in October 2021. A COI-barcoding analysis was performed to attain a molecular characterization of our specimens and probate our morphological identification. However, because no sequence of G. musculana was present in major gene databases and the similarity of our sequences with those attributed to Garella ruficirra (Hampson, 1905) (Lepidoptera: Nolidae) made clear that these taxa deserved further scrutiny regarding their specific distinction. Some subtle differences in the male terminalia could be found between them and their vast geographic distributions, but the strong similarity in most features calls for further morphological and genetical insights on a broad set of samples to assess whether they represent two closely related, substantially parapatric species, or a unique, geographically varying entity. Solving this issue may turn out crucial in the identification and proper management of walnut moths of the genus Garella.     

Detection and Genotyping of Campylobacter jejuni and Campylobacter coli by Use of DNA Oligonucleotide Arrays

Campylobacter have emerged as the most common bacterial food-borne illness in the developed world. The ability to reduce Campylobacter infections in humans is linked to the full comprehension of the principal key aspects of its infection cycle. A microbial diagnostic microarray detecting Campylobacter housekeeping, structural, and virulence associated genes was designed and validated using genomic DNA from reference and field strains of Campylobacter jejuni and coli isolated from human, chicken, and raw milk. This microarray was confirmed to be a powerful diagnostic tool for monitoring emerging Campylobacter pathotypes as well as for epidemiological, environmental, and phylogenetic studies including the evaluation of genome plasticity.     

Toluene vapour removal in a laboratory-scale biofilter

A bench-scale biofilter with a 0.5-m high filter bed, inoculated with a toluene-degrading strain of Acinetobacter sp. NCIMB 9689, was used to study toluene removal from a synthetic waste air stream. Different sets of continuous tests were conducted at influent toluene concentrations ranging over 0.1–4.0 g m⁻³ and at superficial gas velocities ranging over 17.8–255 m h⁻¹. The maximum volumetric toluene removal rate for the biofilter (242 g m⁻³ h⁻¹) was obtained at a superficial gas velocity of 127.5 m h⁻¹ (corresponding to a residence time of 28 s) and a toluene inlet concentration of 4.0 g m⁻³. Under these operating conditions, toluene removal efficiency was only 0.238, which suggested that effective operation required higher residence times. Removal efficiencies higher than 0.9 were achieved at organic loads less than 113.7 g m⁻³ h⁻¹. A macro-kinetic study, performed using concentration profiles along the bioreactor, revealed this process was limited by diffusion at organic loads less than 100 g m⁻³ h⁻¹ and by biological reaction beyond this threshold. Received: 10 October 1999 / Received revision: 15 February 2000 / Accepted: 18 February 2000     

Mycelium-bound carboxylesterase from Aspergillus oryzae: an efficient catalyst for acetylation in organic solvent

Dry mycelium of a strain of Aspergillus oryzae efficiently catalyzed the esterification between free acetic acid and primary alcohols (geraniol and ethanol) in organic solvent. The growth conditions to obtain high activity of mycelium-bound enzymes were firstly evaluated. A medium containing Tween 80 as carbon source furnished mycelium with the highest activity in the hydrolysis of alpha-naphthyl esters (alpha-N-acetate, butyrate, caprylate). Dry mycelium was employed to select suited conditions for an efficient acetylation of ethanol and geraniol in heptane. Maximum productions were obtained using 30 g l(-)(1) of lyophilized cells: 12.4 g l(-)(1) of geranyl acetate were produced at 80 degrees C starting from 75 mM geraniol and acetic acid (84% molar conversion) and 4.1 g l(-)(1) of ethyl acetate at 50 degrees C from 50 mM ethanol and acetic acid (94% molar conversion) after 24 h. The stability of the mycelium-bound carboxylesterases are notable since only 10-30% loss of activity was observed after 14 days at temperatures between 30 and 50 degrees C.     

Gradual translocation of spatial correlates of neuronal firing in the hippocampus toward prospective reward locations

In a continuous T-maze alternation task, CA1 complex-spike neurons in the hippocampus differentially fire as the rat traverses overlapping segments of the maze (i.e., the stem) repeatedly via alternate routes. The temporal dynamics of this phenomenon were further investigated in the current study. Rats learned the alternation task from the first day of acquisition and the differential firing pattern in the stem was observed accordingly. More importantly, we report a phenomenon in which spatial correlates of CA1 neuronal ensembles gradually changed from their original firing locations, shifting toward prospective goal locations in the continuous T-maze alternation task. The relative locations of simultaneously recorded firing fields, however, were preserved within the ensemble spatial representation during this shifting. The within-session shifts in preferred firing locations in the absence of any changes in the environment suggest that certain cognitive factors can significantly alter the location-bound coding scheme of hippocampal neurons.     

Changes in hormonal profile, gonads and sperm quality of Argyrosomus regius (Pisces, Scianidae) during the first sexual differentiation and maturation

In the present study, sexual gonadal differentiation and first sexual maturation of Meagre (Argyrosomus regius) was studied, based upon the annual changes in gonadosomatic index (GSI), gonadal histology, and the plasma steroid hormones, testosterone (T), 11-ketotestosterone (11-KT), and estradiol (E2). In addition, spermatozoa characteristics were evaluated by measuring sperm motility and morphology. Results demonstrated that Meagre completes sex differentiation at 10 to 12 mo of age, and are group-synchronous spawners, which reach puberty at 2 (mean length 26.8 ± 0.7 cm, mean weight 920 ± 75 g; N = 10) and 3 (mean length 35.8 ± 0.8 cm, mean weight 1610 ± 89 g; N = 10) years of age for males and females, respectively. In males, during the sex differentiation period, T levels were significantly higher with respect to those of 11-KT; this suggests that T has a key role in the early phases of the sex differentiation. During the spawning season an increase in plasma concentrations of all hormones was observed with 11-KT levels being significantly higher that those of T. In females, during the sex differentiation period, there was an increase in E2 plasma levels, while during the first spawning season, a significant increase of T and E2 levels were measured. Regarding sperm characteristics, the measured curvilinear velocity (VCL) and straight-linear velocity (VSL), resulted in the same order of magnitude with respect to those measured in other marine fish, while the average path velocity (VAP) was similar to that measured in the European Eel. The head of Meagre spermatozoa presents as oval shaped with a surface area of approximately 3.66 μm² and a perimeter of approximately 6.65 μm. All these findings represent an important basis for further investigation on the reproductive biology of this specie and may assist the farmers to improve seed production in aquaculture.     

Diversity and physiological characterization of d-xylose-fermenting yeasts isolated from the brazilian amazonian forest

Background

This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates.

Methodology/Principal Findings

A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB)-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L) culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g) and productivities (0.62 g/L·h to 0.75 g/L·h). Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g), with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g) and productivity (0.2 g/L·h), while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers.

Conclusions/Significance

This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates.     

Aquaporin inhibition changes protein phosphorylation pattern following sperm motility activation in fish

Our previous studies demonstrated that osmolality is the key signal in sperm motility activation in Sparus aurata spermatozoa. In particular, we have proposed that the hyper-osmotic shock triggers water efflux from spermatozoa via aquaporins. This water efflux determines the cell volume reduction and, in turn, the rise in the intracellular concentration of ions. This increase could lead to the activation of adenylyl cyclase and of the cAMP-signaling pathway, causing the phosphorylation of sperm proteins and then the initiation of sperm motility. This study confirms the important role of sea bream AQPs (Aqp1a and Aqp10b) in the beginning of sperm motility. In fact, when these proteins are inhibited by HgCl₂, the phosphorylation of some proteins (174 kDa protein of head; 147, 97 and 33 kDa proteins of flagella), following the hyper-osmotic shock, was inhibited (totally or partially). However, our results also suggest that more than one transduction pathways could be activated when sea bream spermatozoa were ejaculated in seawater, since numerous proteins showed an HgCl₂(AQPs)-independent phosphorylation state after motility activation. The role played by each different signal transduction pathways need to be clarified.