Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

This study presents an effective technology for the olive processing industry to remediate olive washing water. A 14.5-L enclosed tubular photobioreactor was inoculated with a stable microalgal-bacterial consortium obtained by screening strains well adapted to olive washing water. The capacity of an enclosed tubular photobioreactor to remove toxic compounds was evaluated under photosynthesis conditions and without any external supply of oxygen. The results showed that the dominant green microalgae Scenedesmus obliquus, Chlorella vulgaris and the cyanobacteria Anabaena sp. and bacteria present in olive washing water (i.e. Pantoea agglomerans and Raoultella terrigena) formed a synergistic association that was resistant to toxic pollutants present in the effluent and during the initial biodegradation process, which resulted in the breakdown of the pollutant. Total phenolic compounds, COD, BOD5, turbidity and colour removals of 90.3 ± 11.4, 80.7 ± 9.7, 97.8 ± 12.7, 82.9 ± 8.4 and 83.3 ± 10.4 %, respectively, were recorded in the photobioreactor at 3 days of hydraulic retention time. Graphical abstract Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

Immobilization of Delftia tsuruhatensis in macro-porous cellulose and biodegradation of phenolic compounds in repeated batch process.

Delftia tsuruhatensis BM90, previously isolated from Tyrrhenian Sea and selected for its ability to degrade a wide array of phenolic compounds, was immobilized in chemically modified macro porous cellulose. The development of bacterial adhesion on the selected carrier was monitored by scanning electron microscopy. Evident colonization started already after 8h of incubation. After 72h, almost all the carrier surface was covered by the bacterial cells. Extracellular bacterial structures, such as pili or fimbriae, contributed to carrier colonization and cell attachment. Immobilized cells of D. tsuruhatensis were tested for their ability to biodegrade a pool of 20 phenols in repeated batch process. During the first activation batch (72h), 90% of phenols degradation was obtained already in 48h. In the subsequent batches (up to 360h), same degradation was obtained after 24h only. By contrast, free cells were slower: to obtain almost same degradation, 48h were needed. Thus, process productivity, achieved by the immobilized cells, was double than that of free cells. Specific activity was also higher suggesting that the use of immobilized D. tsuruhatensis BM90 could be considered very promising in order to obtain an efficient reusable biocatalyst for long-term treatment of phenols containing effluents.

Efficient removal of pollutants from olive washing wastewater in bubble-column bioreactor by Trametes versicolor.

The white-rot fungi Panus tigrinus, Funalia trogii and Trametes versicolor have been tested in shake flasks for the reduction of olive washing wastewater (OWW) pollutants and production of oxidases on OWW-based media. P. tigrinus was rejected for its scarce performance. F. trogii showed best production of laccase (27 000 Ug(-1)), while T. versicolor appeared a good pollutant degrader reducing colour, COD and phenols by 60, 72 and 87%, respectively. Only T. versicolor grew well in bubble-column bioreactor: its OWW depollution, in continuous process, led to colour, COD and phenols reduction by 65%, 73% and 89%, respectively. Optimal dilution rate was 0.225d(-1) (0.225 m(3) of effluent treated daily per m(3) of bioreactor). Thus, a small bioreactor (10 m(3)) could treat daily the amount of OWW produced by a standard olive washing machine (2m(3)d(-1)). For these reasons, this process could be proposed as a simple, efficient and low-cost OWW treatment.

The chitinolytic activity of Penicillium janthinellum P9: purification, partial characterization and potential applications.

AIMS: To purify and characterize the chitinolytic activity of Penicillium janthinellum P9 and to evaluate possible uses of the purified enzymes in the control of fungal growth and spore germination. METHODS AND RESULTS: The chitinolytic activity of P. janthinellum P9 was associated to two beta-N-acetyl-hexosaminidases (CHI1 and CHI2) that were purified by preparative isoelectric focusing and preparative electrophoresis and partially characterized. Treatment of test fungi with purified enzyme solutions caused reduced spore germination, reduction of hyphal length and mycelial damage. The combined action of the two enzymes and a systemic fungicide completely inactivated pests and food-spoiling moulds such as Fusarium solanii, P. canescens and Cladosporium cladosporioides. Treatment with the two enzymes increased germination of freeze-dried fungal spores. CONCLUSION: The chitinolytic activity of P. janthinellum P9 is associated with two extracellular beta-N-acetyl-hexosaminidases that can cause damage to the cell walls of other fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: This appears to be the first report on the characterization of extracellular chitinolytic enzymes produced by a Penicillium strain. The results of this study might have some impact in the applied research field.

Immobilized cell technology applied in solubilization of insoluble inorganic (rock) phosphates and P plant acquisition.

This paper reviews current knowledge of the production of organic acids by immobilized microorganisms with a simultaneous solubilization of rock phosphate in fermentation and soil conditions. The most widely applied methods are based on the passive immobilization in preformed porous carriers and entrapment of the microbial cells in natural gels. In general, immobilized systems show higher acid producing and rock phosphate solubilizing activity than freely suspended cells. The potential of gel-entrapped P-solubilizers and mycorrhizal fungi as microbial soil inoculants is also pointed out. Some advantages and constraints of using immobilized cells are discussed and a special emphasis on further research is given.

Repeated-batch production of pigments by immobilised Monascus purpureus.

Extracellular pigment production by immobilised Monascus purpureus C322 has been studied in repeated-batch processes using different immobilising carriers such as Ca-alginate, polyurethane sponge, active carbon and pearlite. With Ca-alginate, pigment production was maximum (30.5 UA470 as process mean production, three batches) while the cell leakage was negligible (0.4 g 1(-1) free biomass) and the bead mechanical stability good; with this carrier, an extended repeated-batch fermentation (nine batches, 55 days) was carried out: the process pigment productivity was 3.87 UA470 day(-1).

Inactivation of Mucor plumbeus by the combined actions of chitinase and high hydrostatic pressure.

Sporangiospores were treated with high hydrostatic pressure and/or fungal chitinase in order to study the inhibition of germination and growth of the food spoiling mold Mucor plumbeus. Total fungal inhibition was obtained either at 4.0 kbar or by 10 U/ml of chitinase from Penicillium janthinellum. A pretreatment with 1 U/ml of the same chitinase reduced the pressure necessary to obtain complete spore inhibition to 3 kbar.

Chitinolytic activity at low temperature of an Antarctic strain (A3) of Verticillium lecanii.

The chitinolytic activity of Verticillium cfr. lecanii A3, a strain isolated from continental Antarctica, was compared to those of two selected strains of Trichoderma harzianum. After 72 h of incubation at 25 degrees C in media containing chitin as the sole carbon source, all strains showed the same enzyme activity (ca. 230 mU/ml); at 15 degrees C, the levels of enzyme activity of the three strains were similar to those obtained at 25 degrees C. At 5 degrees C, in contrast, the activity of V. lecanii was ca. 4 times higher than those of both strains of T. harzianum (203 and 57 mU/ml, respectively; incubation time 144 h). The chitinase of V. lecanii, purified by preparative isoelectric focusing and ion-exchange chromatography, was shown to be a glycoprotein with apparent molecular weight of 45 kDa and isoelectric point of 4.9. The enzyme was active over a broad range of temperatures (5-60 degrees C): at 5 degrees C, its relative activity was still 50% of that recorded at 40 degrees C (optimal temperature). V. lecanii and its purified chitinase showed clear inhibitory effects on the growth of some test moulds such as Mucor plumbeus, Cladosporium cladosporioides, Aspergillus versicolor and Penicillium verrucosum: observations under the light and scanning electron microscopes revealed that growth inhibition was accompanied by mycelial damage and cell lysis.

[In vitro synthesis of interleukin 2 (IL-2) by T lymphocytes extracted from a lymphoepithelial thymoma. Purification and biochemical characterization]. / Sintesi di interleuchina 2 (IL-2) in vitro da parte di T-linfociti estratti da timoma linfoepiteliale. Purificazione e caratterizzazione biochimica.

T (E+) lymphocytes purified from lymphoepithelial thymoma surgically removed from an asymptomatic 12 yrs old girl were cultured in presence of PHA-P; culture supernatant contained a T cell growth factor (IL-2) biochemically different from that purifiable from supernatants of normal T cells. Differences in molecular weight, isoelectric point and ion exchange elution pattern would allow to compare this abnormal IL-2, (named Thy-IL-2 from Thymus) to that already characterized from the HUT 102 T cell line (L-TCGF peak II). A comparison of biochemical properties of Thy-IL-2 and normal IL-2 (N-IL-2) is also presented; the biological significance of such differences are discussed.