Eliana Flávia Camporese Sérvulo

Lipopeptide Surfactant Production by Bacillus subtilis Grown on Low-Cost Raw Materials

The production of biosurfactant by Bacillus subtilis ATCC 6633 was investigated using commercial sugar, sugarcane juice and cane molasses, sugarcane juice alcohol stillage, glycerol, mannitol, and soybean oil. Commercial sugar generated the minimum values of surface tension, with the best results (28.7 mN/m, (relative critical micelle concentration [CMC−1] of 78.6) being achieved with 10 g of substrate/L in 48 h. At a pH between 7.0 and 8.0, a higher production of surface-active compounds and a greater emulsifier activity was also observed. Enrichment of the culture medium with trace minerals and EDTA showed maximum yields, whereas supplementation with yeast extract stimulated only cell growth. The kinetic studies revealed that biosurfactant production is a cell growth-associated process; surface tension, CMC, and emulsification index values of 29.6 dyn/cm, 82.3, and 57%, respectively, were achieved, thus indicating that it is feasible to produce biosurfactants from a renewable and low-cost carbon source.

Kinetic study of heavy crude oils by thermal analysis

The present work investigates the thermal behavior and kinetic of four types of petroleum samples: a medium crude oil—P1, one heavy oil—P2, and two extra heavy oils—P3 and P4 by TG, DTG, and DSC methods. Thus, this study may contribute to the characterization of petroleum with different °API values.

Optimizing Carbon/Nitrogen Ratio for Biosurfactant Production by a Bacillus subtilis Strain

A Bacillus subtilis strain isolated from contaminated soil from a refinery has been screened for biosurfactant production in crystal sugar (sucrose) with different nitrogen sources (NaNO3, (NH4)2SO4, urea, and residual brewery yeast). The highest reduction in surface tension was achieved with a 48-h fermentation of crystal sugar and ammonium nitrate. Optimization of carbon/nitrogen ratio (3, 9, and 15) and agitation rate (50, 150, and 250 rpm) for biosurfactant production was carried out using complete factorial design and response surface analysis. The condition of C/N 3 and 250 rpm allowed the maximum increase in surface activity of biosurfactant. A suitable model has been developed, having presented great accordance experimental data. Preliminary characterization of the bioproduct suggested it to be a lipopeptide with some isomers differing from those of a commercial surfactin.

Enhancement of Rhamnolipid Production in Residual Soybean Oil by an Isolated Strain of Pseudomonas aeruginosa

In the present work, the production of rhamnolipid from residual soybean oil (RSO) from food frying facilities was studied using a strain of Pseudomonas aeruginosa of contaminated lagoon, isolated from a hydrocarbon contaminated soil. The optimization of RSO, ammonium nitrate, and brewery residual yeast concentrations was accomplished by a central composite expeirmental design and surface response analysis. The experiments were performed in 500-mL Erlenmeyer flasks containing 50 mL of mineral medium, at 170 rpm and 30 ± 1°C, for a 48-h fermentation period. Rhamnolipid production has been monitored by measurements of surface tension, rhamnose concentration, and emulsifying activity. The best-planned results, located on the central point, have corresponded to 22 g/L of RSO, 5.625 g/L of NH4NO3, and 11.5 g/L of brewery yeast. At the maximum point the values for rhamnose and emulsifying index were 2.2 g/L and 100%, respectively.

Effect of Process Parameters on Production of a Biopolymer by Rhizobium sp

The production of biopolymers by a Rhizobium strain was studied under batch and bioreactor conditions. The best viscosity levels were obtained under low mannitol concentrations as well as low agitation and aeration conditions. Infrared spectra indicated the presence of chemical groups characteristic of microbially produced biopolymers, including C = O and O-acetyl groups. Thermogravimetric analysis showed the characteristic degradation profiles of the exopolysaccharide produced (T(onset) = 290degreesC). The experimental design showed that a low substrate concentration (10.0 g/L), and low aeration (0.2 vvm) and agitation (200 rpm) levels should be used. The maximum yield of the process was a Yp/s (g/g) of 0.19 +/- 0.1, obtained under optimized conditions.

Production of Bacillus sphaericus Entomopathogenic Biomass Using Brewery Residues

The use of brewery residues—yeast and trub—has been evaluated aiming to minimize the costs of the industrial production of Bacillus sphaericus-based bioinsecticide. Both brewery residues promoted growth and sporulation of the three B. sphaericus strains that were isolated from Brazilian soils (S1, S2, and S20). However, distinct growth and sporulation behaviors were observed in relation to the different nutritional conditions and strain used. The maximum sporulation percentage was obtained through the cultivation of S20 strain in brewery residual yeast. In general, the entomopathogenic biomasses produced showed good results for toxicity to Culex larvae. The minimum values of larvae population (LC50) were observed for the S20 strain grown on yeast brewery residue-containing media. After fermentation, a considerable decrease in the organic material of alternative media was verified, although the residual values were still higher than that considered appropriate for effluent discharge.

Brewery Wastes Reuse for Protease Production by Lactic Acid Bacteria Fermentation

This study evaluated the use of three solid brewery wastes: brewers spent grain, hot trub and residual brewers yeast, as alternative media for the cultivation of lactic acid bacteria to evaluate their potential for proteolytic enzyme production. Initially, a mixture experimental design was used to evaluate the effect of each residue, as well as different mixtures (with the protein content set at 4%) in the enzyme production. At predetermined intervals, the solid and liquid fractions were separated and the extracellular proteolytic activity was determined. After selecting the best experimental conditions, a second experiment, factorial experimental design, was developed in order to evaluate the protein content in the media (1 to 7%) and the addition of fermentable sugar (glucose, 1 to 7%). Among the wastes, residual yeast showed the highest potential for the production of extracellular enzymes, generating a proteolytic extract with 2.6 U/mL in 3 h. However, due to the low content of the fermentable sugars in the medium, the addition of glucose also had a positive effect, increasing the proteolytic activity to 4.9 U/mL. The best experimental conditions of each experimental design were reproduced for comparison, and the enzyme content was separated by ethanol precipitation. The best medium produced a precipitated protein with proteolytic activity of 145.5 U/g.

World market and biotechnological production of itaconic acid

The itaconic acid (IA) world market is expected to exceed 216 million of dollars by 2020 as a result of an increasing demand for bio-based chemicals. The potential of this organic acid produced by fermentation mainly with filamentous fungi relies on the vast industrial applications of polymers derived from it. The applications may be as a superabsorbent polymer for personal care or agriculture, unsaturated polyester resin for the transportation industry, poly(methyl methacrylate) for electronic devices, among many others. However, the existence of other substitutes and the high production cost limit the current IA market. IA manufacturing is done mainly in China and other Asia–Pacific countries. Higher economic feasibility and production worldwide may be achieved with the use of low-cost feedstock of local origin and with the development of applications targeted to specific local markets. Moreover, research on the biological pathway for IA synthesis and the effect of medium composition are important for amplifying the knowledge about the production of that biochemical with great market potential.

Generation, characterization and reuse of solid wastes from a biodiesel production plant

The aim of this study was to identify and characterize industrial solid wastes generated by a biodiesel production plant in Brazil, as well as to present strategies for the management of these materials. This plant produces every year around 100,000tons of biodiesel from vegetable oils and animal fats. The methodology of the study included technical visits, interviews with the operational and environmental management staff as well as analysis of documents, reports and computerized data systems. An approach to reduce the generation of hazardous waste was investigated. It was take into account the amount of raw material that was processed, reduction of landfill disposal, and the maximization of the their recycling and reuse. The study also identified the sources of waste generation and accordingly prepared an evaluation matrix to determine the types of waste with the higher potential for minimization. The most important residue of the process was the filter material impregnated with oil and biodiesel, requiring, therefore, measures for its minimization. The use of these residues in the production of ceramic artefacts (light bricks) was considered to be very promising, since no significant effect on the physico-chemical and mechanical properties of the artefacts produced was observed. Phytotoxicity test using seeds of Lactuva sativa (lettuce), Brassica juncea (mustard), Abelmoschus esculentus (okra), Chrysanthemum leucanthemum (daisy), Dendranthema grandiflorum (chrysanthemum) and Allium porrum (leek) were carried out. The results clearly show incorporation of the waste material into bricks did not influence relative germination and relative root elongation in comparison to control tests.

Biosurfactant-assisted phytoremediation of multi-contaminated industrial soil using sunflower (Helianthus annuus L.)

ABSTRACT This study evaluated the use of commercial rhamnolipid biosurfactant supplementation in the phytoremediation of a soil via sunflower (Helianthus annuus L.) cultivation. The soil, obtained from an industrial area, was co-contaminated with heavy metals and petroleum hydrocarbons. The remediation tests were monitored for 90 days. The best results for removal of contaminants were obtained from the tests in which the sunflower plants were cultivated in soil with 4 mg kg−1 of the rhamnolipid. Under these conditions, reductions of 58% and 48% were obtained in the total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbon (PAH) concentrations, respectively; reductions in the concentrations of the following metals were also achieved: Ni (41%), Cr (30%), Pb (29%), and Zn (20%). The PCR-DGGE analysis of soil samples collected before and after the treatments verified that the plant cultivation and biosurfactants supplementation had little effect on the structure of the dominant bacterial community in the soil. The results indicated that sunflower cultivation with the addition of a biosurfactant is a viable and efficient technology to treat soils co-contaminated with heavy metals and petroleum hydrocarbons.