Combination of food wastes for an efficient production of nisin in realkalized fed-batch cultures

Biochemical Engineering Journal

https://doi.org/10.1016/j.bej.2017.03.012

Nisin production by Lactococcus lactis CECT 539 was studied in four realkalized fed-batch cultures in diluted whey with feeding with lactose- and glucose-containing substrates. The first and third cultures were fed with mixtures of whey (W) and a 400 g/L concentrated glucose (CG), or with a concentrated mussel processing waste (CMPW) and CG, respectively.

The second and fourth cultures were respectively performed under the same conditions as in the first and third fermentations. However, these cultures were supplemented with mixtures of W plus a 2% (w/v) yeast extract (WYE2) and CG (second culture), or with CMPW plus a 2% (w/v) yeast extract (CMPWYE2) (fourth culture) after sample extractions at 132 and 168 h, respectively. From these times, each culture was fed with mixtures of WYE2 and CG, or CMPWYE2 and CG, respectively.

The final concentrations of nisin obtained in the third (223.98 BU/mL) and fourth (350.61 BU/mL) cultures, fed with glucose-containing substrates (CG and CMPW), were considerably higher than those obtained in the first (108.00 BU/mL) and second (158.53 BU/mL) cultures fed with the mixture of lactose- and glucose-containing substrates (W and CG).

Sepia ink as a surrogate for colloid transport tests in porous media

Journal of Contaminant Hydrology, 191, 2016, 88–98

http://dx.doi.org/10.1016/j.jconhyd.2016.05.005

We examined the suitability of the ink of Sepia officinalis as a surrogate for transport studies of microorganisms and microparticles in porous media. Sepia ink is an organic pigment consisted on a suspension of eumelanin, and that has several advantages for its use as a promising material for introducing the frugal-innovation in the fields of public health and environmental research: very low cost, non-toxic, spherical shape, moderate polydispersivity, size near large viruses, non-anomalous electrokinetic behavior, low retention in the soil, and high stability.

Electrokinetic determinations and transport experiments in quartz sand columns and soil columns were done with purified suspensions of sepia ink. Influence of ionic strength on the electrophoretic mobility of ink particles showed the typical behavior of polystyrene latex spheres. Breakthrough curve (BTC) and retention profile (RP) in quartz sand columns showed a depth dependent and blocking adsorption model with an increase in adsorption rates with the ionic strength. Partially saturated transport through undisturbed soil showed less retention than in quartz sand, and matrix exclusion was also observed. Quantification of ink in leachate fractions by light absorbance is direct, but quantification in the soil profile with moderate to high organic matter content was rather cumbersome.

We concluded that sepia ink is a suitable cheap surrogate for exploring transport of pathogenic viruses, bacteria and particulate contaminants in groundwater, and could be used for developing frugal-innovation related with the assessment of soil and aquifer filtration function, and monitoring of water filtration systems in low-income regions.

Simultaneous production of amylases and proteases by Bacillus subtilis in brewery wastes

Brazilian Journal of Microbiology, 47, 2016, 665–674

http://dx.doi.org/10.1016/j.bjm.2016.04.019

The simultaneous production of amylase (AA) and protease (PA) activity by Bacillus subtilis UO-01 in brewery wastes was studied by combining the response surface methodology with the kinetic study of the process. The optimum conditions (T = 36.0 °C and pH = 6.8) for high biomass production (0.92 g/L) were similar to the conditions (T = 36.8 °C and pH = 6.6) for high AA synthesis (9.26 EU/mL). However, the maximum PA level (9.77 EU/mL) was obtained at pH 7.1 and 37.8 °C. Under these conditions, a considerably high reduction (between 69.9 and 77.8%) of the initial chemical oxygen demand of the waste was achieved. In verification experiments under the optimized conditions for production of each enzyme, the AA and PA obtained after 15 h of incubation were, respectively, 9.35 and 9.87 EU/mL. By using the Luedeking and Piret model, both enzymes were classified as growth-associated metabolites. Protease production delay seemed to be related to the consumption of non-protein and protein nitrogen. These results indicate that the brewery waste could be successfully used for a high scale production of amylases and proteases at a low cost.

Phosphorus retention on forest and vineyard soil samples, mussel shell, pine-sawdust, and on pyritic, granitic and waste materials

Geoderma, 280 (2016) 8–13

http://dx.doi.org/10.1016/j.geoderma.2016.06.003

Focusing on P, we used batch-type experiments to study P retention on various materials: a forest soil sample, a vineyard soil sample, finely and coarsely ground mussel shell, pine-sawdust, pyritic material, granitic material, mussel shell calcination ash, slate processing fines, and three different mixtures that included three components: sewage sludge, mussel shell ash, and calcined mussel shell or pine wood ash. The pyritic material and the mussel shell ash showed the highest P retention capacity, reaching > 95%. The lowest P retention (< 60%) corresponded to the pine-sawdust and slate processing fines. Data fitted satisfactorily to the Freundlich model, unless in the case of pine-sawdust and slate fines; however, only forest and vineyard soil samples can be satisfactorily adjusted to the Langmuir model. These results could be useful to program appropriate management practices, especially when focusing on controlling P concentrations in different environmental compartments, as well as to correctly recycle the by-products and waste materials assayed.

F sorption/desorption on two soils and on different by-products and waste materials

Environmental Science and Pollution Research (2016) 23, 14676–14685

DOI: 10.1007/s11356-016-6959-8

We used batch-type experiments to study F sorption/desorption on a forest soil, a vineyard soil, pyritic material, granitic material, finely and coarsely ground mussel shell, mussel shell calcination ash, oak wood ash, pine-sawdust, slate processing fines, and three different mixtures that included three components: sewage sludge, mussel shell ash, and calcined mussel shell or pine wood ash. The three waste mixtures, forest soil, pyritic material, and shell ash showed high sorption capacity (73–91 % of added F) and low desorption, even when 100 mg F L−1 was added. All these materials (and to a lower extent wood ash) could be useful to remove F from polluted media (as certain soils, dumping sites, and contaminated waters). The vineyard soil, the granitic material, mussel shell, slate fines, and pine-sawdust were less effective in F removal. In most cases, sorption data fitted better to the Freundlich than to the Langmuir equation. These results can be useful to program the correct management of the soils, by-products, and waste materials assayed, mostly in situations where F concentrations are excessive and F removal should be promoted.

Build-up of carbon fractions in technosol-biochar amended partially reclaimed mine soil grown with Brassica juncea

Journal of Soils and Sediments

May 2016, Volume 16, Issue 5, pp 1529–1537

DOI: 10.1007/s11368-016-1358-9

Soil organic carbon (SOC) and its labile fractions are strong determinants of physical, chemical and biological properties. The objective of the present work was to evaluate the effects of organic amendments (technosol made of wastes and biochar) and Brassica juncea L. on the soil C fractions in a reclaimed mine soil.

The studied soil was from a former copper mine that was subsequently partially reclaimed with vegetation and wastes. A greenhouse experiment was carried out to amend the mine soil with different proportions of technosol and biochar mixture and planting B. juncea. B. juncea plants can tolerate high levels of metals and can produce a large amount of biomass in relatively short periods of time.

The results showed that with the addition of biochar and wastes, soil pH increased from 2.7 to 6.18, SOC from undetectable to 105 g kg−1 and soil total nitrogen (TN) from undetectable to 11.4 g kg−1. Amending with wastes and biochar also increased dissolved organic carbon (DOC) from undetectable to 5.82 g kg−1, carbon in the free organic matter (FOM) from undetectable to 30.42 g kg−1, FAP (carbon in fulvic acids removed with phosphoric acid) from undetectable to 24.14 g kg−1 and also increased the humification ratio, the humification index, the polymerisation rate and the organic carbon in the humified fractions (humic acids, fulvic acids and humin). Soils amended and vegetated with B. juncea showed lower FOM values and higher humification index values than the soils amended only with biochar and wastes.

This study concludes that the combined addition of wastes and biochar has a greater potential for both increasing and improving organic carbon fractions in mine soils. The authors recommend the application of biochar and technosol made of wastes as a soil amendment combined with B. juncea on soils that are deficient in organic matter, since they increased all of the SOC fractions in the studied copper mine soil.

Contribution of waste and biochar amendment to the sorption of metals in a copper mine tailing

CATENA
Volume 137, February 2016, Pages 120–125
http://dx.doi.org/10.1016/j.catena.2015.09.010

One technique applied to restore degraded or contaminated soils is to use amendments made of different types of waste materials, which in turn may contain metals such as Cu, Pb and Zn. For this reason it is important to determine the capacity of the soil to retain these materials, and to compare the sorption capacity between an amended soil and another unamended soil. The aim of this study was to determine the chemical behaviour of these metals in the soil after applying the amendment, and how it affected the soil's sorption capacity. Another aim was to study the contribution of contaminating elements from the amendment itself. The amendments used in this study were a mixture made of waste material (sewage sludges, sludges from an aluminium plant, ash, food industry wastes, and sands from a wastewater treatment plant) and biochar (biomass of Acacia dealbata) (97%:3%) in different soil/amendment proportions. The soil was from a mine tailing. The mine tailings were amended with the mixture of waste and biochar which had a higher sorption capacity than the soil from the pond. The samples with amendment had a greater affinity for Cu, Pb and Zn than the mine soil. The results obtained show that adding a mixture made of waste and biochar favours the retention of Cu, Pb and Zn in mine tailing from metal mines.

Nickel, Lead and Zinc Sorption in a Reclaimed Settling Pond Soil

Pedosphere

Volume 26, Issue 1, February 2016, Pages 39-48

doi:10.1016/S1002-0160(15)60020-0

The wastes used to amend soils sometimes have high concentrations of metals such as nickel (Ni), lead (Pb) and zinc (Zn). To determine the capacity of soils to retain these metals, the sorption capacities of different mine soils with and without reclamation treatments (tree vegetation and waste amendment) for Ni, Pb and Zn in individual and competitive situations were evaluated using the batch sorption technique. The untreated settling pond soil had low capacity for Ni, Pb and Zn retention. The site amended with wastes (sewage sludges and paper mill residues) increased the sorption capacity most, probably because of the higher concentrations of soil components with high retention capacity such as carbon and clay fraction. No significant competition was observed between metals in the competitive sorption experiment, indicating that the maximum of sorption was not achieved by adding 0.5 mmol L−1 of metal. We can conclude that, despite the possible additions of Ni, Pb and Zn from wastes to degraded soils, sewage sludges and paper mill residues have a high sorption capacity that would prevent the metals from being in a mobile form.

Cu retention in an acid soil amended with perlite winery waste

Environmental Science and Pollution Research (2016), 23, 3789–3798

DOI: 10.1007/s11356-015-5639-4

The effect of perlite waste from a winery on general soil characteristics and Cu adsorption was assessed. The studied soil was amended with different perlite waste concentrations corresponding to 10, 20, 40 and 80 Mg ha−1. General soil characteristics and Cu adsorption and desorption curves were determined after different incubation times (from 1 day to 8 months). The addition of perlite waste to the soil increased the amounts of organic matter as well as soil nutrients such as phosphorus and potassium, and these increments were stable with time. An increase in Cu adsorption capacity was also detected in the perlite waste-amended soils. The effect of perlite waste addition to the soil had special relevance on its Cu adsorption capacity at low coverage concentrations and on the energy of the soil-Cu bonds.

As(V) and P Competitive Sorption on Soils, By-Products and Waste Materials

Int. J. Environ. Res. Public Health 2015, 12(12), 15706-15715

doi:10.3390/ijerph121215016

Batch-type experiments were used to study competitive As(V) and P sorption on various soils and sorbent materials. The materials assayed were a forest soil, a vineyard soil, pyritic material, granitic material, coarsely and finely ground mussel shell, calcinated mussel shell ash, pine sawdust and slate processing fines. Competition between As(V) and P was pronounced in the case of both soils, granitic material, slate fines, both shells and pine sawdust, showing more affinity for P. Contrary, the pyritic material and mussel shell ash showed high and similar affinity for As(V) and P. These results could be useful to make a correct use of the soils and materials assayed when focusing on As and P removal in solid or liquid media, in circumstances where both pollutants may compete for sorption sites.