Dynamic Effect of Operational Regulation on the Mesophilic BioMethanation of Grape Marc

Wine production annually generates an estimated 11 million metric tonnes of grape marc (GM) worldwide. The diversion of this organic waste away from landfill and towards its use in the generation of renewable energy has been investigated. This study aimed to evaluate the effectiveness of operational parameters relating to the treatment regime and inoculum source in the extraction of methane from GM under unmixed anaerobic conditions at 35 °C. The study entailed the recirculation of a previously acclimated sludge (120 days) as downstream inoculum, an increased loading volume (1.3 kg) and a low substrate-to-inoculum ratio (10:3 SIR). The results showed that an incorporation of accessible operational controls can effectively enhance cumulative methane yield (0.145 m3 CH4 kg−1 VS), corresponding to higher amounts of digestible organics converted. The calculated average volumetric methane productivity equalled 0.8802 L CH4 LWork−1 d−1 over 33.6 days whilst moderate pollutant removal (43.50% COD removal efficiency) was achieved. Molecular analyses identified Firmicutes and Bacteroidetes phyla as core organisms for hydrolytic and fermentative stages in trophic relationships with terminal electron acceptors from the methane-producing Methanosarcina genus. Economic projections established that the cost-effective operational enhancements were sustainable for valorisation from grape marc by existing wineries and distilleries.

Exhausted Grape Marc Derived Biochars: Effect of Pyrolysis Temperature on the Yield and Quality of Biochar for Soil Amendment

The present study focuses on the valorisation of winery industry wastes through slow pyrolysis of exhausted grape marc (EGM). The optimal pyrolysis parameters were firstly identified by small scale experiments carried out using thermogravimetric analysis. Nine pyrolysis temperatures were tested and their influence on the decomposition of the EGM residue and biochar yield was evaluated. Then, biochar production was conducted in a pilot plant at three chosen temperatures (450, 500 and 550 °C) at which the biochar was shown to be stable. The effects of biochar application to soil with respect to plant (ryegrass) growth was also evaluated. Pyrolysis of EGM at the 450–550 °C temperature range has been shown to generate thermally stable and nutrient-rich biochars, but only the biochar produced at 450 °C showed a marked benefit effect of ryegrass growth.

PSXIV-6 País grape marc (Vitis vinifera, País) inclusion in concentrate diets reduces ammonia nitrogen but not methane production in an in vitro batch culture

País Grape (Vitis vinifera L.) is an ancestral variety used in Chilean wine industry. It has a higher content of proanthocyanidins than commercial varieties such as Carmenère or Pinot Noir, resulting in País grape marc (PGM) with high contents of condensed tannins. As such, PGM inclusion in ruminant diets would have the potential to reduce enteric methane (CH4) emissions and decrease urinary N excretion. The objective of this study was to evaluate the effects of substitution of mixed hay (MH) with PGM in a high concentrate diet [65% dry matter (DM)] on in vitro dry matter disappearance (IVDMD), ruminal fermentation parameters, gas and CH4 production. Treatments were: T1 (Control) = 20% MH, 15% corn silage, 65% concentrate; T2 = 10% MH, 10% PGM, 15% corn silage, 65% concentrate; T3 = 20% PGM, 15% corn silage, 65% concentrate. The study was a randomized complete design with 3 treatment and 3 replicates, incubated for 24 h at 39º C. Data were compared by Tukey test and polynomial contrasts. There was a linear reduction in NH3-N (P = 0.001) as dietary PGM increased. Inclusion of PGM reduced NH3-N by 50% when added at 10% DM, and 71.7% at 20% DM. However, there also was 4% reduction in IVDMD (P ≤ 0.001) and gas production (P = 0.012) in the 20% GM diet. There were no treatment effects (P ≥ 0.05) on CH4 production or yield. Fermentation efficiency determined by the partition factor increased linearly (P = 0.013) as PGM inclusion increased, suggesting that it increases organic matter to be degraded. Based on this study it could be concluded that PGM is an alternative source of fiber for ruminants on concentrate diets, as it can result in improved rumen fermentation efficiency and a substantial reduction in ruminal ammonia nitrogen concentration (NH3-N).

PSXIII-4 Effects of “País” grape marc on in vitro methane production and ruminal fermentation parameters of a forage diet

Grape marc (GM) is a viticulture by-product used as cattle supplement in periods of shortage of conventional feed sources. It contains fats, high concentrations of polyphenols and has been reported to reduce enteric methane (CH4) emissions. In-vitro batch culture was used to study the effects of substitution of mixed hay (MH) for a traditional Chilean variety (Vitis vinifera “País”) of GM on in vitro dry matter disappearance (IVDMD), rumen fermentation parameters (short chain fatty acids, pH, partitioning factor), gas and CH4 production in a 60% forage diet (dry matter, DM). The study was a randomized complete design with 3 treatments and 3 replicates, incubated for 24 h at 39º C. Treatments were: T1 (Control): 20% MH, 40% corn silage, 40% concentrate; T2 = 10% MH, 10% GM, 40% corn silage, 40% concentrate; T3 = 20% GM, 40% corn silage, 40% concentrate. Means were compared with the Tukey test (P < 0.05), and polynomial contrasts. Substitution of MH with GM significantly reduced ammonia nitrogen (NH3-N) by 50% (P < 0.05), although it did not affect IVDMD, gas production or other rumen fermentation parameters (P > 0.05). Total CH4 (mg) linearly decreased (P = 0.013) as concentrations of GM increased. Methane production (mg/g DM incubated) and yield (mg/g DM digested) decreased linearly (P = 0.002 and P = 0.003, respectively) as inclusion of GM increased. Inclusion of GM at 20% reduced CH4 production by 19% and CH4 yield by 16.4%. These results indicate that partial substitution of dietary fiber sources with traditional Chilean País GM in high fiber diets is a viable feeding alternative, and can decrease environmental impact (lower CH4 and ammonia emissions) of ruminant livestock, without negatively affecting rumen fermentation parameters.

DEVELOPMENT OF THE REAL-TIME PCR METHODOLOGY FOR TESTING MYCOTOXIGENIC MICROORGANISMS IN GRAPE MARC

Agro-industrial waste management is an important problem of modern society as agriculture and food industry are important sources of waste. Wine production generates a considerable amount of winemaking waste (grape marc). Grape marc can be a source of natural dyes, antioxidants and could have various applications, if it is confirmed that it does not contain technogenic contaminants or unwanted microorganisms, for example, producers of mycotoxins. The paper developed the Real -Time Polymerase Chain Reaction (Real-Time PCR) methodology for testing the presence of potentially mycotoxogenic fungal species capable of producing ochratoxin A (OTA), which could be applied before grape marc processing. Based on the non-ribosomal peptide sequence of OTA, involved in ochratoxin biosynthesis, the primers have been developed for the detection of microorganisms potentially capable of producing ochratoxin A.

Evaluation of Calcium Alginate-Based Biopolymers as Potential Component of Membranes for Recovering Biosurfactants from Corn Steep Water

Corn steep water (CSW) is a complex agro-food stream that is used as a source of cost-competitive biosurfactants, since they are produced spontaneously in the steeping process of corn, avoiding production costs. Nevertheless, the extraction of biosurfactants from CSW using sustainable processes is still a challenge. Consequently, the use of calcium alginate membranes could present a novel and sustainable technology for recovering biosurfactants from aqueous streams. Therefore, the aim of this work is to evaluate calcium alginate-based biopolymers, without and with the presence of grape marc as an additive, as a key component of membranes for the recovery of biosurfactants in corn steep water. Biosurfactants are present in CSW, together with other inorganic solutes and biomolecules, such as organic acids, sugars, cations, anions as well as metals. Hence, the competition of these mentioned compounds for the active sites of the calcium alginate-based biopolymers was high. However, they showed a good adsorption capacity for biosurfactants, recovering around 55 ± 2% and 47 ± 1%, of biosurfactants from CSW using both calcium alginate-based biopolymers, with and without biodegraded grape marc. Regarding adsorption capacity, it was 54.8 ± 0.6 mg biosurfactant/g bioadsorbent for the biopolymer containing grape marc, and 46.8 ± 0.4 mg biosurfactant/g bioadsorbent for the calcium alginate-based biopolymer alone. Based on these results, it could be postulated that the formulation of green membranes, based on calcium alginate-based polymers, could be an interesting alternative for the recovery of biosurfactants from aqueous streams including CSW.