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María Dolores Carro - One of the best experts on this subject based on the ideXlab platform.
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effects of modifications to retain protozoa in continuous culture Fermenters on ruminal fermentation microbial populations and microbial biomass assessed by two different methods
Animal Feed Science and Technology, 2018Co-Authors: I Cabezaluna, María Dolores Carro, J Fernandezyepes, E MolinaalcaideAbstract:Abstract An important limitation of continuous-culture Fermenters is their inability of maintaining microbial populations similar to those observed in the rumen, especially protozoa numbers, which usually decrease markedly or even disappear. Two approaches (a polyurethane-sponge (SP) and a filter system (FIL) for additionally retaining protozoa were tested in continuous culture system already designed to retain protozoa ( Muetzel et al., 2009 ), and their effects on microbial populations, fermentation parameters and microbial biomass were assessed. Two 14-day incubation runs were carried out with 6 Fermenters, and in each run two Fermenters were randomly assigned to each of the experimental treatments (control, SP and FIL). Total protozoa numbers assessed by microscopic counting were 1.7 and 2.1 times greater in SP and FIL Fermenters than in control ones on day 14, although differences did not reach the significance level (P = 0.855). Protozoal DNA concentration on day 14 were 1.6 and 1.4 times greater in SP and FIL Fermenters, respectively, than in control ones, but differences were not significant (P = 0.524). Results from protozoal DNA concentrations determined in each Fermenter on the different sampling days (n = 48) were positively correlated (P 0.05) fermentation parameters, which reached a steady-state after 6 days of incubation. Values of microbial biomass determined using purine bases as a microbial marker were significantly correlated with the amount of bacterial plus protozoal DNA (r = 0.794; P = 0.002; n = 12) in each Fermenter. In conclusion, the two tested modifications increased the protozoa numbers in continuous-culture Fermenters, and the FIL allowed maintaining a proportion of holotrich protozoa similar to that in the ruminal fluid used as inoculum.
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comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and rusitec Fermenters ii protozoa population and diversity of bacterial communities
Journal of Dairy Science, 2010Co-Authors: María Dolores Carro, M E Martinez, Maria Jose Ranilla, Maria L Tejido, Cristina SaroAbstract:Four ruminally and duodenally cannulated sheep and 8 Rusitec Fermenters were used to determine the effects of dietary characteristics on microbial populations and bacterial diversity. The purpose of the study was to assess how closely Fermenters can mimic the differences between diets found in vivo. The 4 experimental diets contained forage to concentrate (F:C) ratios of 70:30 (high forage; HF) or 30:70 (high concentrate; HC) with either alfalfa hay (A) or grass hay (G) as the forage. Total bacterial numbers were greater in the rumen of sheep fed HF diets compared with those fed HC diets, whereas the opposite was found in Fermenters. The numbers of cellulolytic bacteria were not affected by F:C ratio in any fermentation system, but cellulolytic numbers were 2.7 and 1.8 times greater in sheep than in Fermenters for HF and HC diets, respectively. Neither total bacterial nor cellulolytic numbers were affected by the type of forage in sheep or Fermenters. Decreasing F:C ratio increased total protozoa and Entodiniae numbers in sheep by about 29 and 25%, respectively, but it had no effect in Fermenters. Isotrichidae and Ophryoscolecinae numbers in sheep were not affected by changing F:C ratio, but both disappeared completely from Fermenters fed HC diets. Total protozoa and Entodiniae numbers were greater in sheep fed A diets than in those fed G diets, whereas the opposite was found in Fermenters. Results indicate that under the conditions of the present study, protozoa population in Rusitec Fermenters was not representative of that in the rumen of sheep fed the same diets. In addition, protozoa numbers in Fermenters were 121 and 226 times lower than those in the sheep rumen for HF and HC diets, respectively. The automated ribosomal intergenic spacer analysis of the 16S ribosomal DNA was used to analyze the diversity of liquid- and solid-associated bacteria in both systems. A total of 170 peaks were detected in the automated ribosomal intergenic spacer analysis electropherograms of bacterial pellets across the full set of 64 samples, from which 160 were detected in at least 1 individual from each system (sheep or Fermenter). Diversity of liquid-associated bacterial pellets was greater with G diets in Fermenters but seemed to be unaffected by diet in sheep. Bacterial diversity in solid-associated bacteria pellets was greater for G diets compared with A diets in sheep and Fermenters. Different conditions in the Fermenters compared with sheep rumen might have caused a selection of some bacterial strains.
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influence of exogenous fibrolytic enzymes and fumarate on methane production microbial growth and fermentation in rusitec Fermenters
British Journal of Nutrition, 2007Co-Authors: L A Giraldo, Maria L Tejido, Maria Jose Ranilla, María Dolores CarroAbstract:Two incubation runs were conducted with Rusitec Fermenters to investigate the effects of three additive treatments (mixed fibrolytic enzymes from Trichoderma longibrachiatum (FE), disodium fumarate (FUM) and both additives (MIX)) on rumen microbial growth and fermentation of a grass hay:concentrate (600:400g/kgDM) substrate. Each Fermenter received daily 20g substrate DM. Application rate (per g substrate DM) was 34·3 endoglucanase, 0·57 exoglucanase, 24·7 xylanase and 5·51 amylase units for FE and 30mg fumarate for FUM. MIX Fermenters received both additives. Both FE and MIX increased (P,0·05) daily production of acetate, butyrate and methane, substrate DM and fibre disappearance at 6 and 48h incubation, daily flow of microbial-N, and the microbial colonisation of substrate at 6h incubation. Compared to FE, MIX treatment increased (P,0·05) propionate production by 28% and decreased (P,0·05) the acetate:propionate ratio, but no other differences between both treatments were found (P.0·05). Supplementing with FUM increased (P,0·05) volatile fatty acid production by 11% and decreased (P,0·05) the acetate:propionate ratio, but did not affect (P.0·05) any other variable, thus suggesting that observed effects were due to fermentation of FUM itself. The lack of effects of FUM and the absence of differences between FE and MIX on most of the measured variables would indicate that beneficial effects found in MIX Fermenters were mainly due to the action of FE. Combining FE and FUM as feed additives under the conditions of the present experiment did not further improve rumen fermentation, compared to FE alone. Fibrolytic enzymes: Fumarate: Rumen microbial growth: Rusitec
E Molinaalcaide - One of the best experts on this subject based on the ideXlab platform.
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effects of modifications to retain protozoa in continuous culture Fermenters on ruminal fermentation microbial populations and microbial biomass assessed by two different methods
Animal Feed Science and Technology, 2018Co-Authors: I Cabezaluna, María Dolores Carro, J Fernandezyepes, E MolinaalcaideAbstract:Abstract An important limitation of continuous-culture Fermenters is their inability of maintaining microbial populations similar to those observed in the rumen, especially protozoa numbers, which usually decrease markedly or even disappear. Two approaches (a polyurethane-sponge (SP) and a filter system (FIL) for additionally retaining protozoa were tested in continuous culture system already designed to retain protozoa ( Muetzel et al., 2009 ), and their effects on microbial populations, fermentation parameters and microbial biomass were assessed. Two 14-day incubation runs were carried out with 6 Fermenters, and in each run two Fermenters were randomly assigned to each of the experimental treatments (control, SP and FIL). Total protozoa numbers assessed by microscopic counting were 1.7 and 2.1 times greater in SP and FIL Fermenters than in control ones on day 14, although differences did not reach the significance level (P = 0.855). Protozoal DNA concentration on day 14 were 1.6 and 1.4 times greater in SP and FIL Fermenters, respectively, than in control ones, but differences were not significant (P = 0.524). Results from protozoal DNA concentrations determined in each Fermenter on the different sampling days (n = 48) were positively correlated (P 0.05) fermentation parameters, which reached a steady-state after 6 days of incubation. Values of microbial biomass determined using purine bases as a microbial marker were significantly correlated with the amount of bacterial plus protozoal DNA (r = 0.794; P = 0.002; n = 12) in each Fermenter. In conclusion, the two tested modifications increased the protozoa numbers in continuous-culture Fermenters, and the FIL allowed maintaining a proportion of holotrich protozoa similar to that in the ruminal fluid used as inoculum.
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garlic derived compounds modify ruminal fatty acid biohydrogenation and induce shifts in the butyrivibrio community in continuous culture Fermenters
Animal Feed Science and Technology, 2013Co-Authors: Eva Ramosmorales, E Molinaalcaide, Gonzalo Martinezfernandez, Leticia Abecia, A I Martingarcia, D R YanezruizAbstract:Abstract Garlic essential oil contains a variety of fat soluble organosulfur compounds with antibacterial activity. Nevertheless, only recent studies have evaluated garlic oil and its constituents as modulators of ruminal processes. The present study was undertaken to evaluate the potential of diallyl disulfide (DDS) and propyl propane thiosulfinate (PTS) to modulate rumen biohydrogenation in vitro . Six continuous-culture Fermenters, inoculated with rumen fluid from goats, were used in two replicated incubation runs of 12 days each. Two Fermenters per run received either a control diet (without additive) or the same diet with 80 μl/L of DDS or 200 μl/L of PTS daily. At the end of each incubation run, samples of Fermenter contents were taken for fatty acid analysis. The DDS addition resulted in lower (P=0.012) total saturated fatty acids (SFA) and higher monounsaturated fatty acids (MUFA; P=0.001) and polyunsaturated fatty acids (PUFA; P=0.018) contents as compared to the control. Increases in trans -10, cis -12 CLA (P=0.065), trans -10 18:1 (P trans -11-18:1) (P=0.009) were also observed. Similar results were found for PTS addition, although significant differences with the control group were detected only for PUFA and trans -10 18:1 amounts. Additionally, 1 mL of the Fermenter contents was incubated in vitro with 0.167 g/L of linoleic acid ( cis -9, cis -12 18:2; LA) for 0, 1, 3, 6, 9 and 24 h. Vaccenic acid and trans -10 18:1 accumulated to higher concentrations (P=0.054 at 9 h and P=0.021 at 3 h, respectively) when LA was incubated with the Fermenter contents treated with DDS and PTS. Garlic derived compounds did not affect the amount of total bacteria (P=0.936) or abundances of Butyrivibrio proteoclasticus (P=0.693); although PTS increased the abundance of Butyrivibrio fibrisolvens (P=0.001), in comparison to the control and DDS treatments. Differences in the Butyrivibrio group structure were observed from the cluster analysis, which showed segregation for Fermenters with garlic derived compounds from those without additives. It was concluded that adding DDS and PTS to the diet of Fermenters modified the fatty acid of rumen contents, with potential health benefits of ruminant products. These changes in biohydrogenation appeared to be related to shifts within the Butyrivibrio bacterial community. In vivo studies are now required to confirm the potential of these compounds.
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effects of concentrate replacement by feed blocks on ruminal fermentation and microbial growth in goats and single flow continuous culture Fermenters
Journal of Animal Science, 2009Co-Authors: E Molinaalcaide, M R Pascual, G Cantalapiedrahijar, E Y Moralesgarcia, A I MartingarciaAbstract:The effect of replacing concentrate with 2 different feed blocks (FB) on ruminal fermentation and microbial growth was evaluated in goats and in single-flow continuous-culture Fermenters. Diets consisted of alfalfa hay plus concentrate and alfalfa hay plus concentrate with 1 of the 2 studied FB. Three trials were carried out with 6 rumen-fistulated Granadina goats and 3 incubation runs in 6 single-flow continuous-culture Fermenters. Experimental treatments were assigned randomly within each run, with 2 repetitions for each diet. At the end of each in vivo trial, the rumen contents were obtained for inoculating the Fermenters. For each incubation run, the Fermenters were inoculated with ruminal fluid from goats fed the same diet supplied to the corresponding Fermenter flask. The average pH values, total and individual VFA, and NH₃-N concentrations, and acetate:propionate ratios in the rumen of goats were not affected (P greater-than-or-equal 0.10) by diet, whereas the microbial N flow (MNF) and efficiency were affected (P [less-than or equal to] 0.001), with the greatest values observed for the diet without FB. In Fermenters, the diet affected pH (P < 0.001), propionate concentrations (P = 0.01), acetate:propionate ratio (P = 0.03), carbohydrate digestibility (P greater-than-or-equal 0.05), and total (P = 0.02), NH₃ (P = 0.005), and non-NH₃ (P = 0.02) N flows, whereas the efficiency of VFA production was not affected (P = 0.75). The effect of diet on MNF and efficiency depended on the bacterial pellet used as a reference. An effect (P < 0.05) of diet on the composition of solid- and liquid-associated bacteria was observed. The compositions of liquid-associated bacteria in the Fermenter contents and effluent were similar (P = 0.05). Differences (P < 0.001) between in vivo and in vitro values for most fermentation variables and bacterial pellet compositions were found. Partial replacement of the concentrate with FB did not greatly compromise carbohydrate fermentation in unproductive goats. However, this was not the case for MNF and efficiency. Differences between the results obtained in vivo and in vitro indicate a need to identify conditions in Fermenters that allow better simulation of fermentation, microbial growth, and bacterial pellet composition in vivo. Reduced feeding cost could be achieved with the inclusion of FB in the diets of unproductive goats without altering rumen fermentation.
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fermentation characteristics and microbial growth promoted by diets including two phase olive cake in continuous Fermenters
Journal of Animal Physiology and Animal Nutrition, 2007Co-Authors: Abdelmajid Moumen, D R Yanezruiz, Ignacio Martingarcia, E MolinaalcaideAbstract:Summary Two-phase olive cake (2POC) is the by-product obtained from the so called ‘two-phase’ procedure to extract olive oil by mechanical methods. After the mechanical extraction the 2POC is dried and most of the remaining oil extracted by chemical means. The production of the crude by-product may reach more than 4 millions t/year in Spain (MAPA, 2003), most of it in areas (Southeast) with shortage of pastures and conventional feeds for ruminants. Six continuous Fermenters, inoculated with ruminal liquor from wethers or goats, were fed lucerne hay (LH); LH plus a concentrate including dried two-phase olive cake (LHCO) and; diet LHCO added with polyethylene glycol (LHCOP). The highest pH values and ammonia N (NH3-N) output were found in Fermenters fed diet LH (6.19 and 6.35 for pH, and 53.7 and 68.9 mg NH3N/day, respectively, in fermentes inoculated with rumen liquor from sheep and goats) without differences due to the inoculum origin. The digestibility of carbohydrates (CHO) was affected (p 0.05) with inoculum from wethers and goats [26.4 and 28.1 and 35.2 and 33.5 g bacterial N/kg digested CHO, respectively, obtained by using diamino pimelic acid (DAPA) and purine bases (PB) as microbial markers]. The lowest (p < 0.05) values were found in Fermenters fed diets LHCOP and LH, estimated, respectively, from DAPA and PB (21.9 and 29.0 g bacterial N/kg digested CHO). The substitution of a part of lucerne hay by a concentrate including dried 2POC does not seem to cause important differences in efficiency of VFA production. Results concerning bacterial protein synthesis are not so clear since values estimated from DAPA and PB did not show similar trends. Neither inoculum origin nor PEG had important effects on fermentation characteristics. The DAPA could be an adequate marker in continuous Fermenters, with comparative purposes, as protozoa are not present and, estimated protein synthesis values are similar to those obtained in vivo with similar diets using urinary excretion of PD (Yanez Ruiz et al., 2004b). Further research is needed to state the optimal proportion of 2POC in practical diets for ruminants at both maintenance and production stages.
William Martin - One of the best experts on this subject based on the ideXlab platform.
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physiological limits to life in anoxic subseafloor sediment
Fems Microbiology Reviews, 2020Co-Authors: William D. Orsi, Wolfgang Buckel, Bernhard Schink, William MartinAbstract:In subseafloor sediment, microbial cell densities exponentially decrease with depth into the fermentation zone. Here, we address the classical question of 'why are cells dying faster than they are growing?' from the standpoint of physiology. The stoichiometries of fermentative ATP production and consumption in the fermentation zone place bounds on the conversion of old cell biomass into new. Most fermentable organic matter in deep subseafloor sediment is amino acids from dead cells because cells are mostly protein by weight. Conversion of carbon from fermented dead cell protein into methanogen protein via hydrogenotrophic and acetoclastic methanogenesis occurs at ratios of ∼200:1 and 100:1, respectively, while Fermenters can reach conversion ratios approaching 6:1. Amino acid fermentations become thermodynamically more efficient at lower substrate and product concentrations, but the conversion of carbon from dead cell protein into Fermenter protein is low because of the high energetic cost of translation. Low carbon conversion factors within subseafloor anaerobic feeding chains account for exponential declines in cellular biomass in the fermentation zone of anoxic sediments. Our analysis points to the existence of a life-death transition zone in which the last biologically catalyzed life processes are replaced with purely chemical reactions no longer coupled to life.
A I Martingarcia - One of the best experts on this subject based on the ideXlab platform.
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garlic derived compounds modify ruminal fatty acid biohydrogenation and induce shifts in the butyrivibrio community in continuous culture Fermenters
Animal Feed Science and Technology, 2013Co-Authors: Eva Ramosmorales, E Molinaalcaide, Gonzalo Martinezfernandez, Leticia Abecia, A I Martingarcia, D R YanezruizAbstract:Abstract Garlic essential oil contains a variety of fat soluble organosulfur compounds with antibacterial activity. Nevertheless, only recent studies have evaluated garlic oil and its constituents as modulators of ruminal processes. The present study was undertaken to evaluate the potential of diallyl disulfide (DDS) and propyl propane thiosulfinate (PTS) to modulate rumen biohydrogenation in vitro . Six continuous-culture Fermenters, inoculated with rumen fluid from goats, were used in two replicated incubation runs of 12 days each. Two Fermenters per run received either a control diet (without additive) or the same diet with 80 μl/L of DDS or 200 μl/L of PTS daily. At the end of each incubation run, samples of Fermenter contents were taken for fatty acid analysis. The DDS addition resulted in lower (P=0.012) total saturated fatty acids (SFA) and higher monounsaturated fatty acids (MUFA; P=0.001) and polyunsaturated fatty acids (PUFA; P=0.018) contents as compared to the control. Increases in trans -10, cis -12 CLA (P=0.065), trans -10 18:1 (P trans -11-18:1) (P=0.009) were also observed. Similar results were found for PTS addition, although significant differences with the control group were detected only for PUFA and trans -10 18:1 amounts. Additionally, 1 mL of the Fermenter contents was incubated in vitro with 0.167 g/L of linoleic acid ( cis -9, cis -12 18:2; LA) for 0, 1, 3, 6, 9 and 24 h. Vaccenic acid and trans -10 18:1 accumulated to higher concentrations (P=0.054 at 9 h and P=0.021 at 3 h, respectively) when LA was incubated with the Fermenter contents treated with DDS and PTS. Garlic derived compounds did not affect the amount of total bacteria (P=0.936) or abundances of Butyrivibrio proteoclasticus (P=0.693); although PTS increased the abundance of Butyrivibrio fibrisolvens (P=0.001), in comparison to the control and DDS treatments. Differences in the Butyrivibrio group structure were observed from the cluster analysis, which showed segregation for Fermenters with garlic derived compounds from those without additives. It was concluded that adding DDS and PTS to the diet of Fermenters modified the fatty acid of rumen contents, with potential health benefits of ruminant products. These changes in biohydrogenation appeared to be related to shifts within the Butyrivibrio bacterial community. In vivo studies are now required to confirm the potential of these compounds.
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effects of concentrate replacement by feed blocks on ruminal fermentation and microbial growth in goats and single flow continuous culture Fermenters
Journal of Animal Science, 2009Co-Authors: E Molinaalcaide, M R Pascual, G Cantalapiedrahijar, E Y Moralesgarcia, A I MartingarciaAbstract:The effect of replacing concentrate with 2 different feed blocks (FB) on ruminal fermentation and microbial growth was evaluated in goats and in single-flow continuous-culture Fermenters. Diets consisted of alfalfa hay plus concentrate and alfalfa hay plus concentrate with 1 of the 2 studied FB. Three trials were carried out with 6 rumen-fistulated Granadina goats and 3 incubation runs in 6 single-flow continuous-culture Fermenters. Experimental treatments were assigned randomly within each run, with 2 repetitions for each diet. At the end of each in vivo trial, the rumen contents were obtained for inoculating the Fermenters. For each incubation run, the Fermenters were inoculated with ruminal fluid from goats fed the same diet supplied to the corresponding Fermenter flask. The average pH values, total and individual VFA, and NH₃-N concentrations, and acetate:propionate ratios in the rumen of goats were not affected (P greater-than-or-equal 0.10) by diet, whereas the microbial N flow (MNF) and efficiency were affected (P [less-than or equal to] 0.001), with the greatest values observed for the diet without FB. In Fermenters, the diet affected pH (P < 0.001), propionate concentrations (P = 0.01), acetate:propionate ratio (P = 0.03), carbohydrate digestibility (P greater-than-or-equal 0.05), and total (P = 0.02), NH₃ (P = 0.005), and non-NH₃ (P = 0.02) N flows, whereas the efficiency of VFA production was not affected (P = 0.75). The effect of diet on MNF and efficiency depended on the bacterial pellet used as a reference. An effect (P < 0.05) of diet on the composition of solid- and liquid-associated bacteria was observed. The compositions of liquid-associated bacteria in the Fermenter contents and effluent were similar (P = 0.05). Differences (P < 0.001) between in vivo and in vitro values for most fermentation variables and bacterial pellet compositions were found. Partial replacement of the concentrate with FB did not greatly compromise carbohydrate fermentation in unproductive goats. However, this was not the case for MNF and efficiency. Differences between the results obtained in vivo and in vitro indicate a need to identify conditions in Fermenters that allow better simulation of fermentation, microbial growth, and bacterial pellet composition in vivo. Reduced feeding cost could be achieved with the inclusion of FB in the diets of unproductive goats without altering rumen fermentation.
Enrico Drioli - One of the best experts on this subject based on the ideXlab platform.
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Continuous production of bioethanol from sugarcane bagasse and downstream purification using membrane integrated bioreactor
Catalysis Today, 2017Co-Authors: Koel Saha, Abhishek Maharana, Stefano Curcio, Jaya Sikder, Sudip Chakraborty, Enrico DrioliAbstract:Abstract Bioethanol is the most widely used transportation fuel and is often employed as an alternate to conventional petroleum fuel. The most important challenge in bioethanol production process is to achieve nearly pure ethanol by downstream purification. Production of ethanol from sugarcane bagasse was studied in a membrane integrated hybrid bioreactor for 115 h using yeast strain Saccharomyces cerevisiae. The fermented product was subjected to continuous microfiltration after 20 h of batch fermentation and 100% rejection of microorganism was achieved at this state. A maximum cell density of 2.4 of was reached in the Fermenter during fermentation. The maximum cell density reached in the Fermenter during fermentation was 2.4 g/l. While studying the membrane performance during microfiltration, a flux decrease from 44.4 l/m2h to 8.4 l/m2h was observed after 65 h of continuous filtration at constant 3 bar transmembrane pressure. The permeate samples obtained from microfiltration were subjected to nanofiltration in order to recycle unconverted glucose from water ethanol mixture. During nanofiltration, the membrane performance revealed 58–86% rejection of glucose, a maximum ethanol concentration of 43.2 g/l in the permeate and the reduction of membrane flux from 41.4 l/m2h to 8.2 l/m2h after 19 h of continuous filtration at 10 bar transmembrane pressure. This membrane based approach for bioethanol production employs a sustainable and clean technology which comes up with low or no waste generation.
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study of a cell recycle membrane fermentor for the production of lactic acid by lactobacillus bulgaricus
Industrial & Engineering Chemistry Research, 2002Co-Authors: Lidietta Giorno, Katarzyna Chojnacka, L Donato, Enrico DrioliAbstract:The aim of this experimental work was to study a cell-recycle membrane fermentor for the production of lactic acid. Initially, the fermentation and the ultrafiltration processes were studied separately; afterward, they were combined to obtain a hybrid system. Batch fermentation lasted for about 25 h, giving a yield of about 62% and a productivity of about 0.43 g/(L h). The fermented broth coming from these experiments was used to characterize the polyamide (PA) and polysulfone (PS) membranes with different nominal molecular-weight cutoffs used for the filtration step. The behavior of the permeate flux as a function of transmembrane pressure was investigated. The hydraulic resistance of membrane and fouling components was evaluated. The highest contribution to the reduction of flux was due to reversible fouling. This is because the experiments were carried out at a low axial velocity (in the range between 0.35 and 0.650 m/s) so that the cells would not be damaged and aeration would not occur (as this is an...
