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- ItemA brief dataset on the model-based evaluation of the growth performance of Bacillus coagulans and l-lactic acid production in a lignin-supplemented medium(Amsterdam : Elsevier, 2017) Glaser, Robert; Venus, JoachimThe data presented in this article are related to the research article entitled “Model-based characterization of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium (R. Glaser and J. Venus, 2016) [1]”. This data survey provides the information on characterization of three Bacillus coagulans strains. Information on cofermentation of lignocellulose-related sugars in lignin-containing media is given. Basic characterization data are supported by optical-density high-throughput screening and parameter adjustment to logistic growth models. Lab scale fermentation procedures are examined by model adjustment of a Monod kinetics-based growth model. Lignin consumption is analyzed using the data on decolorization of a lignin-supplemented minimal medium.
- ItemAssessing the organic fraction of municipal solid wastes for the production of lactic acid(Amsterdam [u.a.] : Elsevier, 2019) López-Gómez, J. Pablo; Latorre-Sánchez, Marcos; Unger, Peter; Schneider, Roland; Coll Lozano, Caterina; Venus, JoachimWith an estimated yearly production of about 140 Mt in the EU, conventionally, the organic fraction of municipal solid wastes (OFMSW) has been disposed in landfills with negative environmental effects. Nonetheless, the chemical composition of this residue make it a substrate with great bioconversion potential. In this study, OFMSW from Spanish municipal treatment plants, were evaluated for the production of LA. Samples were identified according to the sorting mechanisms employed for their collection in: (A) separately collected, (B) non-separately collected and (C) separately collected+paper/cardboard. Enzymatic hydrolysis was used to produce hydrolysates A, B and C accordingly. Hydrolysate A showed the highest total sugars and glucose content with values of 70 and 55 g·L−1, respectively. Following the characterisation, a screening showed that growth of B. coagulans was possible in all three hydrolysates. Furthermore, lab scale fermentations showed that LA final concentrations could reach around 60 g·L−1, with yields from total sugars of above 0.60 g·g−1. A technical scale fermentation of the hydrolysate A resulted in a final LA concentration of 60.7 g·L−1, a yield of 0.71 g·g−1 with a productivity of 2.68 g·L−1·h−1. Overall, it was estimated that 0.23 g of LA could be produced from one g of dry OFMSW.
- ItemDirect production of lactic acid based on simultaneous saccharification and fermentation of mixed restaurant food waste(Amsterdam : Elsevier, 2016) Pleissner, Daniel; Demichelis, Francesca; Mariano, Silvia; Fiore, Silvia; Gutiérrez, Ivette Michelle Navarro; Schneider, Roland; Venus, JoachimThis study introduces to a one-step process for the fermentative production of L(+)-lactic acid from mixed restaurant food waste. Food waste was used as carbon and nitrogen source in simultaneous saccharification and fermentation (SSF) using Lactobacillus sp. or Streptococcus sp. strains for L(+)-lactic acid production. Waste consisted of (w/w) 33.5% starch, 14.8% proteins, 12.9% fat and 8.5% free sugars. Lactobacillus sp. strains showed a productivity of 0.27–0.53 g L−1 h−1 and a yield of 0.07–0.14 g g−1 of theoretically available sugars, while Streptococcus sp. more efficiently degraded the food waste material and produced lactic acid at a maximum rate of 2.16 g L−1 h−1 and a yield of 0.81 g g−1. For SSF, no enzymes were added or other hydrolytic treatments were carried out. Outcomes revealed a linear relationship between lactic acid concentration and solid-to-liquid ratio when Streptococcus sp. was applied. Statistically, from a 20% (w/w) dry food waste blend 52.4 g L−1 lactic acid can be produced. Experimentally, 58 g L−1 was achieved in presence of 20% (w/w), which was the highest solid-to-liquid ratio that could be treated using the equipment applied. Irrespective if SSF was performed at laboratory or technical scale, or under non-sterile conditions, Streptococcus sp. efficiently liquefied food waste and converted the released nutrients directly into lactic acid without considerable production of other organic acids, such as acetic acid. Downstream processing including micro- and nanofiltration, electrodialysis, chromatography and distillation gave a pure 702 g L−1 L(+)-lactic acid formulation.
- ItemRecent advances in d-lactic acid production from renewable resources: Case studies on agro-industrial waste streams(Zagreb : Faculty of Food Technology and Biotechnology, University of Zagreb, 2019) Alexandri, Maria; Schneider, Roland; Mehlmann, Kerstin; Venus, JoachimThe production of biodegradable polymers as alternatives to petroleum-based plastics has gained significant attention in the past years. To this end, polylactic acid (PLA) constitutes a promising alternative, finding various applications from food packaging to pharmaceuticals. Recent studies have shown that d-lactic acid plays a vital role in the production of heat-resistant PLA. At the same time, the utilization of renewable resources is imperative in order to decrease the production cost. This review aims to provide a synopsis of the current state of the art regarding d-lactic acid production via fermentation, focusing on the exploitation of waste and byproduct streams. An overview of potential downstream separation schemes is also given. Additionally, three case studies are presented and discussed, reporting the obtained results utilizing acid whey, coffee mucilage and hydrolysate from rice husks as alternative feedstocks for d-lactic acid production. © 2019, University of Zagreb.
- ItemCo-fermentation of the main sugar types from a beechwood organosolv hydrolysate by several strains of Bacillus coagulans results in effective lactic acid production(Amsterdam : Elsevier, 2018) Glaser, Robert; Venus, JoachimBacillus coagulans is an interesting facultative anaerobic microorganism for biotechnological production of lactic acid that arouses interest. To determine the efficiency of biotechnological production of lactic acid from lignocellulosic feedstock hydrolysates, five Bacillus coagulans strains were grown in lignocellulose organosolv hydrolysate from ethanol/water-pulped beechwood. Parameter estimation based on a Monod-type model was used to derive the basic key parameters for a performance evaluation of the batch process. Three of the Bacillus coagulans strains, including DSM No. 2314, were able to produce lactate, primarily via uptake of glucose and xylose. Two other strains were identified as having the ability of utilizing cellobiose to a high degree, but they also had a lower affinity to xylose. The lactate yield concentration varied from 79.4 ± 2.1 g/L to 93.7 ± 1.4 g/L (85.4 ± 4.7 % of consumed carbohydrates) from the diluted organosolv hydrolysate.
- ItemFermentative lactic acid production from coffee pulp hydrolysate using Bacillus coagulans at laboratory and pilot scales(Amsterdam : Elsevier, 2016) Pleissner, Daniel; Neu, Anna-Katrin; Mehlmann, Kerstin; Schneider, Roland; Puerta-Quintero, Gloria Inés; Venus, JoachimIn this study, the lignocellulosic residue coffee pulp was used as carbon source in fermentative l(+)-lactic acid production using Bacillus coagulans. After thermo-chemical treatment at 121 °C for 30 min in presence of 0.18 mol L−1 H2SO4 and following an enzymatic digestion using Accellerase 1500 carbon-rich hydrolysates were obtained. Two different coffee pulp materials with comparable biomass composition were used, but sugar concentrations in hydrolysates showed variations. The primary sugars were (g L−1) glucose (20–30), xylose (15–25), sucrose (5–11) and arabinose (0.7–10). Fermentations were carried out at laboratory (2 L) and pilot (50 L) scales in presence of 10 g L−1 yeast extract. At pilot scale carbon utilization and lactic acid yield per gram of sugar consumed were 94.65% and 0.78 g g−1, respectively. The productivity was 4.02 g L−1 h−1. Downstream processing resulted in a pure formulation containing 937 g L−1 l(+)-lactic acid with an optical purity of 99.7%.
- ItemFrontiers in the expansion of bioproducts(London : Hindawi, 2016) Cota, Junio; Venus, Joachim; Hoffmam, Zaira B.; Ribeiro, Lucas F.[no abstract available]
- ItemScreening of Bacillus coagulans strains in lignin supplemented minimal medium with high throughput turbidity measurements(Amsterdam : Elsevier, 2014) Glaser, Robert; Venus, JoachimThe aim of this study was to extend the options for screening and characterization of microorganism through kinetic growth parameters. In order to obtain data, automated turbidimetric measurements were accomplished to observe the response of strains of Bacillus coagulans. For the characterization, it was decided to examine the influence of varying concentrations of lignin with respect to bacterial growth. Different mathematical models are used for comparison: logistic, Gompertz, Baranyi and Richards and Stannard. The growth response was characterized by parameters like maximum growth rate, maximum population, and the lag time. In this short analysis we present a mathematical approach towards a comparison of different microorganisms. Furthermore, it can be demonstrated that lignin in low concentrations can have a positive influence on the growth of B. coagulans.