Joachim Venus

Fermentative utilization of coffee mucilage using Bacillus coagulans and investigation of down-stream processing of fermentation broth for optically pure l(+)-lactic acid production.

In this study, mucilage, a residue from coffee production, was investigated as substrate in fermentative l(+)-lactic acid production. Mucilage was provided as liquid suspension consisting glucose, galactose, fructose, xylose and sucrose as free sugars (up to 60gL(-1)), and used directly as medium in Bacillus coagulans batch fermentations carried out at 2 and 50L scales. Using mucilage and 5gL(-1) yeast extract as additional nitrogen source, more than 40gL(-1) lactic acid was obtained. Productivity and yield were 4-5gL(-1)h(-1) and 0.70-0.77g lactic acid per g of free sugars, respectively, irrespective the scale. Similar yield was found when no yeast extract was supplied, the productivity, however, was 1.5gL(-1)h(-1). Down-stream processing of culture broth, including filtration, electrodialysis, ion exchange chromatography and distillation, resulted in a pure lactic acid formulation containing 930gL(-1)l(+)-lactic acid. Optical purity was 99.8%.

Techno-economic analysis of a food waste valorization process via microalgae cultivation and co-production of plasticizer, lactic acid and animal feed from algal biomass and food waste

A techno-economic study of food waste valorization via fungal hydrolysis, microalgae cultivation and production of plasticizer, lactic acid and animal feed was simulated and evaluated by Super-Pro Designer®. A pilot-scale plant was designed with a capacity of 1 metric ton day(-1) of food waste with 20 years lifetime. Two scenarios were proposed with different products: Scenario (I) plasticizer & lactic acid, Scenario (II) plasticizer & animal feed. It was found that only Scenario I was economically feasible. The annual net profits, net present value, payback period and internal rate of return were US

Fermentative lactic acid production from coffee pulp hydrolysate using Bacillus coagulans at laboratory and pilot scales.

422,699, US

Utilization of protein-rich residues in biotechnological processes.

3,028,000, 7.56 years and 18.98%, respectively. Scenario II was not economic viable due to a deficit of US

Investigation of food waste valorization through sequential lactic acid fermentative production and anaerobic digestion of fermentation residues

42,632 per year. Sensitivity analysis showed that the price of lactic acid was the largest determinant of the profitability in Scenario I, while the impact of the variables was very close in Scenario II.

Cultivation and Fractionation of Leguminous Biomass for Lactic Acid Production

In 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 30min in presence of 0.18molL(-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 (gL(-1)) glucose (20-30), xylose (15-25), sucrose (5-11) and arabinose (0.7-10). Fermentations were carried out at laboratory (2L) and pilot (50L) scales in presence of 10gL(-1) yeast extract. At pilot scale carbon utilization and lactic acid yield per gram of sugar consumed were 94.65% and 0.78gg(-1), respectively. The productivity was 4.02gL(-1)h(-1). Downstream processing resulted in a pure formulation containing 937gL(-1)l(+)-lactic acid with an optical purity of 99.7%.

Microorganisms for the Production of Lactic Acid and Organic Lactates

A drawback of biotechnological processes, where microorganisms convert biomass constituents, such as starch, cellulose, hemicelluloses, lipids, and proteins, into wanted products, is the economic feasibility. Particularly the cost of nitrogen sources in biotechnological processes can make up a large fraction of total process expenses. To further develop the bioeconomy, it is of considerable interest to substitute cost-intensive by inexpensive nitrogen sources. The aim of this mini-review was to provide a comprehensive insight of utilization methods of protein-rich residues, such as fish waste, green biomass, hairs, and food waste. The methods described include (i) production of enzymes, (ii) recovery of bioactive compounds, and/or (iii) usage as nitrogen source for microorganisms in biotechnological processes. In this aspect, the utilization of protein-rich residues, which are conventionally considered as waste, allows the development of value-adding processes for the production of bioactive compounds, biomolecules, chemicals, and materials.

From lignin to nylon: Cascaded chemical and biochemical conversion using metabolically engineered Pseudomonas putida

This work concerns the investigation of the sequential production of lactic acid (LA) and biogas from food waste (FW). LA was produced from FW using a Streptococcus sp. strain via simultaneous saccharification and fermentation (SSF) and separate enzymatic hydrolysis and fermentation (SHF). Via SHF a yield of 0.33gLA/gFW (productivity 3.38gLA/L·h) and via SSF 0.29gLA/gFW (productivity 2.08gLA/L·h) was obtained. Fermentation residues and FW underwent anaerobic digestion (3wt% TS). Biogas yields were 0.71, 0.74 and 0.90Nm3/kgVS for FW and residues from SSF and SHF respectively. The innovation of the approach is considering the conversion of FW into two different products through a biorefinery concept, therefore making economically feasible LA production and valorising its fermentative residues. Finally, a mass balance of three different outlines with the aim to assess the amount of LA and biogas that may be generated within different scenarios is presented.

Screening of Bacillus coagulans strains in lignin supplemented minimal medium with high throughput turbidity measurements

Chemical industries are set to increase the proportion of renewable feedstock in their production in the decades ahead. Green Biorefineries that divide fresh green biomass into cakes and juice deliver valuable products for various industrial uses. Press juice can be used to produce lactic acid (LA), a promising building blok for the future. In this study, optimal cultivation and fractionation processes for generating a fermentation medium from legumes for lactic acid production by Bacillus coagulans are analyzed. The contents of press juices from alfalfa cultivated on arable land at three different sites and from a clover-grass mixture on a grassland site taken on different sampling dates are compared. In addition, fresh biomass yields from the different biomass samples are examined. This paper focuses on the methods applied, and provides initial results. Yield differences of up to 40 % and 60 % were recorded between different study sites and sampling dates, respectively. Fermentation analysis of the different samples revealed that press juices can supplement the main parts of nutrients for lactic acid bacteria, producing economically interesting amounts of lactic acid. These findings could increase the use of lactic acid in chemical industries and bring about a shift towards a higher proportion of renewables, namely legumes, in the processing chain.

Model-based characterisation of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium

Biorefineries consider lactic acid as one of the most promising platform chemicals which are being extensively used in a wide range of food and nonfood applications. Since lactic acid is produced via biotechnological processes, the microbial strains are in the focus of interest, besides all the other aspects of raw materials, fermentation mode, etc.