• Fermentation Tests
    At Celignis Analytical

Fermentation is a well-known industrial process; however, development of fermentation processes requires knowledge of an array of important fators including: biomass, the microbes used for fermentation, nutrient media, and fermentation conditions.

Here at Celignis our team is highly experienced in numerous types of fermentations and can help you determine and optimise the potenital yields of an array of different fermentation products. If you already have a technology, e.g. pre-treatment and/or hydrolysis, that produces a sugars-containing liquid then we can undertake fermentation tests directly on that. Alternatively, if you are starting with a feedstock and looking for the best approach to get your targetted fermentation product(s) in high yield then we can help you optimise the whole process, covering pre-treatment, hydrolysis and the subsequent fermentation.

Types of Fermentations We Undertake


Fermentation can be divided into three types:

Bacterial Fermenation

Yeast and Fungal Fermenation

Algal Fermenation

1. Bacterial Fermentation

Bacteria are mainly used to produce organic acids and alcohols by anaerobic fermentation and enzymes by aerobic fermentation processes. Very well-known natural fermenters are lactic acid bacteria (LAB) for lactic acid production and Bacillus species such as B. subtilis, B. amyloliquefaciens, B. licheniformis, B. megaterium etc. for the production of enzymes, antibiotics, surfactins, and biopolymers.

Get more info...Bacterial Fermentation









We have expertise in the following bacterial fermentations:

Lactic Acid Fermentation - At Celignis we have expertise and experience in screening lactic acid bacteria for the selection of substrate- and product-tolerant strains. We can also develop: fed-batch strategies to achieve high cell mass, and in situ product recovery techniques to separate lactic acid from the fermentation broth. We will work with you and develop bespoke lactic acid fermentation methods for your feedstock or industrial waste streams.
Get more info...Lactic Acid Fermentation



Propionic Acid Fermentation - We can perform anaerobic fermentations and develop fermentation strategies to achieve high cell mass and in situ product recovery techniques. We can screen your feedstock for propionic acid production, adapt the strain to any inhibitors present in the feed, and develop bespoke fermentation and product recovery processes.
Get more info...Propionic Acid Fermentation



Butyric Acid Fermentation - We have strong expertise in Clostridial fermentation. We can isolate and or adapt the strains that are suitable for your feedstock and can develop fermentation strategies to reduce substrate and product inhibition. We will innovate with you for you.
Get more info...Butyric Acid Fermentation



Butanol Fermentation - At Celignis, we have considerable expertise in Clostridial fermentation and especially butanol fermentation. Our Chief Innovation Officer Dr Lalitha Gottumukkala has extensively worked in this area and has isolated novel strains and developed novel methods for non-acetogenic butanol fermentation as part of her PhD.
Get more info...Butanol Fermentation



1,3-PDO Fermentation - At Celignis, we have expertise and experience in performing anaerobic fermentations and developing fermentation strategies to achieve high cell mass and in situ product recovery techniques. We can screen your feedstock for 1,3 PDO production, adapt the strain to any inhibitors present in the feed and develop bespoke fermentation and product recovery process.
Get more info...1,3-PDO Fermentation



Polyhydoxy Alkanoates (PHAs) Production - We have experience in enrichment of desired microorganisms, fed-batch and continuous fermentations with cell-recycling. We can design and develop the most suitable process for your feedstock by using mixed or mono-culture fermentations. We can also develop cost-efficient downstream processing steps for efficient PHA extraction by using non-toxic and environmentally friendly techniques.
Get more info...PHAs Production





2. Yeast and Fungal Fermentation

Yeast fermentation is one of the oldest fermentations and is used in everyday life to produce a variety of commodity products including bread, beer, wine, cheese, and soy sauce. A few decades ago, yeast gained popularity as an industrial strain for biorefinery and biofuel applications.

Get more info...Yeast Fermentation









We have expertise in the following yeast and fungal fermentations:

Ethanol Production - We can use a variety of yeast types to produce bioethanol. We can ferment the liquids obtained in a prior hydorlysis step (separate hydrolysis and fermentation, SHF) or we can combine the hydrolysis and fermentation stages usingf simultaneous saccharification and fermentaiton (SSF) or simultaneous saccharification and co-fermentation (SSCF) processes.
Get more info...Ethanol Production



Glycerol Production - Bio-glycerol can be produced in high glucose concentrations using osmo-tolerant yeasts.
Get more info...Glycerol Production



Single Cell Oils (SCOs) Production - We can use selected yeast and fungal strains to produce lipids in a variety of substrates such as different types of sugars, glycerol, etc.
Get more info...Single Cell Oils Production



Emulsifiers Production - For this application it is important to optimise the process for product quality and quantity. This is only possible through detailed understanding of microbial strain, its metabolism and needs. We can guide you through and optimise the process.
Get more info...Emulsifiers Production





3. Microalgal Fermentation

Algal cultivation is complicated and requires optimisation to achieve high biomass yields. Algal biomass production depends on nutrient uptake and other environmental conditions such as temperature, pH, salt concentration etc. It is important to select the strain based on the type of production (open ponds, photobioreactors), feedstock and application. We have particular expertise in the evaluation and optimisation of algae thorugh our Chief Innovation Officer, Lalitha, who is currently undertaking a Marie-Curie funded project at Celignis on this topic.

Get more info...Microalgae Fermentation






Contact Us For Further Details

We are available to answer any questions you may have on how to get high value chemicals and biofuels from biomass through fermentation processes. Just get in touch with us by sending us an email info@celignis.com, giving us a call at (+353) 61 371 725, or through our contact form.

Get more info...Get in Touch





Publications on Fermentation By The Celignis Team

Haigh K.F, Petersen A.M, Gottumukkala, L, Mandegari M, Naleli, K, Gorgens J.F (2018) Simulation and comparison of processes for biobutanol production from lignocellulose via ABE fermentation, Biofuels, Bioproducts and Biorefining 12(6): 1023-1036

Six conceptual process scenarios for the production of biobutanol from lignocellulosic biomass through acetone?butanol?ethanol (ABE) fermentation, using reported data on process performances, were developed with ASPEN Plus® V8.2 software. The six scenarios covered three fermentation strategies, i.e. batch separate hydrolysis and fermentation (SHF), continuous SHF, and batch simultaneous saccharification and fermentation (SSF) integrated with gas stripping (GS). The two downstream processing options considered were double?effect distillation (DD) and liquid?liquid extraction and distillation (LLE&D). It was found that the SSF?GS/DD scenario was the most energy efficient with a liquid fuel efficiency of 24% and an overall efficiency of 31%. This was also the scenario with the best economic outcome, with an internal rate of return (IRR) of 15% and net present value (NPV) of US$387 million. The SSF?GS/DD scenario was compared to a similar molasses process, based on the product flow rates, and it was found that the molasses process was more energy efficient with a gross energy value (GEV) of 23?MJ?kg1 butanol compared to ?117?MJ?kg1 butanol for the lignocellulosic process. In addition, the molasses?based process was more profitable with an IRR of 36% compared to 21%. However, the energy requirements for the molasses process were supplied from fossil fuels, whereas for the lignocellulose processes a portion of the feedstock was diverted to provide process energy. Improved environmental performance is therefore associated with the lignocellulosic process.

Vodonik M, Vrabec K, Hellwig P, Benndrof D, Sezun M, Gregori A, Gottumukkala L.D, Andersen R.C, Reichel U (2018) Valorisation of deinking sludge as a substrate for lignocellulolytic enzymes production by Pleurotus ostreatus, Journal of Cleaner production 197(1): 253-263

Disposal of waste sludges produced in large amounts in the pulp and paper industry imposes significant environmental and economical problems. One strategy to address these issues involves revalorization of paper mill sludges by their application as substrates for microbial production of biotechnologically relevant enzymes. The application of lignocellulolytic enzymes in paper, textile and bioenergy industries is encouraged in order to decrease chemicals and energy consumptions. In the following work, deinking sludge was assessed as a substrate for production of lignocellulases. Based on the results of growth and activity screenings, Pleurotus ostreatus PLAB was chosen as the most promising candidate among 30 tested strains and its secretome was further studied by quantitative enzyme assays and mass spectrometry. While endoglucanase and xylanase activities detected in P. ostreatus secretome produced on deinking sludge were similar to activities of cultures grown on other lignocellulosic substrates, average laccase activity was significantly higher (46?000 U/kg DIS). Mass spectrometry identification of the most prominent proteins in the secretome of the target strain confirmed that significant amounts of different lignin-modifying oxidases were produced on this substrate despite its low lignin content, indicating the presence of other inducible compounds. The findings of this study suggest deinking sludge may represent a good substrate for fungal production of the aforementioned enzymes with broad biotechnological applications, including bioremediation, paper and bioenergy industries.

Gottumukkala L.D, Haigh K, Gorgens J (2017) Trends and advances in conversion of lignocellulosic biomass to biobutanol: microbes, bioprocesses and industrial viability, Renewable and Sustainable Energy Reviews 76: 963-973

Biobutanol has gained attention as an alternative renewable transportation fuel for its superior fuel properties and widespread applications in chemical industry, primarily as a solvent. Conventional butanol fermentation has drawbacks that include strain degeneration, end-product toxicity, by-product formation, low butanol concentrations and high substrate cost. The complexity of Clostridium physiology and close control between sporulation phase and ABE fermentation has made it demanding to develop industrially potent strains. In addition to the isolation and engineering of superior butanol producing bacteria, the development of advanced cost-effective technologies for butanol production from feedstock like lignocellulosic biomass has become the primary research focus. High process costs associated with complex feedstocks, product toxicity and low product concentrations are few of the several bioprocess challenges involved in biobutanol production. The article aims to assess the challenges in lignocellulosic biomass to biobutanol conversion and identify key process improvements that can make biobutanol commercially viable.

Boshoff A, Gottumukka L.D, Van Rensburg E, Gorgens J (2016) Paper sludge (PS) to bioethanol: Evaluation of virgin and recycle mill sludge for low enzyme, high-solids fermentationl, Bioresource technology 23: 103-111

Paper sludge (PS) from the paper and pulp industry consists primarily of cellulose and ash and has significant potential for ethanol production. Thirty-seven PS samples from 11 South African paper and pulp mills exhibited large variation in chemical composition and resulting ethanol production. Simultaneous saccharification and fermentation (SSF) of PS in fed-batch culture was investigated at high solid loadings and low enzyme dosages. Water holding capacity and viscosity of the PS influenced ethanol production at elevated solid loadings of PS. High viscosity of PS from virgin pulp mills restricted the solid loading to 18% (w/w) at an enzyme dosage of 20 FPU/gram dry PS (gdPS), whereas an optimal solid loading of 27% (w/w) was achieved with corrugated recycle mill PS at 11 FPU/gdPS. Ethanol concentration and yield of virgin pulp and corrugated recycle PS were 34.2 g/L at 66.9% and 45.5 g/L at 78.2%, respectively.

Robus C.L.L, Gottumukkala, L.D, Van Rensburg E, Gorgens J.F. (2016) Feasible process development and techno-economic evaluation of paper sludge to bioethanol conversion: South African paper mills scenario, Renewable energy 92: 333-345

Paper sludge samples collected from recycling mills exhibited high ash content in the range of 54.59%–65.50% and glucose concentrations between 21.97% and 31.11%. Washing the sludge reduced the total ash content to between 10.7% and 19.31% and increased the concentration of glucose, xylose and lignin. Samples were screened for ethanol production and fed-batch simultaneous saccharification and fermentation (SSF) was optimised for the washed samples that resulted in highest and lowest ethanol concentrations. Maximum ethanol concentrations of 57.31 g/L and 47.72 g/L (94.07% and 85.34% of the maximum theoretical yield, respectively) was predicted for high and low fermentative potential samples, respectively, and was experimentally achieved with 1% deviation. A generic set of process conditions were established for the conversion of high ash-containing paper sludge to ethanol. Techno-economic analysis based on three different revenue scenarios, together with Monte Carlo analysis revealed 95% probability of achieving IRR values in excess of 25% at a paper sludge feed rate of 15 t/d. Feed rates of 30 t/d and 50 t/d exhibited a cumulative probability of 100%. This study presents the technical feasibility and economic viability of paper mills expansion towards bioethanol production from paper sludge.

Gottumukkala L.D. Gorgens J.F (2016) Biobutanol production from lignocellulosics, Biofuels Production and future perspectives, Singh R.S, Pandey A, Gnansounou E, Taylor & Francis group

Next-generation biofuels from renewable sources have gained interest among research investigators, industrialists, and governments due to major concerns on the volatility of oil prices, climate change, and depletion of oil reserves. Biobutanol has drawn signicant attention as an alternative transportation fuel due to its superior fuel properties over ethanol. e advantages of butanol are its high energy content, better blending with gasoline, less hydroscopic nature, lower volatility, direct use in convention engines, low corrosiveness, etc. Butanol production through (acetone, butanol, and ethanol) ABE fermentation is a well-established process, but it has several drawbacks like feedstock cost, strain degeneration, product toxicity, and low product concentrations. Lignocellulosic biomass is considered as the most abundant, renewable, low-cost feedstock for biofuels. Production of butanol from lignocellulosic biomass is more complicated due to the recalcitrance of feedstock and inhibitors generated during the pretreatment and hydrolysis process. Advanced fermentation and product recovery techniques are being researched to make biobutanol industrially viable.

Sajna K.P, Sukumaran R.K, Gottumukkala L.D, Pandey A (2015) Crude oil biodegradation aided by biosurfactants from Pseudozyma sp. NII 08165 or its culture broth, Bioresource technology 191: 133-139

The aim of this work was to evaluate the biosurfactants produced by the yeast Pseudozyma sp. NII 08165 for enhancing the degradation of crude oil by a model hydrocarbon degrading strain, Pseudomonas putida MTCC 1194. Pseudozyma biosurfactants were supplemented at various concentrations to the P. putida culture medium containing crude oil as sole carbon source. Supplementation of the biosurfactants enhanced the degradation of crude oil by P. putida; the maximum degradation of hydrocarbons was observed with a 2.5 mg L?1 supplementation of biosurfactants. Growth inhibition constant of the Pseudozyma biosurfactants was 11.07 mg L?1. It was interesting to note that Pseudozyma sp. NII 08165 alone could also degrade diesel and kerosene. Culture broth of Pseudozyma containing biosurfactants resulted up to ?46% improvement in degradation of C10–C24 alkanes by P. putida. The enhancement in degradation efficiency of the bacterium with the culture broth supplementation was even more pronounced than that with relatively purer biosurfactants.

Thomas L, Joseph A, Gottumukkala L.D. (2014) Xylanase and cellulase systems of Clostridium sp.: an insight on molecular approaches for strain improvement, Bioresource technology 158: 343-350

Bioethanol and biobutanol hold great promise as alternative biofuels, especially for transport sector, because they can be produced from lignocellulosic agro-industrial residues. From techno-economic point of view, the bioprocess for biofuels production should involve minimal processing steps. Consolidated bioprocessing (CBP), which combines various processing steps such as pretreatment, hydrolysis and fermentation in a single bioreactor, could be of great relevance for the production of bioethanol and biobutanol or solvents (acetone, butanol, ethanol), employing clostridia. For CBP, Clostridium holds best promise because it possesses multi-enzyme system involving cellulosome and xylanosome, which comprise several enzymes such as cellulases and xylanases. The aim of this article was to review the recent developments on enzyme systems of clostridia, especially xylanase and cellulase with an effort to analyse the information available on molecular approaches for the improvement of strains with ultimate aim to improve the efficiencies of hydrolysis and fermentation.

Gottumukkala L.D, Parameswaran B, Valappil S.K, Pandey A (2014) Growth and butanol production by Clostridium sporogenes BE01 in rice straw hydrolysate: kinetics of inhibition by organic acids and the strategies for their removal, Biomass Conversion and Biorefinery 4(3): 277-283

Growth inhibition kinetics of a novel non-acetone forming butanol producer, Clostridium sporogenes BE01, was studied under varying concentrations of acetic and formic acids in rice straw hydrolysate medium. Both the organic acids were considered as inhibitors as they could inhibit the growth of the bacterium, and the inhibition constants were determined to be 1.6 and 0.76 g/L, respectively, for acetic acid and formic acid. Amberlite resins—XAD 4, XAD 7, XAD 16, and an anion exchange resin—Seralite 400 were tested for the efficient removal of these acidic inhibitors along with minimal adsorption of sugars and essential minerals present in the hydrolysate. Seralite 400 was an efficient adsorbent of acids, with minimal affinity towards minerals and sugars. Butanol production was evaluated to emphasize the effect of minerals loss and acids removal by the resins during detoxification.

Gottumukkala, L. D, Valappi, S. K. (2013) Biobutanol production from rice straw by a non acetone producing Clostridium sporogenes BE01, Bioresource Technology 145: 182-187

Biobutanol from lignocellulosic biomass has gained much attention due to several advantages over bioethanol. Though microbial production of butanol through ABE fermentation is an established technology, the use of lignocellulosic biomass as feedstock presents several challenges. In the present study, biobutanol production from enzymatic hydrolysate of acid pretreated rice straw was evaluated using Clostridium sporogenes BE01. This strain gave a butanol yield of 3.43 g/l and a total solvent yield of 5.32 g/l in rice straw hydrolysate supplemented with calcium carbonate and yeast extract. Hydrolysate was analyzed for the level of inhibitors such as acetic acid, formic acid and furfurals which affect the growth of the organism and in turn ABE fermentation. Methods for preconditioning the hydrolysate to remove toxic end products were done so as to improve the fermentation efficiency. Conditions of ABE fermentation were fine tuned resulting in an enhanced biobutanol reaching 5.52 g/l.

Gottumukkala L.D, Parameswaran B, Valappil S.K, Mathiyazhakan, K (2013) Biobutanol production from rice straw by a non acetone producing Clostridium sporogenes BE01, Bioresource technology 145: 182-187

Biobutanol from lignocellulosic biomass has gained much attention due to several advantages over bioethanol. Though microbial production of butanol through ABE fermentation is an established technology, the use of lignocellulosic biomass as feedstock presents several challenges. In the present study, biobutanol production from enzymatic hydrolysate of acid pretreated rice straw was evaluated using Clostridium sporogenes BE01. This strain gave a butanol yield of 3.43 g/l and a total solvent yield of 5.32 g/l in rice straw hydrolysate supplemented with calcium carbonate and yeast extract. Hydrolysate was analyzed for the level of inhibitors such as acetic acid, formic acid and furfurals which affect the growth of the organism and in turn ABE fermentation. Methods for preconditioning the hydrolysate to remove toxic end products were done so as to improve the fermentation efficiency. Conditions of ABE fermentation were fine tuned resulting in an enhanced biobutanol reaching 5.52 g/l.

Sajna K.V, Sukumaran R.K, Gottumukkala L.D, Jayamurthy H, Dhar K.S (2013) Studies on structural and physical characteristics of a novel exopolysaccharide from Pseudozyma sp. NII 08165, International Journal of Biological Macromolecules 59: 84-89

Link

The aim of this work was to study the production of exopolysaccharide (EPS) from a novel ustilaginomycetes yeast strain Pseudozyma sp. NII 08165. The culture produced 3.5g/l EPS on fourth day of fermentation in a glucose-based medium. The structural characterization revealed that the EPS was a polymer of glucose, galactose and mannose in the ratio of 2.4:5.0:2.6 with a molecular weight of 1.7MDa. The pseudoplastic behaviour of aqueous EPS with a thermal stability up to 220 C indicated its potential utility as a thickening or gelling agent in food industry. SEM studies of the EPS showed that it had compact film-like structure, which could make it a useful in preparing plasticized films. The AFM studies showed that EPS had spike-shaped microstructure. Physical properties of the exopolysaccharide determined further indicated its possible potential in different industrial applications.

Singhania R.R, Sukumaran R.K, Rajasree K.P, Mathew A, Gottumukkala L.D, Pandey A (2011) Properties of a major ?-glucosidase-BGL1 from Aspergillus niger NII-08121 expressed differentially in response to carbon sources, Process Biochemistry 46(7): 1521-1524

Aspergillus niger NII-08121/MTCC 7956 exhibited differences in expression of ?-glucosidase (BGL) in response to carbon sources provided in the medium. Activity staining with methyl umbelliferyl ?-d-glucopyranoside (MUG) indicated that four different isoforms of BGL were expressed when A. niger was grown under submerged fermentation with either lactose or cellulose, whereas only two were expressed when wheat bran or rice straw was used as the carbon source. Among the four isoforms of BGL expressed during lactose supplementation, two were found to retain 92% and 82% activity respectively in presence of 250 mM glucose in the MUG assay. The major ?-glucosidase (BGL1) was purified to homogeneity by electro elution from a Native PAGE gel. The purified 120 kDa protein was active at 50 °C and was stable for 48 h without any loss of activity. The optimum pH and temperature were 4.8 and 70 °C respectively.

Parameswaran, B, Raveendran S, Singhania, R.R, Surender V, L Devi, Nagalakshmi S, Kurien N, Sukumaran R.K, Pandey A. (2010) Bioethanol production from rice straw: an overview, Bioresource technology 101(13): 4767-4774

Rice straw is an attractive lignocellulosic material for bioethanol production since it is one of the most abundant renewable resources. It has several characteristics, such as high cellulose and hemicelluloses content that can be readily hydrolyzed into fermentable sugars. But there occur several challenges and limitations in the process of converting rice straw to ethanol. The presence of high ash and silica content in rice straw makes it an inferior feedstock for ethanol production. One of the major challenges in developing technology for bioethanol production from rice straw is selection of an appropriate pretreatment technique. The choice of pretreatment methods plays an important role to increase the efficiency of enzymatic saccharification thereby making the whole process economically viable. The present review discusses the available technologies for bioethanol production using rice straw.

Aswathy U.S, Sukumaran R.K, Devi G.L, Rajasree K.P, Singhania R.R. (2010) Bio-ethanol from water hyacinth biomass: an evaluation of enzymatic saccharification strategy, Bioresource technology 101(3): 925-930

Biomass feedstock having less competition with food crops are desirable for bio-ethanol production and such resources may not be localized geographically. A distributed production strategy is therefore more suitable for feedstock like water hyacinth with a decentralized availability. In this study, we have demonstrated the suitability of this feedstock for production of fermentable sugars using cellulases produced on site. Testing of acid and alkali pretreatment methods indicated that alkali pretreatment was more efficient in making the sample susceptible to enzyme hydrolysis. Cellulase and ?-glucosidase loading and the effect of surfactants were studied and optimized to improve saccharification. Redesigning of enzyme blends resulted in an improvement of saccharification from 57% to 71%. A crude trial on fermentation of the enzymatic hydrolysate using the common baker’s yeast Saccharomyces cerevisiae yielded an ethanol concentration of 4.4 g/L.



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