Fermentation Process For Production Research Articles

Metabolic control analysis enabled the improvement of the L-cysteine production process with Escherichia coli

L-cysteine is an amino acid with relevance to the pharmaceutical, food, feed, and cosmetic industry. The environmental and societal impact of its chemical production has led to the development of more sustainable fermentative L-cysteine production processes with engineered E. coli based on glucose and thiosulfate as sulphur source. Still, most of the published processes show low yields. For the identification of further metabolic engineering targets, engineered E. coli cells were withdrawn from a fed-batch production process, followed by in vivo metabolic control analysis (MCA) based on the data of short-term perturbation experiments, metabolomics (LC–MS), and thermodynamic flux analysis (TFA). In vivo MCA indicated that the activities of the L-cysteine synthases of the cells withdrawn from the production process might be limiting, and we hypothesised that the L-cysteine precursor O-acetylserine (OAS) might be exported from the cells faster than it took to transform OAS into L-cysteine. By increasing the expression of the L-cysteine synthases, either sulfocysteine synthase or L-cysteine synthase, which transform OAS into L-cysteine, an improvement of up to 70% in specific L-cysteine productivity and up to 47% in the final L-cysteine concentration was achieved in standardised fed-batch processes thereby increasing the yield on glucose by more than 85 to 9.2% (w/w).Key points• Metabolic control analysis was applied to analyse L-cysteine production with E. coli• OAS export was faster than its transformation to L-cysteine• Overexpression of L-cysteine synthases improved L-cysteine productivity and yield

Visual Tools for Food Safety Assessment of Biotechnological Products

Food biotechnology, a revolutionary discipline, has transformed the way we produce, process and consume our food. It has enabled the development of new methods of crop genetic improvement, the creation of functional foods with health benefits, and the optimization of fermentation and food production processes. It has also provided innovative solutions to address the global challenges of food security and sustainability, while opening up new possibilities for nutrition and human health.

Autochthonous Microbes to Produce Ligurian Taggiasca Olives (Imperia, Liguria, NW Italy) in Brine

Table olives are considered high-quality food, and Italy has a wealth of varieties and typical features that are truly unique in the world (about eighty cultivars of table olives or dual-purpose olives, four of which are protected by the protected designation of origin—PDO), and it is the second largest European consumer, behind Spain. The Taggiasca olive does not have a PDO, but it is very appreciated not only in the region of production (Liguria), but also in all the Italian regions and abroad. Autochthonous microbes (bacteria, yeasts, and filamentous fungi) are essential in the fermentative processes for brine olive production. However, these microbial communities that colonised the olive drupes are affected by the environmental conditions and the fermentation treatments. Hence the importance of studying and comparing olive microbes from different farms and investigating the relationships between bacteria, yeasts, and filamentous fungi to speed up the deamarisation process. Our results showed that yeasts are dominant relative to lactobacteria in all three brines studied, and Wickerhamomyces anomalus was the most performant fungus for the oleuropein degradation. The latter represents the best candidate for the realisation of a microbial starter.

Microbial production of trans-aconitic acid

Trans-aconitic acid (TAA) is a promising bio-based chemical with the structure of unsaturated tricarboxylic acid, and also has the potential to be a non-toxic nematicide as a potent inhibitor of aconitase. However, TAA has not been commercialized because the traditional production processes of plant extraction and chemical synthesis cannot achieve large-scale production at a low cost. The availability of TAA is a serious obstacle to its widespread application. In this study, we developed an efficient microbial synthesis and fermentation production process for TAA. An engineered Aspergillus terreus strain producing cis-aconitic acid and TAA was constructed by blocking itaconic acid biosynthesis in the industrial itaconic acid-producing strain. Through heterologous expression of exogenous aconitate isomerase, we further designed a more efficient cell factory to specifically produce TAA. Subsequently, the fermentation process was developed and scaled up step-by-step, achieving a TAA titer of 60 g L−1 at the demonstration scale of a 20 m3 fermenter. Finally, the field evaluation of the produced TAA for control of the root-knot nematodes was performed in a field trial, effectively reducing the damage of the root-knot nematode. Our work provides a commercially viable solution for the green manufacturing of TAA, which will significantly facilitate biopesticide development and promote its widespread application as a bio-based chemical.

Multi-criteria analysis of cell-recycle based continuous lactic acid production process

ABSTRACT This study focuses on the optimization of the cell-recycle based continuous lactic acid (LA) fermentation production process with the estimation of improved kinetic parameters. The non-dominated sorting genetic algorithm II (NSGA-II) is used considering seven variables and five imposed constraints for multi-objective optimization (MOO) study. Three objectives namely LA productivity, substrate conversion, and yield are formed for the maximization purpose. Three different cases are constructed by using a combination of two bi-objectives and one tri-objective optimization problem, and the modified differential evolution (MDE) algorithm is used to individually optimize each case. Pareto ranking is carried out for MOO, and the best optimal solution is determined using the technique for order preference by similarity to the ideal solution (TOPSIS) method. The highest value of volumetric productivity of LA (184.363 kg/m3.h) is reported in case-4a. The highest yield (1.176) is reported in case-2, while the highest substrate conversion (0.963) is reported in case-1.

Bacterial nanocellulose from symbiotic culture of bacteria and yeast kombucha prepared with lemongrass tea and sucrose: Optimization and characterization

Bacterial nanocellulose (BNC) can be produced using a variety of substrates as fermentation medium for use in various biomaterial applications. This study aimed to optimize the production of and characterize the BNC derived from lemongrass leaves (L-BNC) obtained by symbiotic culture of bacteria and yeast (SCOBY) kombucha. The lemongrass leaves (10, 15, and 20 g/L) and sugar (30, 50, and 70 g/L) were incubated for 14 d at 30 °C. The optimal treatment was used to ferment kombucha for 21 days at 30 °C, with initial SCOBY inoculum of 3% w/v and kombucha of 10% v/v for the resulting L-BNC. The L-BNC was characterized using scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy, Fourier-transform Infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). The optimal parameters of the lemongrass kombucha fermentation production process were lemongrass content 10 g/L and sugar content 30 g/L with the incubation period of two weeks for 56.8 g/L of SCOBY production. The SEM analysis of L-BNC revealed a three-dimensional fibrous extremely fine network of randomly arranged nanofibrils with diameter of 163 ± 34 nm and hydrogen bonds present in L-BNC fibril units. Meanwhile, XRD results showed a crystallinity of 67.2%.

High-efficiency production of the antimicrobial peptide pediocin PA-1 in metabolically engineered Corynebacterium glutamicum using a microaerobic process at acidic pH and elevated levels of bivalent calcium ions

BackgroundPediocin PA-1 is a bacteriocin of recognized value with applications in food bio-preservation and the medical sector for the prevention of infection. To date, industrial manufacturing of pediocin PA-1 is limited by high cost and low-performance. The recent establishment of the biotechnological workhorse Corynebacterium glutamicum as recombinant host for pediocin PA-1 synthesis displays a promising starting point towards more efficient production.ResultsHere, we optimized the fermentative production process. Following successful simplification of the production medium, we carefully investigated the impact of dissolved oxygen, pH value, and the presence of bivalent calcium ions on pediocin production. It turned out that the formation of the peptide was strongly supported by an acidic pH of 5.7 and microaerobic conditions at a dissolved oxygen level of 2.5%. Furthermore, elevated levels of CaCl2 boosted production. The IPTG-inducible producer C. glutamicum CR099 pXMJ19 Ptac pedACDCg provided 66 mg L−1 of pediocin PA-1 in a two-phase batch process using the optimized set-up. In addition, the novel constitutive strain Ptuf pedACDCg allowed successful production without the need for IPTG.ConclusionsThe achieved pediocin titer surpasses previous efforts in various microbes up to almost seven-fold, providing a valuable step to further explore and develop this important bacteriocin. In addition to its high biosynthetic performance C. glutamicum proved to be highly robust under the demanding producing conditions, suggesting its further use as host for bacteriocin production.

Synergetic effect evaluation of light and mass transfer enhancement strategies on photo fermentative biohydrogen production process: Illumination, shake, and high solid level

During the process of photo fermentative biohydrogen production (PFHP) with high substrate concentration from agricultural waste, the interphase light and mass transfer behavior is hindered, caused by the suspension flow of substrates, resulting in low hydrogen production performance. In the paper, shake and lighting supplied strategy was investigated to soften the restrictions of high substrate concentration of corncob to improve the hydrogen yield and light energy conversion. The response surface methodology (RSM) was adopted to optimize the influence of variables on hydrogen production (substrate concentration, light intensity and shake intensity). Results showed that the maximum hydrogen yield of 48 mL/g TS and the maximum light energy conversion efficiency of 11.04% were obtained at the condition of 150 rpm, 6000 Lux and substrate concentration 55.56 g/L, increased by 603.85% and 598.63% than the static condition, respectively. RSM showed the synergistic effect between variables significantly affected the hydrogen production performance, the optimal enhancement strategies were: shake intensity 153.33 rpm, light intensity 6155.56 Lux and substrate concentration 57.71 g/L. 4.71% error of the predicted cumulative hydrogen yield (490.41 mL) and the actual cumulative hydrogen yield (468.34 mL) indicating the fitting effect of the model was satisfactory.

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production, storage and treatment processes

Antibiotic fermentation residue (AFR) is nutrient-rich solid waste generated from fermentative antibiotic production process. It is demonstrated that AFR contains high-concentration of remaining antibiotics, and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals. However, the dominate microorganisms and antibiotic resistance genes (ARGs) in AFRs have not been adequately explored, hampering understanding on the potential antibiotic resistance risk development caused by AFRs. Herein, seven kinds of representative AFRs along their production, storage, and treatment processes were collected, and multiple methods including amplicon sequencing, metagenomic sequencing, and bioinformatic approaches were adopted to explore the biological characteristics of AFRs. As expected, antibiotic fermentation producer was found as the predominant species in raw AFRs, which were collected at the outlet of fermentation tanks. However, except for producer species, more environment-derived species persisted in stored AFRs, which were temporarily stored at a semi-open space. Lactobacillus genus, classified as Firmicutes phylum and Bacilli class, became predominant bacterial taxa in stored AFRs, which might attribute to its tolerance to high concentration of antibiotics. Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species (e.g., Lactobacillus genus) tended to carry ARGs conferring resistance to the remaining antibiotic. However, after thermal treatment, remaining antibiotic could be efficiently removed from AFRs, and microorganisms together with DNA could be strongly destroyed. In sum, the main risk from the AFRs was the remaining antibiotic, while environment-derived bacteria which tolerate extreme environment, survived in ARFs with high content antibiotics, and may carry ARGs. Thus, hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.

Slow‐varying batch process monitoring based on canonical variate analysis

AbstractMost industrial batch processes display normal slow changes over batches because of the influence of external factors. The question of how to take this slow‐varying behaviour into account during dynamic process monitoring remains a challenge for researchers. To address the above issue, a slow‐varying batch process monitoring method is proposed for multiphase batch processes. It makes subtraction between two different batches with a certain interval for pre‐treating the original data and subsequently utilizes a canonical variate analysis (CVA) algorithm with kernel density estimation (KDE) for fault detection. For each subphase, the proposed method can extract a variable‐wise dynamic characteristic with the time evolution for every single batch and capture statistical features of slow variations along batch direction simultaneously. It is less sensitive to normal gradual changes with a low false‐positive rate. The performance of the proposed method for batch process monitoring was tested on a numerical simulation system and penicillin fermentation production process with comparison to multiphase CVA, multiphase slow feature analysis (SFA), multiphase principal component analysis (PCA), and traditional CVA without phase division. The achieved results clearly demonstrate the effectiveness of the proposed method, which is a remarkable and promising tool for modelling and monitoring batch processes with regular slow‐varying characteristics.

Real-time monitoring of kefir-facilitated milk fermentation using microbial potentiometric sensors

Considering that fermentation is a microorganism-mediated redox process, an underlying hypothesis was postulated that the microbial potentiometric sensor technology could be used to monitor dairy fermentation or other similar food production processes. It was also hypothesized that the signal characteristics could be exploited to correlate the mass of inoculum and the fermentation completion time. Three objectives were addressed to test these hypotheses. First, a set of fermentation experiments were employed to measure the changes in the open-circuit potential signals from two carbon-based microbial potentiometric sensor (MPS) electrodes exposed to varying kefir inoculum to milk ratios. Second, the MPS signal patterns were analyzed to determine what signals were indicative of completion of the fermentation process. Third, regression analyses were conducted to determine the level of correlation between the fermentation completion time and the mass of the inoculum under constant conditions. The hypothesized capabilities of this technology for monitoring kefir fermentation processes of milk were validated. The MPS technology could be used to monitor kefir fermentation in real-time with high reproducibility. The regression analysis approach was able to discern a correlation between the fermentation completion time and the mass of kefir inoculum characterized with coefficients of determination R2 > 0.94. Furthermore, the results from the MPS signal patterns offered unique perspectives at various phases of the fermentation process, which open new avenues to better understand fermentation. This study demonstrates that, when coupled with appropriate signal analysis tools and methodologies, the MPS technology offers unparalleled opportunities for real-time monitoring, optimization, and management of industrial-scale fermentation and other food or beverage production processes which are facilitated by microbial activity.

Fermentation for the production of biobased chemicals in a circular economy: a perspective for the period 2022–2050

A critical review of the potential of fermentation processes for production of bulk chemicals in a future circular economy.

Response of cattle manure anaerobic digestion to zinc oxide nanoparticles: Methane production, microbial community, and functions

The increasing use of zinc oxide nanoparticles (ZnO NPs) as feed additives has raised huge environmental concerns in the anaerobic digestion (AD) of livestock wastes. In this study the 30-day effect of ZnO NPs on AD performance of cattle manure was investigated under optimal conditions (temperature=55 °C, initial pH=10, total solids contents=10%), which were obtained from response surface methodology. Results showed that ZnO NPs (5–100 mg/g TS) promoted the accumulation of soluble chemical oxygen demand, soluble protein and polysaccharide, but inhibited their following fermentation and methane production processes. This inhibition became stronger as ZnO NPs concentration increased, leading to the methane production declined by 84.55% (5 mg/ g TS), 92.39% (30 mg/g TS), and 93.72% (100 mg/g TS), respectively. High-throughput sequencing results demonstrated that the decrease in the abundances of functional bacteria from 72.11% to 11.24% (in families Ruminococcaceae and Lachnospiraceae), and of methanogens from 96.82% to < 1% (in genus Methanothermobacter) led to poor fermentation and methanogenesis, respectively. Predictive functional analysis indicated that ZnO NPs can enhance abundances of AD-friendly functional genes instead of possible genetic expression, resulting in the low methane production. Our findings highlight a deep understanding of the role of ZnO NPs in cattle manure AD and are critical for guiding feed additive application.

Effect of Castor Oil on Bioprocess Parameters of Erythromycin Fermentation by Saccharopolyspora Erythraea.

Background: Increased economic competitiveness in the biopharmaceutical industry requires continuous improvement of bioprocesses. In this regard compositions of fermentation media have an important role in bioprocesses.Objectives: The modification of the culture medium has proven effective in enhancing the yield and productivity of fermentation processes. The objective was to investigate the influence of castor oil as the main carbon source for Saccharopolyspora erythraea, on the yield of antibiotic fermentative production.Material and Methods: The titer of erythromycin was evaluated in Saccharopolyspora erythraea cultures, containing various concentrations of castor oil, in comparison to the control culture containing rapeseed oil.Results: The results showed an enhancement in erythromycin production when 50 g.L-1and 40 g.L-1of castor oil were added to the fermentation culture instead of rapeseed oil, respectively. The highest amount of production was obtained on the eleventh day of fermentation time in all media.Conclusion: Erythromycin production in the control medium was relatively less than that of the treatments, indicating that S. erythraea consumed castor oil as a rich alternative carbon source. The results show that castor oil was more suitable as a carbon source for erythromycin production than a medium containing rapeseed oil.

Engineering robust microorganisms for organic acid production.

Organic acids are an important class of compounds that can be produced by microbial conversion of renewable feedstocks and have huge demands and broad applications in food, chemical, and pharmaceutical industries. An economically viable fermentation process for production of organic acids requires robust microbial cell factories with excellent tolerance to low pH conditions, high concentrations of organic acids, and lignocellulosic inhibitors. In this review, we summarize various strategies to engineer robust microorganisms for organic acid production and highlight their applications in a few recent examples.

Analysis of methods for quantifying yeast cell concentration in complex lignocellulosic fermentation processes

Cell mass and viability are tightly linked to the productivity of fermentation processes. In 2nd generation lignocellulose-based media quantitative measurement of cell concentration is challenging because of particles, auto-fluorescence, and intrinsic colour and turbidity of the media. We systematically evaluated several methods for quantifying total and viable yeast cell concentrations to validate their use in lignocellulosic media. Several automated cell counting systems and stain-based viability tests had very limited applicability in such samples. In contrast, manual cell enumeration in a hemocytometer, plating and enumeration of colony forming units, qPCR, and in situ dielectric spectroscopy were further investigated. Parameter optimization to measurements in synthetic lignocellulosic media, which mimicked typical lignocellulosic fermentation conditions, resulted in statistically significant calibration models with good predictive capacity for these four methods. Manual enumeration of cells in a hemocytometer and of CFU were further validated for quantitative assessment of cell numbers in simultaneous saccharification and fermentation experiments on steam-exploded wheat straw. Furthermore, quantitative correlations could be established between these variables and in situ permittivity. In contrast, qPCR quantification suffered from inconsistent DNA extraction from the lignocellulosic slurries. Development of reliable and validated cell quantification methods and understanding their strengths and limitations in lignocellulosic contexts, will enable further development, optimization, and control of lignocellulose-based fermentation processes.

Transformation of ochratoxin A during bread-making processes

Ochratoxin A (OTA) – secondary metabolite of fungi from genera Aspergillus and Penicillium may mainly contaminate cereal-based food. Thermal processing (including baking) may reduce the levels of OTA, but may also produce racemic mixtures with the 2′R-ochratoxin A (2′R-OTA) isomer. In this study, the stability of OTA during rye bread production processes and pizza wheat base production processes (including dough kneading, dough fermentation, and baking) was investigated. The bread was prepared using a rye flour naturally contaminated with OTA (concentration 6.41 ± 0.52 μg/kg) and yeast. The bread was baked for 40 min at 180 °C, or for 70 min at 240 °C. The pizza bases were prepared by using wheat flour artificially contaminated with OTA (concentration 8.0 or 18.0 μg/kg). The bases were baked for 8 min at 320 °C or for 6 min at 370 °C. No statistically significant changes in OTA concentration were found after the dough kneading and fermentation production process stages. OTA concentrations in the crumb of the baked breads and pizza bases were also similar to the concentrations in the fermented dough. However, OTA concentrations in the crust decreased as compared to the fermented dough by 25.6% for the bread baked at 180 °C, 23% for the bread baked at 240 °C, and 8.0%–25.4% for the pizza bases, depending on the OTA concentration in the dough and the baking temperature (lower concentrations were associated with higher temperatures). Partial degradation of OTA in the crust of the baked products was accompanied by slight OTA racemization. Approximately 3.5% of the OTA in the crust of the rye bread baked at 240 °C was transformed into 2′R-OTA, increasing its level to 0.18 μg/kg. Briefly, 2.2%–10.1% of the OTA in the crust of the pizza bases was transformed into 2′R-OTA, increasing its levels to 0.13–1.57 μg/kg, depending on the baking temperature (higher concentrations were associated with higher temperature). It is worth noting that so far, apart from a few studies on transformation of OTA during roasting of coffee beans, these mechanisms during baking of cereal-based products are practically unknown.

The effect of legen treatment on fermentation process in production of nata de legen

Palmyra palm (Borassus flabellifer) is one of the most widely cultivated plants in Indonesia, especially in Gresik, East Java. The number of Palmyra palm trees in that area is estimated to be approximately 5,000,000. The Palmyra palm tree produces a large amount of legen obtained by tapping the palm flower and its use now is only limited as a beverage. By processing the legen into the nata, it would increase its selling price and the local people’s income. In this research, the method used to produce the nata de legen was by fermenting the legen using the microbial Acetobacter xylinum. This method was the same as for producing the nata de coco from coconut water. There were various methods of pre-treatment of the legen before the fermentation process. The legen was stored at room temperature 30°C, cooled in a refrigerator for 2 hours, or heated at 100°C for 10 minutes, with incubation time was 10 days respectively. The results showed that the quality of the nata de legen was affected by the pre-treatment of the legen. The best quality of the nata obtained was its thickness of the 4 mm and the cellulose content of 23.25% under pre-treatment condition at 100°C

Development and Optimization of the Triterpenoid and Sterol Production Process with Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum Strain G0017 (Agaricomycetes), in Liquid Submerged Fermentation at Large Scale.

Ganoderma lucidum mycelia are rich in active substances such as triterpenoids and sterols. However, reports on the development of effective submerged fermentation processes are lacking and the resulting total triterpene and sterol yield is still quite low. In this study, a new G. lucidum strain G0017 mycelium isolated by screening was studied in a 3-L fermenter to investigate the effect of aeration rate in liquid submerged fermentation production of triterpenoids and sterols. By fitting the specific mycelial growth rate and the specific production rate of the triterpenoid and sterol model, an effective multistage aeration rate control process for triterpenoid and sterol fermentation production was developed. This process was validated and proven in 3-L and 50-L fermenters. The resulting yields of triterpenoids and sterols were 3.34 and 3.46 g/L, respectively, which were 69.54% and 75.63% higher than the fixed aeration rate of 1.50 volume of air per volume of liquid per minute. This optimized fermentation production process conceivably could be applied to larger-scale industrial production and perhaps also to improve liquid submerged fermentation processes with relevant edible and medicinal mushrooms.

Partial Characterization of Glucoamylase Crude Enzyme Produced by &lt;em&gt;Aspergillus&lt;/em&gt; and &lt;em&gt;Rhizopus&lt;/em&gt; Strains

Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production of beer and ethanol. In this work glucoamylase enzyme produced by six fungal strains were previously isolated from different Sudanese soils, crop seeds, rotten fruits and pieces of moistened bread designated as Aspergillus awamori (A1and A7), A. niger (A10) , A. tamari (Aw), A. terrus (At) and Rhizous oryzae (R3) in a liquid culture was evaluated and characterized. The maximum temperature of glucoamylase activity are found to be in the range of 60-70˚C and at pH value of 5.0-6.0 and the activity of all enzymes from all isolates increased with increase of the concentration of soluble starch. Also the activity of the enzyme from all isolates under study increase with increase of time reaction.