Lactic Fermentation Research Articles

Sustainable use of agricultural residues to improve corn silage quality: Co-ensiling with oregano oil residues

The study aimed to evaluate the effect of oregano essential oil extraction residues (ORES) on the fermentation quality of corn silage. Non-fungal infected (NFI) and fungal infected (FI) corn were ensiled with 20% (wet weight) of ORES for 180 d. The inclusion of ORES delayed pH decline regardless of fungal infection. The inclusion of ORES did not adversely affect lactic acid (LA) production in NFI silages but retarded the initial LA fermentation of FI silages. Co-ensiling corn with ORES significantly decreased ethanol content. Co-ensiling FI corn with ORES significantly increased the fungal Chao1 and Shannon indices compared to FI-CON silages but did not affect the bacterial Chao1 and Shannon indices. The fungal infection aggravated the risk of Paenibacillus and Clostridium contamination, which was mitigated by co-ensiling with ORES. In conclusion, fungal infection suppressed ensiling fermentation, and heightened the risk of proliferation of undesirable bacteria, while ORES relieved these risks. Ensiling ORES with corn as forages is a potential and promising strategy for the efficient reusing of agro-industrial waste.

Lactic Acid Production from Distiller’s Dried Grains Dilute Acid Hydrolysates

Lactic acid (LA) is an important chemical with diverse applications in various industries. LA can be produced by the fermentation of different substrates by many microorganisms such as bacteria, fungi, yeasts, and algae. Lactic acid bacteria (LAB) are generally accepted as the main producers of LA. A distinct characteristic of LAB is the complexity of the fermentation media. Distiller’s dried grains with solubles (DDGS), a by-product from bioethanol production, represent a promising substitute for costly sugars in the nutrition media for LA production. In the present paper, the possibility of using dilute acid DDGS hydrolysates as a substrate for LA fermentation was investigated. The influence of different factors (acid concentration, time, pressure, solid-to-liquid ratio) on the reducing sugars (RS) obtained was studied. Additional enzyme hydrolysis was carried out to increase RS content in the hydrolysates. LA production from hydrolysates without and with control of the pH during fermentation was monitored and compared with lactose as a substrate. Inhibition of the process was observed in both substrates in the absence of pH control which was overcome in the case of pH control. A mathematical model based on the Verhulst and Ludeking–Piret equations was proposed and tested, showing very good agreement with experimental data.

Pressure-tolerant survival mechanism of Schizophyllum commune 20R-7-F01 isolated from deep sediments 2 kilometers below the seafloor

In anaerobic high hydrostatic pressure (HHP) sedimentary environments below the seafloor, fungi are found to dominate the eukaryotic communities, playing crucial ecological roles. However, the specific mechanisms by which fungi adapt to anaerobic HHP environments remain unclear. In this study, we investigated Schizophyllum commune 20R-7-F01 isolated from coal-bearing sediments at a depth of 2 km below the seafloor. By assessing the cell viability, biomass, and cell wall thickness changes of strain 20-7-1 under different HHP conditions, we observed that, compared to 0.1 MPa, strain 20-7-1 exhibited slower growth rates and decreased cell viability at 15 MPa and 35 MPa, yet demonstrated significant pressure tolerance. Transcriptomic and metabolomic analyses revealed that this strain activated the carbohydrate metabolic process to simultaneously utilize ethanol and lactic acid fermentation pathway. Additionally, it activates the oxidoreductase activity and hydrolase activity pathways to detoxify intracellular reactive oxygen species (ROS). Activation of the metal ion binding pathway increases the proportion of unsaturated fatty acids in the cell membrane, while instigation of the integral component of membrane pathway maintains cell wall structural stability. Furthermore, activation of the DNA repair pathway repairs DNA damage, demonstrating its comprehensive adaptive mechanisms against the HHP stress. These research findings deepen our understanding of fungal survival strategies and adaptation mechanisms in extreme environments, laying the groundwork for further exploration of their roles in cycling of carbon, nitrogen, sulfur, and other elements in the deep biosphere.

Yellow Mustard Protein a Immunoreactivity Reduction Through Seed Germination, Lactic Acid Fermentation, and Cooking.

Food allergens are becoming increasingly threatening and are disrupting the health and social structure of a significantly large population worldwide. Proteins from mustard are among the well-recognized food allergens which affect many sensitive individuals. Many processing methods are continually being explored to reduce allergen immunoreactivity and for developing hypoallergenic foods. Cooking, germination, and fermentation have been evaluated to attenuate the immunoreactivity of food allergens. The objective of this study is to evaluate the effect of seed germination, lactic acid fermentation, and/or cooking on yellow mustard seed protein immunoreactivity (IR) (protein A) using ELISA techniques. Samples from five-day germination at 35-40 °C and three-day fermentation between 25 °C and 35 °C were evaluated. The germination and fermentation processes yielded varying reductions in the IRs of mustard proteins, with a combined yield of about 90% reduction. When complemented with further stovetop cooking, protein IR reduction was extended up to 98%, while cooking alone resulted only in about a 70% reduction. FTIR results confirmed that changes in mustard protein conformation maybe due to the unfolding and/or denaturation of mustard proteins. These processing methods are beneficial as they not only help reduce the native mustard protein IR, but also increased inherent antioxidant activities in germinated and fermented mustard seeds.

Lactobacillus pentosus enabled bioleaching of red mud at high pulp density and simultaneous production of lactic acid without supplementation of neutralizers

Heterogenous bioleaching by microorganisms producing organic acids is deemed as a compelling pathway for the recovery of valuable metals from red mud, but it is often performed at low pulp density, making this process not economically competitive. Here, Lactobacillus pentosus was employed to bioleach red mud at high pulp density and simultaneously produce lactic acid. The bioleaching performance of L. pentosus was first compared with Aspergillus niger and Gluconobacter oxydans, two most commonly used bioleaching strains. At 20 wt% pulp density and with pure glucose as a carbon source, L. pentosus could leach 31 % Al from red mud, while the leaching efficiency did not exceed 1 % for other two strains. Increasing the pulp density to even 30 wt% did not compromise the leaching efficiency of L. pentosus. When the enzymatic hydrolysate of rice straw was used to replace pure glucose as a carbon source, a comparable leaching efficiency of 30 % for Al was achieved, demonstrating that rice straw could be a cheap and renewable feedstock for bioleaching. Moreover, the alkali contained in red mud eliminated the addition of costly neutralizer as did in traditional lactic acid fermentation, enabling the simultaneous production of approximately 80 g/L lactic acid. Overall, this study offered a potentially economical and effective pathway for the bioleaching of red mud at high pulp density, and opened a new avenue for the production of lactic acid from lignocellulosic biomass.

Metabolites Generated from Foods Through Lactic Fermentation and Their Benefits on the Intestinal Microbiota and Health.

Metabolites generated in foods with lactic fermentation have been subject of research in recent years due to different beneficial effects attributed to them on the microbiota and health in general, including their properties as antihypertensives, antioxidants, anti-inflammatory, immunomodulatory, and antimicrobial, among others. The present review aims to systematically analyze the results of original research that evaluates effects on the microbiota and health in general, mediated by metabolites generated from the lactic fermentation of foods. The review was carried out in the PubMed database, three studies in humans, four invivo studies in murine models, four in vitro studies, and the rest focused on the quantification of biofunctional qualities in fermented foods were analyzed. The results of the studies compiled in this systematic review reveal the potential of different food matrices and microorganisms to generate metabolites through lactic fermentation with important properties and effects on the intestinal microbiota and other health benefits. Among these benefits is the increase in short chain fatty acids to which anti-inflammatory properties are associated, as well as bioactive peptides with antihypertensive, antithrombotic, antioxidant, anti-inflammatory, and antimicrobial properties.

Fermentation Profile, Bacterial Community Structure, Co-Occurrence Networks, and Their Predicted Functionality and Pathogenic Risk in High-Moisture Italian Ryegrass Silage

This study aimed to assess the fermentation characteristics, bacterial community structure, co-occurrence networks, and their predicted functionality and pathogenic risk in high-moisture Italian ryegrass (IR; Lolium multiflorum Lam.) silage. The IR harvested at heading stage (208 g dry matter (DM)/kg fresh weight) was spontaneously ensiled in plastic silos (10 L scale). Triplicated silos were opened after 1, 3, 7, 15, 30, and 60 days of fermentation, respectively. The bacterial community structure on days 3 and 60 were investigated using high-throughput sequencing technology, and 16S rRNA-gene predicted functionality and phenotypes were determined by PICRUSt2 and BugBase tools, respectively. After 60 days, the IR silage exhibited good ensiling characteristics indicated by large amounts of acetic acid (~58.7 g/kg DM) and lactic acid (~91.5 g/kg DM), relatively low pH (~4.20), acceptable levels of ammonia nitrogen (~87.0 g/kg total nitrogen), and trace amounts of butyric acid (~1.59 g/kg DM). Psychrobacter was prevalent in fresh IR, and Lactobacillus became the most predominant genus after 3 and 60 days. The ensilage process reduced the complexity of the bacterial community networks in IR silage. The bacterial functional pathways in fresh and ensilaged IR are primarily characterized by the metabolism of carbohydrate and amino acid. The pyruvate kinase and 1-phosphofructokinase were critical in promoting lactic acid fermentation. A greater (p < 0.01) abundance of the “potentially pathogenic” label was noticed in the bacterial communities of ensiled IR than fresh IR. Altogether, the findings indicated that the high-moisture IR silage exhibited good ensiling characteristics, but the potential for microbial contamination and pathogens still remained after ensiling.

Development of plant-based yogurt from munguba (Pachira aquatica) seeds: Stability and predictive growth of lactic acid cultures

Lactic fermentation is employed to enhance the nutritional quality of plant-based milks, and exploring underutilized plant matrices like munguba (Pachira aquatica) can bring innovation to the plant-based beverage market. This study aimed to develop a yogurt from munguba seeds and investigate the fermentation kinetics of lactic acid bacteria (LAB), as well as the product's stability during storage. Munguba seed milk was prepared through cleaning, peeling, blanching, blending, filtering, and storing at 5 °C. Fermentation was conducted with Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus fermentum at 36 °C, and microbial growth was monitored to construct a LAB growth curve. Ultra High Temperature (UHT) whole cow's milk was used for comparison. Munguba seed milk fermented for 9 h showed LAB growth from 3.89 to 8.22 log CFU/mL, while UHT cow's milk fermented for 6 h showed LAB growth from 4.55 to 6.33 log CFU/mL. The Baranyi model showed good fits for both data sets (R2 of 0.9528 for munguba milk and 0.9340 for UHT milk). Specific growth rates, doubling times, and multiplication rates were higher for munguba milk (μ of 1.10 h^-1, td of 0.66 h, MR of 1.59 h^-1) compared to UHT milk (μ of 0.85 h^-1, td of 0.84 h, MR of 1.22 h^-1). LAB, mold, and yeast counts, pH, and lactic acid content remained stable over 31 days of refrigerated storage of munguba seed yogurt. These results indicate that munguba seed milk is a promising substrate for fermented beverages and beneficial microorganisms.

Non-Conventional Brewers' Spent Grains, an Alternative Raw Material in Bread-Making.

The main objective of this experiment was to investigate the technological potential of upcycling unsparged non-conventional brewers' spent grains (BSGs) in bread-making and assess the comparative quality of bread enriched with non-fermented and lactic acid-fermented BSGs obtained from mashes brewed with starch adjuncts of buckwheat and oats. After the runoff of the first wort, unsparged non-conventional BSGs with approximately 75% moisture, acidic pH, and yield in the soluble extract above 56.6% (w/w d.m.) were used in substituting wheat flour with 5 and 15% (w/w d.m.) in bread-making recipes. The highest loaf volume value (318.68 cm3/100 g) was observed for 5% fermented buckwheat-BSG addition. Except for the samples with 5% fermented BSGs, specific volumes decreased. Crumb moisture was reduced by up to 22% for all samples, with this parameter related to bread weight. Bread porosity, elasticity, acidity, and overall sensory acceptability were better for fermented than non-fermented BSGs. The results proved that non-conventional BSGs with buckwheat and oats addition have the potential to be valorized in new bread assortments, and lactic acid fermentation applied to the BSGs is beneficial, even for overall sensory acceptability and quality of baked end-products. Technological, buckwheat-BSG was more convenient than oats-BSG. Further research continues to optimize and upscale Technology Readiness Levels.

Exploring the Presence of Cannabinoids in Hemp-Infused Fermented Milk Drinks: An Analysis of Pre- and Post-Fermentation Levels.

Yoghurts are the most popular fermented dairy products. Consumer attention is directed towards products containing inputs that enrich the product with bioactive substances. The growing interest in the Cannabis sativa L. plant has resulted in the development of a market for hemp products. The main aim of this research work was to determine the effect of the lactic fermentation process on the stability of cannabinoids in fermented milk beverages containing hemp inputs (hemp oil, dried hemp, ethanolic hemp extract) at 0.5, 1 and 2% (w/v). The effect of the type of hemp input on the technological process (i.e., pH value, viability of LAB during 28 days of storage) was also checked and the sensory quality of the prepared samples was evaluated. It was shown that the choice of type/form and amount of hemp addition influenced the final cannabinoid content of the product after fermentation and post-fermentation, but no effect on the survival of yoghurt bacteria or pH changes during storage was confirmed. Fermented milk drinks containing hemp oil had the highest cannabinoid content. The QDA results of the sensory evaluation of the yoghurts show that the most acceptable product in terms of overall quality is the yoghurt containing 0.5% hemp extract and 2% hemp oil.

Influences of Lactiplantibacillus plantarum dy-1 Fermentation on the Bitterness of Bitter Melon Juice, the Composition of Saponin Compounds, and Their Bioactivities.

Lactic acid bacteria fermentation is a beneficial bioprocessing method that can improve the flavor, transform nutrients, and maintain the biological activity of foods. The aim of this study is to investigate the effects of Lactiplantibacillus plantarum dy-1 fermentation on the nutritional components, flavor and taste properties, and composition of saponin compounds and their hypolipidemic and antioxidant activities. The results suggested that the total polyphenol content increased, and the soluble polysaccharides and total saponin contents decreased in fermented bitter melon juice (FJ) compared with those in non-fermented bitter melon juice (NFJ). The determination of volatile flavor substances by GC-MS revealed that the response values of acetic acid, n-octanol, sedumol, etc., augmented significantly, and taste analysis with an electronic tongue demonstrated lower bitterness and higher acidity in FJ. Furthermore, UPLC-Q-TOF-MS/MS testing showed a significant decrease in bitter compounds, including momordicines I and II, and a significant increase in the active saponin momordicine U in the fermented bitter melon saponin group (FJBMS). The in vitro assays indicated that FJBMS exhibited similar antioxidant activities as the non-fermented bitter melon saponin group (NFBMS). The in vitro results show that both NFBMS and FJBMS, when used at 50 μg/mL, could significantly reduce fat accumulation and the malondialdehyde (MDA) content and increased the catalase (CAT) activity, while there was no significant difference in the bioactivities of NFBMS and FJBMS. In conclusion, Lactiplantibacillus plantarum dy-1 fermentation is an effective means to lower the bitterness value of bitter melon and preserve the well-known bioactivities of its raw materials, which can improve the edibility of bitter melon.

Innovative Lactic Acid Production Techniques Driving Advances in Silage Fermentation

Lactic acid (LA) plays a crucial role in the silage process, which occurs through LA fermentation. Consequently, there is a strong correlation between lactic acid production and the efficiency of the silage. However, traditional methods face challenges like long fermentation times, low acid production, and unstable quality, limiting agricultural preservation. This paper aims to explore innovations in lactic acid production technologies and show how these technologies have driven the development of silage fermentation for agricultural conservation. First, the important role of LA in agricultural preservation and the limitations of traditional silage techniques are presented. Next, advancements in LA production methods are thoroughly examined, covering the selection of microbial strains and the substitution of fermentation substrates. Following this, new technologies for silage fermentation are explored, drawing from innovations in LA production. These include the selection of LA strains, optimization of fermentation conditions, and improvements in fermentation techniques. These innovations have proven effective in increasing LA production, improving feed quality, extending shelf life, and providing new solutions to enhance agricultural production and sustainability.

Biochemical and microbial characterization of a forest litter-based bio-fertilizer produced in batch culture by fermentation under different initial oxygen concentrations.

This work focused on the physico-chemical, biochemical and microbiological characterization of a new organic fertilizer based on fermented forest litter (FFL) mixed with agro-industrial by-products, on the culture realized in airtight glass bottle. Under strict anaerobiosis (0% initial oxygen concentration (IOC)), after a 16-day batch culture, the bottle-headspace analysis showed that the specific CO2 production rate was low (0.014 mL/h.g dry matter) compared to those reached under aerobic conditions (e.g. 0.464 mL/h.g dm at 21% IOC). Moreover, the culture displayed a slight fermented fruity odour, mainly due to ethanol and ethyl acetate detected in the headspace (335 µL and 58.6 µL accumulated, respectively). The FFL organic matter degradation followed by infrared spectroscopy and catabolic potential and diversity characterized by BIOLOG® EcoPlates were poor and pH dropped to 4.54. The microbiome's metabolism was oriented toward lactic fermentation with medium acidification, enrichment in lactic acid bacteria (LAB), depletion in fungi and absence of pathogens. By increasing IOC from 0 to 21%, the respirometric activity, and the catabolic potential and diversity increased. However, some enterobacteria were detected above 5% IOC. Ethanol and ethyl acetate decreased strongly with IOC, and aromatics and proteins contained in the solid matrix remained in the culture. This study showed the importance of oxygen on the final product. A 2% IOC was found to ensure an optimal balance between LAB development, preservation of functional catabolic diversity and bio-product free of microbial pathogens.

Lactic acid bacteria sequential fermentation improves viable counts and quality of fermented apple juice via generating two logarithmic phases

This study investigated the impact of lactic acid bacteria (LAB) sequential fermentation on viable counts and apple juice quality. The optimal fermentation conditions were obtained by a step-by-step optimization process, including pH 4.5, temperature 37 °C, the second inoculation time 16 h, total fermentation time 40 h and fermentation sequence (first 21,805 + 21,828, second 20,241). Under the optimal conditions, sequential fermentation allowed LAB to experience two logarithmic phases, increasing viable counts to 1.38 × 108 CFU/mL, exceeding simultaneous fermentation for 24 h and 40 h by 4.10 × 107 CFU/mL and 5.40 × 107 CFU/mL, respectively. This process enhanced sugar utilization, yielding more lactic acid and polyphenols. Furthermore, sequential fermentation improved DPPH (71.71 %) and ABTS (84.79 %) scavenging rates, and enriched volatile compounds, particularly beta-Damascenone, potentially contributing to floral and richer apple flavor. Sequential fermentation also achieved optimal sensory acceptability. This study proposes a novel strategy for high-density LAB fermentation to produce high-quality apple juice.

Studying the Influence of Salt Concentrations on Betalain and Selected Physical and Chemical Properties in the Lactic Acid Fermentation Process of Red Beetroot

This study emphasizes the significance of optimizing salt content during the fermentation of red beetroot to produce healthier and high-quality fermented products. It investigates the impact of different salt levels on fermentation, analyzing various parameters such as pH levels, dry matter content, total acidity, salt content, color changes, pigment content, and lactic acid bacteria count. This study identifies the most favorable salt concentration for bacterial growth during fermentation and storage as 2–3%. It was evaluated that salt levels fluctuated significantly during fermentation, with nearly 50% of the added salt absorbed by the beetroot tissues, mainly when lower salt concentrations were used. The fermentation process had a negative effect on the content of betalain pigments, as well as yellow pigments, including vulgaxanthin-I. It was also found that fermentation and storage affected the proportions of red pigments, with betacyanins proving to be more stable than betaxanthins, and that salt addition affected negatively pH and total acidity while causing an increase in yellow color. The pH was negatively correlated with the duration of the process, the amount of red pigment, and bacterial count. The results indicate that lower salt levels can lead to favorable physicochemical and microbiological parameters, allowing for the production of fermented red beetroot with reduced salt content without compromising quality.

Effects of fermentation with Lactobacillus plantarum on rice flour: The role of granular characteristics

This study examined the effects of lactic acid bacteria fermentation on the physicochemical and functional properties of the flours from two rice varieties, Shindongjin (SF) and Hitomebore (HF), both with similar amylose content. Fermentation with Lactobacillus plantarum over 48 h resulted in significant changes. Protein content decreased substantially in both varieties, especially in SF, and amylose content increased. Swelling power and solubility also increased more in SF. The gel hardness of fermented SF increased by approximately 22 %, whereas HF showed minimal change. These differences are due to variations in granule rigidity and starch molecule leaching. SF granules maintained rigidity and a robust external network due to higher amylose leaching. In contrast, the lower initial rigidity and higher amylopectin leaching in HF hindered strong gel network formation. These findings offer insights into the structural and molecular mechanisms of rice fermentation with lactic acid bacteria.

Tissue derivatization for visualizing lactate and pyruvate in mouse testis tissues using matrix-assisted laser desorption/ionization-mass spectrometry imaging

Pyruvate and lactate are the final metabolites of the glycolytic system that are formed under oxygen-rich and anaerobic conditions, respectively. They play an important role in energy metabolism. Obtaining a tissue distribution image of pyruvate and lactate holds great significance in molecular biology because the glycolytic system plays an essential role in diseases, such as tumors and diabetes; microbial activities, such as alcohol production and lactic acid fermentation; and maintaining homeostasis in the gut environment. However, it is difficult to obtain images of the distribution of in vivo metabolites because of the low detection sensitivities of current methods. In this study, a novel derivatization method for pyruvate and lactate was developed using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to detect pyruvate and lactate in vivo and obtain biodistribution images. We investigated derivatization methods using readily available 3-nitrophenylhydrazine (3NPH), the addition of which improves the sensitivity of pyruvate detection, and the distribution of pyruvate in mouse testes was successfully visualized. Furthermore, the distribution of lactate in the mouse testes could be visualized, and improved detection sensitivity for the main metabolites of the tricarboxylic acid cycle was demonstrated. This derivatization method can be used to detect carboxyl-containing metabolites, including pyruvate, via MALDI-MSI. Furthermore, 3NPH forms amide bonds with carbonyl, phosphate, and carboxyl groups, suggesting the possibility of visualizing its distribution in many metabolites.Graphical

Game changer for anaerobic fermentation of paper mulberry: Sucrose-loaded biochar enhancing microbial communities and lactic acid fermentation

This study investigated biochar effects, either alone or combined with sucrose, on fermentation quality, microbial communities, and in vitro rumen digestion of anaerobic fermented paper mulberry. The biochar alkaline functional groups bind to lactic acid, reducing acid inhibition and promoting Lactiplantibacillus proliferation. Owing to the low sugar content of paper mulberry, lactic acid bacteria in the biochar group primarily underwent heterofermentation, resulting in the lowest lactic and highest acetic acid contents. Treated with sucrose-loaded biochar, the increased substrate supported homofermentation, leading to the highest lactic and lowest acetic acid contents, with a 15.0 % increase in lactic acid and a 22.2 % decrease in ammoniacal nitrogen compared with the control after 75 days. In vitro rumen tests showed that the biochar-sucrose group had the highest dry matter degradation rate (45.9 %) and a 24.2 % reduction in methane emissions. Concludingly, sucrose-loaded biochar is recommended as effective for lactic acid production under anaerobic conditions.

Production of Magnesium Dilactate through Lactic Acid Fermentation with Magnesium Carbonate.

Magnesium dilactate is increasingly sought after for its applications in the pharmaceutical, food, and dietary supplement industries due to its essential role in various physiological processes. This study explores a sustainable method for synthesizing magnesium dilactate through lactic acid fermentation using tomato juice, coupling the neutralization of lactic acid with hydrated magnesium carbonate hydroxide. Utilizing the lactic acid bacteria Lactobacillus paracasei and Lactobacillus plantarum, fermentation was optimized in a 50% diluted MRS medium supplemented with glucose and tomato juice supplemented with glucose, yielding a maximum lactate concentration of 107 g/L. Notably, fermentation in diluted media proved more effective than in undiluted tomato juice, highlighting the inhibitory effects of certain organic compounds and the physical nature of the original tomato juice. Post-fermentation, magnesium lactate was crystallized, achieving high recovery rates of up to 95.9%. Characterization of the product through X-ray diffraction and scanning electron microscopy confirmed its crystalline purity. This research underscores the viability of tomato juice as a fermentation substrate, promoting the valorization of agricultural by-products while providing an eco-friendly alternative to traditional chemical synthesis methods for magnesium dilactate production.

Digital model of biochemical reactions in lactic acid bacterial fermentation of simple glucose and biowaste substrates

As concerns about the environmental impacts of biowaste disposal increase, lactic acid bacterial fermentation is becoming increasingly popular. Current academic research is aimed at the process optimization by developing digital bioreactors. The primary focus is to develop a digital model mimicking the biochemical reactions. In the light of this, this paper intended to build a digital model of biochemical reactions during the fermentation process of both glucose and biowaste substrates, including white pasta and organic municipal waste. For this purpose, near-infrared (NIR) and mid-infrared (MIR) spectroscopy techniques were used to collect spectral information during the fermentation process. Next, the samples were analyzed by High Pressure Liquid Chromatography (HPLC) to measure their glucose, fructose, arabinose, xylose, disaccharide, lactic acid, and acetic acid contents. The results showed that learning algorithms trained on MIR spectra accurately estimated the biochemical reactions for both glucose and biowaste substrates. For the glucose substrate, the results showed R-squared of 0.97 and RMSE of 4.69 g/L for glucose, and R-squared of 0.98 and RMSE of 2.74 g/L for lactic acid. In the case of biowaste substrate, estimations included glucose (R-squared = 0.97, RMSE = 4.69 g/L), fructose (R-squared = 0.88, RMSE = 1.47 g/L), arabinose (R-squared = 0.98, RMSE = 0.55 g/L), xylose (R-squared = 0.93, RMSE = 1.11 g/L), disaccharide (R-squared = 0.90, RMSE = 0.55 g/L), total sugar (R-squared = 0.98, RMSE = 3.79 g/L), lactic acid (R-squared = 0.98, RMSE = 2.74 g/L), and acetic acid (R-squared = 0.97, RMSE = 0.36 g/L). Regarding NIR spectral data, the predictive models were accurate when the substrate was glucose, however, they failed to accurately estimate the chemical reactions in the case of biowaste substrate. The findings of this study can be used to fulfill the requirements for a continuous fermentation process with the objective of maximizing lactic acid production.