Bioconversion of agro-industrial by-products to lactic acid usingLactobacillus sakeiand twoPediococcusspp. strains

Recent advances in microbial high-value utilization of brewer's spent grain

Mitigating the adverse impacts of agricultural and industrial by-products on human populations and the environment is essential. It is crucial to continually explore methods to upgrade and reengineer these by-products. Brewer's Spent Grain (BSG), the primary by-product of the beer brewing process, constitutes approximately 85% of these by-products. Its high moisture content and rich nutritional profile make BSG a promising candidate for microbial utilization. Consequently, valorizing high-yield, low-cost BSG through microbial fermentation adds significant value. This paper provides a comprehensive overview of two valorization pathways for BSG via microbial processing, tailored to the desired end products: utilizing fermented BSG as a nutritional supplement in human or animal diets, or cultivating edible fungi using BSG as a substrate. The review also explores the microbial fermentation of BSG to produce valuable metabolites, laying a theoretical foundation for its high-value utilization.

A critical review on the biotechnological potential of Brewers' waste: Challenges and future alternatives

In order to comply with the stringent discharge guidelines issued by governmental organizations to protect the ecosystem, the substantial amounts of effluent and sturdy wastes produced by the beer brewing process need to be discarded or handled in the most affordable and secure manner. Huge quantities of waste material released with each brew bestow a significant opportunity for the brewing sector to move towards sustainability. The concept of circular economy and the development of technological advancements in brewery waste processing have spurred interest to valorize brewery waste for implementation in various sectors of medical and food science, industrial science, and many more intriguing fields. Biotechnological methods for valorizing brewery wastes are showing a path towards green chemistry and are feasible and advantageous to environment. The study unfolds most recent prospectus for brewery waste usage and discusses major challenges with brewery waste treatment and valorization and offers suggestions for further work.

Nutritional quality and organic acid profile of rice bran fermented with lactic acid bacteria isolated from horse feces

The study aimed to determine the effect of Limosilactobacillus equigenerosi and Ligilactobacillus equi as inoculants for solid-state fermentation (SSF) in the proximate composition of nutrients and organic acid profile of rice bran (RB). The RB was treated with distilled water (DW) without inoculant (control), L. equigenerosi (T1 ), L. equi (T2 ), and L. equigenerosi and L. equi 1:1 (v:v) (T3 ). For the treatments, 90 mL of culture was pelleted and suspended with DW. Each treatment was replicated three times and incubated for 4, 7, and 10 days at 37°C. The crude protein, ether extract, crude ash, crude fiber, neutral detergent fiber, and acid detergent fiber were increased (P < 0.05) in fermented RB. The lactate and total organic acid produced were increased by the addition of lactic acid bacteria (LAB) (P < 0.01), and the highest concentrations were recorded in treatments containing L. equi (T2 and T3 ). Acetate production in T1 was highest than in control, T2 , and T3 (P < 0.01). The results showed that LAB isolated from horse feces in combination with SSF can improve the quality of RB as an ingredient for animal feed based on the higher concentrations of protein, carbohydrates, minerals, and organic acids.

Latilactobacillus sakei: a candidate probiotic with a key role in food fermentations and health promotion

Latilactobacillus sakei is used extensively in industrial production and food fermentations. The species is primarily derived from fermented meat and vegetable products and is also found in human feces. Genomics and metabolomics have revealed unique metabolic pathways in L. sakei and molecular mechanisms underlying its competitive advantages in different habitats, which are mostly attributed to its flexible carbohydrate metabolism, cold tolerance, acid and salt tolerance, ability to cope with oxygen changes, and heme uptake. In recent years, probiotic effects of L. sakei and its metabolites have been identified, including the ability to effectively alleviate metabolic syndrome, inflammatory bowel disease, and atopic dermatitis. This review summarizes the genomic and metabolic characteristics of L. sakei and its metabolites and describes their applications, laying a foundation for their expanded use across the food and healthcare industries.

Recent advances in biotechnological valorization of brewers' spent grain

Brewers' spent grain (BSG) is the most abundant by-product of beer-brewing. BSG is rich in nutrients such as protein, fiber, minerals, and vitamins, and therefore it is conventionally used as low-cost animal feed. On the other hand, alternative utilization of BSG has gained increased attention during recent years due to technological progress in its processing and the emergence of the concept of circular economy. The valorization of BSG through biotechnological approaches is environmentally friendly and sustainable. This review was focused on recent advancements in the conversion of BSG into value-added products, including bioenergy (ethanol, butanol, hydrogen, biodiesel, and biogas), organic acids, enzymes, xylitol, oligosaccharides, and single cell protein, via biotechnological approaches. In addition, the potential applications of BSG as immobilization matrices in bioprocesses have been reviewed.

Lactic acid production - producing microorganisms and substrates sources-state of art

Lactic acid is an organic compound produced via fermentation by different microorganisms that are able to use different carbohydrate sources. Lactic acid bacteria are the main bacteria used to produce lactic acid and among these, Lactobacillus spp. have been showing interesting fermentation capacities. The use of Bacillus spp. revealed good possibilities to reduce the fermentative costs. Interestingly, lactic acid high productivity was achieved by Corynebacterium glutamicum and E. coli, mainly after engineering genetic modification. Fungi, like Rhizopus spp. can metabolize different renewable carbon resources, with advantageously amylolytic properties to produce lactic acid. Additionally, yeasts can tolerate environmental restrictions (for example acidic conditions), being the wild-type low lactic acid producers that have been improved by genetic manipulation. Microalgae and cyanobacteria, as photosynthetic microorganisms can be an alternative lactic acid producer without carbohydrate feed costs. For lactic acid production, it is necessary to have substrates in the fermentation medium. Different carbohydrate sources can be used, from plant waste as molasses, starchy, lignocellulosic materials as agricultural and forestry residues. Dairy waste also can be used by the addition of supplementary components with a nitrogen source.