Biosynthesis of Lactobionic Acid in Whey-Containing Medium by Microencapsulated and Free Bacteria of Pseudomonas taetrolens

Developed and emerging 1,4-butanediol commercial production strategies: forecasting the current status and future possibility

1,4-Butanediol (1,4-BDO) is a valuable industrial chemical that is primarily produced via several energy-intensive petrochemical processes based on fossil-based raw materials, leading to issues related to: non-renewability, environmental contamination, and high production costs. 1,4-BDO is used in many chemical reactions to develop a variety of useful, valuable products, such as: polyurethane, Spandex intermediates, and polyvinyl pyrrolidone (PVP), a water-soluble polymer with numerous personal care and pharmaceutical uses. In recent years, to satisfy the growing need for 1,4-BDO, there has been a major shift in focus to sustainable bioproduction via microorganisms using: recombinant strains, metabolic engineering, synthetic biology, enzyme engineering, bioinformatics, and artificial intelligence-guided algorithms. This article discusses the current status of the development of: various chemical and biological production techniques for 1,4-BDO, advances in biological pathways for 1,4-BDO biosynthesis, prospects for future production strategies, and the difficulties associated with environmentally friendly and bio-based commercial production strategies.

An in vitro gastrointestinal model to evaluate the tolerance of encapsulated Lactobacillus and Lactococcus strains with synbiotic containing lactobionic acid via lyophilization technique to harsh gastric conditions during storage time

Probiotics are living microorganisms that have potential health benefits for the host when administered in the correct proportions. However, for these beneficial effects to be produced, viable probiotic cells need to reach the human intestine. This study used a gastrointestinal model to represent the pH variation and gastric enzymes that are involved in the digestion process. Eight Lactobacillus strains and one Lactococcus strain were encapsulated using sodium alginate. The aim of this study was to compare free probiotic bacteria with encapsulated probiotic bacteria and determine the number of viable probiotic cells that might reach the human intestine. Microencapsulation of probiotic organisms followed the extrusion method with an alginate compound. Microencapsulated and free probiotic bacteria were inoculated into 200 ml of MRS (Man, Rogosa, Sharpe) broth. Simulated gastric juice and bile and pancreatic salt were used to test the tolerance of free Lactobacillus and Lactococcus species and microencapsulated bacteria to acid pH and enzymes. To enumerate the microencapsulated probiotic organisms, the bacteria were released from the capsules after total digestion with sodium citrate solution. The number of live bacteria (as CFU/g) was determined using the plate count method on MRS plates incubated at 37 °C for 48 h. Bacterial cell viability was determined on MRS agar duplicate plates at different dilutions. The results indicated that microencapsulation of probiotic bacteria showed improved viability over free cells when given 2 h of exposure to acidic conditions, and also for 2 h of exposure to bile and pancreatic salt. Encapsulation with alginate can protect probiotic bacteria from acidic conditions and bile salts. This study attempted also to produce synbiotic preparations with lactobionic acid using nontoxic encapsulating substances. The microorganisms used were stabilized with protective substances, and their stability during storage was checked under room temperature conditions. The final modification of the method, involving placing the capsules in a solution of skimmed milk with 5 % sucrose and 0.35 % ascorbic acid, resulted in an increase in the survival rate of some strains of microorganisms during microencapsulation and lyophilization and demonstrated stability during storage at room temperature.

Multi-Enzymatic Synthesis of Lactobionic Acid Using Wood-Degrading Enzymes Produced by White Rot Fungi

Enzymes produced by white rot fungi are involved in the synthesis of secondary metabolites with valuable biotechnological properties. One of these metabolites is lactobionic acid (LBA). The aim of this study was to characterize a novel enzyme system consisting of a cellobiose dehydrogenase from Phlebia lindtneri (PlCDH), a laccase from Cerrena unicolor (CuLAC), a redox mediator (ABTS or DCPIP), and lactose as a substrate. We used quantitative (HPLC) and qualitative methods (TLC, FTIR) to characterise the obtained LBA. The free radical scavenging effect of the synthesised LBA was assessed with the DPPH method. Bactericidal properties were tested against Gram-negative and Gram-positive bacteria. We obtained LBA in all the systems tested; however, the study showed that the temperature of 50 °C with the addition of ABTS was the most advantageous condition for the synthesis of lactobionic acid. A mixture with 13 mM LBA synthesised at 50 °C with DCPIP showed the best antioxidant properties (40% higher compared with the commercial reagent). Furthermore, LBA had an inhibitory effect on all the bacteria tested, but the effect was better against Gram-negative bacteria with growth inhibition no lower than 70%. Summarizing the obtained data, lactobionic acid derived in a multienzymatic system is a compound with great biotechnological potential.

Anaerobic Digestion of Agri-Food Wastes for Generating Biofuels

Presently, fossil fuels are extensively employed as major sources of energy, and their uses are considered unsustainable due to emissions of obnoxious gases on the burning of fossil fuels, which can lead to severe environmental complications, including human health. To tackle these issues, various processes are developing to waste as a feed to generate eco-friendly fuels. The biological production of fuels is considered to be more beneficial than physicochemical methods due to their environmentally friendly nature, high rate of conversion at ambient physiological conditions, and less energy-intensive. Among various biofuels, hydrogen (H₂) is considered as a wonderful due to high calorific value and generate water molecule as end product on the burning. The H₂ production from biowaste is demonstrated, and agri-food waste can be potentially used as a feedstock due to their high biodegradability over lignocellulosic-based biomass. Still, the H₂ production is uneconomical from biowaste in fuel competing market because of low yields and increased capital and operational expenses. Anaerobic digestion is widely used for waste management and the generation of value-added products. This article is highlighting the valorization of agri-food waste to biofuels in single (H₂) and two-stage bioprocesses of H₂ and CH₄ production.

Evaluation of Microencapsulated Synbiotic Preparations Containing Lactobionic Acid

The aim of this paper was to assess the prebiotic properties of lactobionic acid in the human gastrointestinal model. Five different strains of probiotic, or potentially probiotic, bacteria were used in the microencapsulation process; these were Lactobacillus casei Shirota, Lactococcus lactis ATCC1, Lactobacillus fermentum, Bifidobacterium bifidum DSM 20456, and Bifidobacterium bifidum DSM 20082. Starch with a concentration of 4% (w/v) and a degree of substitution of 0.03 was used to produce the microcapsules. The alginian microcapsules we produced functioned as a protective barrier for the probiotic microorganisms closed in them, protecting them from adverse conditions in the human digestive tract. The microorganisms could thus survive the encapsulation process and the in vitro model digestion process while retaining the ability to produce biomass. Factors such as pH and time affect the solution of alginate microcapsules. The capsule solution began when a pH of 7.4 was reached; this corresponded to pH in the target probiotic site, an in vitro model of the colon. The capsules had completely dissolved after 24 h of digestion at a pH of 8. The addition of lactobionic acid stimulated the growth of probiotic and potentially probiotic bacteria, thus confirming its prebiotic properties.